Sample records for bilateral dorsolateral prefrontal
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van 't Wout, Mascha; Kahn, René S; Sanfey, Alan G; Aleman, André
2005-11-07
Although decision-making is typically seen as a rational process, emotions play a role in tasks that include unfairness. Recently, activation in the right dorsolateral prefrontal cortex during offers experienced as unfair in the Ultimatum Game was suggested to subserve goal maintenance in this task. This is restricted to correlational evidence, however, and it remains unclear whether the dorsolateral prefrontal cortex is crucial for strategic decision-making. The present study used repetitive transcranial magnetic stimulation in order to investigate the causal role of the dorsolateral prefrontal cortex in strategic decision-making in the Ultimatum Game. The results showed that repetitive transcranial magnetic stimulation over the right dorsolateral prefrontal cortex resulted in an altered decision-making strategy compared with sham stimulation. We conclude that the dorsolateral prefrontal cortex is causally implicated in strategic decision-making in healthy human study participants.
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Listen, learn, like! Dorsolateral prefrontal cortex involved in the mere exposure effect in music
DEFF Research Database (Denmark)
Green, Anders Christian; Bærentsen, Klaus B.; Stødkilde-Jørgensen, Hans
2012-01-01
, participants rated liking for each melody and, later, their recognition of them. Participants showed learning effects, better recognising melodies heard more often. Melodies heard most often were most liked, consistent with the mere exposure effect. We found neural activations as a function of previous...... exposure in bilateral dorsolateral prefrontal and inferior parietal cortex, probably reflecting retrieval and working memory-related processes. This was despite the fact that the task during scanning was to judge liking, not recognition, thus suggesting that appreciation of music relies strongly on memory...
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Directory of Open Access Journals (Sweden)
Sonia Doallo
Full Text Available Binge drinking or heavy episodic drinking is a high prevalent pattern of alcohol consumption among young people in several countries. Despite increasing evidence that binge drinking is associated with impairments in executive aspects of working memory (i.e. self-ordered working memory, processes known to depend on the mid-dorsolateral prefrontal cortex (Brodmann areas 46 and 9, less is known about the impact of binge drinking on prefrontal gray matter integrity. Here, we investigated the effects of binge drinking on gray matter volume of mid- dorsolateral prefrontal cortex in youths. We used voxel-based morphometry on the structural magnetic resonance images of subjects reporting a persistent (at least three years binge drinking pattern of alcohol use (n = 11; age 22.43 ± 1.03 and control subjects (n = 21; age 22.18 ± 1.08 to measure differences in gray matter volume between both groups. In a region of interest analysis of the mid-dorsolateral prefrontal cortex, after co-varying for age and gender, we observed significantly larger gray matter volume in the left mid-dorsolateral prefrontal cortex (Brodmann areas 46 and 9 in binge drinkers in comparison with control subjects. Furthermore, there was a significant positive correlation between left mid-dorsolateral prefrontal cortex volume and Self-Ordered Pointing Test (SOPT total errors score in binge drinkers. The left mid-dorsolateral prefrontal cortex volume also correlated with the quantity and speed of alcohol intake. These findings indicate that a repeated exposure to alcohol -that does not meet criteria for alcohol dependence- throughout post-adolescent years and young adulthood is linked with structural anomalies in mid-dorsolateral prefrontal regions critically involved in executive aspects of working memory.
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Institute of Scientific and Technical Information of China (English)
Jun Xia; Minjie Yang; Yi Lei; Yicheng Zhou
2010-01-01
Previous studies using magnetic resonance imaging(MRI)and functional MRI to study depression have primarily focused on proton magnetic resonance spectroscopy(1H-MRS)appearance in various areas of the brain and volume measurements in the limbic system.However,results have not been consistent.To the best of our knowledge,very little is known about the relationship between 1H-MRS appearance and depression inventory.In the present study,the relationship between 1H-MRS appearance in depressive patients and Minnesota Multiphasic Personality Inventory-2 scale was analyzed.MRI and 1H-MRS exhibited widened sulci and cisterns,as well as an absence of abnormal signals in depressive patients.In addition,N-acetyl aspartate/total creatine ratios in bilateral hippocampi and dorsolateral prefrontal cortex were significantly less in depressive patients than in control subjects(P < 0.01).In contrast,choline-containing compounds/total creatine ratios in the dorsolateral prefrontal cortex were significantly greater in depressive patients than in control subjects(P < 0.01).These ratios significantly and positively correlated with patient total depression scores as assessed using the Minnesota Multiphasic Personality Inventory-2 scale(r=0.934 7,0.878 7,P < 0.01).These results suggested that 1H-MRS could be used to reveal a reduced number of neurons in the hippocampus and dorsolateral prefrontal cortex,as well as altered membrane phospholipid metabolism in the dorsolateral prefrontal cortex,in patients with depressive disorder.Abnormal mechanisms partially reflected severity of depressive disorder.
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Fumi eKatsuki
2012-05-01
Full Text Available The dorsolateral prefrontal and posterior parietal cortex are two parts of a broader brain network involved in the control of cognitive functions such as working memory, spatial attention, and decision making. The two areas share many functional properties and exhibit similar patterns of activation during the execution of mental operations. However, neurophysiological experiments in non-human primates have also documented subtle differences, revealing functional specialization within the fronto-parietal network. These differences include the ability of the dorsolateral prefrontal cortex to influence memory performance, attention allocation and motor responses to a greater extent, and to resist interference by distracting stimuli. In recent years, distinct cellular and anatomical differences have been identified, offering insights into how functional specialization is achieved. This article reviews the common functions and functional differences between the dorsolateral prefrontal and posterior parietal cortex, and their underlying mechanisms.
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Dlabac-de Lange, Jozarni J; Liemburg, Edith J; Bais, Leonie; van de Poel-Mustafayeva, Aida T; de Lange-de Klerk, Elly S M; Knegtering, Henderikus; Aleman, André
Prefrontal repetitive Transcranial Magnetic Stimulation (rTMS) may improve negative symptoms in patients with schizophrenia, but few studies have investigated the underlying neural mechanism. This study aims to investigate changes in the levels of glutamate and glutamine (Glx, neurotransmitter and precursor) and N-Acetyl Aspartate (NAA) in the left dorsolateral prefrontal cortex of patients with schizophrenia treated with active bilateral prefrontal rTMS as compared to sham-rTMS, as measured with 1 H-Magnetic Resonance Spectroscopy ( 1 H-MRS). Patients were randomized to a 3-week course of active or sham high-frequency rTMS. Pre-treatment and post-treatment 1 H-MRS data were available for 24 patients with schizophrenia with moderate to severe negative symptoms (Positive and Negative Syndrome Scale (PANSS) negative subscale ≥ 15). Absolute metabolite concentrations were calculated using LCModel with the water peak as reference. To explore the association between treatment condition and changes in concentration of Glx and NAA, we applied a linear regression model. We observed an increase of Glx concentration in the active treatment group and a decrease of Glx concentration in the group receiving sham treatment. The association between changes in Glx concentration and treatment condition was significant. No significant associations between changes in NAA and treatment condition were found. Noninvasive neurostimulation with high-frequency bilateral prefrontal rTMS may influence Glx concentration in the prefrontal cortex of patients with schizophrenia. Larger studies are needed to confirm these findings and further elucidate the underlying neural working mechanism of rTMS. Copyright © 2016 Elsevier Inc. All rights reserved.
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Listen, learn, like! Dorsolateral prefrontal cortex involved in the mere exposure effect in music.
Green, Anders C; Bærentsen, Klaus B; Stødkilde-Jørgensen, Hans; Roepstorff, Andreas; Vuust, Peter
2012-01-01
We used functional magnetic resonance imaging to investigate the neural basis of the mere exposure effect in music listening, which links previous exposure to liking. Prior to scanning, participants underwent a learning phase, where exposure to melodies was systematically varied. During scanning, participants rated liking for each melody and, later, their recognition of them. Participants showed learning effects, better recognising melodies heard more often. Melodies heard most often were most liked, consistent with the mere exposure effect. We found neural activations as a function of previous exposure in bilateral dorsolateral prefrontal and inferior parietal cortex, probably reflecting retrieval and working memory-related processes. This was despite the fact that the task during scanning was to judge liking, not recognition, thus suggesting that appreciation of music relies strongly on memory processes. Subjective liking per se caused differential activation in the left hemisphere, of the anterior insula, the caudate nucleus, and the putamen.
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Hirosawa R
2013-07-01
Full Text Available Rikuei Hirosawa,1 Jin Narumoto,1 Yuki Sakai,1 Seiji Nishida,2 Takuya Ishida,1 Takashi Nakamae,1 Yuichi Takei,3 Kenji Fukui1 1Department of Psychiatry, Graduate School of Medicine, Kyoto Prefectural University of Medicine, Kyoto, 2Maizuru Medical Center, Kyoto, 3Department of Psychiatry and Neuroscience, Gunma University Graduate School of Medicine, Gunma, Japan Background: Near-infrared spectroscopy has helped our understanding of the neurobiological mechanisms of psychiatric disorders and has advantages including noninvasiveness, lower cost, and ease of use compared with other imaging techniques, like functional magnetic resonance imaging. The verbal fluency task is the most common and well established task used to assess cognitive activation during near-infrared spectroscopy. Recent functional neuroimaging studies have shown that the orbitofrontal cortex and other brain regions, including the dorsolateral prefrontal cortex, may play important roles in the pathophysiology of obsessive-compulsive disorder (OCD. This study aimed to evaluate hemodynamic responses in the dorsolateral prefrontal cortex in patients with OCD using near-infrared spectroscopy during the verbal fluency task and to compare these with dorsolateral prefrontal cortex responses in healthy controls. Methods: Twenty patients with OCD and 20 controls matched for age, gender, handedness, and estimated intelligence quotient participated in this study. The verbal fluency task was used to elicit near-infrared spectroscopic activation and consisted of a 30-second pre-task, followed by three repetitions of a 20-second verbal fluency task (total 60 seconds, followed by a 70-second post-task period. The near-infrared spectroscopy experiment was conducted on the same day as surveys of obsessive-compulsive symptoms, depression, and anxiety. Z-scores for changes in the concentration of oxygenated hemoglobin were compared between the OCD patients and controls in 14 channels set over the
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Nakamura-Palacios, Ester Miyuki; Lopes, Isabela Bittencourt Coutinho; Souza, Rodolpho Albuquerque; Klauss, Jaisa; Batista, Edson Kruger; Conti, Catarine Lima; Moscon, Janine Andrade; de Souza, Rodrigo Stênio Moll
2016-10-01
Here, we report some electrophysiologic and imaging effects of the transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (dlPFC) in drug addiction, notably in alcohol and crack-cocaine dependence. The low resolution electromagnetic tomography (LORETA) analysis obtained through event-related potentials (ERPs) under drug-related cues, more specifically in its P3 segment (300-500 ms) in both, alcoholics and crack-cocaine users, showed that the ventral medial prefrontal cortex (vmPFC) was the brain area with the largest change towards increasing activation under drug-related cues in those subjects that kept abstinence during and after the treatment with bilateral tDCS (2 mA, 35 cm(2), cathodal left and anodal right) over dlPFC, applied repetitively (five daily sessions). In an additional study in crack-cocaine, which showed craving decreases after repetitive bilateral tDCS, we examined data originating from diffusion tensor imaging (DTI), and we found increased DTI parameters in the left connection between vmPFC and nucleus accumbens (NAcc), such as the number of voxels, fractional anisotropy (FA) and apparent diffusion coefficient (ADC), in tDCS-treated crack-cocaine users when compared to the sham-tDCS group. This increasing of DTI parameters was significantly correlated with craving decreasing after the repetitive tDCS. The vmPFC relates to the control of drug seeking, possibly by extinguishing this behavior. In our studies, the bilateral dlPFC tDCS reduced relapses and craving to the drug use, and increased the vmPFC activation under drug cues, which may be of a great importance in the control of drug use in drug addiction.
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Dorsolateral Prefrontal Contributions to Human Intelligence
Barbey, Aron K.; Colom, Roberto; Grafman, Jordan
2012-01-01
Although cognitive neuroscience has made remarkable progress in understanding the involvement of the prefrontal cortex in executive control functions for human intelligence, the necessity of the dorsolateral prefrontal cortex (dlPFC) for key competencies of general intelligence and executive function remains to be well established. Here we studied human brain lesion patients with dlPFC lesions to investigate whether this region is computationally necessary for performance on neuropsychological tests of general intelligence and executive function, administering the Wechsler Adult Intelligence Scale (WAIS) and subtests of the Delis Kaplan Executive Function System (D-KEFS) to three groups: dlPFC lesions (n = 19), non-dlPFC lesions (n = 152), and no brain lesions (n = 55). The key results indicate that: (1) patients with focal dlPFC damage exhibit lower scores, at the latent variable level, than controls in general intelligence (g) and executive function; (2) dlPFC patients demonstrate lower scores than controls in several executive measures; and (3) these latter differences are no longer significant when the pervasive influence of the general factor of intelligence (g) is statistically removed. The observed findings support a central role for the dlPFC in general intelligence and make specific recommendations for the interpretation and application of the WAIS and D-KEFS to the study of high-level cognition in health and disease. PMID:22634247
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Listen, Learn, Like! Dorsolateral Prefrontal Cortex Involved in the Mere Exposure Effect in Music
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Anders C. Green
2012-01-01
Full Text Available We used functional magnetic resonance imaging to investigate the neural basis of the mere exposure effect in music listening, which links previous exposure to liking. Prior to scanning, participants underwent a learning phase, where exposure to melodies was systematically varied. During scanning, participants rated liking for each melody and, later, their recognition of them. Participants showed learning effects, better recognising melodies heard more often. Melodies heard most often were most liked, consistent with the mere exposure effect. We found neural activations as a function of previous exposure in bilateral dorsolateral prefrontal and inferior parietal cortex, probably reflecting retrieval and working memory-related processes. This was despite the fact that the task during scanning was to judge liking, not recognition, thus suggesting that appreciation of music relies strongly on memory processes. Subjective liking per se caused differential activation in the left hemisphere, of the anterior insula, the caudate nucleus, and the putamen.
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Burrus, Caley
2013-11-01
The United States has a high rate of child maltreatment, with nearly 12 in 1000 children being victims of abuse or neglect. Child abuse strongly predicts negative life outcomes, especially in areas of emotional and mental health. Abused children are also more likely than their peers to engage in violence and enter the juvenile justice system, as well as to become abusive parents themselves. Research has shown that child abuse and trauma can lead to decreased hippocampal volume, which could be indicative of abnormal hippocampal development. Hippocampal development appears to directly affect the development of the dorsolateral prefrontal cortex, a brain area responsible for emotion regulation, cognitive reappraisal, and general executive function. Therefore, I hypothesize that if child abuse results in abnormal hippocampal development, which leads to abnormal dorsolateral prefrontal cortex development, many of the correlated risk factors of child abuse, such as emotionally-laden parenting and unfavorable cognitive distortions regarding children's behaviors, may be in part caused by underdevelopment or abnormal functioning of the dorsolateral prefrontal cortex, as a function of the individual's own experiences with abuse during childhood. If this hypothesis is supported with future research, more targeted, successful, and cost-effective prevention and treatment protocols could ensue. For instance, programs that have been empirically shown to increase the activity of the dorsolateral prefrontal cortex, such as cognitive behavioral therapy, could be effective in decreasing the incidence of intergenerational transfer of abuse. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Reduced dorso-lateral prefrontal cortex in treatment resistant schizophrenia.
Zugman, André; Gadelha, Ary; Assunção, Idaiane; Sato, João; Ota, Vanessa K; Rocha, Deyvis L; Mari, Jair J; Belangero, Sintia I; Bressan, Rodrigo A; Brietzke, Elisa; Jackowski, Andrea P
2013-08-01
Treatment resistance affects up to one third of patients with schizophrenia (SCZ). A better understanding of its biological underlying processes could improve treatment. The aim of this study was to compare cortical thickness between non-resistant SCZ (NR-SCZ), treatment-resistant SCZ (TR-SCZ) patients and healthy controls (HC). Structural MRI scans were obtained from 3 groups of individuals: 61 treatment resistant SCZ individuals, 67 non-resistant SCZ and 80 healthy controls. Images were analyzed using cortical surface modelling (implemented in freesurfer package) to identify group differences in cortical thickness. Statistical significant differences were identified using Monte-Carlo simulation method with a corrected p-cluster<0.01. Patients in the TR-SCZ group showed a widespread reduction in cortical thickness in frontal, parietal, temporal and occipital regions bilaterally. NR-SCZ group had reduced cortex in two regions (left superior frontal cortex and left caudal middle frontal cortex). TR-SCZ group also showed decreased thickness in the left dorsolateral prefrontal cortex (DLPFC) when compared with patients from NR-SCZ group. The reduction in cortical thickness in DLPFC indicates a more severe form of the disease or a specific finding for this group. Alterations in this region should be explored as a putative marker for treatment resistance. Prospective studies, with individuals being followed from first episode psychosis until refractoriness is diagnosed, are needed to clarify these hypotheses. Copyright © 2013 Elsevier B.V. All rights reserved.
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van't Wout, M; Kahn, RS; Sanfey, AG; Aleman, A
2005-01-01
Although decision-making is typically seen as a rational process, emotions play a role in tasks that include unfairness. Recently, activation in the right dorsolateral prefrontal cortex during offers experienced as unfair in the Ultimatum Game was suggested to subserve goal maintenance in this task.
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Dorsolateral Prefrontal Cortex Drives Mesolimbic Dopaminergic Regions to Initiate Motivated Behavior
Ballard, Ian C.; Murty, Vishnu P.; Carter, R. McKell; MacInnes, Jeffrey J.; Huettel, Scott A.; Adcock, R. Alison
2011-01-01
How does the brain translate information signaling potential rewards into motivation to get them? Motivation to obtain reward is thought to depend on the midbrain, (particularly the ventral tegmental area, VTA), the nucleus accumbens (NAcc), and the dorsolateral prefrontal cortex (dlPFC), but it is not clear how the interactions amongst these regions relate to reward-motivated behavior. To study the influence of motivation on these reward-responsive regions and on their interactions, we used ...
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Chen, Xingui; Tao, Longxiang; Li, Jingjing; Wu, Jiaonan; Zhu, Chunyan; Yu, Fengqiong; Zhang, Lei; Zhang, Jingjie; Qiu, Bensheng; Yu, Yongqiang; He, Xiaoxuan
2017-01-01
Abstract Background: Tamoxifen is the most widely used drug for treating patients with estrogen receptor-sensitive breast cancer. There is evidence that breast cancer patients treated with tamoxifen exhibit cognitive dysfunction. However, the underlying neural mechanism remains unclear. The present study aimed to investigate the neural mechanisms underlying working memory deficits in combination with functional connectivity changes in premenopausal women with breast cancer who received long-term tamoxifen treatment. Methods: A total of 31 premenopausal women with breast cancer who received tamoxifen and 32 matched healthy control participants were included. The participants completed n-back tasks and underwent resting-state functional magnetic resonance imaging, which measure working memory performance and brain functional connectivity, respectively. A seed-based functional connectivity analysis within the whole brain was conducted, for which the dorsolateral prefrontal cortex was chosen as the seed region. Results: Our results indicated that the tamoxifen group had significant deficits in working memory and general executive function performance and significantly lower functional connectivity of the right dorsolateral prefrontal cortex with the right hippocampus compared with the healthy controls. There were no significant changes in functional connectivity in the left dorsolateral prefrontal cortex within the whole brain between the tamoxifen group and healthy controls. Moreover, significant correlations were found in the tamoxifen group between the functional connectivity strength of the dorsolateral prefrontal cortex with the right hippocampus and decreased working memory performance. Conclusion: This study demonstrates that the prefrontal cortex and hippocampus may be affected by tamoxifen treatment, supporting an antagonistic role of tamoxifen in the long-term treatment of breast cancer patients. PMID:28177081
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Tachibana Atsumichi
2012-05-01
Full Text Available Abstract Background The Kana Pick-out Test (KPT, which uses Kana or Japanese symbols that represent syllables, requires parallel processing of discrete (pick-out and continuous (reading dual tasks. As a dual task, the KPT is thought to test working memory and executive function, particularly in the prefrontal cortex (PFC, and is widely used in Japan as a clinical screen for dementia. Nevertheless, there has been little neurological investigation into PFC activity during this test. Methods We used functional magnetic resonance imaging (fMRI to evaluate changes in the blood oxygenation level-dependent (BOLD signal in young healthy adults during performance of a computerized KPT dual task (comprised of reading comprehension and picking out vowels and compared it to its single task components (reading or vowel pick-out alone. Results Behavioral performance of the KPT degraded compared to its single task components. Performance of the KPT markedly increased BOLD signal intensity in the PFC, and also activated sensorimotor, parietal association, and visual cortex areas. In conjunction analyses, bilateral BOLD signal in the dorsolateral PFC (Brodmann's areas 45, 46 was present only in the KPT. Conclusions Our results support the central bottleneck theory and suggest that the dorsolateral PFC is an important mediator of neural activity for both short-term storage and executive processes. Quantitative evaluation of the KPT with fMRI in healthy adults is the first step towards understanding the effects of aging or cognitive impairment on KPT performance.
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Tachibana, Atsumichi; Noah, J Adam; Bronner, Shaw; Ono, Yumie; Hirano, Yoshiyuki; Niwa, Masami; Watanabe, Kazuko; Onozuka, Minoru
2012-05-28
The Kana Pick-out Test (KPT), which uses Kana or Japanese symbols that represent syllables, requires parallel processing of discrete (pick-out) and continuous (reading) dual tasks. As a dual task, the KPT is thought to test working memory and executive function, particularly in the prefrontal cortex (PFC), and is widely used in Japan as a clinical screen for dementia. Nevertheless, there has been little neurological investigation into PFC activity during this test. We used functional magnetic resonance imaging (fMRI) to evaluate changes in the blood oxygenation level-dependent (BOLD) signal in young healthy adults during performance of a computerized KPT dual task (comprised of reading comprehension and picking out vowels) and compared it to its single task components (reading or vowel pick-out alone). Behavioral performance of the KPT degraded compared to its single task components. Performance of the KPT markedly increased BOLD signal intensity in the PFC, and also activated sensorimotor, parietal association, and visual cortex areas. In conjunction analyses, bilateral BOLD signal in the dorsolateral PFC (Brodmann's areas 45, 46) was present only in the KPT. Our results support the central bottleneck theory and suggest that the dorsolateral PFC is an important mediator of neural activity for both short-term storage and executive processes. Quantitative evaluation of the KPT with fMRI in healthy adults is the first step towards understanding the effects of aging or cognitive impairment on KPT performance.
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Estudio de la asimetría interhemisférica en la corteza prefrontal dorsolateral de sujetos humanos
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Hernán J. Pimienta J.
2005-03-01
Full Text Available Se presentan los resultados de un trabajo de investigación encaminado a establecer las diferencias entre los hemisferios cerebrales de la corteza prefrontal dorsolateral: áreas 46 laeral y 7 medial, de sujetos humanos.
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Pérez-Díaz, Francisco; Díaz, Estrella; Sánchez, Natividad; Vargas, Juan Pedro; Pearce, John M; López, Juan Carlos
2017-01-01
Recent studies support the idea that stimulus processing in latent inhibition can vary during the course of preexposure. Controlled attentional mechanisms are said to be important in the early stages of preexposure, while in later stages animals adopt automatic processing of the stimulus to be used for conditioning. Given this distinction, it is possible that both types of processing are governed by different neural systems, affecting differentially the retrieval of information about the stimulus. In the present study we tested if a lesion to the dorso-lateral striatum or to the medial prefrontal cortex has a selective effect on exposure to the future conditioned stimulus (CS). With this aim, animals received different amounts of exposure to the future CS. The results showed that a lesion to the medial prefrontal cortex enhanced latent inhibition in animals receiving limited preexposure to the CS, but had no effect in animals receiving extended preexposure to the CS. The lesion of the dorso-lateral striatum produced a decrease in latent inhibition, but only in animals with an extended exposure to the future conditioned stimulus. These results suggest that the dorsal striatum and medial prefrontal cortex play essential roles in controlled and automatic processes. Automatic attentional processes appear to be impaired by a lesion to the dorso-lateral striatum and facilitated by a lesion to the prefrontal cortex.
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Hashimoto, T; Arion, D; Unger, T; Maldonado-Avilés, JG; Morris, HM; Volk, DW; Mirnics, K; Lewis, DA
2007-01-01
In subjects with schizophrenia, impairments in working memory are associated with dysfunction of the dorsolateral prefrontal cortex (DLPFC). This dysfunction appears to be due, at least in part, to abnormalities in γ-aminobutyric acid (GABA)-mediated inhibitory circuitry. To test the hypothesis that altered GABA-mediated circuitry in the DLPFC of subjects with schizophrenia reflects expression changes of genes that encode selective presynaptic and postsynaptic components of GABA neurotransmis...
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Yamagishi, Toshio; Takagishi, Haruto; Fermin, Alan de Souza Rodrigues; Kanai, Ryota; Li, Yang; Matsumoto, Yoshie
2016-05-17
Human prosociality has been traditionally explained in the social sciences in terms of internalized social norms. Recent neuroscientific studies extended this traditional view of human prosociality by providing evidence that prosocial choices in economic games require cognitive control of the impulsive pursuit of self-interest. However, this view is challenged by an intuitive prosociality view emphasizing the spontaneous and heuristic basis of prosocial choices in economic games. We assessed the brain structure of 411 players of an ultimatum game (UG) and a dictator game (DG) and measured the strategic reasoning ability of 386. According to the reflective norm-enforcement view of prosociality, only those capable of strategically controlling their selfish impulses give a fair share in the UG, but cognitive control capability should not affect behavior in the DG. Conversely, we support the intuitive prosociality view by showing for the first time, to our knowledge, that strategic reasoning and cortical thickness of the dorsolateral prefrontal cortex were not related to giving in the UG but were negatively related to giving in the DG. This implies that the uncontrolled choice in the DG is prosocial rather than selfish, and those who have a thicker dorsolateral prefrontal cortex and are capable of strategic reasoning (goal-directed use of the theory of mind) control this intuitive drive for prosociality as a means to maximize reward when there are no future implications of choices.
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Inequality signals in dorsolateral prefrontal cortex inform social preference models.
Holper, Lisa; Burke, Christopher J; Fausch, Christoph; Seifritz, Erich; Tobler, Philippe N
2018-05-01
Humans typically display inequality aversion in social situations, which manifests itself as a preference for fairer distributions of resources. However, people differ in the degree to which they dislike being worse off [disadvantageous inequality (DI) aversion] or better off [advantageous inequality (AI) aversion] than others. Competing models explain such behavior by focusing on aversion to payoff differences, maximization of total payoff or reciprocity. Using functional near-infrared spectroscopy, we asked which of these theories could better explain dorsolateral prefrontal cortex (dlPFC) activity while participants accepted or punished fair vs unfair monetary transfers in an anonymous norm compliance task. We found that while all participants exhibited DI aversion, there were substantial differences in preferences for AI, which were strongly predicted by dlPFC activation. Model comparisons revealed that both punishment behavior and prefrontal activity were best explained by a model that allowed for AI seeking rather than imposing aversion. Moreover, enhancing this model by taking into account behavioral response times, as a proxy for choice difficulty, further improved model fits. Our data provide evidence that the dlPFC encodes subjective values of payoff inequality and that this representation is richer than envisaged by standard models of social preferences.
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Patrizia eTurriziani
2012-04-01
Full Text Available A debated question in the literature is the degree of anatomical and functional lateralization of the executive control processes subserved by the dorsolateral prefrontal cortex (DLPFC during recognition memory retrieval.We investigated if transient inhibition and excitation of the left and right DLPFC at retrieval by means of repetitive transcranial magnetic stimulation (rTMS modulate recognition memory performance in 100 healthy controls (HCs and in 8 patients with Mild Cognitive Impairment (MCI. Recognition memory tasks of faces, buildings and words were used in different experiments.rTMS-inhibition of the right DLPFC enhanced recognition memory of verbal and non verbal material in both HCs and MCIs. rTMS-excitation of the same region in HCs deteriorated memory performance.Bilateral recruitment of the DLPFC could represent a dysfunctional use of brain resources in recognition memory. Inhibitory rTMS of the right DLPFC may modulate the activity in this dysfunctional network enhancing function in HCs or restoring an adaptive equilibrium in MCI.
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Armita Golkar
Full Text Available The lateral prefrontal and orbitofrontal cortices have both been implicated in emotion regulation, but their distinct roles in regulation of negative emotion remain poorly understood. To address this issue we enrolled 58 participants in an fMRI study in which participants were instructed to reappraise both negative and neutral stimuli. This design allowed us to separately study activations reflecting cognitive processes associated with reappraisal in general and activations specifically related to reappraisal of negative emotion. Our results confirmed that both the dorsolateral prefrontal cortex (DLPFC and the lateral orbitofrontal cortex (OFC contribute to emotion regulation through reappraisal. However, activity in the DLPFC was related to reappraisal independently of whether negative or neutral stimuli were reappraised, whereas the lateral OFC was uniquely related to reappraisal of negative stimuli. We suggest that relative to the lateral OFC, the DLPFC serves a more general role in emotion regulation, perhaps by reflecting the cognitive demand that is inherent to the regulation task.
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Xiang-Yun Ma
2017-01-01
Full Text Available Background/Objective. Menopausal depression (MD is characterized by depressive symptoms along with hormonal fluctuations. We investigate brain function alteration between major depressive disorder (MDD and MD. Methods. The difference in oxygenated hemoglobin (Oxy-Hb for the prefrontal cortex (PFC was compared retrospectively among 90 females presented with 30 MDD, 30 MD, and 30 healthy controls (HCs using verbal fluency task (VFT with near-infrared spectroscopy (NIRS. Results. We observed a significant difference in Oxy-Hb alteration in the left dorsolateral PFC (DLPFC using VFT with NIRS (channel 18, P=0.007 between the MD and MDD groups. A significant difference in Oxy-Hb levels was observed among the three groups in the bilateral DLPFC (channels 18, 27, 33, 39, 41, and 45; P<0.05. Compared to the HCs, the MD group presented lower Oxy-Hb activation in the right DLPFC (channel 41; P=0.048 and the left DLPFC (channels 18, 39, and 45; P<0.05, and the MDD group presented lower Oxy-Hb activation in the right DLPFC (channels 27, 33, and 41; P<0.05 and the left DLPFC (channels 39 and 45; P<0.05. Conclusion. Abnormal hemodynamics of the left DLPFC can differentiate MD from MDD by NIRS.
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Dlabac-de Lange, J. J.; Bais, L.; van Es, F. D.; Visser, B. G. J.; Reinink, E.; Bakker, B.; van den Heuvel, E. R.; Aleman, A.; Knegtering, H.
Background. Few studies have investigated the efficacy of repetitive transcranial magnetic stimulation (rTMS) treatment for negative symptoms of schizophrenia, reporting inconsistent results. We aimed to investigate whether 10 Hz stimulation of the bilateral dorsolateral prefrontal cortex during 3
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Hsing-Chang Ni
2017-05-01
Full Text Available Intermittent theta burst stimulation (iTBS, a patterned repetitive transcranial magnetic stimulation, was applied over the posterior superior temporal sulcus (pSTS or dorsolateral prefrontal cortex (DLPFC to explore its impact in adults with autism spectrum disorder (ASD. Among 25 adults with ASD, 19 (mean age: 20.8 years completed the randomized, sham-controlled, crossover trial. Every participant received iTBS over the bilateral DLPFC, bilateral pSTS and inion (as a sham control stimulation in a randomized order with a 1-week interval. Neuropsychological functions were assessed using the Conners' Continuous Performance Test (CCPT and the Wisconsin Card Sorting Test (WCST. Behavioral outcomes were measured using the Yale-Brown Obsessive Compulsive Scale (Y-BOCS and the Social Responsiveness Scale (SRS. In comparison to that in the sham stimulation, the reaction time in the CCPT significantly decreased following single DLPFC session (p = 0.04, effect size = 0.71 while there were no significant differences in the CCPT and WCST following single pSTS session. Besides, the results in behavioral outcomes were inconsistent and had discrepancy between reports of parents and patients. In conclusion, a single session of iTBS over the bilateral DLPFC may alter the neuropsychological function in adults with ASD. The impacts of multiple-sessions iTBS over the DLPFC or pSTS deserve further investigations.
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International Nuclear Information System (INIS)
Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun
2007-01-01
We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging
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Energy Technology Data Exchange (ETDEWEB)
Bang, Seong Ae; Cho, Sang Soo; Yoon, Eun Jin; Kim, Ji Sun; Lee, Byung Chul; Kim, Yu Kyeong; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)
2007-07-01
We previously demonstrated dopamine (DA) release in the bilateral striatal regions following prefrontal repetitive transcranial magnetic stimulation (rTMS) in young subjects. Several lines of evidence support substantial age-related changes in human dopaminergic neurotransmission. One possible explanation is alteration of cortico striatal neural connection with aging. Therefore, we investigated how frontal activation by rTMS influences striatal DA release in the elderly with SPECT measurements of striatal binding of [123I]iodobenzamide (lBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy elderly male subjects (age, 64 3 y) were studied with brain [123I]IBZM SPECT under three conditions (resting, sham stimulation, and active rTMS over left dorsolateral prefrontal cortex (DLPFC)), while receiving a bolus plus constant infusion of [123I]IBZM. rTMS session consisted of three blocks. In each block, 15 trains of 2 sec duration were delivered with 10 Hz stimulation frequency and 100% motor threshold. Striatal V3', calculated as (striatal - occipital)/occipital radioactivity, was measured under equilibrium condition at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over left DLPFC induced no significant change in V3' in the right striatum compared with baseline condition (0.91 0.25 vs. 0.96 0.25, P = NS). Interestingly, left striatal V3' showed a significant increase after rTMS over left DLPFC compared with sham condition (1.09 0.33 vs. 0.93 0.27, P < 0.05; 17.0 11.1% increase). These results are discrepant from previous ones from young subjects, who showed frontal rTMS-induced reduction of striatal V3', indicating rTMS-induced striatal DA release. We found no significant striatal DA release induced by rTMS over DLPFC in healthy elderly subjects using in vivo binding competition techniques. These results may support an altered cortico striatal circuit in normal aging.
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Differential involvement of left prefrontal cortex in inductive and deductive reasoning.
Goel, Vinod; Dolan, Raymond J
2004-10-01
While inductive and deductive reasoning are considered distinct logical and psychological processes, little is known about their respective neural basis. To address this issue we scanned 16 subjects with fMRI, using an event-related design, while they engaged in inductive and deductive reasoning tasks. Both types of reasoning were characterized by activation of left lateral prefrontal and bilateral dorsal frontal, parietal, and occipital cortices. Neural responses unique to each type of reasoning determined from the Reasoning Type (deduction and induction) by Task (reasoning and baseline) interaction indicated greater involvement of left inferior frontal gyrus (BA 44) in deduction than induction, while left dorsolateral (BA 8/9) prefrontal gyrus showed greater activity during induction than deduction. This pattern suggests a dissociation within prefrontal cortex for deductive and inductive reasoning.
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Spike-timing-dependent plasticity in the human dorso-lateral prefrontal cortex.
Casula, Elias Paolo; Pellicciari, Maria Concetta; Picazio, Silvia; Caltagirone, Carlo; Koch, Giacomo
2016-12-01
Changes in the synaptic strength of neural connections are induced by repeated coupling of activity of interconnected neurons with precise timing, a phenomenon known as spike-timing-dependent plasticity (STDP). It is debated if this mechanism exists in large-scale cortical networks in humans. We combined transcranial magnetic stimulation (TMS) with concurrent electroencephalography (EEG) to directly investigate the effects of two paired associative stimulation (PAS) protocols (fronto-parietal and parieto-frontal) of pre and post-synaptic inputs within the human fronto-parietal network. We found evidence that the dorsolateral prefrontal cortex (DLPFC) has the potential to form robust STDP. Long-term potentiation/depression of TMS-evoked cortical activity is prompted after that DLPFC stimulation is followed/preceded by posterior parietal stimulation. Such bidirectional changes are paralleled by sustained increase/decrease of high-frequency oscillatory activity, likely reflecting STDP responsivity. The current findings could be important to drive plasticity of damaged cortical circuits in patients with cognitive or psychiatric disorders. Copyright © 2016 Elsevier Inc. All rights reserved.
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Bosch, Oliver G.; Wagner, Michael; Jessen, Frank; Kühn, Kai-Uwe; Joe, Alexius; Seifritz, Erich; Maier, Wolfgang; Biersack, Hans-Jürgen; Quednow, Boris B.
2013-01-01
Introduction 3,4-Methylenedioxymethamphetamine (MDMA, “ecstasy”) is a recreational club drug with supposed neurotoxic effects selectively on the serotonin system. MDMA users consistently exhibit memory dysfunction but there is an ongoing debate if these deficits are induced mainly by alterations in the prefrontal or mediotemporal cortex, especially the hippocampus. Thus, we investigated the relation of verbal memory deficits with alterations of regional cerebral brain glucose metabolism (rMRGlu) in recreational MDMA users. Methods Brain glucose metabolism in rest was assessed using 2-deoxy-2-(18F)fluoro-D-glucose positron emission tomography (18FDG PET) in 19 male recreational users of MDMA and 19 male drug-naïve controls. 18FDG PET data were correlated with memory performance assessed with a German version of the Rey Auditory Verbal Learning Test. Results As previously shown, MDMA users showed significant impairment in verbal declarative memory performance. PET scans revealed significantly decreased rMRGlu in the bilateral dorsolateral prefrontal and inferior parietal cortex, bilateral thalamus, right hippocampus, right precuneus, right cerebellum, and pons (at the level of raphe nuclei) of MDMA users. Among MDMA users, learning and recall were positively correlated with rMRGlu predominantly in bilateral frontal and parietal brain regions, while recognition was additionally related to rMRGlu in the right mediotemporal and bihemispheric lateral temporal cortex. Moreover, cumulative lifetime dose of MDMA was negatively correlated with rMRGlu in the left dorsolateral and bilateral orbital and medial PFC, left inferior parietal and right lateral temporal cortex. Conclusions Verbal learning and recall deficits of recreational MDMA users are correlated with glucose hypometabolism in prefrontal and parietal cortex, while word recognition was additionally correlated with mediotemporal hypometabolism. We conclude that memory deficits of MDMA users arise from combined
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Electrical stimulation of the dorsolateral prefrontal cortex improves memory monitoring.
Chua, Elizabeth F; Ahmed, Rifat
2016-05-01
The ability to accurately monitor one's own memory is an important feature of normal memory function. Converging evidence from neuroimaging and lesion studies have implicated the dorsolateral prefrontal cortex (DLPFC) in memory monitoring. Here we used high definition transcranial direct stimulation (HD-tDCS), a non-invasive form of brain stimulation, to test whether the DLPFC has a causal role in memory monitoring, and the nature of that role. We used a metamemory monitoring task, in which participants first attempted to recall the answer to a general knowledge question, then gave a feeling-of-knowing (FOK) judgment, followed by a forced choice recognition task. When participants received DLPFC stimulation, their feeling-of-knowing judgments were better predictors of memory performance, i.e., they had better memory monitoring accuracy, compared to stimulation of a control site, the anterior temporal lobe (ATL). Effects of DLPFC stimulation were specific to monitoring accuracy, as there was no significant increase in memory performance, and if anything, there was poorer memory performance with DLPFC stimulation. Thus we have demonstrated a causal role for the DLPFC in memory monitoring, and showed that electrically stimulating the left DLPFC led people to more accurately monitor and judge their own memory. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Jiang, Ke; Wu, Shi; Shi, Zhenhao; Liu, Mingyan; Peng, Maoying; Shen, Yang; Yang, Juan
2018-08-01
Individual self-esteem is dominated more by agency than by communion. However, prior research has mainly focused on one's agentic/communal self-evaluation, while little is known about how one endorses others' agentic/communal evaluation of the self. The present study investigated the associations between trait self-esteem and fundamental dimensions of social cognition, i.e. agency vs. communion, during both self-evaluation and endorsement of others' evaluation of oneself. We also investigated the neural mechanisms underlying the relationship between trait self-esteem and agentic self-evaluation. Behavioral results revealed that self-esteem was positively correlated with the agentic ratings from self-evaluation and endorsement of others' evaluation of the self, and that the agentic self-evaluation was a significant full mediator between self-esteem and endorsement of others' agentic evaluation. Whole-brain regression analysis revealed that self-esteem was negatively correlated with right dorsolateral prefrontal and bilateral thalamic response to agentic self-evaluation. A possible interpretation is that low self-esteem people both hold a more self-critical attitude about the self and have less certainty or clarity of their self-concepts than high self-esteem people do. These findings have important implication for understanding the neural and cognitive mechanisms underlying self-esteem's effect on one's agentic self-evaluations. Copyright © 2018 Elsevier B.V. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Cho, Sang Soo; Yoon, Eun Jin; Kim, Yu Kyeong; Lee, Won Woo; Kim, Sang Eun [Seoul National University College of Medicine, Seoul (Korea, Republic of)
2005-07-01
Animal study suggests that prefrontal cortex plays an important Animal studies suggest that prefrontal cortex plays an important role in the modulation of dopamine (DA) release in subcortical areas. However, little is known about the relationship between DA release and prefrontal activation in human. We investigated whether repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (DLPFC) influences DA release in human striatum with SPECT measurements of striatal binding of [123I)iodobenzamide (IBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy male volunteers (age, 25{+-}2 yr) were studied with brain [123I]IBZM SPECT under three conditions (resting, Sham stimulation, and active rTMS over left DLPFC), while receiving a bolus plus constant infusion of [123I]IBZM DLPFC was defined as a 6 cm anterior and 1cm lateral from the primary motor cortex. rTMS session consisted of three blocks, in each block, 15 trains of 2 see duration were delivered with 10 Hz stimulation frequency, 100% motor threshold, and between-train intervals of 10 sec. Striatal V3', calculated as (striatal - occipital) / occipital activity ratio, was measured under equilibrium condition, at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over DLPFC induced reduction of V3' in the ipsilateral and contralateral striatum by 9.7% {+-} 1.3% and 10.6% {+-} 3.2%, respectively, compared with sham procedures (P < 0.01 and P < 0.01, respectively), indicating striatal DA release elicited by rTMS over DLPFC. V3' reduction in the ipsilateral caudate nucleus was greater than that in the contralateral caudate nucleus (9.9% {+-} 4.5% vs. 6.6% {+-} 3.1%, P < 0.05). These data demonstrate DA release in human striatum induced by rTMS over DLPFC, supporting that cortico-striatal fibers originating in prefrontal cortex are involved in local DA release.
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International Nuclear Information System (INIS)
Cho, Sang Soo; Yoon, Eun Jin; Kim, Yu Kyeong; Lee, Won Woo; Kim, Sang Eun
2005-01-01
Animal study suggests that prefrontal cortex plays an important Animal studies suggest that prefrontal cortex plays an important role in the modulation of dopamine (DA) release in subcortical areas. However, little is known about the relationship between DA release and prefrontal activation in human. We investigated whether repetitive transcranial magnetic stimulation (rTMS) over left dorsolateral prefrontal cortex (DLPFC) influences DA release in human striatum with SPECT measurements of striatal binding of [123I)iodobenzamide (IBZM), a DA D2 receptor radioligand that is sensitive to endogenous DA. Five healthy male volunteers (age, 25±2 yr) were studied with brain [123I]IBZM SPECT under three conditions (resting, Sham stimulation, and active rTMS over left DLPFC), while receiving a bolus plus constant infusion of [123I]IBZM DLPFC was defined as a 6 cm anterior and 1cm lateral from the primary motor cortex. rTMS session consisted of three blocks, in each block, 15 trains of 2 see duration were delivered with 10 Hz stimulation frequency, 100% motor threshold, and between-train intervals of 10 sec. Striatal V3', calculated as (striatal - occipital) / occipital activity ratio, was measured under equilibrium condition, at baseline and after sham and active rTMS. Sham stimulation did not affect striatal V3'. rTMS over DLPFC induced reduction of V3' in the ipsilateral and contralateral striatum by 9.7% ± 1.3% and 10.6% ± 3.2%, respectively, compared with sham procedures (P < 0.01 and P < 0.01, respectively), indicating striatal DA release elicited by rTMS over DLPFC. V3' reduction in the ipsilateral caudate nucleus was greater than that in the contralateral caudate nucleus (9.9% ± 4.5% vs. 6.6% ± 3.1%, P < 0.05). These data demonstrate DA release in human striatum induced by rTMS over DLPFC, supporting that cortico-striatal fibers originating in prefrontal cortex are involved in local DA release
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Fitzgibbon, Bernadette Mary; Kirkovski, Melissa; Bailey, Neil Wayne; Thomson, Richard Hilton; Eisenberger, Naomi; Enticott, Peter Gregory; Fitzgerald, Paul Bernard
2017-06-01
The dorsolateral prefrontal cortex (DLPFC) is thought to play a key role in the cognitive control of emotion and has therefore, unsurprisingly, been implicated in the regulation of physical pain perception. This brain region may also influence the experience of social pain, which has been shown to activate similar neural networks as seen in response to physical pain. Here, we applied sham or active low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) to the left DLPFC, previously shown to exert bilateral effects in pain perception, in healthy participants. Following stimulation, participants played the "Cyberball Task"; an online ball-tossing game in which the subject participant is included or excluded. Compared to sham, rTMS did not modulate behavioural response to social exclusion. However, within the active rTMS group only, greater trait personal distress was related to enhanced negative outcomes to social exclusion. These results add further support to the notion that the effect of brain stimulation is not homogenous across individuals, and indicates the need to consider baseline individual differences when assessing response to brain stimulation. This seems particularly relevant in social neuroscience investigations, where trait factors may have a meaningful effect.
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International Nuclear Information System (INIS)
Weinberger, D.R.; Berman, K.F.; Illowsky, B.P.
1988-01-01
We previously reported that compared with normals, patients with chronic schizophrenia have reduced regional cerebral blood flow (rCBF) in dorsolateral prefrontal cortex (DLPFC) during performance of the Wisconsin Card Sort Test (WCS), a DLPFC-related cognitive task, but not during nonprefrontal tasks, such as a simple number-matching (NM) test. We also found that unlike normals, patients failed to activate DLPFC during the WCS over their own baseline (NM) level. To explore the reproducibility of these findings, a new cohort of 16 medication-free patients underwent a series of xenon 133 inhalation rCBF studies under the following conditions: at rest, while performing the WCS, and while performing NM. The results confirmed our earlier findings. In addition, the concentrations in cerebrospinal fluid of homovanillic acid and 5-hydroxyindoleacetic acid correlated with prefrontal rCBF during the WCS but not during the NM test or at rest. The results show that behavior-specific hypofunction of DLPFC in schizophrenia is reproducible, and they implicate a monoaminergic mechanism
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Directory of Open Access Journals (Sweden)
Massimiliano Conson
Full Text Available Recent neurofunctional studies suggested that lateral prefrontal cortex is a domain-general cognitive control area modulating computation of social information. Neuropsychological evidence reported dissociations between cognitive and affective components of social cognition. Here, we tested whether performance on social cognitive and affective tasks can be modulated by transcranial direct current stimulation (tDCS over dorsolateral prefrontal cortex (DLPFC. To this aim, we compared the effects of tDCS on explicit recognition of emotional facial expressions (affective task, and on one cognitive task assessing the ability to adopt another person's visual perspective. In a randomized, cross-over design, male and female healthy participants performed the two experimental tasks after bi-hemispheric tDCS (sham, left anodal/right cathodal, and right anodal/left cathodal applied over DLPFC. Results showed that only in male participants explicit recognition of fearful facial expressions was significantly faster after anodal right/cathodal left stimulation with respect to anodal left/cathodal right and sham stimulations. In the visual perspective taking task, instead, anodal right/cathodal left stimulation negatively affected both male and female participants' tendency to adopt another's point of view. These findings demonstrated that concurrent facilitation of right and inhibition of left lateral prefrontal cortex can speed-up males' responses to threatening faces whereas it interferes with the ability to adopt another's viewpoint independently from gender. Thus, stimulation of cognitive control areas can lead to different effects on social cognitive skills depending on the affective vs. cognitive nature of the task, and on the gender-related differences in neural organization of emotion processing.
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International Nuclear Information System (INIS)
Hasegawa, Akira; Utsumi, Hiroya
2006-01-01
In order to clarify the extent of dysexecutive function of patients with subcortical infarctions, participants of this study underwent neuropsychological tests and single photon emission computerized tomography (SPECT). These participants were categorized into two groups; patients with basal ganglia lesions (BG group) (n=5) and those with white matter lesions (WM group) (n=12). Participants were administered executive function tests as a part of a comprehensive neuropsychological battery. Administered executive measures included the Wisconsin Card Sorting Test (WCST), the Ruff Figural Fluency Test (RFFT), the Controlled Oral Word Association Test (COWAT), and the Trait Making Test; Parts A and B. There were no group differences in their age, years of education and global cognitive performance. Student's t-tests were conducted to determine group differences in executive function. As a result, the number of total errors, the number of perseverative errors and the number of categories completed on the WCST were significantly worse for the BG group than for the WM group. These groups did not differ on other measures administered. In addition, all participants underwent SPECT, and their results were compared with the normal control data. Hypoperfusion was found on parts of the bilateral frontal, temporal, and parietal lobes for the BG and WM groups. These tendencies stood out in the right hemisphere of the BG group. The BG group exhibited decreased cerebral blood flow (CBF) on the area of right side dorsolateral prefrontal cortex (DLPFC) (e.g., Brodmann area 44). These analyses revealed that individuals with BG lesions showed significant executive declines that might be associated with decreased CBF in the subcortical-frontal system. It may support the idea that BG is connected with DLPFC via frontal-subcortical neuronal circuit. Patients with BG lesions may experience dysexecutive function due to the phenomenon of diaschisis from the disruption of this circuit. (author)
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International Nuclear Information System (INIS)
Berman, K.F.; Illowsky, B.P.; Weinberger, D.R.
1988-01-01
In previous studies we found that patients with chronic schizophrenia had lower regional cerebral blood flow (rCBF) in dorsolateral prefrontal cortex (DLPFC) than did normal subjects during performance of the Wisconsin Card Sort Test, an abstract reasoning task linked to DLPFC function. This was not the case during less complex tasks. To examine further whether this finding represented regionally circumscribed pathophysiology or a more general correlate of abstract cognition, 24 medication-free patients and 25 age- and sex-matched normal control subjects underwent rCBF measurements with the xenon 133 technique while they performed two tasks: Raven's Progressive Matrices (RPM) and an active baseline control task. While performing RPM, normal subjects activated posterior cortical areas over baseline, but did not activate DLPFC, as had been seen during the Wisconsin Card Sort Test. Like normal subjects, patients showed maximal rCBF elevations posteriorly and, moreover, they had no significant DLPFC or other cortical deficit while performing RPM. These results suggest that DLPFC dysfunction in schizophrenia is linked to pathophysiology of a regionally specific neural system rather than to global cortical dysfunction, and that this pathophysiology is most apparent under prefrontally specific cognitive demand
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Bogdanov, Mario; Schwabe, Lars
2016-01-27
Stress is known to impair working memory performance. This disruptive effect of stress on working memory has been linked to a decrease in the activity of the dorsolateral prefrontal cortex (dlPFC). In the present experiment, we tested whether transcranial direct current stimulation (tDCS) of the dlPFC can prevent stress-induced working memory impairments. We tested 120 healthy participants in a 2 d, sham-controlled, double-blind between-subjects design. Participants completed a test of their individual baseline working memory capacity on day 1. On day 2, participants were exposed to either a stressor or a control manipulation before they performed a visuospatial and a verbal working memory task. While participants completed the tasks, anodal, cathodal, or sham tDCS was applied over the right dlPFC. Stress impaired working memory performance in both tasks, albeit to a lesser extent in the verbal compared with the visuospatial working memory task. This stress-induced working memory impairment was prevented by anodal, but not sham or cathodal, stimulation of the dlPFC. Compared with sham or cathodal stimulation, anodal tDCS led to significantly better working memory performance in both tasks after stress. Our findings indicate a causal role of the dlPFC in working memory impairments after acute stress and point to anodal tDCS as a promising tool to reduce cognitive deficits related to working memory in stress-related mental disorders, such as depression, schizophrenia, or post-traumatic stress disorder. Working memory deficits are prominent in stress-related mental disorders, such as depression, schizophrenia, or post-traumatic stress disorder. Similar working memory impairments have been observed in healthy individuals exposed to acute stress. So far, attempts to prevent such stress-induced working memory deficits focused mainly on pharmacological interventions. Here, we tested the idea that transcranial direct current stimulation of the dorsolateral prefrontal
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Directory of Open Access Journals (Sweden)
Olle Eriksson
Full Text Available To investigate potential quantitative and qualitative differences in brain serotonergic activity between women with Premenstrual Dysphoria (PMD and asymptomatic controls.Serotonin-augmenting drugs alleviate premenstrual mood symptoms in the majority of women with PMD while serotonin-depleting diets worsen PMD symptoms, both indicating intrinsic differences in brain serotonergic activity in women with PMD compared to asymptomatic women.Positron-emission tomography with the immediate precursor of serotonin, 5-hydroxytryptophan (5-HTP, radiolabelled by 11C in the beta-3 position, was performed in the follicular and luteal phases for 12 women with PMD and 8 control women. Brain radioactivity-a proxy for serotonin precursor uptake and synthesis-was measured in 9 regions of interest (ROIs: the right and left sides of the medial prefrontal cortex, dorsolateral prefrontal cortex, putamen and caudate nucleus, and the single "whole brain".There were no significant quantitative differences in brain 5-HTP-derived activity between the groups in either of the menstrual phases for any of the 9 ROIs. However, multivariate analysis revealed a significant quantitative and qualitative difference between the groups. Asymptomatic control women showed a premenstrual right sided relative increase in dorsolateral prefrontal cortex 5-HTP derived activity, whereas PMD women displayed the opposite (p = 0.0001. Menstrual phase changes in this asymmetry (premenstrual-follicular correlated with changes in self ratings of 'irritability' for the entire group (rs = -0.595, p = 0.006. The PMD group showed a strong inverse correlation between phase changes (premenstrual-follicular in plasma levels of estradiol and phase changes in the laterality (dx/sin of radiotracer activity in the dorsolateral prefrontal ROI (rs = -0.635; 0.027. The control group showed no such correlation.Absence of increased premenstrual right-sided relative 5-HTP-derived activity of the dorsolateral
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A dorsolateral prefrontal cortex semi-automatic segmenter
Al-Hakim, Ramsey; Fallon, James; Nain, Delphine; Melonakos, John; Tannenbaum, Allen
2006-03-01
Structural, functional, and clinical studies in schizophrenia have, for several decades, consistently implicated dysfunction of the prefrontal cortex in the etiology of the disease. Functional and structural imaging studies, combined with clinical, psychometric, and genetic analyses in schizophrenia have confirmed the key roles played by the prefrontal cortex and closely linked "prefrontal system" structures such as the striatum, amygdala, mediodorsal thalamus, substantia nigra-ventral tegmental area, and anterior cingulate cortices. The nodal structure of the prefrontal system circuit is the dorsal lateral prefrontal cortex (DLPFC), or Brodmann area 46, which also appears to be the most commonly studied and cited brain area with respect to schizophrenia. 1, 2, 3, 4 In 1986, Weinberger et. al. tied cerebral blood flow in the DLPFC to schizophrenia.1 In 2001, Perlstein et. al. demonstrated that DLPFC activation is essential for working memory tasks commonly deficient in schizophrenia. 2 More recently, groups have linked morphological changes due to gene deletion and increased DLPFC glutamate concentration to schizophrenia. 3, 4 Despite the experimental and clinical focus on the DLPFC in structural and functional imaging, the variability of the location of this area, differences in opinion on exactly what constitutes DLPFC, and inherent difficulties in segmenting this highly convoluted cortical region have contributed to a lack of widely used standards for manual or semi-automated segmentation programs. Given these implications, we developed a semi-automatic tool to segment the DLPFC from brain MRI scans in a reproducible way to conduct further morphological and statistical studies. The segmenter is based on expert neuroanatomist rules (Fallon-Kindermann rules), inspired by cytoarchitectonic data and reconstructions presented by Rajkowska and Goldman-Rakic. 5 It is semi-automated to provide essential user interactivity. We present our results and provide details on
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Lepage, Martin
2004-03-01
Several brain imaging studies have implicated prefrontal regions bilaterally during cued-recall memory tasks and yet the functional significance of these regions remains poorly understood. Using PET, we examined the neural activity in prefrontal regions of 15 subjects while they performed three cued-recall tasks differing in pre-experimental semantic associations between cues and targets. This manipulation produced varying levels of retrieval performance when one member (a semantic category name) of the triad was used as a cue for the retrieval of the other two members. The percentage of items correctly recalled was 10, 46, and 70 in the low, medium, and high cued-recall conditions, respectively. Linear contrast analyses of the PET data identified brain regions where neural activity varied with the number of items retrieved from memory. A left lateral prefrontal region showed maximal activity during the high cued-recall condition, which likely reflects processes involved in retrieval success and possibly in the generation of memory responses. Three right prefrontal regions (anterior and dorsolateral) showed maximal activity during the low cued-recall condition, which likely reflects processes involved in memory search/monitoring. These findings add further support for a bilateral prefrontal contribution to memory cued-recall tasks and point to differential roles of the two hemispheres.
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Feng, Xiao; Peng, Li; Chang-Quan, Long; Yi, Lei; Hong, Li
2014-09-01
Most previous studies investigating relational reasoning have used visuo-spatial materials. This fMRI study aimed to determine how relational complexity affects brain activity during inductive reasoning, using numerical materials. Three numerical relational levels of the number series completion task were adopted for use: 0-relational (e.g., "23 23 23"), 1-relational ("32 30 28") and 2-relational ("12 13 15") problems. The fMRI results revealed that the bilateral dorsolateral prefrontal cortex (DLPFC) showed enhanced activity associated with relational complexity. Bilateral inferior parietal lobule (IPL) activity was greater during the 1- and 2-relational level problems than during the 0-relational level problems. In addition, the left fronto-polar cortex (FPC) showed selective activity during the 2-relational level problems. The bilateral DLPFC may be involved in the process of hypothesis generation, whereas the bilateral IPL may be sensitive to calculation demands. Moreover, the sensitivity of the left FPC to the multiple relational problems may be related to the integration of numerical relations. The present study extends our knowledge of the prefrontal activity pattern underlying numerical relational processing. Copyright © 2014 Elsevier B.V. All rights reserved.
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Institute of Scientific and Technical Information of China (English)
Michela Balconi
2013-01-01
The ability to recall and recognize facts we experienced in the past is based on a complex mechanism in which several cerebral regions are implicated.Neuroimaging and lesion studies agree in identifying the frontal lobe as a crucial structure for memory processes,and in particular for working memory and episodic memory and their relationships.Furthermore,with the introduction of transcranial magnetic stimulation (TMS) a new way was proposed to investigate the relationships between brain correlates,memory functions and behavior.The aim of this review is to present the main findings that have emerged from experiments which used the TMS technique for memory analysis.They mainly focused on the role of the dorsolateral prefrontal cortex in memory process.Furthermore,we present state-of-the-art evidence supporting a possible use of TMS in the clinic.Specifically we focus on the treatment of memory deficits in depression and anxiety disorders.
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Tomasino, Barbara; Fabbro, Franco
2016-02-01
Mindfulness meditation is a form of attention control training. The training exercises the ability to repeatedly focus attention. We addressed the activation changes related to an 8-weeks mindfulness-oriented focused attention meditation training on an initially naïve subject cohort. Before and after training participants underwent an fMRI experiment, thus, although not strictly a cross over design, they served as their internal own control. During fMRI they exercised focused attention on breathing and body scan as compared to resting. We found increased and decreased activation in different parts of the prefrontal cortex (PFC) by comparing pre- vs. post-mindfulness training (MT) during breathing and body scan meditation exercises that were compared against their own resting state. In the post-MT (vs. pre-MT) meditation increased activation in the right dorsolateral PFC and in the left caudate/anterior insula and decreased activation in the rostral PFC and right parietal area 3b. Thus a brief mindfulness training caused increased activation in areas involved in sustaining and monitoring the focus of attention (dorsolateral PFC), consistent with the aim of mindfulness that is exercising focused attention mechanisms, and in the left caudate/anterior insula involved in attention and corporeal awareness and decreased activation in areas part of the "default mode" network and is involved in mentalizing (rostral PFC), consistent with the ability trained by mindfulness of reducing spontaneous mind wandering. Copyright © 2015 Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Anthony Charles Ruocco
2016-05-01
Full Text Available Self-harm is a potentially lethal symptom of borderline personality disorder (BPD that often improves with dialectical behavior therapy (DBT. While DBT is effective for reducing self-harm in many patients with BPD, a small but significant number of patients either does not improve in treatment or ends treatment prematurely. Accordingly, it is crucial to identify factors that may prospectively predict which patients are most likely to benefit from and remain in treatment. In the present preliminary study, twenty-nine actively self-harming patients with BPD completed brain-imaging procedures probing activation of the prefrontal cortex during impulse control prior to beginning DBT and after seven months of treatment. Patients that reduced their frequency of self-harm the most over treatment displayed lower levels of neural activation in the bilateral dorsolateral prefrontal cortex prior to beginning treatment, and they showed the greatest increases in activity within this region after seven months of treatment. Prior to starting DBT, treatment non-completers demonstrated greater activation than treatment-completers in the medial prefrontal cortex and right inferior frontal gyrus. Reductions in self-harm over the treatment period were associated with increases in activity in right dorsolateral prefrontal cortex even after accounting for improvements in depression, mania, and BPD symptom severity. These findings suggest that pre-treatment patterns of activation in the prefrontal cortex underlying impulse control may be prospectively associated with improvements in self-harm and treatment attrition for patients with BPD treated with DBT.
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Yuan, Kai; Yu, Dahua; Bi, Yanzhi; Wang, Ruonan; Li, Min; Zhang, Yajuan; Dong, Minghao; Zhai, Jinquan; Li, Yangding; Lu, Xiaoqi; Tian, Jie
2017-09-01
Although the activation of the prefrontal cortex (PFC) and the striatum had been found in smoking cue induced craving task, whether and how the functional interactions and white matter integrity between these brain regions contribute to craving processing during smoking cue exposure remains unknown. Twenty-five young male smokers and 26 age- and gender-matched nonsmokers participated in the smoking cue-reactivity task. Craving related brain activation was extracted and psychophysiological interactions (PPI) analysis was used to specify the PFC-efferent pathways contributed to smoking cue-induced craving. Diffusion tensor imaging (DTI) and probabilistic tractography was used to explore whether the fiber connectivity strength facilitated functional coupling of the circuit with the smoking cue-induced craving. The PPI analysis revealed the negative functional coupling of the left dorsolateral prefrontal cortex (DLPFC) and the caudate during smoking cue induced craving task, which positively correlated with the craving score. Neither significant activation nor functional connectivity in smoking cue exposure task was detected in nonsmokers. DTI analyses revealed that fiber tract integrity negatively correlated with functional coupling in the DLPFC-caudate pathway and activation of the caudate induced by smoking cue in smokers. Moreover, the relationship between the fiber connectivity integrity of the left DLPFC-caudate and smoking cue induced caudate activation can be fully mediated by functional coupling strength of this circuit in smokers. The present study highlighted the left DLPFC-caudate pathway in smoking cue-induced craving in smokers, which may reflect top-down prefrontal modulation of striatal reward processing in smoking cue induced craving processing. Hum Brain Mapp 38:4644-4656, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
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Exon microarray analysis of human dorsolateral prefrontal cortex in alcoholism.
Manzardo, Ann M; Gunewardena, Sumedha; Wang, Kun; Butler, Merlin G
2014-06-01
Alcohol abuse is associated with cellular and biochemical disturbances that impact upon protein and nucleic acid synthesis, brain development, function, and behavioral responses. To further characterize the genetic influences in alcoholism and the effects of alcohol consumption on gene expression, we used a highly sensitive exon microarray to examine mRNA expression in human frontal cortex of alcoholics and control males. Messenger RNA was isolated from the dorsolateral prefrontal cortex (dlPFC; Brodmann area 9) of 7 adult alcoholic (6 males, 1 female, mean age 49 years) and 7 matched controls. Affymetrix Human Exon 1.0 ST array was performed according to standard procedures and the results analyzed at the gene level. Microarray findings were validated using quantitative reverse transcription polymerase chain reaction, and the ontology of disturbed genes characterized using Ingenuity Pathway Analysis (IPA). Decreased mRNA expression was observed for genes involved in cellular adhesion (e.g., CTNNA3, ITGA2), transport (e.g., TF, ABCA8), nervous system development (e.g., LRP2, UGT8, GLDN), and signaling (e.g., RASGRP3, LGR5) with influence over lipid and myelin synthesis (e.g., ASPA, ENPP2, KLK6). IPA identified disturbances in network functions associated with neurological disease and development including cellular assembly and organization impacting on psychological disorders. Our data in alcoholism support a reduction in expression of dlPFC mRNA for genes involved with neuronal growth, differentiation, and signaling that targets white matter of the brain. Copyright © 2014 by the Research Society on Alcoholism.
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Kim, Chobok; Chung, Chongwook; Kim, Jeounghoon
2013-11-06
Previous experience affects our behavior in terms of adjustments. It has been suggested that the conflict monitor-controller system implemented in the prefrontal cortex plays a critical role in such adjustments. Previous studies suggested that there exists multiple conflict monitor-controller systems associated with the level of information (i.e., stimulus and response levels). In this study, we sought to test whether different types of conflicts occur at the same information processing level (i.e., response level) are independently processed. For this purpose, we designed a task paradigm to measure two different types of response conflicts using color-based and location-based conflict stimuli and measured the conflict adaptation effects associated with the two types of conflicts either independently (i.e., single conflict conditions) or simultaneously (i.e., a double-conflict condition). The behavioral results demonstrated that performance on current incongruent trials was faster only when the preceding trial was the same type of response conflict regardless of whether they included a single- or double-conflict. Imaging data also showed that anterior cingulate and dorsolateral prefrontal cortices operate in a task-specific manner. These findings suggest that there may be multiple monitor-controller loops for color-based and location-based conflicts even at the same response level. Importantly, our results suggest that double-conflict processing is qualitatively different from single-conflict processing although double-conflict shares the same sources of conflict with two single-conflict conditions. © 2013 Published by Elsevier B.V.
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DEFF Research Database (Denmark)
Miskowiak, K. W.; Kjærstad, H. L.; Støttrup, M. M.
2017-01-01
prefrontal cortex (dlPFC) (P=.016). Exploratory whole-brain analysis revealed a bilateral decrease in working memory-related dlPFC activity in the ValVal group vs the ValMet group which was not associated with differences in working memory performance during fMRI. Outside the MRI scanner, Val carriers...... performed worse in the CANTAB Spatial Working Memory task than Met homozygotes (P≤.006), with deficits being most pronounced in Val homozygotes. CONCLUSIONS: The association between Val allelic load, dlPFC activity and WM impairment points to a putative role of aberrant PFC dopamine tonus in the cognitive......-O-methyltransferase (COMT) gene is associated with reduced prefrontal cortex dopamine and exaggerated working memory-related prefrontal activity. This functional magnetic resonance imaging (fMRI) study investigated for the first time whether the COMT Val158Met genotype modulates prefrontal activity during spatial working...
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Minamoto, Takehiro; Osaka, Mariko; Yaoi, Ken; Osaka, Naoyuki
2014-01-01
Different people make different responses when they face a frustrating situation: some punish others (extrapunitive), while others punish themselves (intropunitive). Few studies have investigated the neural structures that differentiate extrapunitive and intropunitive individuals. The present fMRI study explored these neural structures using two different frustrating situations: an ego-blocking situation which blocks a desire or goal, and a superego-blocking situation which blocks self-esteem. In the ego-blocking condition, the extrapunitive group (n = 9) showed greater activation in the bilateral ventrolateral prefrontal cortex, indicating that these individuals prefer emotional processing. On the other hand, the intropunitive group (n = 9) showed greater activation in the left dorsolateral prefrontal cortex, possibly reflecting an effortful control for anger reduction. Such patterns were not observed in the superego-blocking condition. These results indicate that the prefrontal cortex is the source of individual differences in aggression direction in the ego-blocking situation.
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Directory of Open Access Journals (Sweden)
Xu Han
2018-02-01
Full Text Available Internet gaming disorder (IGD, a major behavior disorder, has gained increasing attention. Recent studies indicate altered resting-state static functional connectivity (FC of the dorsolateral prefrontal cortex (DLPFC in subjects with IGD. Whereas static FC often provides information on functional changes in subjects with IGD, investigations of temporal changes in FC between the DLPFC and the other brain regions may shed light on the dynamic characteristics of brain function associated with IGD. Thirty subjects with IGD and 30 healthy controls (HCs matched for age, gender and education status were recruited. Using the bilateral DLPFC as seeds, static FC and dynamic FC maps were calculated and compared between groups. Correlations between alterations in static FC and dynamic FC and clinical variables were also investigated within the IGD group. The IGD group showed significantly lower static FC between the right DLPFC and the left rolandic operculum while higher static FC between the right DLPFC and the left pars triangularis when compared to HCs. The IGD group also had significantly decreased dynamic FC between the right DLPFC and the left insula, right putamen and left precentral gyrus, and increased dynamic FC in the left precuneus. Moreover, the dynamic FC between the right DLPFC and the left insula was negatively correlated with the severity of IGD. Dynamic FC can be used as a powerful supplement to static FC, helping us obtain a more comprehensive understanding of large-scale brain network activity in IGD and put forward new ideas for behavioral intervention therapy for it.
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Hsu, Chia-Fen; Sonuga-Barke, Edmund J S
2016-08-01
fMRI studies have implicated the medial prefrontal cortex and medial temporal lobe, components of the default mode network (DMN), in episodic prospection. This study compared quantitative EEG localized to these DMN regions during prospection and during resting and while waiting for rewards. EEG was recorded in twenty-two adults while they were asked to (i) envision future monetary episodes; (ii) wait for rewards and (iii) rest. Activation sources were localized to core DMN regions. EEG power and phase coherence were compared across conditions. Prospection, compared to resting and waiting, was associated with reduced power in the medial prefrontal gyrus and increased power in the bilateral medial temporal gyrus across frequency bands as well as greater phase synchrony between these regions in the delta band. The current quantitative EEG analysis confirms prior fMRI research suggesting that medial prefrontal and medial temporal gyrus interactions are central to the capacity for episodic prospection. Copyright © 2016 Elsevier B.V. All rights reserved.
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Hutcherson, Cendri A; Plassmann, Hilke; Gross, James J; Rangel, Antonio
2012-09-26
Cognitive regulation is often used to influence behavioral outcomes. However, the computational and neurobiological mechanisms by which it affects behavior remain unknown. We studied this issue using an fMRI task in which human participants used cognitive regulation to upregulate and downregulate their cravings for foods at the time of choice. We found that activity in both ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC) correlated with value. We also found evidence that two distinct regulatory mechanisms were at work: value modulation, which operates by changing the values assigned to foods in vmPFC and dlPFC at the time of choice, and behavioral control modulation, which operates by changing the relative influence of the vmPFC and dlPFC value signals on the action selection process used to make choices. In particular, during downregulation, activation decreased in the value-sensitive region of dlPFC (indicating value modulation) but not in vmPFC, and the relative contribution of the two value signals to behavior shifted toward the dlPFC (indicating behavioral control modulation). The opposite pattern was observed during upregulation: activation increased in vmPFC but not dlPFC, and the relative contribution to behavior shifted toward the vmPFC. Finally, ventrolateral PFC and posterior parietal cortex were more active during both upregulation and downregulation, and were functionally connected with vmPFC and dlPFC during cognitive regulation, which suggests that they help to implement the changes to the decision-making circuitry generated by cognitive regulation.
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Amemori, Ken-ichi; Amemori, Satoko
2015-01-01
The judgment of whether to accept or to reject an offer is determined by positive and negative affect related to the offer, but affect also induces motivational responses. Rewarding and aversive cues influence the firing rates of many neurons in primate prefrontal and cingulate neocortical regions, but it still is unclear whether neurons in these regions are related to affective judgment or to motivation. To address this issue, we recorded simultaneously the neuronal spike activities of single units in the dorsolateral prefrontal cortex (dlPFC) and the anterior cingulate cortex (ACC) of macaque monkeys as they performed approach–avoidance (Ap–Av) and approach–approach (Ap–Ap) decision-making tasks that can behaviorally dissociate affective judgment and motivation. Notably, neurons having activity correlated with motivational condition could be distinguished from neurons having activity related to affective judgment, especially in the Ap–Av task. Although many neurons in both regions exhibited similar, selective patterns of task-related activity, we found a larger proportion of neurons activated in low motivational conditions in the dlPFC than in the ACC, and the onset of this activity was significantly earlier in the dlPFC than in the ACC. Furthermore, the temporal onsets of affective judgment represented by neuronal activities were significantly slower in the low motivational conditions than in the other conditions. These findings suggest that motivation and affective judgment both recruit dlPFC and ACC neurons but with differential degrees of involvement and timing. PMID:25653353
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Directory of Open Access Journals (Sweden)
Bidhan eLamichhane
2015-09-01
Full Text Available Diverse cortical structures are known to coordinate activity as a network in relaying and processing of visual information to discriminate visual objects. However, how this discrimination is achieved is still largely unknown. To contribute to answering this question, we used face-house categorization tasks with three levels of noise in face and house images in functional magnetic resonance imaging (fMRI experiments involving thirty-three participants. The behavioral performance error and response time (RT were correlated with noise in face-house images. We then built dynamical causal models (DCM of fMRI blood-oxygenation level dependent (BOLD signals from the face and house category-specific regions in ventral temporal cortex, the fusiform face area (FFA and parahippocampal place area (PPA, and the dorsolateral prefrontal cortex (dlPFC. We found a strong feed-forward intrinsic connectivity pattern from FFA and PPA to dlPFC. Importantly, the feed-forward connectivity to dlPFC was significantly modulated by the perception of both faces and houses. The dlPFC-BOLD activity, the connectivity from FFA and PPA to the dlPFC all increased with noise level. These results suggest that the FFA-PPA-dlPFC network plays an important role for relaying and integrating competing sensory information to arrive at perceptual decisions.
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Kong, Xia; Wei, Dongtao; Li, Wenfu; Cun, Lingli; Xue, Song; Zhang, Qinglin; Qiu, Jiang
2015-01-01
Loneliness is an unpleasant and distressing feeling that a person experiences when he/she perceives that his/her social relationships are lacking in someway, either quantitatively or qualitatively; this can be linked to anxiety, depression, and suicide risk. Previous studies have found that certain personality traits (which are temporally stable and heritable) are predictors of loneliness. However, little empirical evidence is available on the brain structures associated with loneliness, as well as how personality traits impact the relationship between loneliness and brain structure. Thus, the current study used voxel-based morphometry to identify the brain structures underlying individual differences in loneliness (as measured by the UCLA Loneliness Scale) in a large sample, and then, applied multiple mediation analyses to explore the nature of the influence of personality traits on the relationship between loneliness and brain structure. The results showed that lonely individuals had greater regional gray matter volume in the left dorsolateral prefrontal cortex (DLPFC), which might reflect immature functioning in terms of emotional regulation. More importantly, we found that neuroticism and extraversion partially mediated the relationship between the left DLPFC and loneliness. In summary, through morphometric and multiple mediation analyses, this paper further validates the influence of both neuroticism and extraversion on loneliness.
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Diwadkar, V A; Carpenter, P A; Just, M A
2000-07-01
Functional MRI was used to determine how the constituents of the cortical network subserving dynamic spatial working memory respond to two types of increases in task complexity. Participants mentally maintained the most recent location of either one or three objects as the three objects moved discretely in either a two- or three-dimensional array. Cortical activation in the dorsolateral prefrontal (DLPFC) and the parietal cortex increased as a function of the number of object locations to be maintained and the dimensionality of the display. An analysis of the response characteristics of the individual voxels showed that a large proportion were activated only when both the variables imposed the higher level of demand. A smaller proportion were activated specifically in response to increases in task demand associated with each of the independent variables. A second experiment revealed the same effect of dimensionality in the parietal cortex when the movement of objects was signaled auditorily rather than visually, indicating that the additional representational demands induced by 3-D space are independent of input modality. The comodulation of activation in the prefrontal and parietal areas by the amount of computational demand suggests that the collaboration between areas is a basic feature underlying much of the functionality of spatial working memory. Copyright 2000 Academic Press.
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Smirni, Daniela; Turriziani, Patrizia; Mangano, Giuseppa Renata; Cipolotti, Lisa; Oliveri, Massimiliano
2015-01-01
The role of the Dorsolateral Prefrontal Cortex (DLPFC) in recognition memory has been well documented in lesion, neuroimaging and repetitive Transcranial Magnetic Stimulation (rTMS) studies. The aim of the present study was to investigate the effects of transcranial Direct Current Stimulation (tDCS) over the left and the right DLPFC during the delay interval of a non-verbal recognition memory task. 36 right-handed young healthy subjects participated in the study. The experimental task was an Italian version of Recognition Memory Test for unknown faces. Study included two experiments: in a first experiment, each subject underwent one session of sham tDCS and one session of left or right cathodal tDCS; in a second experiment each subject underwent one session of sham tDCS and one session of left or right anodal tDCS. Cathodal tDCS over the right DLPFC significantly improved non verbal recognition memory performance, while cathodal tDCS over the left DLPFC had no effect. Anodal tDCS of both the left and right DLPFC did not modify non verbal recognition memory performance. Complementing the majority of previous studies, reporting long term memory facilitations following left prefrontal anodal tDCS, the present findings show that cathodal tDCS of the right DLPFC can also improve recognition memory in healthy subjects.
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Directory of Open Access Journals (Sweden)
Takehiro Minamoto
Full Text Available Different people make different responses when they face a frustrating situation: some punish others (extrapunitive, while others punish themselves (intropunitive. Few studies have investigated the neural structures that differentiate extrapunitive and intropunitive individuals. The present fMRI study explored these neural structures using two different frustrating situations: an ego-blocking situation which blocks a desire or goal, and a superego-blocking situation which blocks self-esteem. In the ego-blocking condition, the extrapunitive group (n = 9 showed greater activation in the bilateral ventrolateral prefrontal cortex, indicating that these individuals prefer emotional processing. On the other hand, the intropunitive group (n = 9 showed greater activation in the left dorsolateral prefrontal cortex, possibly reflecting an effortful control for anger reduction. Such patterns were not observed in the superego-blocking condition. These results indicate that the prefrontal cortex is the source of individual differences in aggression direction in the ego-blocking situation.
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International Nuclear Information System (INIS)
Li, D.; Shen, J.; Zan, S.; Sun, B.; Zuo, C.; Guan, Y.; Zhao, Y.
2006-01-01
The aim of the study was to evaluate the changes in regional cerebral metabolic rate of glucose (rCMRGIu) induced by bilateral subthalamic nucleus (STN) stimulation in advanced Parkinson's disease (PD). 18 F-Fluorodeoxyglucose (FDG) PET data obtained before and one month after stimulation were analyzed with statistical parametric mapping (SPM). As a result of clinically effective bilateral STN stimulation, rCMRGIu increased in lateral globus pallidus (GP), upper brain stem, dorsolateral prefrontal cortex (DLPFC) and posterior parietal-occipital cortex, and decreased in the orbital frontal cortex and parahippocampus gyrus (p <0.001). We conclude that the alleviation of clinical symptoms in advanced PD by bilateral STN stimulation may be the result of activation of both ascending and descending pathways from STN and of restoration of the impaired higher-order cortex functions. (author)
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Directory of Open Access Journals (Sweden)
Stanley I Rapoport
Full Text Available Phosphoinositides, lipid-signaling molecules, participate in diverse brain processes within a wide metabolic cascade.Gene transcriptional networks coordinately regulate the phosphoinositide cascade during human brain Development and Aging.We used the public BrainCloud database for human dorsolateral prefrontal cortex to examine age-related expression levels of 49 phosphoinositide metabolic genes during Development (0 to 20+ years and Aging (21+ years.We identified three groups of partially overlapping genes in each of the two intervals, with similar intergroup correlations despite marked phenotypic differences between Aging and Development. In each interval, ITPKB, PLCD1, PIK3R3, ISYNA1, IMPA2, INPPL1, PI4KB, and AKT1 are in Group 1, PIK3CB, PTEN, PIK3CA, and IMPA1 in Group 2, and SACM1L, PI3KR4, INPP5A, SYNJ1, and PLCB1 in Group 3. Ten of the genes change expression nonlinearly during Development, suggesting involvement in rapidly changing neuronal, glial and myelination events. Correlated transcription for some gene pairs likely is facilitated by colocalization on the same chromosome band.Stable coordinated gene transcriptional networks regulate brain phosphoinositide metabolic pathways during human Development and Aging.
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Directory of Open Access Journals (Sweden)
Maria Kuehne
Full Text Available Attitude to morality, reflecting cultural norms and values, is considered unique to human social behavior. Resulting moral behavior in a social environment is controlled by a widespread neural network including the dorsolateral prefrontal cortex (DLPFC, which plays an important role in decision making. In the present study we investigate the influence of neurophysiological modulation of DLPFC reactivity by means of transcranial direct current stimulation (tDCS on moral reasoning. For that purpose we administered anodal, cathodal, and sham stimulation of the left DLPFC while subjects judged the appropriateness of hard moral personal dilemmas. In contrast to sham and cathodal stimulation, anodal stimulation induced a shift in judgment of personal moral dilemmas towards more non-utilitarian actions. Our results demonstrate that alterations of left DLPFC activity can change moral judgments and, in consequence, provide a causal link between left DLPFC activity and moral reasoning. Most important, the observed shift towards non-utilitarian actions suggests that moral decision making is not a permanent individual trait but can be manipulated; consequently individuals with boundless, uncontrollable, and maladaptive moral behavior, such as found in psychopathy, might benefit from neuromodulation-based approaches.
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Similar or different? The role of the ventrolateral prefrontal cortex in similarity detection.
Directory of Open Access Journals (Sweden)
Béatrice Garcin
Full Text Available Patients with frontal lobe syndrome can exhibit two types of abnormal behaviour when asked to place a banana and an orange in a single category: some patients categorize them at a concrete level (e.g., "both have peel", while others continue to look for differences between these objects (e.g., "one is yellow, the other is orange". These observations raise the question of whether abstraction and similarity detection are distinct processes involved in abstract categorization, and that depend on separate areas of the prefrontal cortex (PFC. We designed an original experimental paradigm for a functional magnetic resonance imaging (fMRI study involving healthy subjects, confirming the existence of two distinct processes relying on different prefrontal areas, and thus explaining the behavioural dissociation in frontal lesion patients. We showed that: 1 Similarity detection involves the anterior ventrolateral PFC bilaterally with a right-left asymmetry: the right anterior ventrolateral PFC is only engaged in detecting physical similarities; 2 Abstraction per se activates the left dorsolateral PFC.
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Rapinesi, Chiara; Kotzalidis, Georgios D; Ferracuti, Stefano; Girardi, Nicoletta; Zangen, Abraham; Sani, Gabriele; Raccah, Ruggero N; Girardi, Paolo; Pompili, Maurizio; Del Casale, Antonio
2018-04-03
Dorsolateral prefrontal cortex (DLPFC) is critically involved in mood and alcohol use disorders. We aimed to investigate the safety of intervention with add-on bilateral prefrontal high-frequency deep transcranial magnetic stimulation (dTMS) and between-group differences in treatment response in patients with different types of depressive episodes, including major depressive episodes in the course of major depressive disorder (MDD), bipolar disorder, type I (BD-I), and MDD with alcohol use disorder (MDAUD). We conducted a 6-month open-label study, involving 82 patients with DSM-5 Depressive Episode. Of these, 41 had diagnosis of MDD, 20 BD-I, and 21 MDAUD. All patients received standard drug treatment and add-on dTMS over the bilateral DLPFC with left prevalence for four weeks, with five sessions in each week. We rated mood state with the Hamilton Depression Rating Scale (HDRS) at baseline, one-month, and six-month follow-up visits. Mean total HDRS scores dropped from 22.8 (SD = 5.9) at baseline to 10.4 (SD = 3.6) at 1 month, to 10.0 (SD = 4.5) at 6 months, while response/remission were 70.73% (N = 58) and 19.51% (N = 16) at 1 month and 76.83% (N = 63) and 32.93% (27) at 6 months, respectively, with no between-group differences. No patient experienced any side effects. High-frequency DLPFC dTMS was well tolerated and did not significantly differ on improvement of depression in MDD, BD-I, and MDAUD. Copyright © 2018 Elsevier B.V. All rights reserved.
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Maren Strenziok
Full Text Available Prefrontal cortex mediates cognitive control by means of circuitry organized along dorso-ventral and rostro-caudal axes. Along the dorso-ventral axis, ventrolateral PFC controls semantic information, whereas dorsolateral PFC encodes task rules. Along the rostro-caudal axis, anterior prefrontal cortex encodes complex rules and relationships between stimuli, whereas posterior prefrontal cortex encodes simple relationships between stimuli and behavior. Evidence of these gradients of prefrontal cortex organization has been well documented in fMRI studies, but their functional correlates have not been examined with regard to integrity of underlying white matter tracts. We hypothesized that (a the integrity of specific white matter tracts is related to cognitive functioning in a manner consistent with the dorso-ventral and rostro-caudal organization of the prefrontal cortex, and (b this would be particularly evident in healthy older adults. We assessed three cognitive processes that recruit the prefrontal cortex and can distinguish white matter tracts along the dorso-ventral and rostro-caudal dimensions -episodic memory, working memory, and reasoning. Correlations between cognition and fractional anisotropy as well as fiber tractography revealed: (a Episodic memory was related to ventral prefrontal cortex-thalamo-hippocampal fiber integrity; (b Working memory was related to integrity of corpus callosum body fibers subserving dorsolateral prefrontal cortex; and (c Reasoning was related to integrity of corpus callosum body fibers subserving rostral and caudal dorsolateral prefrontal cortex. These findings confirm the ventrolateral prefrontal cortex's role in semantic control and the dorsolateral prefrontal cortex's role in rule-based processing, in accordance with the dorso-ventral prefrontal cortex gradient. Reasoning-related rostral and caudal superior frontal white matter may facilitate different levels of task rule complexity. This study is the
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Strenziok, Maren; Greenwood, Pamela M; Santa Cruz, Sophia A; Thompson, James C; Parasuraman, Raja
2013-01-01
Prefrontal cortex mediates cognitive control by means of circuitry organized along dorso-ventral and rostro-caudal axes. Along the dorso-ventral axis, ventrolateral PFC controls semantic information, whereas dorsolateral PFC encodes task rules. Along the rostro-caudal axis, anterior prefrontal cortex encodes complex rules and relationships between stimuli, whereas posterior prefrontal cortex encodes simple relationships between stimuli and behavior. Evidence of these gradients of prefrontal cortex organization has been well documented in fMRI studies, but their functional correlates have not been examined with regard to integrity of underlying white matter tracts. We hypothesized that (a) the integrity of specific white matter tracts is related to cognitive functioning in a manner consistent with the dorso-ventral and rostro-caudal organization of the prefrontal cortex, and (b) this would be particularly evident in healthy older adults. We assessed three cognitive processes that recruit the prefrontal cortex and can distinguish white matter tracts along the dorso-ventral and rostro-caudal dimensions -episodic memory, working memory, and reasoning. Correlations between cognition and fractional anisotropy as well as fiber tractography revealed: (a) Episodic memory was related to ventral prefrontal cortex-thalamo-hippocampal fiber integrity; (b) Working memory was related to integrity of corpus callosum body fibers subserving dorsolateral prefrontal cortex; and (c) Reasoning was related to integrity of corpus callosum body fibers subserving rostral and caudal dorsolateral prefrontal cortex. These findings confirm the ventrolateral prefrontal cortex's role in semantic control and the dorsolateral prefrontal cortex's role in rule-based processing, in accordance with the dorso-ventral prefrontal cortex gradient. Reasoning-related rostral and caudal superior frontal white matter may facilitate different levels of task rule complexity. This study is the first to
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Koike, Shinsuke; Takizawa, Ryu; Nishimura, Yukika; Kinou, Masaru; Kawasaki, Shingo; Kasai, Kiyoto
2013-09-01
Caudal regions of the prefrontal cortex, including the dorsolateral (DLPFC) and ventrolateral (VLPFC) prefrontal cortex, are involved in essential cognitive functions such as working memory. In contrast, more rostral regions, such as the frontopolar cortex (FpC), have integrative functions among cognitive functions and thereby contribute crucially to real-world social activity. Previous functional magnetic resonance imaging studies have shown patients with schizophrenia had different DLPFC activity pattern in response to cognitive load changes compared to healthy controls; however, the spatial relationship between the caudal and rostral prefrontal activation has not been evaluated under less-constrained conditions. Twenty-six patients with schizophrenia and 26 age-, sex-, and premorbid-intelligence-matched healthy controls participated in this study. Hemodynamic changes during n-back working memory tasks with different cognitive loads were measured using multi-channel near-infrared spectroscopy (NIRS). Healthy controls showed significant task-related activity in the bilateral VLPFC and significant task-related decreased activity in the DLPFC, with greater signal changes when the task required more cognitive load. In contrast, patients with schizophrenia showed activation in the more rostral regions, including bilateral DLPFC and FpC. Neither decreased activity nor greater activation in proportion to elevated cognitive load occurred. This multi-channel NIRS study demonstrated that activation intensity did not increase in patients with schizophrenia associated with cognitive load changes, suggesting hypo-frontality as cognitive impairment in schizophrenia. On the other hand, patients had broader prefrontal activity in areas such as the bilateral DLPFC and FpC regions, thus suggesting a hyper-frontality compensatory response. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Yoon, Jong H; Grandelis, Anthony; Maddock, Richard J
2016-11-16
The discovery of neural mechanisms of working memory (WM) would significantly enhance our understanding of complex human behaviors and guide treatment development for WM-related impairments found in neuropsychiatric conditions and aging. Although the dorsolateral prefrontal cortex (DLPFC) has long been considered critical for WM, we still know little about the neural elements and pathways within the DLPFC that support WM in humans. In this study, we tested whether an individual's DLPFC gamma-aminobutryic acid (GABA) content predicts individual differences in WM task performance using a novel behavioral approach. Twenty-three healthy adults completed a task that measured the unique contribution of major WM components (memory load, maintenance, and distraction resistance) to performance. This was done to address the possibility that components have differing GABA dependencies and the failure to parse WM into components would lead to missing true associations with GABA. The subjects then had their DLPFC GABA content measured by single-voxel proton magnetic spectroscopy. We found that individuals with lower DLPFC GABA showed greater performance degradation with higher load, accounting for 31% of variance, p (corrected) = 0.015. This relationship was component, neurochemical, and brain region specific. DLPFC GABA content did not predict performance sensitivity to other components tested; DLPFC glutamate + glutamine and visual cortical GABA content did not predict load sensitivity. These results confirm the involvement of DLPFC GABA in WM load processing in humans and implicate factors controlling DLPFC GABA content in the neural mechanisms of WM and its impairments. This study demonstrated for the first time that the amount of gamma-aminobutryic acid (GABA), the major inhibitory neurotransmitter of the brain, in an individual's prefrontal cortex predicts working memory (WM) task performance. Given that WM is required for many of the most characteristic cognitive and
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Pripfl, Jürgen; Lamm, Claus
2015-02-01
Recent neuroscience theories suggest that different kinds of self-regulation may share a common psychobiological mechanism. However, empirical evidence for a domain general self-regulation mechanism is scarce. The aim of this study was to investigate whether focused anodal transcranial direct current stimulation (tDCS), facilitating the activity of the dorsolateral prefrontal cortex (dlPFC), acts on a domain general self-regulation mechanism and thus modulates both affective and appetitive self-regulation. Twenty smokers participated in this within-subject sham controlled study. Effects of anodal left, anodal right and sham tDCS over the dlPFC on affective picture appraisal and nicotine craving-cue appraisal were assessed. Anodal right tDCS over the dlPFC reduced negative affect in emotion appraisal, but neither modulated regulation of positive emotion appraisal nor of craving appraisal. Anodal left stimulation did not induce any significant effects. The results of our study show that domain specific self-regulation networks are at work in the prefrontal cortex. Focused tDCS modulation of this specific self-regulation network could probably be used during the first phase of nicotine abstinence, during which negative affect might easily result in relapse. These findings have implications for neuroscience models of self-regulation and are of relevance for the development of brain stimulation based treatment methods for neuropsychiatric disorders associated with self-regulation deficits. Copyright © 2014 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.
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Anodal tDCS of dorsolateral prefontal cortex during an Implicit Association Test
Gladwin, T.E.; den Uyl, T.E.; Wiers, R.W.
2012-01-01
Anodal stimulation of dorsolateral prefrontal cortex by transcranial Direct Current Stimulation (tDCS) has been shown to enhance performance on working memory tasks. However, it is not yet known precisely which aspects of working memory - a broad theoretical concept including short-term memory and
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Directory of Open Access Journals (Sweden)
Brandon R McFadden
Full Text Available Consumers prefer to pay low prices and increase animal welfare; however consumers are typically forced to make tradeoffs between price and animal welfare. Campaign advertising (i.e., advertising used during the 2008 vote on Proposition 2 in California may affect how consumers make tradeoffs between price and animal welfare. Neuroimaging data was used to determine the effects of brain activation in dorsolateral prefrontal cortex (dlPFC on choices making a tradeoff between price and animal welfare and responsiveness to campaign advertising. Results indicated that activation in the dlPFC was greater when making choices that forced a tradeoff between price and animal welfare, compared to choices that varied only by price or animal welfare. Furthermore, greater activation differences in right dlPFC between choices that forced a tradeoff and choices that did not, indicated greater responsiveness to campaign advertising.
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McFadden, Brandon R; Lusk, Jayson L; Crespi, John M; Cherry, J Bradley C; Martin, Laura E; Aupperle, Robin L; Bruce, Amanda S
2015-01-01
Consumers prefer to pay low prices and increase animal welfare; however consumers are typically forced to make tradeoffs between price and animal welfare. Campaign advertising (i.e., advertising used during the 2008 vote on Proposition 2 in California) may affect how consumers make tradeoffs between price and animal welfare. Neuroimaging data was used to determine the effects of brain activation in dorsolateral prefrontal cortex (dlPFC) on choices making a tradeoff between price and animal welfare and responsiveness to campaign advertising. Results indicated that activation in the dlPFC was greater when making choices that forced a tradeoff between price and animal welfare, compared to choices that varied only by price or animal welfare. Furthermore, greater activation differences in right dlPFC between choices that forced a tradeoff and choices that did not, indicated greater responsiveness to campaign advertising.
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Directory of Open Access Journals (Sweden)
Laura Serra
Full Text Available A novel approach based on diffusion tractography was used here to characterise the cortico-thalamic connectivity in two patients, both presenting with an isolated bilateral infarct in the thalamus, but exhibiting partially different cognitive and behavioural profiles. Both patients (G.P. and R.F. had a pervasive deficit in episodic memory, but only one of them (R.F. suffered also from a dysexecutive syndrome. Both patients had an MRI scan at 3T, including a T1-weighted volume. Their lesions were manually segmented. T1-volumes were normalised to standard space, and the same transformations were applied to the lesion masks. Nineteen healthy controls underwent a diffusion-tensor imaging (DTI scan. Their DTI data were normalised to standard space and averaged. An atlas of Brodmann areas was used to parcellate the prefrontal cortex. Probabilistic tractography was used to assess the probability of connection between each voxel of the thalamus and a set of prefrontal areas. The resulting map of corticothalamic connections was superimposed onto the patients' lesion masks, to assess whether the location of the thalamic lesions in R.F. (but not in G. P. implied connections with prefrontal areas involved in dysexecutive syndromes. In G.P., the lesion fell within areas of the thalamus poorly connected with prefrontal areas, showing only a modest probability of connection with the anterior cingulate cortex (ACC. Conversely, R.F.'s lesion fell within thalamic areas extensively connected with the ACC bilaterally, with the right dorsolateral prefrontal cortex, and with the left supplementary motor area. Despite a similar, bilateral involvement of the thalamus, the use of connectivity-based segmentation clarified that R.F.'s lesions only were located within nuclei highly connected with the prefrontal cortical areas, thus explaining the patient's frontal syndrome. This study confirms that DTI tractography is a useful tool to examine in vivo the effect of focal
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Directory of Open Access Journals (Sweden)
Bahar Salavati
2018-04-01
Full Text Available Background: Long-term potentiation (LTP depends on glutamatergic neurotransmission and is modulated by cholinergic, dopaminergic and GABAergic inputs. Paired associative stimulation (PAS is a neurostimulation paradigm that, when combined with electroencephalography (EEG, assesses LTP-like activity (PAS-induced LTP in the dorsolateral prefrontal cortex (DLPFC. Thus, we conducted a study to assess the role of cholinergic, dopaminergic, GABAergic and glutamatergic neurotransmission on PAS-induced LTP in the DLPFC. We hypothesized that increasing the dopaminergic tone with L-DOPA and the cholinergic tone with rivastigmine will enhance PAS-induced LTP, while increasing the GABAergic tone with baclofen and inhibiting glutamatergic neurotransmission with dextromethorphan will reduce it compared to placebo.Methods: In this randomized controlled, double-blind cross-over within-subject study, 12 healthy participants received five sessions of PAS to the DLPFC in a random order, each preceded by the administration of placebo or one of the four active drugs. PAS-induced LTP was assessed after each drug administration and compared to PAS-induced LTP after placebo.Results: As predicted, L-DOPA and rivastigmine resulted in enhanced PAS-induced LTP in the DLPFC and dextromethorphan inhibited it compared to placebo. In contrast, baclofen did not significantly suppress PAS-induced LTP compared to placebo.Conclusions: This study provides a novel approach to study DLPFC neuroplasticity and its modulation in patients with brain disorders that are associated with abnormalities in these neurochemical systems. This study was based on a single dose administration of each drug. Given that these drugs are typically administered chronically, future studies should assess the effects of chronic administration.
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Whole genome grey and white matter DNA methylation profiles in dorsolateral prefrontal cortex.
Sanchez-Mut, Jose Vicente; Heyn, Holger; Vidal, Enrique; Delgado-Morales, Raúl; Moran, Sebastian; Sayols, Sergi; Sandoval, Juan; Ferrer, Isidre; Esteller, Manel; Gräff, Johannes
2017-06-01
The brain's neocortex is anatomically organized into grey and white matter, which are mainly composed by neuronal and glial cells, respectively. The neocortex can be further divided in different Brodmann areas according to their cytoarchitectural organization, which are associated with distinct cortical functions. There is increasing evidence that brain development and function are governed by epigenetic processes, yet their contribution to the functional organization of the neocortex remains incompletely understood. Herein, we determined the DNA methylation patterns of grey and white matter of dorsolateral prefrontal cortex (Brodmann area 9), an important region for higher cognitive skills that is particularly affected in various neurological diseases. For avoiding interindividual differences, we analyzed white and grey matter from the same donor using whole genome bisulfite sequencing, and for validating their biological significance, we used Infinium HumanMethylation450 BeadChip and pyrosequencing in ten and twenty independent samples, respectively. The combination of these analysis indicated robust grey-white matter differences in DNA methylation. What is more, cell type-specific markers were enriched among the most differentially methylated genes. Interestingly, we also found an outstanding number of grey-white matter differentially methylated genes that have previously been associated with Alzheimer's, Parkinson's, and Huntington's disease, as well as Multiple and Amyotrophic lateral sclerosis. The data presented here thus constitute an important resource for future studies not only to gain insight into brain regional as well as grey and white matter differences, but also to unmask epigenetic alterations that might underlie neurological and neurodegenerative diseases. © 2017 Wiley Periodicals, Inc.
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Miotto, Eliane C; Savage, Cary R; Evans, Jonathan J; Wilson, Barbara A; Martin, Maria G M; Balardin, Joana B; Barros, Fabio G; Garrido, Griselda; Teixeira, Manoel J; Amaro Junior, Edson
2013-03-01
Memory deficit is a frequent cognitive disorder following acquired prefrontal cortex lesions. In the present study, we investigated the brain correlates of a short semantic strategy training and memory performance of patients with distinct prefrontal cortex lesions using fMRI and cognitive tests. Twenty-one adult patients with post-acute prefrontal cortex (PFC) lesions, twelve with left dorsolateral PFC (LPFC) and nine with bilateral orbitofrontal cortex (BOFC) were assessed before and after a short cognitive semantic training using a verbal memory encoding paradigm during scanning and neuropsychological tests outside the scanner. After the semantic strategy training both groups of patients showed significant behavioral improvement in verbal memory recall and use of semantic strategies. In the LPFC group, greater activity in left inferior and medial frontal gyrus, precentral gyrus and insula was found after training. For the BOFC group, a greater activation was found in the left parietal cortex, right cingulated and precuneus after training. The activation of these specific areas in the memory and executive networks following cognitive training was associated to compensatory brain mechanisms and application of the semantic strategy. Copyright © 2012 Elsevier B.V. All rights reserved.
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Stress amplifies sex differences in primate prefrontal profiles of gene expression.
Lee, Alex G; Hagenauer, Megan; Absher, Devin; Morrison, Kathleen E; Bale, Tracy L; Myers, Richard M; Watson, Stanley J; Akil, Huda; Schatzberg, Alan F; Lyons, David M
2017-11-02
Stress is a recognized risk factor for mood and anxiety disorders that occur more often in women than men. Prefrontal brain regions mediate stress coping, cognitive control, and emotion. Here, we investigate sex differences and stress effects on prefrontal cortical profiles of gene expression in squirrel monkey adults. Dorsolateral, ventrolateral, and ventromedial prefrontal cortical regions from 18 females and 12 males were collected after stress or no-stress treatment conditions. Gene expression profiles were acquired using HumanHT-12v4.0 Expression BeadChip arrays adapted for squirrel monkeys. Extensive variation between prefrontal cortical regions was discerned in the expression of numerous autosomal and sex chromosome genes. Robust sex differences were also identified across prefrontal cortical regions in the expression of mostly autosomal genes. Genes with increased expression in females compared to males were overrepresented in mitogen-activated protein kinase and neurotrophin signaling pathways. Many fewer genes with increased expression in males compared to females were discerned, and no molecular pathways were identified. Effect sizes for sex differences were greater in stress compared to no-stress conditions for ventromedial and ventrolateral prefrontal cortical regions but not dorsolateral prefrontal cortex. Stress amplifies sex differences in gene expression profiles for prefrontal cortical regions involved in stress coping and emotion regulation. Results suggest molecular targets for new treatments of stress disorders in human mental health.
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Directory of Open Access Journals (Sweden)
Jianbiao Li
2017-06-01
Full Text Available Selective accessibility mechanisms indicate that anchoring effects are results of selective retrieval of working memory. Neuroimaging studies have revealed that the right dorsolateral prefrontal cortex (DLPFC is closely related to memory retrieval and performance. However, no research has investigated the effect of changing the cortical excitability in right DLPFC on anchoring effects. Transcranial direct current stimulation (tDCS can modulate the excitability of the human cerebral cortex, while anodal and cathodal tDCS are postulated to increase or decrease cortical activity, respectively. In this study, we used tDCS to investigate whether effects of increased or decreased right DLPFC excitability influence anchoring effects in willingness to pay (WTP experiments. Ninety participants were first randomly assigned to receive either anodal, cathodal, or sham stimulation of 15 min, then they performed a valuation task regarding WTP. The results showed that anchoring effects were negatively related to activities of right DLPFC: the anodal stimulation diminished anchoring effects while the cathodal stimulation increased anchoring effects. These outcomes provide one of the first instances of neural evidence for the role of the right DLPFC in anchoring effects and support psychological explanations of the selective accessibility mechanisms and cognitive sets.
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Vassena, Eliana; Gerrits, Robin; Demanet, Jelle; Verguts, Tom; Siugzdaite, Roma
2018-04-26
Preparing for a mentally demanding task calls upon cognitive and motivational resources. The underlying neural implementation of these mechanisms is receiving growing attention because of its implications for professional, social, and medical contexts. While several fMRI studies converge in assigning a crucial role to a cortico-subcortical network including Anterior Cigulate Cortex (ACC) and striatum, the involvement of Dorsolateral Prefrontal Cortex (DLPFC) during mental effort anticipation has yet to be replicated. This study was designed to target DLPFC contribution to anticipation of a difficult task using functional Near Infrared Spectroscopy (fNIRS), as a more cost-effective tool measuring cortical hemodynamics. We adapted a validated mental effort task, where participants performed easy and difficult mental calculation, and measured DLPFC activity during the anticipation phase. As hypothesized, DLPFC activity increased during anticipation of a hard task as compared to an easy task. Besides replicating previous fMRI work, these results establish fNIRS as an effective tool to investigate cortical contributions to anticipation of effortful behavior. This is especially useful if one requires testing large samples (e.g., to target individual differences), populations with contraindication for functional MRI (e.g., infants or patients with metal implants), or subjects in more naturalistic environments (e.g., work or sport). Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Hermann, Derik; Sartorius, Alexander; Welzel, Helga; Walter, Sigrid; Skopp, Gisela; Ende, Gabriele; Mann, Karl
2007-06-01
Cannabinoids present neurotoxic and neuroprotective properties in in vitro studies, inconsistent alterations in human neuroimaging studies, neuropsychological deficits, and an increased risk for psychotic episodes. Proton magnetic resonance spectroscopy ((1)H-MRS), neuropsychological testing, and hair analysis for cannabinoids was performed in 13 male nontreatment-seeking recreational cannabis users and 13 male control subjects. A significantly diminished N-acetylaspartate/total creatine (NAA/tCr) ratio in the dorsolateral prefrontal cortex (DLPFC) was observed in cannabis users (p = .0003). The NAA/tCr in the putamen/globus pallidum region correlated significantly with cannabidiol (R(2) = .66, p = .004). Results of the Wisconsin Card Sorting test, Trail making Test, and D2 test for attention were influenced by cannabinoids. Chronic recreational cannabis use is associated with an indication of diminished neuronal and axonal integrity in the DLPFC in this study. As chronic cannabis use is a risk factor for psychosis, these results are interesting because diminished NAA/tCr ratios in the DLPFC and neuropsychological deficits were also reported in schizophrenia. The strong positive correlation of NAA/tCr and cannabidiol in the putamen/globus pallidum is in line with neuroprotective properties of cannabidiol, which were also observed in in vitro model studies of Parkinson's disease.
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International Nuclear Information System (INIS)
Ye, Ting; Peng, Jing; Nie, Binbin; Gao, Juan; Liu, Jiangtao; Li, Yang; Wang, Gang; Ma, Xin; Li, Kuncheng
2012-01-01
Background: The aim of this study was to investigate resting-state functional connectivity alteration of the right dorsolateral prefrontal cortex (DLPFC) in patients with first-episode major depressive disorder (MDD). Methods: Twenty-two first-episode MDD patients and thirty age-, gender- and education-matched healthy control subjects were enrolled. Rest state functional magnetic resonance images and structure magnetic resonance images were scanned. The functional connectivity analysis was done based on the result of voxel-based morphometry (VBM). And the right DLPFC was chosen as the seed region of interests (ROI), as its gray matter density (GMD) decreased in the MDD patients compared with controls and its GMD values were negative correlation with the Hamilton Depression Rating Scale (HDRS) scores. Results: Compared to healthy controls, the MDD patients showed increased functional connectivity with right the DLPFC in the left dorsal anterior cingulate cortex (ACC), left parahippocampal gyrus (PHG), thalamus and precentral gyrus. In contrast, there were decreased functional connectivity between the right DLPFC and right parietal lobe. Conclusions: By applying the VBM results to the functional connectivity analysis, the study suggested that abnormality of GMD in right DLPFC might be related to the functional connectivity alteration in the pathophysiology of MDD, which might be useful in further characterizing structure–function relations in this disorder.
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Energy Technology Data Exchange (ETDEWEB)
Ye, Ting, E-mail: yeting@ihep.ac.cn [Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Graduate School of Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Peng, Jing, E-mail: ppengjjing@sina.com.cn [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); Nie, Binbin, E-mail: niebb@ihep.ac.cn [Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Gao, Juan, E-mail: gaojuan@ihep.ac.cn [Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Graduate School of Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Liu, Jiangtao, E-mail: Liujiangtao813@sina.com [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); Li, Yang, E-mail: Liyang2007428@hotmail.com [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Wang, Gang, E-mail: gangwang@gmail.com [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Ma, Xin, E-mail: lijianshe@medmail.com.cn [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Li, Kuncheng [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); and others
2012-12-15
Background: The aim of this study was to investigate resting-state functional connectivity alteration of the right dorsolateral prefrontal cortex (DLPFC) in patients with first-episode major depressive disorder (MDD). Methods: Twenty-two first-episode MDD patients and thirty age-, gender- and education-matched healthy control subjects were enrolled. Rest state functional magnetic resonance images and structure magnetic resonance images were scanned. The functional connectivity analysis was done based on the result of voxel-based morphometry (VBM). And the right DLPFC was chosen as the seed region of interests (ROI), as its gray matter density (GMD) decreased in the MDD patients compared with controls and its GMD values were negative correlation with the Hamilton Depression Rating Scale (HDRS) scores. Results: Compared to healthy controls, the MDD patients showed increased functional connectivity with right the DLPFC in the left dorsal anterior cingulate cortex (ACC), left parahippocampal gyrus (PHG), thalamus and precentral gyrus. In contrast, there were decreased functional connectivity between the right DLPFC and right parietal lobe. Conclusions: By applying the VBM results to the functional connectivity analysis, the study suggested that abnormality of GMD in right DLPFC might be related to the functional connectivity alteration in the pathophysiology of MDD, which might be useful in further characterizing structure–function relations in this disorder.
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Music improves verbal memory encoding while decreasing prefrontal cortex activity: an fNIRS study.
Ferreri, Laura; Aucouturier, Jean-Julien; Muthalib, Makii; Bigand, Emmanuel; Bugaiska, Aurelia
2013-01-01
Listening to music engages the whole brain, thus stimulating cognitive performance in a range of non-purely musical activities such as language and memory tasks. This article addresses an ongoing debate on the link between music and memory for words. While evidence on healthy and clinical populations suggests that music listening can improve verbal memory in a variety of situations, it is still unclear what specific memory process is affected and how. This study was designed to explore the hypothesis that music specifically benefits the encoding part of verbal memory tasks, by providing a richer context for encoding and therefore less demand on the dorsolateral prefrontal cortex (DLPFC). Twenty-two healthy young adults were subjected to functional near-infrared spectroscopy (fNIRS) imaging of their bilateral DLPFC while encoding words in the presence of either a music or a silent background. Behavioral data confirmed the facilitating effect of music background during encoding on subsequent item recognition. fNIRS results revealed significantly greater activation of the left hemisphere during encoding (in line with the HERA model of memory lateralization) and a sustained, bilateral decrease of activity in the DLPFC in the music condition compared to silence. These findings suggest that music modulates the role played by the DLPFC during verbal encoding, and open perspectives for applications to clinical populations with prefrontal impairments, such as elderly adults or Alzheimer's patients.
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Music improves verbal memory encoding while decreasing prefrontal cortex activity: an fNIRS study
Directory of Open Access Journals (Sweden)
Laura eFerreri
2013-11-01
Full Text Available Listening to music engages the whole brain, thus stimulating cognitive performance in a range of non purely musical activities such as language and memory tasks. This article addresses an ongoing debate on the link between music and memory for words. While evidence on healthy and clinical populations suggests that music listening can improve verbal memory in a variety of situations, it is still unclear what specific memory process is affected and how. This study was designed to explore the hypothesis that music specifically benefits the encoding part of verbal memory tasks, by providing a richer context for encoding and therefore less demand on the dorsolateral prefrontal cortex (DLPFC. 22 healthy young adults were subjected to functional near-infrared spectroscopy (fNIRS imaging of their bilateral DLPFC while encoding words in the presence of either a music or a silent background. Behavioral data confirmed the facilitating effect of music background during encoding on subsequent item recognition. fNIRS results revealed significantly greater activation of the left hemisphere during encoding (in line with the HERA model of memory lateralization and a sustained, bilateral decrease of activity in the DLPFC in the music condition compared to silence. These findings suggest that music modulates the role played by the DLPFC during verbal encoding, and open perspectives for applications to clinical populations with prefrontal impairments, such as elderly adults or Alzheimer's patients.
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Brain structure in schizophrenia vs. psychotic bipolar I disorder: A VBM study.
Nenadic, Igor; Maitra, Raka; Langbein, Kerstin; Dietzek, Maren; Lorenz, Carsten; Smesny, Stefan; Reichenbach, Jürgen R; Sauer, Heinrich; Gaser, Christian
2015-07-01
While schizophrenia and bipolar disorder have been assumed to share phenotypic and genotypic features, there is also evidence for overlapping brain structural correlates, although it is unclear whether these relate to shared psychotic features. In this study, we used voxel-based morphometry (VBM8) in 34 schizophrenia patients, 17 euthymic bipolar I disorder patients (with a history of psychotic symptoms), and 34 healthy controls. Our results indicate that compared to healthy controls schizophrenia patients show grey matter deficits (pright dorsolateral prefrontal, as well as bilaterally in ventrolateral prefrontal and insular cortical areas, thalamus (bilaterally), left superior temporal cortex, and minor medial parietal and parietooccipital areas. Comparing schizophrenia vs. bipolar I patients (pleft dorsolateral prefrontal cortex, and left cerebellum. Compared to healthy controls, the deficits in bipolar I patients only reached significance at prights reserved.
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Directory of Open Access Journals (Sweden)
Stefano eBembich
2014-06-01
Full Text Available Prefrontal cortex plays an important role in decision making (DM, supporting choices in the ordinary uncertainty of everyday life. To assess DM in an unpredictable situation, a playing card task, such as the Iowa Gambling Task (IGT, has been proposed. This task is supposed to specifically test emotion-based learning, linked to the integrity of the ventromedial prefrontal cortex (VMPFC. However, the dorsolateral prefrontal cortex (DLPFC has demonstrated a role in IGT performance too. Our aim was to study, by multichannel near-infrared spectroscopy, the contribution of DLPFC to the IGT execution over time. We tested the hypothesis that low and high risk choices would differentially activate DLPFC, as IGT execution progressed. We enrolled 11 healthy adults. To identify DLPFC activation associated with IGT choices, we compared regional differences in oxy-haemoglobin variation, from baseline to the event. The time course of task execution was divided in four periods, each one consisting of 25 choices, and DLPFC activation was distinctly analyzed for low and high risk choices in each period. We found different time courses in DLPFC activation, associated with low or high risk choices. During the first period, a significant DLPFC activation emerged with low risk choices, whereas, during the second period, we found a cortical activation with high risk choices. Then, DLPFC activation decreased to non-significant levels during the third and fourth period. This study shows that DLPFC involvement in IGT execution is differentiated over time and according to choice risk level. DLPFC is activated only in the first half of the task, earlier by low risk and later by high risk choices. We speculate that DLPFC may sustain initial and more cognitive functions, such as attention shifting and response inhibition. The lack of DLPFC activation, as the task progresses, may be due to VMPFC activation, not detectable by fNIRS, which takes over the IGT execution in its
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Directory of Open Access Journals (Sweden)
Shahram Oveisgharan
2017-02-01
Full Text Available Background: Two previous studies, which investigated transcranial direct current stimulation (tDCS use in motor recovery after acute ischemic stroke, did not show tDCS to be effective in this regard. We speculated that additional left dorsolateral prefrontal cortex (DLPFC stimulation may enhance post stroke motor recovery. Methods: In the present randomized clinical trial, 20 acute ischemic stroke patients were recruited. Patients received real motor cortex (M1 stimulation in both arms of the trial. The two arms differed in terms of real vs. sham stimulation over the left DLPFC. Motor component of the Fugl-Meyer upper extremity assessment (FM and Action Research Arm Test (ARAT scores were used to assess primary outcomes, and non-linear mixed effects models were used for data analyses. Results: Primary outcome measures improved more and faster among the real stimulation group. During the first days of stimulations, sham group’s FM scores increased 1.2 scores per day, while real group’s scores increased 1.7 scores per day (P = 0.003. In the following days, FM improvement decelerated in both groups. Based on the derived models, a hypothetical stroke patient with baseline FM score of 15 improves to 32 in the sham stimulation group and to 41 in the real stimulation group within the first month after stroke. Models with ARAT scores yielded nearly similar results. Conclusion: The current study results showed that left DLPFC stimulation in conjunction with M1 stimulation resulted in better motor recovery than M1 stimulation alone.
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Chou, Po-Han; Lin, Wei-Hao; Hung, Chao-An; Chang, Chiung-Chih; Li, Wan-Rung; Lan, Tsuo-Hung; Huang, Min-Wei
2016-12-13
Despite an increasing number of reports on the associations between chronic occupational stress and structural and functional changes of the brain, the underlying neural correlates of perceived occupational stress is still not clear. Perceived stress reflects the extents to which situations are appraised as stressful at a given point in one's life. Using near-infrared spectroscopy, we investigated the associations between perceived occupational stress and cortical activity over the bilateral frontotemporal regions during a verbal fluency test. Sixty-eight participants (17 men, 51 women), 20-62 years of age were recruited. Perceived occupational stress was measured using the Chinese version of Job Content Questionnaire, and the Chinese version of the Copenhagen Burnout Inventory. We found statistically significant negative associations between occupational burnout and brain cortical activity over the fronto-polar and dorsolateral prefrontal cortex during the VFT (r = -0.343 to -0.464). In conclusion, our research demonstrated a possible neural basis of perceived occupational stress that are distributed across the prefrontal cortex.
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Working Memory Modulates Glutamate Levels in the Dorsolateral Prefrontal Cortex during 1H fMRS
Directory of Open Access Journals (Sweden)
Eric A. Woodcock
2018-03-01
Full Text Available Glutamate is involved in excitatory neurotransmission and metabolic processes related to brain function. Previous studies using proton functional magnetic resonance spectroscopy (1H fMRS have demonstrated elevated cortical glutamate levels by 2–4% during visual and motor stimulation, relative to periods of no stimulation. Here, we extended this approach to working memory cognitive task performance, which has been consistently associated with dorsolateral prefrontal cortex (dlPFC activation. Sixteen healthy adult volunteers completed a continuous visual fixation “rest” task followed by a letter 2-back working memory task during 1H fMRS acquisition of the left dlPFC, which encompassed Brodmann areas 45 and 46 over a 4.5-cm3 volume. Using a 100% automated fitting procedure integrated with LCModel, raw spectra were eddy current-, phase-, and shift-corrected prior to quantification resulting in a 32s temporal resolution or 8 averages per spectra. Task compliance was high (95 ± 11% correct and the mean Cramer-Rao Lower Bound of glutamate was 6.9 ± 0.9%. Relative to continuous passive visual fixation, left dlPFC glutamate levels were significantly higher by 2.7% (0.32 mmol/kg wet weight during letter 2-back performance. Elevated dlPFC glutamate levels reflect increased metabolic activity and excitatory neurotransmission driven by working memory-related cognitive demands. These results provide the first in vivo demonstration of elevated dlPFC glutamate levels during working memory.
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Shang, Yuan-Qi; Xie, Jun; Peng, Wei; Zhang, Jian; Chang, Da; Wang, Ze
2018-04-01
The repetitive application of transcranial magnetic stimulation (rTMS) on left dorsolateral prefrontal cortex (DLPFC) has been consistently shown to be beneficial for treating various neuropsychiatric or neuropsychological disorders, but its neural mechanisms still remain unclear. The purpose of this study was to measure the effects of high-frequency left DLPFC rTMS using cerebral blood flow (CBF) collected from 40 young healthy subjects before and after applying 20 Hz left DLPFC rTMS or SHAM stimulations. Relative CBF (rCBF) changes before and after 20 Hz rTMS or SHAM were assessed with paired-t test. The results show that 20 Hz DLPFC rTMS induced CBF redistribution in the default mode network, including increased rCBF in left medial temporal cortex (MTC)/hippocampus, but reduced rCBF in precuneus and cerebellum. Meanwhile, SHAM stimulation didn't produce any rCBF changes. After controlling SHAM effects, only the rCBF increase in MTC/hippocampus remained. Those data suggest that the beneficial effects of high-frequency rTMS may be through a within-network rCBF redistribution. Copyright © 2018 Elsevier B.V. All rights reserved.
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Neural correlates of memory retrieval in the prefrontal cortex.
Nácher, Verónica; Ojeda, Sabiela; Cadarso-Suárez, Carmen; Roca-Pardiñas, Javier; Acuña, Carlos
2006-08-01
Working memory includes short-term representations of information that were recently experienced or retrieved from long-term representations of sensory stimuli. Evidence is presented here that working memory activates the same dorsolateral prefrontal cortex neurons that: (a) maintained recently perceived visual stimuli; and (b) retrieved visual stimuli from long-term memory (LTM). Single neuron activity was recorded in the dorsolateral prefrontal cortex while trained monkeys discriminated between two orientated lines shown sequentially, separated by a fixed interstimulus interval. This visual task required the monkey to compare the orientation of the second line with the memory trace of the first and to decide the relative orientation of the second. When the behavioural task required the monkey to maintain in working memory a first stimulus that continually changed from trial to trial, the discharge in these cells was related to the parameters--the orientation--of the memorized item. Then, what the monkey had to recall from memory was manipulated by switching to another task in which the first stimulus was not shown, and had to be retrieved from LTM. The discharge rates of the same neurons also varied depending on the parameters of the memorized stimuli, and their response was progressively delayed as the monkey performed the task. These results suggest that working memory activates dorsolateral prefrontal cortex neurons that maintain parametrical visual information in short-term and LTM, and that the contents of working memory cannot be limited to what has recently happened in the sensory environment.
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Mineo, Ludovico; Fetterman, Alexander; Concerto, Carmen; Warren, Michael; Infortuna, Carmenrita; Freedberg, David; Chusid, Eileen; Aguglia, Eugenio; Battaglia, Fortunato
2018-06-01
The phenomenon of motor resonance (the increase in motor cortex excitability during observation of actions) has been previously described. Transcranial magnetic stimulation (TMS) studies have demonstrated a similar effect during perception of implied motion (IM). The left dorsolateral prefrontal cortex (DLPFC) seems to be activated during action observation. Furthermore, the role of this brain area in motor resonance to IM is yet to be investigated. Fourteen healthy volunteers were enrolled into the study. We used transcranial direct current stimulation (tDCS) to stimulate DLPFC aiming to investigate whether stimulation with different polarities would affect the amplitude of motor evoked potential collected during observation of images with and without IM. The results of our experiment indicated that Cathodal tDCS over the left DLPFC prevented motor resonance during observation of IM. On the contrary, anodal and sham tDCS did not significantly modulate motor resonance to IM. The current study expands the understanding of the neural circuits engaged during observation of IM. Our results are consistent with the hypothesis that action understanding requires the interaction of large networks and that the left DLPFC plays a crucial role in generating motor resonance to IM. Copyright © 2018 Elsevier B.V. All rights reserved.
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Terraneo, Alberto; Leggio, Lorenzo; Saladini, Marina; Ermani, Mario; Bonci, Antonello; Gallimberti, Luigi
2016-01-01
Recent animal studies demonstrate that compulsive cocaine seeking strongly reduces prelimbic frontal cortex activity, while optogenetic stimulation of this brain area significantly inhibits compulsive cocaine seeking, providing a strong rationale for applying brain stimulation to reduce cocaine consumption. Thus, we employed repetitive transcranial magnetic stimulation (rTMS), to test if dorsolateral prefrontal cortex (DLPFC) stimulation might prevent cocaine use in humans. Thirty-two cocaine-addicted patients were randomly assigned to either the experimental group (rTMS) on the left DLPFC, or to a control group (pharmacological agents) during a 29-day study (Stage 1). This was followed by a 63-day follow-up (Stage 2), during which all participants were offered rTMS treatment. Amongst the patients who completed Stage 1, 16 were in the rTMS group (100%) and 13 in the control group (81%). No significant adverse events were noted. During Stage 1, there were a significantly higher number of cocaine-free urine drug tests in the rTMS group compared to control (p=0.004). Craving for cocaine was also significantly lower in the rTMS group compared to the controls (p=0.038). Out of 13 patients who completed Stage 1 in the control group, 10 patients received rTMS treatment during Stage 2 and showed significant improvement with favorable outcomes becoming comparable to those of the rTMS group. The present preliminary findings support the safety of rTMS in cocaine-addicted patients, and suggest its potential therapeutic role for rTMS-driven PFC stimulation in reducing cocaine use, providing a strong rationale for developing larger placebo-controlled studies. Trial name: Repetitive transcranial magnetic stimulation (rTMS) in cocaine abusers, URL:〈http://www.isrctn.com/ISRCTN15823943?q=&filters=&sort=&offset=8&totalResults=13530&page=1&pageSize=10&searchType=basic-search〉, ISRCTN15823943. Published by Elsevier B.V.
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Monetary reward activates human prefrontal cortex
International Nuclear Information System (INIS)
Thut, G.; Roelcke, U.; Nienhusmeier, M.; Missimer, J.; Maguire, R.P.; Leenders, K.L.; Schultz, W.
1997-01-01
We present a rCBF PET activation study, in which we demonstrated that reward processing in humans activates a cortical-subcortical network including dorsolateral prefrontal, orbital frontal, thalamic and midbrain regions. It is suggested that, as found for non-human primates, the basal ganglia-thalamo-cortical system is implicated in reward processing. (author) 1 fig., 3 refs
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Richieri, Raphaëlle; Verger, Antoine; Boyer, Laurent; Boucekine, Mohamed; David, Anthony; Lançon, Christophe; Cermolacce, Michel; Guedj, Eric
2018-05-18
Previous clinical trials have suggested that repetitive transcranial magnetic stimulation (rTMS) has a significant antidepressant effect in patients with treatment resistant depression (TRD). However, results remain heterogeneous with many patients without effective response. The aim of this SPECT study was to determine before treatment the predictive value of the connectivity of the stimulated area on further rTMS response in patients with TRD. Fifty-eight TRD patients performed a brain perfusion SPECT before high frequency rTMS of the left dorsolateral prefrontal cortex (DLPFC). A voxel based-analysis was achieved to compare connectivity of the left DLPFC in responders and non-responders using inter-regional correlations (p left DLPFC and the right cerebellum in comparison to non-responders, independently of age, gender, severity of depression, and severity of treatment resistance. The area under the curve for the combination of these two SPECT clusters to predict rTMS response was 0.756 (p left DLPFC predicts rTMS response before treatment. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.
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Konecky, R O; Smith, M A; Olson, C R
2017-06-01
To explore the brain mechanisms underlying multi-item working memory, we monitored the activity of neurons in the dorsolateral prefrontal cortex while macaque monkeys performed spatial and chromatic versions of a Sternberg working-memory task. Each trial required holding three sequentially presented samples in working memory so as to identify a subsequent probe matching one of them. The monkeys were able to recall all three samples at levels well above chance, exhibiting modest load and recency effects. Prefrontal neurons signaled the identity of each sample during the delay period immediately following its presentation. However, as each new sample was presented, the representation of antecedent samples became weak and shifted to an anomalous code. A linear classifier operating on the basis of population activity during the final delay period was able to perform at approximately the level of the monkeys on trials requiring recall of the third sample but showed a falloff in performance on trials requiring recall of the first or second sample much steeper than observed in the monkeys. We conclude that delay-period activity in the prefrontal cortex robustly represented only the most recent item. The monkeys apparently based performance of this classic working-memory task on some storage mechanism in addition to the prefrontal delay-period firing rate. Possibilities include delay-period activity in areas outside the prefrontal cortex and changes within the prefrontal cortex not manifest at the level of the firing rate. NEW & NOTEWORTHY It has long been thought that items held in working memory are encoded by delay-period activity in the dorsolateral prefrontal cortex. Here we describe evidence contrary to that view. In monkeys performing a serial multi-item working memory task, dorsolateral prefrontal neurons encode almost exclusively the identity of the sample presented most recently. Information about earlier samples must be encoded outside the prefrontal cortex or
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Directory of Open Access Journals (Sweden)
Luca Sebastianelli
2015-01-01
Full Text Available We describe the case of a patient who underwent craniectomy for hemorrhage of the left parietal lobe. Three weeks later, orthostatic memory impairment was detected as initial symptom of sinking skin flap syndrome (SSFS. This deficit was examined by neuropsychological testing and associated with a posture-dependent increase in the delta/alpha ratio at the F3 electrode, an electroencephalographic (EEG index related to brain hypoperfusion. This EEG spectral alteration was detected in a brain region that includes the left dorsolateral prefrontal cortex, an area known to be involved in memory processing; therefore we hypothesize that SSFS induced reversible hypoperfusion of this otherwise undamaged cortical region. Neither of these findings was present after cranioplasty. This case suggests that SSFS may induce neuropsychological deficits potentially influencing outcome in the postacute phase and is further evidence supporting the clinical benefits of early cranioplasty.
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Shin, Jung Eun; Choi, Soo-Hee; Lee, Hyeongrae; Shin, Young Seok; Jang, Dong-Pyo; Kim, Jae-Jin
2015-04-03
Schizophrenia is a mental disorder characterized by impairments in diverse thinking and emotional responses, which are related to social perception dysfunction. This fMRI study was designed to investigate a neurobiological basis of social perception deficits of patients with schizophrenia in various social situations of daily life and their relationship with clinical symptoms and social dysfunction. Seventeen patients and 19 controls underwent functional magnetic resonance imaging, during which participants performed a virtual social perception task, containing an avatar's speech with positive, negative or neutral emotion in a virtual reality space. Participants were asked to determine whether or not the avatar's speech was appropriate to each situation. The significant group×appropriateness interaction was seen in the left dorsolateral prefrontal cortex (DLPFC), resulting from lower activity in patients in the inappropriate condition, and left DLPFC activity was negatively correlated with the severity of negative symptoms and positively correlated with the level of social functioning. The significant appropriateness×emotion interaction observed in the left superior temporal sulcus (STS) was present in controls, but absent in patients, resulting from the existence and absence of a difference between the inappropriate positive and negative conditions, respectively. These findings indicate that dysfunction of the DLPFC-STS network may underlie patients' abnormal social perception in various social situations of daily life. Abnormal functioning of this network may contribute to increases of negative symptoms and decreases of social functioning. Copyright © 2014 Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Martin Brüne
Full Text Available Humans incur considerable costs to punish unfairness directed towards themselves or others. Recent studies using repetitive transcranial magnetic stimulation (rTMS suggest that the right dorsolateral prefrontal cortex (DLPFC is causally involved in such strategic decisions. Presently, two partly divergent hypotheses are discussed, suggesting either that the right DLPFC is necessary to control selfish motives by implementing culturally transmitted social norms, or is involved in suppressing emotion-driven prepotent responses to perceived unfairness. Accordingly, we studied the role of the DLPFC in costly (i.e. third party punishment by applying rTMS to the left and right DLPFC before playing a Dictator Game with the option to punish observed unfair behavior (DG-P. In addition, sham stimulation took place. Individual differences in empathy were assessed with the German version of the Interpersonal Reactivity Index. Costly punishment increased (non-significantly upon disruption of the right--but not the left--DLPFC as compared to sham stimulation. However, empathy emerged as a highly significant moderator variable of the effect of rTMS over the right, but not left, DLPFC, suggesting that the right DLPFC is involved in controlling prepotent emotional responses to observed unfairness, depending on individual differences in empathy.
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Directory of Open Access Journals (Sweden)
Sisi Jiang
Full Text Available It has been suggested that working memory deficits is a core feature of symptomatology of schizophrenia, which can be detected in patients and their unaffected relatives. The impairment of working memory has been found related to the abnormal activity of human brain regions in many functional magnetic resonance imaging (fMRI studies. This study investigated how brain region activation was altered in schizophrenia and how it was inherited independently from performance deficits.The authors used fMRI method during N-back task to assess working memory related cortical activation in four groups (N = 20 in each group, matching task performance, age, gender and education: schizophrenic patients, their unaffected biological parents, young healthy controls for the patients and older healthy controls for their parents.Compared to healthy controls, patients showed an exaggerated response in the right dorsolateral prefrontal cortex (brodmann area [BA] 46 and bilateral ventrolateral prefrontal cortex, and had reduced activation in bilateral dorsolateral prefrontal cortex (BA 9. In the conjunction analysis, the effect of genetic risk (parents versus older control shared significantly overlapped activation with effect of disease (patients versus young control in the right middle frontal gyrus (BA 46 and left inferior parietal gyrus (BA 40.Physiological inefficiency of dorsal prefrontal cortex and compensation involvement of ventral prefrontal cortex in working memory function may one physiological characteristics of schizophrenia. And relatively inefficient activation in dorsolateral prefrontal cortex probably can be a promising intermediate phenotype for schizophrenia.
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Directory of Open Access Journals (Sweden)
Meyer Martin
2009-07-01
Full Text Available Abstract Background Little is known about the contribution of transcranial direct current stimulation (tDCS to the exploration of memory functions. The aim of the present study was to examine the behavioural effects of right or left-hemisphere frontal direct current delivery while committing to memory auditory presented nouns on short-term learning and subsequent long-term retrieval. Methods Twenty subjects, divided into two groups, performed an episodic verbal memory task during anodal, cathodal and sham current application on the right or left dorsolateral prefrontal cortex (DLPFC. Results Our results imply that only cathodal tDCS elicits behavioural effects on verbal memory performance. In particular, left-sided application of cathodal tDCS impaired short-term verbal learning when compared to the baseline. We did not observe tDCS effects on long-term retrieval. Conclusion Our results imply that the left DLPFC is a crucial area involved in short-term verbal learning mechanisms. However, we found further support that direct current delivery with an intensity of 1.5 mA to the DLPFC during short-term learning does not disrupt longer lasting consolidation processes that are mainly known to be related to mesial temporal lobe areas. In the present study, we have shown that the tDCS technique has the potential to modulate short-term verbal learning mechanism.
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Chrysikou, Evangelia G; Gorey, Claire; Aupperle, Robin L
2017-03-01
Approach-avoidance conflict (AAC) refers to situations associated with both rewarding and threatening outcomes. The AAC task was developed to measure AAC decision-making. Approach behavior during this task has been linked to self-reported anxiety sensitivity and has elicited anterior cingulate, insula, caudate and right dorsolateral prefrontal cortex (dlPFC) activity, with right lateral PFC tracking the extent of approach behavior. Guided by these results, we used excitatory transcranial direct current stimulation (tDCS) to demonstrate the causal involvement of right dlPFC in AAC decision-making. Participants received anodal tDCS at 1.5mA over either left or right dlPFC or sham stimulation, while performing the AAC task and a control short-term memory task. Analyses of variance (ANOVA) revealed that for individuals with high anxiety sensitivity excitatory right (but not left or sham) dlPFC stimulation elicited measurable decreases in approach behavior during conflict. Excitatory left (but not right or sham) dlPFC simulation improved performance on the control task. These results support a possible asymmetry between the contributions of right and left dlPFC to AAC resolution during emotional decision-making. Increased activity in right dlPFC may contribute to anxiety-related symptoms and, as such, serve as a neurobehavioral target of anxiolytic treatments aiming to decrease avoidance behavior. © The Author (2016). Published by Oxford University Press.
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Sligte, Ilja G; Wokke, Martijn E; Tesselaar, Johannes P; Scholte, H Steven; Lamme, Victor A F
2011-05-01
To guide our behavior in successful ways, we often need to rely on information that is no longer in view, but maintained in visual short-term memory (VSTM). While VSTM is usually broken down into iconic memory (brief and high-capacity store) and visual working memory (sustained, yet limited-capacity store), recent studies have suggested the existence of an additional and intermediate form of VSTM that depends on activity in extrastriate cortex. In previous work, we have shown that this fragile form of VSTM can be dissociated from iconic memory. In the present study, we provide evidence that fragile VSTM is different from visual working memory as magnetic stimulation of the right dorsolateral prefrontal cortex (DLPFC) disrupts visual working memory, while leaving fragile VSTM intact. In addition, we observed that people with high DLPFC activity had superior working memory capacity compared to people with low DLPFC activity, and only people with high DLPFC activity really showed a reduction in working memory capacity in response to magnetic stimulation. Altogether, this study shows that VSTM consists of three stages that have clearly different characteristics and rely on different neural structures. On the methodological side, we show that it is possible to predict individual susceptibility to magnetic stimulation based on functional MRI activity. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Natalia Chechko
2018-05-01
Full Text Available In schizophrenia (SCZ, dysfunction of the dorsolateral prefrontal cortex (DLPFC has been linked to the deficits in executive functions and attention. It has been suggested that, instead of considering the right DLPFC as a cohesive functional entity, it can be divided into two parts (anterior and posterior based on its whole-brain connectivity patterns. Given these two subregions' differential association with cognitive processes, we investigated the functional connectivity (FC profile of both subregions through resting-state data to determine whether they are differentially affected in SCZ. Resting-state magnetic resonance imaging (MRI scans were obtained from 120 patients and 172 healthy controls (HC at 6 different MRI sites. The results showed differential FC patterns for the anterior and posterior parts of the right executive control-related DLPFC in SCZ with the parietal, the temporal and the cerebellar regions, along with a convergent reduction of connectivity with the striatum and the occipital cortex. An increased psychopathology level was linked to a higher difference in posterior vs. anterior FC for the left IFG/anterior insula, regions involved in higher-order cognitive processes. In sum, the current analysis demonstrated that even between two neighboring clusters connectivity could be differentially disrupted in SCZ. Lacking the necessary anatomical specificity, such notions may in fact be detrimental to a proper understanding of SCZ pathophysiology.
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Meer, van Floor; Laan, van der Laura N.; Viergever, Max A.; Adan, Roger A.H.; Smeets, Paul A.M.
2017-01-01
Childhood obesity is a rising problem worldwide mainly caused by overconsumption, which is driven by food choices. In adults, food choices are based on a value signal encoded in the medial prefrontal cortex (mPFC). This signal is modulated by the dorsolateral prefrontal cortex (dlPFC), which is
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Qiao, Jun; Jin, Guixing; Lei, Licun; Wang, Lan; Du, Yaqiang; Wang, Xueyi
2016-01-01
To explore the effect of right dorsolateral prefrontal cortex (DLPFC) repetitive transcranial magnetic stimulation (rTMS) on memory, and its correlation with levels of hippocampal brain metabolites detected by proton magnetic resonance spectroscopy ( 1 H-MRS) in recently detoxified alcohol-dependent patients. In this randomized, double-blind sham-controlled trial, alcohol-dependent patients were enrolled and randomized into two groups: the experimental group (rTMS, 10 Hz, on right DLPFC, 20 sessions) and the control group (sham stimulation). Memory function was assessed using Hopkins Verbal Learning Test-Revised (HVLT-R) and Brief Visuospatial Memory Test-Revised (BVMT-R) before and after treatment. 1 H-MRS was used to detect the levels of N -acetyl aspartic acid (NAA), choline (Cho), and creatine (Cr) in bilateral hippocampi before and after treatment. Thirty-eight patients (18 in the experimental group and 20 in the control group) were included in the analyses. The experimental group showed significantly greater changes in HVLT-R, BVMT-R, NAA/Cr, and Cho/Cr after rTMS from baseline than the control group. The percentage change in BVMT-R and HVLT-R correlated with the percentage change in NAA/Cr and Cho/Cr in the right brain. High-frequency right DLPFC rTMS was associated with improvement in memory dysfunction, which is correlated with levels of hippocampal brain metabolites detected by 1 H-MRS in recently detoxified alcohol-dependent patients.
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Ouerchefani, Riadh; Ouerchefani, Naoufel; Allain, Philippe; Ben Rejeb, Mohamed Riadh; Le Gall, Didier
2017-02-01
Few studies have examined the contribution of different sub-regions of the prefrontal cortex and lesion laterality to decision-making abilities. In addition, there are inconsistent findings about the role of ventromedial and dorsolateral lesions in decision-making deficit. In this study, decision-making processes are investigated following different damaged areas of the prefrontal cortex. We paid particular attention to the contribution of laterality, lesion location and lesion volume in decision-making deficit. Twenty-seven patients with discrete ventromedial lesions, dorsolateral lesions or extended-frontal lesions were compared with normal subjects on the Iowa Gambling Task (IGT). Our results showed that all frontal subgroups were impaired on the IGT in comparison with normal subjects. We noted also that IGT performance did not vary systematically based on lesion laterality or location. More precisely, our lesion analysis revealed that decision-making processes depend on a large cerebral network, including both ventromedial and dorsolateral areas of the prefrontal cortex. Consistent with past findings, our results support the claim that IGT deficit is not solitarily associated with ventromedial prefrontal cortex lesions. Copyright © 2016 Elsevier Inc. All rights reserved.
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Prefrontal activity and impaired memory encoding strategies in schizophrenia.
Guimond, Synthia; Hawco, Colin; Lepage, Martin
2017-08-01
Schizophrenia patients have significant memory difficulties that have far-reaching implications in their daily life. These impairments are partly attributed to an inability to self-initiate effective memory encoding strategies, but its core neurobiological correlates remain unknown. The current study addresses this critical gap in our knowledge of episodic memory impairments in schizophrenia. Schizophrenia patients (n = 35) and healthy controls (n = 23) underwent a Semantic Encoding Memory Task (SEMT) during an fMRI scan. Brain activity was examined for conditions where participants were a) prompted to use semantic encoding strategies, or b) not prompted but required to self-initiate such strategies. When prompted to use semantic encoding strategies, schizophrenia patients exhibited similar recognition performance and brain activity as healthy controls. However, when required to self-initiate these strategies, patients had significant reduced recognition performance and brain activity in the left dorsolateral prefrontal cortex, as well as in the left temporal gyrus, left superior parietal lobule, and cerebellum. When patients were divided based on performance on the SEMT, the subgroup with more severe deficits in self-initiation also showed greater reduction in left dorsolateral prefrontal activity. These results suggest that impaired self-initiation of elaborative encoding strategies is a driving feature of memory deficits in schizophrenia. We also identified the neural correlates of impaired self-initiation of semantic encoding strategies, in which a failure to activate the left dorsolateral prefrontal cortex plays a key role. These findings provide important new targets in the development of novel treatments aiming to improve memory and ultimately patients' outcome. Copyright © 2017. Published by Elsevier Ltd.
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Viswanathan, Pooja; Nieder, Andreas
2017-12-01
The concept of receptive field (RF) describes the responsiveness of neurons to sensory space. Neurons in the primate association cortices have long been known to be spatially selective but a detailed characterisation and direct comparison of RFs between frontal and parietal association cortices are missing. We sampled the RFs of a large number of neurons from two interconnected areas of the frontal and parietal lobes, the dorsolateral prefrontal cortex (dlPFC) and ventral intraparietal area (VIP), of rhesus monkeys by systematically presenting a moving bar during passive fixation. We found that more than half of neurons in both areas showed spatial selectivity. Single neurons in both areas could be assigned to five classes according to the spatial response patterns: few non-uniform RFs with multiple discrete response maxima could be dissociated from the vast majority of uniform RFs showing a single maximum; the latter were further classified into full-field and confined foveal, contralateral and ipsilateral RFs. Neurons in dlPFC showed a preference for the contralateral visual space and collectively encoded the contralateral visual hemi-field. In contrast, VIP neurons preferred central locations, predominantly covering the foveal visual space. Putative pyramidal cells with broad-spiking waveforms in PFC had smaller RFs than putative interneurons showing narrow-spiking waveforms, but distributed similarly across the visual field. In VIP, however, both putative pyramidal cells and interneurons had similar RFs at similar eccentricities. We provide a first, thorough characterisation of visual RFs in two reciprocally connected areas of a fronto-parietal cortical network. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.
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Directory of Open Access Journals (Sweden)
Nathaniel R. Bridges
2018-03-01
Full Text Available Background: Dorsolateral prefrontal cortex (DLPFC low frequency repetitive transcranial magnetic stimulation (LF-rTMS has shown promise as a treatment and investigative tool in the medical and research communities. Researchers have made significant progress elucidating DLPFC LF-rTMS effects—primarily in individuals with psychiatric disorders. However, more efforts investigating underlying molecular changes and establishing links to functional and behavioral outcomes in healthy humans are needed.Objective: We aimed to quantify neuromolecular changes and relate these to functional changes following a single session of DLPFC LF-rTMS in healthy participants.Methods: Eleven participants received sham-controlled neuronavigated 1 Hz rTMS to the region most activated by a 7-letter Sternberg working memory task (SWMT within the left DLPFC. We quantified SWMT performance, functional magnetic resonance activation and proton Magnetic resonance spectroscopy (MRS neurometabolite measure changes before and after stimulation.Results: A single LF-rTMS session was not sufficient to change DLPFC neurometabolite levels and these changes did not correlate with DLPFC activation changes. Real rTMS, however, significantly altered neurometabolite correlations (compared to sham rTMS, both with baseline levels and between the metabolites themselves. Additionally, real rTMS was associated with diminished reaction time (RT performance improvements and increased activation within the motor, somatosensory and lateral occipital cortices.Conclusion: These results show that a single session of LF-rTMS is sufficient to influence metabolite relationships and causes widespread activation in healthy humans. Investigating correlational relationships may provide insight into mechanisms underlying LF-rTMS.
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Directory of Open Access Journals (Sweden)
Yoichi Sawada
Full Text Available The attentional set-shifting deficit that has been observed in Parkinson's disease (PD has long been considered neuropsychological evidence of the involvement of meso-prefrontal and prefrontal-striatal circuits in cognitive flexibility. However, recent studies have suggested that non-dopaminergic, posterior cortical pathologies may also contribute to this deficit. Although several neuroimaging studies have addressed this issue, the results of these studies were confounded by the use of tasks that required other cognitive processes in addition to set-shifting, such as rule learning and working memory. In this study, we attempted to identify the neural correlates of the attentional set-shifting deficit in PD using a compound letter task and 18F-fluoro-deoxy-glucose (FDG positron emission tomography during rest. Shift cost, which is a measure of attentional set-shifting ability, was significantly correlated with hypometabolism in the right dorsolateral prefrontal cortex, including the putative human frontal eye field. Our results provide direct evidence that dysfunction in the dorsolateral prefrontal cortex makes a primary contribution to the attentional set-shifting deficit that has been observed in PD patients.
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Rosen, David S.; Erickson, Brian; Kim, Youngmoo E.; Mirman, Daniel; Hamilton, Roy H.; Kounios, John
2016-01-01
Research on creative cognition reveals a fundamental disagreement about the nature of creative thought, specifically, whether it is primarily based on automatic, associative (Type-1) or executive, controlled (Type-2) processes. We hypothesized that Type-1 and Type-2 processes make differential contributions to creative production that depend on domain expertise. We tested this hypothesis with jazz pianists whose expertise was indexed by the number of public performances given. Previous fMRI studies of musical improvisation have reported that domain expertise is characterized by deactivation of the right-dorsolateral prefrontal cortex (r-DLPFC), a brain area associated with Type-2 executive processing. We used anodal, cathodal, and sham transcranial direct current stimulation (tDCS) applied over r-DLPFC with the reference electrode on the contralateral mastoid (1.5 mA for 15 min, except for sham) to modulate the quality of the pianists' performances while they improvised over chords with drum and bass accompaniment. Jazz experts rated each improvisation for creativity, esthetic appeal, and technical proficiency. There was no main effect of anodal or cathodal stimulation on ratings compared to sham; however, a significant interaction between anodal tDCS and expertise emerged such that stimulation benefitted musicians with less experience but hindered those with more experience. We interpret these results as evidence for a dual-process model of creativity in which novices and experts differentially engage Type-1 and Type-2 processes during creative production. PMID:27899889
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Rosen, David S; Erickson, Brian; Kim, Youngmoo E; Mirman, Daniel; Hamilton, Roy H; Kounios, John
2016-01-01
Research on creative cognition reveals a fundamental disagreement about the nature of creative thought, specifically, whether it is primarily based on automatic, associative (Type-1) or executive, controlled (Type-2) processes. We hypothesized that Type-1 and Type-2 processes make differential contributions to creative production that depend on domain expertise. We tested this hypothesis with jazz pianists whose expertise was indexed by the number of public performances given. Previous fMRI studies of musical improvisation have reported that domain expertise is characterized by deactivation of the right-dorsolateral prefrontal cortex (r-DLPFC), a brain area associated with Type-2 executive processing. We used anodal, cathodal, and sham transcranial direct current stimulation (tDCS) applied over r-DLPFC with the reference electrode on the contralateral mastoid (1.5 mA for 15 min, except for sham) to modulate the quality of the pianists' performances while they improvised over chords with drum and bass accompaniment. Jazz experts rated each improvisation for creativity, esthetic appeal, and technical proficiency. There was no main effect of anodal or cathodal stimulation on ratings compared to sham; however, a significant interaction between anodal tDCS and expertise emerged such that stimulation benefitted musicians with less experience but hindered those with more experience. We interpret these results as evidence for a dual-process model of creativity in which novices and experts differentially engage Type-1 and Type-2 processes during creative production.
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Directory of Open Access Journals (Sweden)
David S Rosen
2016-11-01
Full Text Available Research on creative cognition reveals a fundamental disagreement about the nature of creative thought, specifically, whether it is primarily based on automatic, associative (Type-1 or executive, controlled (Type-2 processes. We hypothesized that Type-1 and Type-2 processes make differential contributions to creative production that depend on domain expertise. We tested this hypothesis with jazz pianists whose expertise was indexed by the number of public performances given. Previous fMRI studies of musical improvisation have reported that domain expertise is characterized by deactivation of the right-dorsolateral prefrontal cortex (r-DLPFC, a brain area associated with Type-2 executive processing. We used anodal, cathodal, and sham transcranial direct-current stimulation (tDCS applied over r-DLPFC with the reference electrode on the contralateral mastoid (1.5mA for 15 min., except for sham to modulate the quality of the pianists’ performances while they improvised over chords with drum and bass accompaniment. Jazz experts rated each improvisation for creativity, aesthetic appeal, and technical proficiency. There was no main effect of anodal or cathodal stimulation on ratings compared to sham; however, a significant interaction between anodal tDCS and expertise emerged such that stimulation benefitted musicians with less experience but hindered those with more experience. We interpret these results as evidence for a dual-process model of creativity in which novices and experts differentially engage Type-1 and Type-2 processes during creative production.
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Silton, Rebecca Levin; Heller, Wendy; Towers, David N; Engels, Anna S; Spielberg, Jeffrey M; Edgar, J Christopher; Sass, Sarah M; Stewart, Jennifer L; Sutton, Bradley P; Banich, Marie T; Miller, Gregory A
2010-04-15
A network of brain regions has been implicated in top-down attentional control, including left dorsolateral prefrontal cortex (LDLPFC) and dorsal anterior cingulate cortex (dACC). The present experiment evaluated predictions of the cascade-of-control model (Banich, 2009), which predicts that during attentionally-demanding tasks, LDLPFC imposes a top-down attentional set which precedes late-stage selection performed by dACC. Furthermore, the cascade-of-control model argues that dACC must increase its activity to compensate when top-down control by LDLPFC is poor. The present study tested these hypotheses using fMRI and dense-array ERP data collected from the same 80 participants in separate sessions. fMRI results guided ERP source modeling to characterize the time course of activity in LDLPFC and dACC. As predicted, dACC activity subsequent to LDLPFC activity distinguished congruent and incongruent conditions on the Stroop task. Furthermore, when LDLPFC activity was low, the level of dACC activity was related to performance outcome. These results demonstrate that dACC responds to attentional demand in a flexible manner that is dependent on the level of LDLPFC activity earlier in a trial. Overall, results were consistent with the temporal course of regional brain function proposed by the cascade-of-control model. Copyright 2009 Elsevier Inc. All rights reserved.
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Kalla, Roger; Muggleton, Neil G; Cowey, Alan; Walsh, Vincent
2009-10-01
Functional neuroimaging studies have shown that the detection of a target defined by more than one feature (for example, a conjunction of colour and orientation) amongst distractors is associated with the activation of a network of brain areas. Dorsolateral prefrontal cortex (DLPFC), along with areas such as the frontal eye fields (FEF) and posterior parietal cortex (PPC), is a component of this network. While transcranial magnetic stimulation (TMS) had shown that both FEF and PPC are necessary for, and not just correlated with, successful conjunction search, this is not the case for DLPFC. To test the hypothesis that this area is also necessary for efficient conjunction search, TMS was applied over DLPFC and the effects on conjunction and feature (in this case colour) search performance compared with those when TMS was delivered over area MT/V5 and a vertex control stimulation condition. DLPFC TMS impaired performance on the conjunction search task but was without effect on feature search, similar to findings when TMS is delivered over PPC or FEF. Vertex TMS had no effects whereas MT/V5 TMS significantly improved performance with a time course that may indicate that this was due to modulation of V4 activity. These findings illustrate that, like FEF and PPC, DLPFC is necessary for fully effective conjunction visual search performance.
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Moore, Tara L; Schettler, Stephen P; Killiany, Ronald J; Rosene, Douglas L; Moss, Mark B
2009-04-01
Executive function is a term used to describe the cognitive processes subserved by the prefrontal cortex (PFC). An extensive body of work has characterized the effects of damage to the PFC in nonhuman primates, but it has focused primarily on the capacity of recognition and working memory. One limitation in studies of the functional parcellation of the PFC has been the absence of tests that assess executive function or its functional components. The current study used an adaptation of the Wisconsin Card Sorting Test, a classic test of frontal lobe and executive function in humans, to assess the effects of bilateral lesions in the dorsolateral PFC on executive function in the rhesus monkey (Macaca mulatta). The authors used the category set-shifting task, which requires the monkey to establish a pattern of responding to a specific category (color or shape) based on reward contingency, maintain that pattern of responding, and then shift to responding to a different category when the reward contingency changes. Rhesus monkeys with lesions of the dorsolateral PFC were impaired in abstraction, establishing a response pattern to a specific category and maintaining and shifting that response pattern on the category set-shifting task. (c) 2009 APA, all rights reserved.
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Stimulation in the dorsolateral prefrontal cortex changes subjective evaluation of percepts.
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Tzu-Ching Chiang
Full Text Available Nelson and Narens have proposed a metacognition model that dissociates the objective processing of information (object-level and the subjective evaluation of the performance (i.e., the metalevel. Neurophysiological evidence also indicates that the prefrontal cortices (PFC are the brain areas which perform the metalevel function [1]-[3]. A corresponding neural mechanism of Nelson and Narens's model, called dynamic filtering theory [4], [5], indicates that object-level processing is distributed in the posterior cortices and regulated by the prefrontal cortices with a filtering or gating mechanism to select appropriate signals and suppress inappropriate signals and noise. Based on this model, a hypothesis can be developed that, in the case of uncertainty or overloading of object-level processing, the prefrontal cortices will become more active in order to modulate signals and noise. This hypothesis is supported by a recent fMRI study [6] showing that the PFC (Brodmann area 9, BA9 was activated when subjects were overloaded in a bimodal attentional task, compared to a unimodal task. Here, we report a study showing that applying repetitive transmagnetic stimulation (rTMS over the BA9 in order to interfere with its functional activity resulted in significant increas in guessed responses, compared to three other control conditions (i.e., no-TMS, sham TMS on BA9, and rTMS on Cz. The results are compatible with the dynamic filtering theory and suggest that a malfunction of the PFC would weaken the quality of meta-cognitive percepts and increase the number of guessed responses.
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NEURAL CORRELATES FOR APATHY: FRONTAL - PREFRONTAL AND PARIETAL CORTICAL - SUBCORTICAL CIRCUITS
Directory of Open Access Journals (Sweden)
Rita Moretti
2016-12-01
Full Text Available Apathy is an uncertain nosographical entity, which includes reduced motivation, abulia, decreased empathy, and lack of emotional invovlement; it is an important and heavy-burden clinical condition which strongly impacts in every day life events, affects the common daily living abilities, reduced the inner goal directed behavior, and gives the heaviest burden on caregivers. Is a quite common comorbidity of many neurological disease, However, there is no definite consensus on the role of apathy in clinical practice, no definite data on anatomical circuits involved in its development, and no definite instrument to detect it at bedside. As a general observation, the occurrence of apathy is connected to damage of prefrontal cortex (PFC and basal ganglia; emotional affective apathy may be related to the orbitomedial PFC and ventral striatum; cognitive apathy may be associated with dysfunction of lateral PFC and dorsal caudate nuclei; deficit of autoactivation may be due to bilateral lesions of the internal portion of globus pallidus, bilateral paramedian thalamic lesions, or the dorsomedial portion of PFC. On the other hand, apathy severity has been connected to neurofibrillary tangles density in the anterior cingulate gyrus and to grey matter atrophy in the anterior cingulate (ACC and in the left medial frontal cortex, confirmed by functional imaging studies. These neural networks are linked to projects, judjing and planning, execution and selection common actions, and through the basolateral amygdala and nucleus accumbens projects to the frontostriatal and to the dorsolateral prefrontal cortex. Therefore, an alteration of these circuitry caused a lack of insight, a reduction of decision-making strategies and a reduced speedness in action decsion, major resposnible for apathy. Emergent role concerns also the parietal cortex, with its direct action motivation control.We will discuss the importance of these circuits in different pathologies
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Dalton, Victoria S; Long, Leonora E; Weickert, Cyndi Shannon; Zavitsanou, Katerina
2011-07-01
A number of studies suggest a dysregulation of the endogenous cannabinoid system in schizophrenia (SCZ). In the present study, we examined cannabinoid CB(1) receptor (CB(1)R) binding and mRNA expression in the dorsolateral prefrontal cortex (DLPFC) (Brodmann's area 46) of SCZ patients and controls, post-mortem. Receptor density was investigated using autoradiography with the CB(1)R ligand [(3)H] CP 55,940 and CB(1)R mRNA expression was measured using quantitative RT-PCR in a cohort of 16 patients with paranoid SCZ, 21 patients with non-paranoid SCZ and 37 controls matched for age, post-mortem interval and pH. All cases were obtained from the University of Sydney Tissue Resource Centre. Results were analyzed using one-way analysis of variance (ANOVA) and post hoc Bonferroni tests and with analysis of covariance (ANCOVA) to control for demographic factors that would potentially influence CB(1)R expression. There was a main effect of diagnosis on [(3)H] CP 55,940 binding quantified across all layers of the DLPFC (F(2,71) = 3.740, p = 0.029). Post hoc tests indicated that this main effect was due to patients with paranoid SCZ having 22% higher levels of CB(1)R binding compared with the control group. When ANCOVA was employed, this effect was strengthened (F(2,67) = 6.048, p = 0.004) with paranoid SCZ patients differing significantly from the control (p = 0.004) and from the non-paranoid group (p = 0.016). In contrast, no significant differences were observed in mRNA expression between the different disease subtypes and the control group. Our findings confirm the existence of a CB(1)R dysregulation in SCZ and underline the need for further investigation of the role of this receptor particularly in those diagnosed with paranoid SCZ.
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Atomoxetine Enhances Connectivity of Prefrontal Networks in Parkinson's Disease.
Borchert, Robin J; Rittman, Timothy; Passamonti, Luca; Ye, Zheng; Sami, Saber; Jones, Simon P; Nombela, Cristina; Vázquez Rodríguez, Patricia; Vatansever, Deniz; Rae, Charlotte L; Hughes, Laura E; Robbins, Trevor W; Rowe, James B
2016-07-01
Cognitive impairment is common in Parkinson's disease (PD), but often not improved by dopaminergic treatment. New treatment strategies targeting other neurotransmitter deficits are therefore of growing interest. Imaging the brain at rest ('task-free') provides the opportunity to examine the impact of a candidate drug on many of the brain networks that underpin cognition, while minimizing task-related performance confounds. We test this approach using atomoxetine, a selective noradrenaline reuptake inhibitor that modulates the prefrontal cortical activity and can facilitate some executive functions and response inhibition. Thirty-three patients with idiopathic PD underwent task-free fMRI. Patients were scanned twice in a double-blind, placebo-controlled crossover design, following either placebo or 40-mg oral atomoxetine. Seventy-six controls were scanned once without medication to provide normative data. Seed-based correlation analyses were used to measure changes in functional connectivity, with the right inferior frontal gyrus (IFG) a critical region for executive function. Patients on placebo had reduced connectivity relative to controls from right IFG to dorsal anterior cingulate cortex and to left IFG and dorsolateral prefrontal cortex. Atomoxetine increased connectivity from the right IFG to the dorsal anterior cingulate. In addition, the atomoxetine-induced change in connectivity from right IFG to dorsolateral prefrontal cortex was proportional to the change in verbal fluency, a simple index of executive function. The results support the hypothesis that atomoxetine may restore prefrontal networks related to executive functions. We suggest that task-free imaging can support translational pharmacological studies of new drug therapies and provide evidence for engagement of the relevant neurocognitive systems.
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Directory of Open Access Journals (Sweden)
Weniger Dorothea
2009-12-01
Full Text Available Abstract Objective To study the neurocognitive profile and its relationship to prefrontal dysfunction in non-demented Parkinson's disease (PD with deficient haptic perception. Methods Twelve right-handed patients with PD and 12 healthy control subjects underwent thorough neuropsychological testing including Rey complex figure, Rey auditory verbal and figural learning test, figural and verbal fluency, and Stroop test. Test scores reflecting significant differences between patients and healthy subjects were correlated with the individual expression coefficients of one principal component, obtained in a principal component analysis of an oxygen-15-labeled water PET study exploring somatosensory discrimination that differentiated between the two groups and involved prefrontal cortices. Results We found significantly decreased total scores for the verbal learning trials and verbal delayed free recall in PD patients compared with normal volunteers. Further analysis of these parameters using Spearman's ranking correlation showed a significantly negative correlation of deficient verbal recall with expression coefficients of the principal component whose image showed a subcortical-cortical network, including right dorsolateral-prefrontal cortex, in PD patients. Conclusion PD patients with disrupted right dorsolateral prefrontal cortex function and associated diminished somatosensory discrimination are impaired also in verbal memory functions. A negative correlation between delayed verbal free recall and PET activation in a network including the prefrontal cortices suggests that verbal cues and accordingly declarative memory processes may be operative in PD during activities that demand sustained attention such as somatosensory discrimination. Verbal cues may be compensatory in nature and help to non-specifically enhance focused attention in the presence of a functionally disrupted prefrontal cortex.
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Meier, Sandra L; Charleston, Alison J; Tippett, Lynette J
2010-11-01
Amyotrophic lateral sclerosis, a progressive disease affecting motor neurons, may variably affect cognition and behaviour. We tested the hypothesis that functions associated with orbitomedial prefrontal cortex are affected by evaluating the behavioural and cognitive performance of 18 participants with amyotrophic lateral sclerosis without dementia and 18 healthy, matched controls. We measured Theory of Mind (Faux Pas Task), emotional prosody recognition (Aprosodia Battery), reversal of behaviour in response to changes in reward (Probabilistic Reversal Learning Task), decision making without risk (Holiday Apartment Task) and aberrant behaviour (Neuropsychiatric Inventory). We also assessed dorsolateral prefrontal function, using verbal and written fluency and planning (One-touch Stockings of Cambridge), to determine whether impairments in tasks sensitive to these two prefrontal regions co-occur. The patient group was significantly impaired at identifying social faux pas, recognizing emotions and decision-making, indicating mild, but consistent impairment on most measures sensitive to orbitomedial prefrontal cortex. Significant levels of aberrant behaviour were present in 50% of patients. Patients were also impaired on verbal fluency and planning. Individual subject analyses involved computing classical dissociations between tasks sensitive to different prefrontal regions. These revealed heterogeneous patterns of impaired and spared cognitive abilities: 33% of participants had classical dissociations involving orbitomedial prefrontal tasks, 17% had classical dissociations involving dorsolateral prefrontal tasks, 22% had classical dissociations between tasks of both regions, and 28% had no classical dissociations. These data indicate subtle changes in behaviour, emotional processing, decision-making and altered social awareness, associated with orbitomedial prefrontal cortex, may be present in a significant proportion of individuals with amyotrophic lateral sclerosis
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Prefrontal system dysfunction and credit card debt.
Spinella, Marcello; Yang, Bijou; Lester, David
2004-10-01
Credit card use often involves a disadvantageous allocation of finances because they allow for spending beyond means and buying on impulse. Accordingly they are associated with increased bankruptcy, anxiety, stress, and health problems. Mounting evidence from functional neuroimaging and clinical studies implicates prefrontal-subcortical systems in processing financial information. This study examined the relationship of credit card debt and executive functions using the Frontal System Behavior Scale (FRSBE). After removing the influences of demographic variables (age, sex, education, and income), credit card debt was associated with the Executive Dysfunction scale, but not the Apathy or Disinhibition scales. This suggests that processes of conceptualizing and organizing finances are most relevant to credit card debt, and implicates dorsolateral prefrontal dysfunction.
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Wang, Jing; Wen, Jian-Bing; Li, Xiao-Li
2018-01-01
Short-term memory refers to the capacity for holding information in mind for a short period of time with conscious memorization. It is an important ability for daily life and is impaired in several neurological and psychiatric disorders. Anodal transcranial direct current stimulation (tDCS) applied to the dorsolateral prefrontal cortex (DLPFC) was reported to enhance the capability of short-term memory in healthy subjects. However, results were not consistent and what is the possible impact factor is not known. One important factor that may significantly influence the effect of tDCS is the timing of tDCS administration. In order to explore whether tDCS impact short-term memory and the optimal timing of tDCS administration, we applied anodal tDCS to the left DLPFC to explore the modulatory effect of online and off-line tDCS on digit span as well as visual short-term memory performance in healthy subjects. Results showed tDCS of the left DLPFC did not influence intentional digit span memory performance, whether before the task or during the task. In addition, tDCS of the DLPFC administered before the task showed no effect on visual short-term memory, while there was a trend of increase in false alarm when tDCS of the DLPFC administered during the task. These results did not provide evidence for the enhancement of short-term memory by tDCS of the left DLPFC in healthy subjects, but it suggested an importance of administration time for visual short-term memory. Further studies are required to taking into account the baseline performance of subjects and time-dependence feature of tDCS. © 2017 John Wiley & Sons Ltd.
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Directory of Open Access Journals (Sweden)
Carlos J. Gómez-Ariza
2017-05-01
Full Text Available Behavioral and neuroimaging data support the distinction of two different modes of cognitive control: proactive, which involves the active and sustained maintenance of task-relevant information to bias behavior in accordance with internal goals; and reactive, which entails the detection and resolution of interference at the time it occurs. Both control modes may be flexibly deployed depending on a variety of conditions (i.e., age, brain alterations, motivational factors, prior experience. Critically, and in line with specific predictions derived from the dual mechanisms of control account (Braver, 2012, findings from neuroimaging studies indicate that the same lateral prefrontal regions (i.e., left dorsolateral cortex and right inferior frontal junction may implement different control modes on the basis of temporal dynamics of activity, which would be modulated in response to external or internal conditions. In the present study, we aimed to explore whether transcraneal direct current stimulation over either the left dorsolateral prefrontal cortex or the right inferior frontal junction would differentially modulate performance on the AX-CPT, a well-validated task that provides sensitive and reliable behavioral indices of proactive/reactive control. The study comprised six conditions of real stimulation [3 (site: left dorsolateral, right dorsolateral and right inferior frontal junction × 2 (polarity: anodal and cathodal], and one sham condition. The reference electrode was always placed extracephalically. Performance on the AX-CPT was assessed through two blocks of trials. The first block took place while stimulation was being delivered, whereas the second block was administered after stimulation completion. The results indicate that both offline cathodal stimulation of the right dorsolateral prefrontal cortex and online anodal stimulation of the right inferior frontal junction led participants to be much less proactive, with such a dissociation
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Zhe Charles Zhou; Chunxiu Yu; Kristin K. Sellers; Flavio Fröhlich
2016-01-01
Visual discrimination requires sensory processing followed by a perceptual decision. Despite a growing understanding of visual areas in this behavior, it is unclear what role top-down signals from prefrontal cortex play, in particular as a function of perceptual difficulty. To address this gap, we investigated how neurons in dorso-lateral frontal cortex (dl-FC) of freely-moving ferrets encode task variables in a two-alternative forced choice visual discrimination task with high- and low-contr...
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Zhu, Frank F; Yeung, Andrew Y; Poolton, Jamie M; Lee, Tatia M C; Leung, Gilberto K K; Masters, Rich S W
2015-01-01
Implicit motor learning is characterized by low dependence on working memory and stable performance despite stress, fatigue, or multi-tasking. However, current paradigms for implicit motor learning are based on behavioral interventions that are often task-specific and limited when applied in practice. To investigate whether cathodal transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) area during motor learning suppressed working memory activity and reduced explicit verbal-analytical involvement in movement control, thereby promoting implicit motor learning. Twenty-seven healthy individuals practiced a golf putting task during a Training Phase while receiving either real cathodal tDCS stimulation over the left DLPFC area or sham stimulation. Their performance was assessed during a Test phase on another day. Verbal working memory capacity was assessed before and after the Training Phase, and before the Test Phase. Compared to sham stimulation, real stimulation suppressed verbal working memory activity after the Training Phase, but enhanced golf putting performance during the Training Phase and the Test Phase, especially when participants were required to multi-task. Cathodal tDCS over the left DLPFC may foster implicit motor learning and performance in complex real-life motor tasks that occur during sports, surgery or motor rehabilitation. Copyright © 2015 Elsevier Inc. All rights reserved.
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Prefrontal Structure Varies as a Function of Pain Symptoms in Chronic Fatigue Syndrome.
van der Schaaf, Marieke E; De Lange, Floris P; Schmits, Iris C; Geurts, Dirk E M; Roelofs, Karin; van der Meer, Jos W M; Toni, Ivan; Knoop, Hans
2017-02-15
Chronic fatigue syndrome (CFS) is characterized by severe fatigue persisting for ≥6 months and leading to considerable impairment in daily functioning. Neuroimaging studies of patients with CFS have revealed alterations in prefrontal brain morphology. However, it remains to be determined whether these alterations are specific for fatigue or whether they relate to other common CFS symptoms (e.g., chronic pain, lower psychomotor speed, and reduced physical activity). We used magnetic resonance imaging to quantify gray matter volume (GMV) and the N-acetylaspartate and N-acetylaspartylglutamate/creatine ratio (NAA/Cr) in a group of 89 women with CFS. Building on previous reports, we tested whether GMV and NAA/Cr in the dorsolateral prefrontal cortex are associated with fatigue severity, pain, psychomotor speed, and physical activity, while controlling for depressive symptoms. We also considered GMV and NAA/Cr differences between patients with CFS and 26 sex-, age-, and education-matched healthy controls. The presence of pain symptoms was the main predictor of both GMV and NAA/Cr in the left dorsolateral prefrontal cortex of patients with CFS. More pain was associated with reduced GMVs and NAA/Cr, over and above the effects of fatigue, depressive symptoms, physical activity, and psychomotor speed. In contrast to previous reports and despite a large representative sample, global GMV did not differ between the CFS and healthy control groups. CFS, as diagnosed by Centers for Disease Control and Prevention criteria, is not a clinical entity reliably associated with reduced GMV. Individual variation in the presence of pain, rather than fatigue, is associated with neuronal alterations in the dorsolateral prefrontal cortex of patients with CFS. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Diego Alejandro Calle Sandoval
2017-07-01
Full Text Available La presente investigación se realizó bajo una metodología cuantitativa comparativa y de corte transversal, la cual tuvo como objetivo la realización de un estudio del rendimiento de las funciones ejecutivas en la corteza prefrontal dorsolateral, orbitofrontal y frontomedial en adolescentes, entre los 14 y 18 años de edad, policonsumidores de sustancias psicoactivas (SPA y vinculados al sistema de responsabilidad penal, en paralelo con adolescentes pertenecientes a una institución educativa que no se encuentran bajo esta misma condición; todos ellos del departamento del Quindío. A la población estudio se le aplicó una prueba neuropsicológica de funciones ejecutivas y lóbulos frontales (BANFE 2, cuyos resultados dan cuenta de que el grado de escolaridad –sea alto o inferior– no es un factor influyente en el rendimiento ejecutivo; además, evidencian diferencias significativas en el rendimiento de las funciones ejecutivas en la población bajo responsabilidad penal con antecedentes de policonsumo, encontrándose alteración en la corteza prefrontal dorsolateral, orbitofrontal y frontomedial, a diferencia de la población estudiantil que no cumple con esta condición.
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Sandrini, Marco; Rossini, Paolo Maria; Miniussi, Carlo
2008-01-01
The functional organization of working memory (WM) in the human prefrontal cortex remains unclear. The present study used repetitive transcranial magnetic stimulation (rTMS) to clarify the role of the dorsolateral prefrontal cortex (dlPFC) both in the types of information (verbal vs. spatial), and the types of processes (maintenance vs.…
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Gay, Aurelia; Jaussent, Isabelle; Sigaud, Torrance; Billard, Stephane; Attal, Jerome; Seneque, Maude; Galusca, Bogdan; Van Den Eynde, Frederique; Massoubre, Catherine; Courtet, Philippe; Guillaume, Sebastien
2016-11-01
Studies suggest that stimulation of the left dorsolateral prefrontal cortex (DLPFC) reduces food craving in bulimic patients, but evidence supporting repetitive transcranial magnetic stimulation (rTMS) as a therapeutic tool is lacking. We investigated the safety and therapeutic efficacy of an adjunct high-frequency rTMS programme targeting the left DLPFC. Forty-seven women with bulimia nervosa were randomised to a real or sham stimulation group. The real group underwent 10 rTMS sessions, each consisting of 20 trains of 5 seconds with 55-second intervals between trains, at a frequency of 10 Hz. The main outcome was the number of binge episodes in the 15 days following the end of stimulation. Overall, no significant improvement in bingeing and purging symptoms was noted after the programme. rTMS was well tolerated. This suggests that 10 sessions of high-frequency rTMS to the left DLPFC provide no greater benefit than placebo. Future studies should consider methodological issues as well as alternative targets. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.
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Ge, Xin; Sun, Yawen; Han, Xu; Wang, Yao; Ding, Weina; Cao, Mengqiu; Du, Yasong; Xu, Jianrong; Zhou, Yan
2017-07-27
It has been reported that internet gaming disorder (IGD) and smokers with nicotine dependence (SND) share clinical characteristics, such as over-engagement despite negative consequences and cravings. This study is to investigate the alterations in the resting-state functional connectivity (rsFC) of the dorsolateral prefrontal cortex (DLPFC) observed in SND and IGD. In this study, 27 IGD, 29 SND, and 33 healthy controls (HC) underwent a resting-state functional magnetic resonance imaging (rs-fMRI) scan. DLPFC connectivity was determined in all participates by investigating the synchronized low-frequency fMRI signal fluctuations using a temporal seed-based correlation method. Compared with the HC group, the IGD and SND groups showed decreased rsFC with DLPFC in the right insula and left inferior frontal gyrus with DLPFC. Compared with SND group, the IGD subjects exhibited increased rsFC in the left inferior temporal gyrus and right inferior orbital frontal gyrus and decreased rsFC in the right middle occipital gyrus, supramarginal gyrus, and cuneus with DLPFC. Our results confirmed that SND and IGD share similar neural mechanisms related to craving and impulsive inhibitions. The significant difference in rsFC with DLPFC between the IGD and SND subjects may be attributed to the visual and auditory stimulation generated by long-term internet gaming.
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Egorova, Natalia; Yu, Rongjun; Kaur, Navneet; Vangel, Mark; Gollub, Randy L; Dougherty, Darin D; Kong, Jian; Camprodon, Joan A
2015-07-01
Placebo and nocebo play an important role in clinical practice and medical research. Modulating placebo/nocebo responses using noninvasive brain stimulation methods, such as transcranial direct current stimulation (tDCS), has the potential to harness these effects to therapeutic benefit in a clinical setting. In this study, we assessed the effect of anodal and cathodal tDCS over the right dorsolateral prefrontal cortex (rDLPFC) on conditioned placebo/nocebo cue response to heat pain. Two matched groups of healthy volunteers were subjected to an identical session of conditioning, during which low and high cues (abstract images) were associated with low and high pain levels, respectively. Twenty-minute 2-mA tDCS (either anodal or cathodal) over the rDLPFC was applied. The influence of tDCS current polarity (anodal vs cathodal) on placebo and nocebo was assessed, using subjects' pain ratings in response to identical pain preceded by the conditioned high or low cues. The duration of cue presentation varied to allow either fully conscious or subliminal processing. Significant placebo and nocebo effects in the anodal but not the cathodal group were elicited with the conditioning paradigm. This study provides evidence of a possibility to modulate the conditioned placebo and nocebo effect by changing the excitability of the rDLPFC using tDCS.
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Garrett, Amy S.; Reiss, Allan L.; Howe, Meghan E.; Kelley, Ryan G.; Singh, Manpreet K.; Adleman, Nancy E.; Karchemskiy, Asya; Chang, Kiki D.
2012-01-01
Objective: Previous functional magnetic resonance imaging (fMRI) studies in pediatric bipolar disorder (BD) have reported greater amygdala and less dorsolateral prefrontal cortex (DLPFC) activation to facial expressions compared to healthy controls. The current study investigates whether these differences are associated with the early or late…
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Directory of Open Access Journals (Sweden)
Ayaka Ishii-Takahashi
2014-01-01
Full Text Available The differential diagnosis of autism spectrum disorders (ASDs and attention deficit hyperactivity disorder (ADHD based solely on symptomatic and behavioral assessments can be difficult, even for experts. Thus, the development of a neuroimaging marker that differentiates ASDs from ADHD would be an important contribution to this field. We assessed the differences in prefrontal activation between adults with ASDs and ADHD using an entirely non-invasive and portable neuroimaging tool, near-infrared spectroscopy. This study included 21 drug-naïve adults with ASDs, 19 drug-naïve adults with ADHD, and 21 healthy subjects matched for age, sex, and IQ. Oxygenated hemoglobin concentration changes in the prefrontal cortex were assessed during a stop signal task and a verbal fluency task. During the stop signal task, compared to the control group, the ASDs group exhibited lower activation in a broad prefrontal area, whereas the ADHD group showed underactivation of the right premotor area, right presupplementary motor area, and bilateral dorsolateral prefrontal cortices. Significant differences were observed in the left ventrolateral prefrontal cortex between the ASDs and ADHD groups during the stop signal task. The leave-one-out cross-validation method using mean oxygenated hemoglobin changes yielded a classification accuracy of 81.4% during inhibitory control. These results were task specific, as the brain activation pattern observed during the verbal fluency task did not differentiate the ASDs and ADHD groups significantly. This study therefore provides evidence of a difference in left ventrolateral prefrontal activation during inhibitory control between adults with ASDs and ADHD. Thus, near-infrared spectroscopy may be useful as an auxiliary tool for the differential diagnosis of such developmental disorders.
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Dirksen, Courtney L; Howard, Julie A; Cronin-Golomb, Alice; Oscar-Berman, Marlene
2006-01-01
This study compared patterns of frontal-lobe dysfunction in alcoholics with Korsakoff’s syndrome (KS: n = 9), non-Korsakoff alcoholics (AL: n = 28), patients with Parkinson’s disease (PD: n = 18), and patients with rupture and repair of the anterior communicating artery (ACoA: n = 4) relative to healthy non-neurological control (NC) participants (n = 70). The tests administered were sensitive to functions of dorsolateral prefrontal and orbito-frontal subsystems. Measures included perseverative errors on the Wisconsin Card Sorting Test (WCST-pe), errors on object alternation (OA), errors on Trails B, number of words generated on the Controlled Oral Word Association Test (COWAT), and number of categories completed on the WCST (WCST-cc). KS patients were as impaired as AL participants on orbitofrontal measures and, on dorsolateral prefrontal measures, were impaired relative to AL participants, whose performance did not differ from controls. Patients with PD also were impaired on tests of orbitofrontal and dorsolateral prefrontal functioning but to a lesser extent than the KS patients. Moreover, most of the PD deficits were driven by the impaired performance of patients whose initial symptoms were on the right side of the body. The ACoA patients were significantly impaired on tests of orbitofrontal but not dorsolateral prefrontal functioning relative to the control group. Together, the results confirm different patterns of frontal-system impairments in patient groups having compromised frontal lobe functioning consequent to varying etiologies. PMID:19412479
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Brain fMRI study of crave induced by cue pictures in online game addicts (male adolescents).
Sun, Yueji; Ying, Huang; Seetohul, Ravi M; Xuemei, Wang; Ya, Zheng; Qian, Li; Guoqing, Xu; Ye, Sun
2012-08-01
To study crave-related cerebral regions induced by game figure cues in online game addicts. fMRI brain imaging was done when the subjects were shown picture cues of the WoW (World of Warcraft, Version: 4.1.014250) game. 10 male addicts of WoW were selected as addicts' group, and 10 other healthy male non-addicts who were matched by age, were used as non-game addicts' group. All volunteers participated in fMRI paradigms. WoW associated cue pictures and neutral pictures were shown. We examined functional cerebral regions activated by the pictures with 3.0 T Philips MRI. The imaging signals' database was analyzed by SPM5. The correlation between game craving scores and different image results were assessed. When the game addicts watch the pictures, some brain areas show increased signal activity namely: dorsolateral prefrontal cortex, bilateral temporal cortex, cerebellum, right inferior parietal lobule, right cuneus, right hippocampus, parahippocampal gyrus, left caudate nucleus. But in these same brain regions we did not observe remarkable activities in the control group. Differential image signal densities of the addict group were subtracted from the health control group, results of which were expressed in the bilateral dorsolateral prefrontal cortex, anterior cingulate cortex, inferior parietal lobe and inferior temporal gyrus, cerebellum, right insular and the right angular gyrus. The increased imaging signal densities were significant and positively correlated with the craving scale scores in the bilateral prefrontal cortex, anterior cingulate cortex and right inferior parietal lobe. Craving of online game addicts was successfully induced by game cue pictures. Crave related brain areas are: dorsolateral prefrontal cortex, anterior cingulate cortex, and right inferior parietal lobe. The brain regions are overlapped with cognitive and emotion related processing brain areas. Copyright © 2012 Elsevier B.V. All rights reserved.
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Kegeles, Lawrence S; Mao, Xiangling; Stanford, Arielle D; Girgis, Ragy; Ojeil, Najate; Xu, Xiaoyan; Gil, Roberto; Slifstein, Mark; Abi-Dargham, Anissa; Lisanby, Sarah H; Shungu, Dikoma C
2012-05-01
Postmortem studies have found evidence of γ-aminobutyric acid (GABA) deficits in fast-spiking, parvalbumin-positive interneurons in the prefrontal cortex in schizophrenia. Magnetic resonance spectroscopy studies in unmedicated patients have reported glutamine or glutamate-glutamine (Glx) elevations in this region. Abnormalities in these transmitters are thought to play a role in cognitive impairments in the illness. To measure GABA and Glx levels in vivo in 2 prefrontal brain regions in unmedicated and medicated patients with schizophrenia and healthy controls. Case-control study. Inpatient psychiatric research unit and associated outpatient clinic. Sixteen unmedicated patients with schizophrenia, 16 medicated patients, and 22 healthy controls matched for age, sex, ethnicity, parental socioeconomic status, and cigarette smoking. Proton magnetic resonance spectroscopy with a 3-T system and the J-edited spin-echo difference method. The GABA and Glx levels were measured in the dorsolateral and medial prefrontal cortex and normalized to the simultaneously acquired water signal. Working memory performance was assessed in all subjects. The GABA and Glx concentrations determined by proton magnetic resonance spectroscopy. In the medial prefrontal cortex region, 30% elevations were found in GABA (P = .02) and Glx (P = .03) levels in unmedicated patients compared with controls. There were no alterations in the medicated patients or in either group in the dorsolateral prefrontal cortex. Both regions showed correlations between GABA and Glx levels in patients and controls. No correlations with working memory performance were found. To our knowledge, this study presents the first GABA concentration measurements in unmedicated patients with schizophrenia, who showed elevations in both GABA and Glx levels in the medial prefrontal cortex but not the dorsolateral prefrontal cortex. Medicated patients did not show these elevations, suggesting possible normalization of levels with
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Christophel, Thomas B; Allefeld, Carsten; Endisch, Christian; Haynes, John-Dylan
2017-05-13
Traditional views of visual working memory postulate that memorized contents are stored in dorsolateral prefrontal cortex using an adaptive and flexible code. In contrast, recent studies proposed that contents are maintained by posterior brain areas using codes akin to perceptual representations. An important question is whether this reflects a difference in the level of abstraction between posterior and prefrontal representations. Here, we investigated whether neural representations of visual working memory contents are view-independent, as indicated by rotation-invariance. Using functional magnetic resonance imaging and multivariate pattern analyses, we show that when subjects memorize complex shapes, both posterior and frontal brain regions maintain the memorized contents using a rotation-invariant code. Importantly, we found the representations in frontal cortex to be localized to the frontal eye fields rather than dorsolateral prefrontal cortices. Thus, our results give evidence for the view-independent storage of complex shapes in distributed representations across posterior and frontal brain regions. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
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Colombo, Barbara; Balzarotti, Stefania; Mazzucchelli, Nicla
2016-04-01
Prior research has shown that right dorsolateral prefrontal cortex may be crucial in cognitive control of affective impulses during decision making. The present study examines whether modulation of r-DLPFC with transcranial direct current stimulation influences attentional behavior and decision-making in a purchase task requiring participants to choose either emotional/attractive or functional/useful objects. 30 participants were shown sixteen pairs of emotionally or functionally designed products while their eye-movements were recorded. Participants were asked to judge aesthetics and usefulness of each object, and to decide which object of each pair they would buy. Results revealed that participants decided to buy the functionally designed objects more often regardless of condition; however, participants receiving anodal stimulation were faster in decision making. Although stimulation of r-DLPFC did not affect the actual purchasing choice and had little effect on visual exploration during decision making, it influenced perceived usefulness and attractiveness, with temporary inhibition of r-DLPFC leading to evaluate functional objects as less attractive. Finally, anodal stimulation led to judge the objects as more useful. The implications of these results are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.
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Diego Alejandro Calle Sandoval; María Alexandra Cuéllar Arias; Paula Andrea Chede García; María Alejandra Quintero Bejarano; Diana Lucía Villamizar Herrera
2017-01-01
La presente investigación se realizó bajo una metodología cuantitativa comparativa y de corte transversal, la cual tuvo como objetivo la realización de un estudio del rendimiento de las funciones ejecutivas en la corteza prefrontal dorsolateral, orbitofrontal y frontomedial en adolescentes, entre los 14 y 18 años de edad, policonsumidores de sustancias psicoactivas (SPA) y vinculados al sistema de responsabilidad penal, en paralelo con adolescentes pertenecientes a una institución educativa q...
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Directory of Open Access Journals (Sweden)
Yifan Wang
2017-12-01
Full Text Available Internet gaming disorder (IGD, defined as the persistent use of online games with ignorance of adverse consequences, has increasingly raised widespread public concerns. This study aimed at elucidating the precise mechanisms underlying IGD by comparing intertemporal decision-making process between 18 IGD participants and 21 matched healthy controls (HCs. Both behavioral and fMRI data were recorded from a delay discounting task. At the behavioral level, the IGD showed a higher discount rate k than HC; and in IGD group, both the reaction time (delay − immediate and the discount rate k were significantly positively correlated with the severity of IGD. At the neural level, the IGD exhibited reduced brain activations in the dorsolateral prefrontal cortex and bilateral inferior frontal gyrus compared to HC during performing delay trials relative to immediate ones. Taken together, the results suggested that IGD showed deficits in making decisions and tended to pursuit immediate satisfaction. The underlying mechanism arises from the deficient ability in evaluating between delayed reward and immediate satisfaction, and the impaired ability in impulse inhibition, which may be associated with the dysfunction of the prefrontal activation. These might be the reason why IGD continue playing online games in spite of facing severe negative consequences.
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Wang, Yifan; Hu, Yanbo; Xu, Jiaojing; Zhou, Hongli; Lin, Xiao; Du, Xiaoxia; Dong, Guangheng
2017-01-01
Internet gaming disorder (IGD), defined as the persistent use of online games with ignorance of adverse consequences, has increasingly raised widespread public concerns. This study aimed at elucidating the precise mechanisms underlying IGD by comparing intertemporal decision-making process between 18 IGD participants and 21 matched healthy controls (HCs). Both behavioral and fMRI data were recorded from a delay discounting task. At the behavioral level, the IGD showed a higher discount rate k than HC; and in IGD group, both the reaction time (delay - immediate) and the discount rate k were significantly positively correlated with the severity of IGD. At the neural level, the IGD exhibited reduced brain activations in the dorsolateral prefrontal cortex and bilateral inferior frontal gyrus compared to HC during performing delay trials relative to immediate ones. Taken together, the results suggested that IGD showed deficits in making decisions and tended to pursuit immediate satisfaction. The underlying mechanism arises from the deficient ability in evaluating between delayed reward and immediate satisfaction, and the impaired ability in impulse inhibition, which may be associated with the dysfunction of the prefrontal activation. These might be the reason why IGD continue playing online games in spite of facing severe negative consequences.
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Prefrontal Hemodynamics of Physical Activity and Environmental Complexity During Cognitive Work.
McKendrick, Ryan; Mehta, Ranjana; Ayaz, Hasan; Scheldrup, Melissa; Parasuraman, Raja
2017-02-01
The aim of this study was to assess performance and cognitive states during cognitive work in the presence of physical work and in natural settings. Authors of previous studies have examined the interaction between cognitive and physical work, finding performance decrements in working memory. Neuroimaging has revealed increases and decreases in prefrontal oxygenated hemoglobin during the interaction of cognitive and physical work. The effect of environment on cognitive-physical dual tasking has not been previously considered. Thirteen participants were monitored with wireless functional near-infrared spectroscopy (fNIRS) as they performed an auditory 1-back task while sitting, walking indoors, and walking outdoors. Relative to sitting and walking indoors, auditory working memory performance declined when participants were walking outdoors. Sitting during the auditory 1-back task increased oxygenated hemoglobin and decreased deoxygenated hemoglobin in bilateral prefrontal cortex. Walking reduced the total hemoglobin available to bilateral prefrontal cortex. An increase in environmental complexity reduced oxygenated hemoglobin and increased deoxygenated hemoglobin in bilateral prefrontal cortex. Wireless fNIRS is capable of monitoring cognitive states in naturalistic environments. Selective attention and physical work compete with executive processing. During executive processing loading of selective attention and physical work results in deactivation of bilateral prefrontal cortex and degraded working memory performance, indicating that physical work and concomitant selective attention may supersede executive processing in the distribution of mental resources. This research informs decision-making procedures in work where working memory, physical activity, and attention interact. Where working memory is paramount, precautions should be taken to eliminate competition from physical work and selective attention.
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Glassman, Lisa H; Kuster, Anootnara T; Shaw, Jena A; Forman, Evan M; Izzetoglu, Meltem; Matteucci, Alyssa; Herbert, James D
2017-06-01
Functional near-infrared (fNIR) spectroscopy is a promising new technology that has demonstrated utility in the study of normal human cognition. We utilized fNIR spectroscopy to examine the effect of social anxiety and performance on hemodynamic activity in the dorsolateral prefrontal cortex (DLPFC). Socially phobic participants and non-clinical participants with varying levels of social anxiety completed a public speaking task in front of a small virtual audience while the DLPFC was being monitored by the fNIR device. The relationship between anxiety and both blood volume (BV) and deoxygenated hemoglobin (Hb) varied significantly as a function of speech performance, such that individuals with low social anxiety who performed well showed an increase in DLPFC activation relative to those who did not perform well. This result suggests that effortful thinking and/or efficient top-down inhibitory control may have been required to complete an impromptu speech task with good performance. In contrast, good performers who were highly socially anxious showed lower DLPFC activation relative to good performers who were low in social anxiety, suggesting autopilot thinking or less-effortful thinking. In poor performers, slight increases in DLPFC activation were observed from low to highly anxious individuals, which may reflect a shift from effortless thinking to heightened self-focused attention. Heightened self-focused attention, poor inhibitory control resulting in excessive fear or anxiety, or low motivation may lower performance. These results suggest that there can be different underlying mechanisms in the brain that affect the level of speech performance in individuals with varying degrees of social anxiety. This study highlights the utility of the fNIR device in the assessment of changes in DLPFC in response to exposure to realistic phobic stimuli, and further supports the potential utility of this technology in the study of the neurophysiology of anxiety disorders.
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Directory of Open Access Journals (Sweden)
Fenghua Tian
2014-01-01
Full Text Available Neuroimaging studies of post-traumatic stress disorder (PTSD-related memory impairments have consistently implicated abnormal activities in the frontal and parietal lobes. However, most studies have used block designs and could not dissociate the multiple phases of working memory. In this study, the involvement of the prefrontal cortex in working memory phases was assessed among veterans with PTSD and age-/gender-matched healthy controls. Multichannel functional near infrared spectroscopy (fNIRS was utilized to measure prefrontal cortex hemodynamic activations during memory of neutral (i.e., not trauma-related forward and backward digit span tasks. An event-related experimental design was utilized to dissociate the different phases (i.e., encoding, maintenance and retrieval of working memory. The healthy controls showed robust hemodynamic activations during the encoding and retrieval processes. In contrast, the veterans with PTSD were found to have activations during the encoding process, but followed by distinct deactivations during the retrieval process. The PTSD participants, but not the controls, appeared to suppress prefrontal activity during memory retrieval. This deactivation was more pronounced in the right dorsolateral prefrontal cortex during the retrieval phase. These deactivations in PTSD patients might implicate an active inhibition of dorsolateral prefrontal neural activity during retrieval of working memory.
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Tian, Fenghua; Yennu, Amarnath; Smith-Osborne, Alexa; Gonzalez-Lima, F; North, Carol S; Liu, Hanli
2014-01-01
Neuroimaging studies of post-traumatic stress disorder (PTSD)-related memory impairments have consistently implicated abnormal activities in the frontal and parietal lobes. However, most studies have used block designs and could not dissociate the multiple phases of working memory. In this study, the involvement of the prefrontal cortex in working memory phases was assessed among veterans with PTSD and age-/gender-matched healthy controls. Multichannel functional near infrared spectroscopy (fNIRS) was utilized to measure prefrontal cortex hemodynamic activations during memory of neutral (i.e., not trauma-related) forward and backward digit span tasks. An event-related experimental design was utilized to dissociate the different phases (i.e., encoding, maintenance and retrieval) of working memory. The healthy controls showed robust hemodynamic activations during the encoding and retrieval processes. In contrast, the veterans with PTSD were found to have activations during the encoding process, but followed by distinct deactivations during the retrieval process. The PTSD participants, but not the controls, appeared to suppress prefrontal activity during memory retrieval. This deactivation was more pronounced in the right dorsolateral prefrontal cortex during the retrieval phase. These deactivations in PTSD patients might implicate an active inhibition of dorsolateral prefrontal neural activity during retrieval of working memory.
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De Witte, Sara; Klooster, Debby; Dedoncker, Josefien; Duprat, Romain; Remue, Jonathan; Baeken, Chris
2018-01-01
Transcranial direct current stimulation (tDCS) involves positioning two electrodes at specifically targeted locations on the human scalp. In neuropsychiatric research, the anode is often placed over the left dorsolateral prefrontal cortex (DLPFC), while the cathode is positioned over a contralateral
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Fleck, M.S.; Daselaar, S.M.; Dobbins, I.G.; Cabeza, R.
2006-01-01
In the episodic retrieval (ER) domain, activations in right dorsolateral prefrontal cortex (DLPFC) are often attributed to postretrieval monitoring. Yet, right DLPFC activations are also frequently found during nonmemory tasks. To investigate the role of this region across different cognitive
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Hoftman, Gil D.; Lewis, David A.
2011-01-01
Schizophrenia is a disorder of cognitive neurodevelopment with characteristic abnormalities in working memory attributed, at least in part, to alterations in the circuitry of the dorsolateral prefrontal cortex. Various environmental exposures from conception through adolescence increase risk for the illness, possibly by altering the developmental trajectories of prefrontal cortical circuits. Macaque monkeys provide an excellent model system for studying the maturation of prefrontal cortical circuits. Here, we review the development of glutamatergic and γ-aminobutyric acid (GABA)-ergic circuits in macaque monkey prefrontal cortex and discuss how these trajectories may help to identify sensitive periods during which environmental exposures, such as those associated with increased risk for schizophrenia, might lead to the types of abnormalities in prefrontal cortical function present in schizophrenia. PMID:21505116
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Dickler, Maya; Lenglos, Christophe; Renauld, Emmanuelle; Ferland, Francine; Edden, Richard A; Leblond, Jean; Fecteau, Shirley
2018-03-15
Gambling disorder is characterized by persistent maladaptive gambling behaviors and is now considered among substance-related and addictive disorders. There is still unmet therapeutic need for these clinical populations, however recent advances indicate that interventions targeting the Glutamatergic/GABAergic system hold promise in reducing symptoms in substance-related and addictive disorders, including gambling disorder. There is some data indicating that transcranial direct current stimulation may hold clinical benefits in substance use disorders and modulate levels of brain metabolites including glutamate and GABA. The goal of the present work was to test whether this non-invasive neurostimulation method modulates key metabolites in gambling disorder. We conducted a sham-controlled, crossover, randomized study, blinded at two levels in order to characterize the effects of transcranial direct current stimulation over the dorsolateral prefrontal cortex on neural metabolites levels in sixteen patients with gambling disorder. Metabolite levels were measured with magnetic resonance spectroscopy from the right dorsolateral prefrontal cortex and the right striatum during active and sham stimulation. Active as compared to sham stimulation elevated prefrontal GABA levels. There were no significant changes between stimulation conditions in prefrontal glutamate + glutamine and N-acetyl Aspartate, or in striatal metabolite levels. Results also indicated positive correlations between metabolite levels during active, but not sham, stimulation and levels of risk taking, impulsivity and craving. Our findings suggest that transcranial direct current stimulation can modulate GABA levels in patients with gambling disorder which may represent an interesting future therapeutic avenue. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Differential patterns of prefrontal MEG activation during verbal & visual encoding and retrieval.
Prendergast, Garreth; Limbrick-Oldfield, Eve; Ingamells, Ed; Gathercole, Susan; Baddeley, Alan; Green, Gary G R
2013-01-01
The spatiotemporal profile of activation of the prefrontal cortex in verbal and non-verbal recognition memory was examined using magnetoencephalography (MEG). Sixteen neurologically healthy right-handed participants were scanned whilst carrying out a modified version of the Doors and People Test of recognition memory. A pattern of significant prefrontal activity was found for non-verbal and verbal encoding and recognition. During the encoding, verbal stimuli activated an area in the left ventromedial prefrontal cortex, and non-verbal stimuli activated an area in the right. A region in the left dorsolateral prefrontal cortex also showed significant activation during the encoding of non-verbal stimuli. Both verbal and non-verbal stimuli significantly activated an area in the right dorsomedial prefrontal cortex and the right anterior prefrontal cortex during successful recognition, however these areas showed temporally distinct activation dependent on material, with non-verbal showing activation earlier than verbal stimuli. Additionally, non-verbal material activated an area in the left anterior prefrontal cortex during recognition. These findings suggest a material-specific laterality in the ventromedial prefrontal cortex during encoding for verbal and non-verbal but also support the HERA model for verbal material. The discovery of two process dependent areas during recognition that showed patterns of temporal activation dependent on material demonstrates the need for the application of more temporally sensitive techniques to the involvement of the prefrontal cortex in recognition memory.
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Levels of integration in cognitive control and sequence processing in the prefrontal cortex.
Bahlmann, Jörg; Korb, Franziska M; Gratton, Caterina; Friederici, Angela D
2012-01-01
Cognitive control is necessary to flexibly act in changing environments. Sequence processing is needed in language comprehension to build the syntactic structure in sentences. Functional imaging studies suggest that sequence processing engages the left ventrolateral prefrontal cortex (PFC). In contrast, cognitive control processes additionally recruit bilateral rostral lateral PFC regions. The present study aimed to investigate these two types of processes in one experimental paradigm. Sequence processing was manipulated using two different sequencing rules varying in complexity. Cognitive control was varied with different cue-sets that determined the choice of a sequencing rule. Univariate analyses revealed distinct PFC regions for the two types of processing (i.e. sequence processing: left ventrolateral PFC and cognitive control processing: bilateral dorsolateral and rostral PFC). Moreover, in a common brain network (including left lateral PFC and intraparietal sulcus) no interaction between sequence and cognitive control processing was observed. In contrast, a multivariate pattern analysis revealed an interaction of sequence and cognitive control processing, such that voxels in left lateral PFC and parietal cortex showed different tuning functions for tasks involving different sequencing and cognitive control demands. These results suggest that the difference between the process of rule selection (i.e. cognitive control) and the process of rule-based sequencing (i.e. sequence processing) find their neuronal underpinnings in distinct activation patterns in lateral PFC. Moreover, the combination of rule selection and rule sequencing can shape the response of neurons in lateral PFC and parietal cortex.
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Directory of Open Access Journals (Sweden)
Bajs Janović M
2014-09-01
Full Text Available Maja Bajs Janović,1,3 Petra Kalember,2 Špiro Janović,1,3 Pero Hrabač,2 Petra Folnegović Grošić,1 Vladimir Grošić,4 Marko Radoš,5 Neven Henigsberg2,61University Department of Psychiatry, Clinical Hospital Center Zagreb, Zagreb, 2Polyclinic Neuron, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, 3University North, Varaždin, 4Psychiatric Hospital Sveti Ivan, Zagreb, 5University Department of Radiology, Clinical Hospital Center Zagreb, Zagreb, 6Psychiatric Clinic Vrapče, Zagreb, CroatiaBackground: The role of brain metabolites as biological correlates of the intensity, symptoms, and course of major depression has not been determined. It has also been inconclusive whether the change in brain metabolites, measured with proton magnetic spectroscopy, could be correlated with the treatment outcome. Methods: Proton magnetic spectroscopy was performed in 29 participants with a first episode of moderate depression occurring in the left dorsolateral prefrontal cortex and left amygdala at baseline and after 8 weeks of antidepressant treatment with escitalopram. The Montgomery-Asberg Depression Rating Scale, the Hamilton Rating Scale for Depression, and the Beck Depression Inventory were used to assess the intensity of depression at baseline and at the endpoint of the study. At endpoint, the participants were identified as responders (n=17 or nonresponders (n=12 to the antidepressant therapy. Results: There was no significant change in the N-acetyl aspartate/creatine ratio (NAA/Cr after treatment with antidepressant medication. The baseline and endpoint NAA/Cr ratios were not significantly different between the responder and nonresponder groups. The correlation between NAA/Cr and changes in the scores of clinical scales were not significant in either group. Conclusion: This study could not confirm any significant changes in NAA after antidepressant treatment in the first episode of moderate depression, or in
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Korponay, Cole; Pujara, Maia; Deming, Philip; Philippi, Carissa; Decety, Jean; Kosson, David S; Kiehl, Kent A; Koenigs, Michael
2017-07-01
Psychopathy is a personality disorder characterized by callous lack of empathy, impulsive antisocial behavior, and criminal recidivism. Studies of brain structure and function in psychopathy have frequently identified abnormalities in the prefrontal cortex. However, findings have not yet converged to yield a clear relationship between specific subregions of prefrontal cortex and particular psychopathic traits. We performed a multimodal neuroimaging study of prefrontal cortex volume and functional connectivity in psychopathy, using a sample of adult male prison inmates (N = 124). We conducted volumetric analyses in prefrontal subregions, and subsequently assessed resting-state functional connectivity in areas where volume was related to psychopathy severity. We found that overall psychopathy severity and Factor 2 scores (which index the impulsive/antisocial traits of psychopathy) were associated with larger prefrontal subregion volumes, particularly in the medial orbitofrontal cortex and dorsolateral prefrontal cortex. Furthermore, Factor 2 scores were also positively correlated with functional connectivity between several areas of the prefrontal cortex. The results were not attributable to age, race, IQ, substance use history, or brain volume. Collectively, these findings provide evidence for co-localized increases in prefrontal cortex volume and intra-prefrontal functional connectivity in relation to impulsive/antisocial psychopathic traits. © The Author (2017). Published by Oxford University Press.
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Jahanshahi, M; Profice, P; Brown, R G; Ridding, M C; Dirnberger, G; Rothwell, J C
1998-08-01
Random number generation is an attention-demanding task that engages working memory and executive processes. Random number generation requires holding information 'on line', suppression of habitual counting, internally driven response generation and monitoring of responses. Evidence from PET studies suggests that the dorsolateral prefrontal cortex (DLPFC) is involved in the generation of random responses. We examined the effects of short trains of transcranial magnetic stimulation (TMS) over the left or right DLPFC or medial frontal cortex on random number generation in healthy normal participants. As in previous evidence, in control trials without stimulation participants performed poorly on the random number generation task, showing repetition avoidance and a tendency to count. Brief disruption of processing with TMS over the left DLPFC changed the balance of the individuals' counting bias, increasing the most habitual counting in ones and reducing the lower probability response of counting in twos. This differential effect of TMS over the left DLPFC on the balance of the subject's counting bias was not obtained with TMS over the right DLPFC or the medial frontal cortex. The results suggest that, with disruption of the left DLPFC with TMS, habitual counting in ones that has previously been suppressed is released from inhibition. From these findings a network modulation model of random number generation is proposed, whereby suppression of habitual responses is achieved through the modulatory influence of the left DLPFC over a number-associative network in the superior temporal cortex. To allow emergence of appropriate random responses, the left DLPFC inhibits the superior temporal cortex to prevent spreading activation and habitual counting in ones.
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Directory of Open Access Journals (Sweden)
Colin Hawco
Full Text Available During episodic memory encoding, elaborative cognitive processing can improve later recall or recognition. While multiple studies examined the neural correlates of encoding strategies, few studies have explicitly focused on the self-initiation of elaborative encoding. Repetitive transcranial magnetic stimulation (rTMS, a method which can transiently disrupt neural activity, was administered during an associative encoding task. rTMS was either applied to the left dorsolateral prefrontal cortex (DLPFC or to the vertex (a control region not involved in memory encoding during presentation of pairs of words. Pairs could be semantically related or not related. Two encoding instructions were given, either cueing participants to analyze semantic relationships (cued condition, or to memorize the pair without any specific strategy cues (the self-initiated condition. Participants filled out a questionnaire regarding their use of memory strategies and performed a cued-recall task. We hypothesized that if the DLPFC plays a role in the self-initiation of elaborative encoding we would observe a reduction in memory performance in the self-initiated condition, particularly for related. We found a significant correlation between the effects of rTMS and strategy use, only in the self-initiated condition with related pairs. High strategy users showed reduced performance following DLPFC stimulation, while low strategy users tended to show increased recall following DLPFC stimulation during encoding. These results suggest the left DLPFC may be involved in the self-initiation of memory strategy use, and individuals may utilize different neural networks depending on their use of encoding strategies.
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Tremblay, Christina; Monetta, Laura; Langlois, Mélanie; Schneider, Cyril
2016-01-01
This single-case research-designed study explored whether intermittent theta-burst stimulation (iTBS) of the right dorsolateral prefrontal cortex (DLPFC) could improve metaphor comprehension in people with Parkinson disease (PD) and language impairments. A right-handed participant with PD diagnosed 9 years ago, receiving long-term treatment with levodopa, and with metaphor comprehension impairment was recruited to undergo 10 sessions of sham stimulation (in 2wk), a washout period (6wk), and then 10 sessions of iTBS (in 2wk). Clinical scores of metaphor comprehension and motor evaluation (Unified Parkinson Disease Rating Scale part III) and transcranial magnetic stimulation to test the excitability of the primary motor cortex (M1) were used at baseline, postsham, post-iTBS, and at 3 follow-ups (8, 14, and 20wk post-iTBS). Metaphor comprehension was improved after iTBS, and the highest scores were obtained 8 weeks later (P=.01). This improvement was correlated with the increase of the right M1 excitability (r=-.86, P=.03) and with the decrease of transcallosal inhibition latency from the left to the right hemisphere (r=-.88, P=.02). Sham yielded no effect (P>.05). Administration of iTBS over the right DLPFC improved metaphor comprehension likely by a long-term influence on brain synaptic plasticity, including improvement of interhemispheric dialogue. More studies are warranted to confirm these findings in larger samples of participants with PD. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
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Adaptation to conflict via context-driven anticipatory signals in the dorsomedial prefrontal cortex.
Horga, Guillermo; Maia, Tiago V; Wang, Pengwei; Wang, Zhishun; Marsh, Rachel; Peterson, Bradley S
2011-11-09
Behavioral interference elicited by competing response tendencies adapts to contextual changes. Recent nonhuman primate research suggests a key mnemonic role of distinct prefrontal cells in supporting such context-driven behavioral adjustments by maintaining conflict information across trials, but corresponding prefrontal functions have yet to be probed in humans. Using event-related functional magnetic resonance imaging, we investigated the human neural substrates of contextual adaptations to conflict. We found that a neural system comprising the rostral dorsomedial prefrontal cortex and portions of the dorsolateral prefrontal cortex specifically encodes the history of previously experienced conflict and influences subsequent adaptation to conflict on a trial-by-trial basis. This neural system became active in anticipation of stimulus onsets during preparatory periods and interacted with a second neural system engaged during the processing of conflict. Our findings suggest that a dynamic interaction between a system that represents conflict history and a system that resolves conflict underlies the contextual adaptation to conflict.
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Jin, Chenwang; Zhang, Ting; Cai, Chenxi; Bi, Yanzhi; Li, Yangding; Yu, Dahua; Zhang, Ming; Yuan, Kai
2016-09-01
Internet Gaming Disorder (IGD) among adolescents has become an important public concern and gained more and more attention internationally. Recent studies focused on IGD and revealed brain abnormalities in the IGD group, especially the prefrontal cortex (PFC). However, the role of PFC-striatal circuits in pathology of IGD remains unknown. Twenty-five adolescents with IGD and 21 age- and gender-matched healthy controls were recruited in our study. Voxel-based morphometric (VBM) and functional connectivity analysis were employed to investigate the abnormal structural and resting-state properties of several frontal regions in individuals with online gaming addiction. Relative to healthy comparison subjects, IGD subjects showed significant decreased gray matter volume in PFC regions including the bilateral dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), anterior cingulate cortex (ACC) and the right supplementary motor area (SMA) after controlling for age and gender effects. We chose these regions as the seeding areas for the resting-state analysis and found that IGD subjects showed decreased functional connectivity between several cortical regions and our seeds, including the insula, and temporal and occipital cortices. Moreover, significant decreased functional connectivity between some important subcortical regions, i.e., dorsal striatum, pallidum, and thalamus, and our seeds were found in the IGD group and some of those changes were associated with the severity of IGD. Our results revealed the involvement of several PFC regions and related PFC-striatal circuits in the process of IGD and suggested IGD may share similar neural mechanisms with substance dependence at the circuit level.
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Guanfacine potentiates the activation of prefrontal cortex evoked by warning signals.
Clerkin, Suzanne M; Schulz, Kurt P; Halperin, Jeffrey M; Newcorn, Jeffrey H; Ivanov, Iliyan; Tang, Cheuk Y; Fan, Jin
2009-08-15
Warning signals evoke an alert state of readiness that prepares for a rapid response by priming a thalamo-frontal-striatal network that includes the dorsolateral prefrontal cortex (DLPFC). Animal models indicate that noradrenergic input is essential for this stimulus-driven activation of DLPFC, but the precise mechanisms involved have not been determined. We tested the role that postsynaptic alpha(2A) adrenoceptors play in the activation of DLPFC evoked by warning cues using a placebo-controlled challenge with the alpha(2A) agonist guanfacine. Sixteen healthy young adults were scanned twice with event-related functional magnetic resonance imaging (fMRI), while performing a simple cued reaction time (RT) task following administration of a single dose of oral guanfacine (1 mg) and placebo in counterbalanced order. The RT task temporally segregates the neural effects of warning cues and motor responses and minimizes mnemonic demands. Warning cues produced a marked reduction in RT accompanied by significant activation in a distributed thalamo-frontal-striatal network, including bilateral DLPFC. Guanfacine selectively increased the cue-evoked activation of the left DLPFC and right anterior cerebellum, although this increase was not accompanied by further reductions in RT. The effects of guanfacine on DLPFC activation were specifically associated with the warning cue and were not seen for visual- or target-related activation. Guanfacine produced marked increases in the cue-evoked activation of DLPFC that correspond to the well-described actions of postsynaptic alpha(2) adrenoceptor stimulation. The current procedures provide an opportunity to test postsynaptic alpha(2A) adrenoceptor function in the prefrontal cortex in the pathophysiology of several psychiatric disorders.
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NOS1 ex1f-VNTR polymorphism influences prefrontal brain oxygenation during a working memory task.
Kopf, Juliane; Schecklmann, Martin; Hahn, Tim; Dresler, Thomas; Dieler, Alica C; Herrmann, Martin J; Fallgatter, Andreas J; Reif, Andreas
2011-08-15
Nitric oxide (NO) synthase produces NO, which serves as first and second messenger in neurons, where the protein is encoded by the NOS1 gene. A functional variable number of tandem repeats (VNTR) polymorphism in the promoter region of the alternative first exon 1f of NOS1 is associated with various functions of human behavior, for example increased impulsivity, while another, non-functional variant was linked to decreased verbal working memory and a heightened risk for schizophrenia. We therefore investigated the influence of NOS1 ex 1f-VNTR on working memory function as reflected by both behavioral measures and prefrontal oxygenation. We hypothesized that homozygous short allele carriers exhibit altered brain oxygenation in task-related areas, namely the dorsolateral and ventrolateral prefrontal cortex and the parietal cortex. To this end, 56 healthy subjects were stratified into a homozygous long allele group and a homozygous short allele group comparable for age, sex and intelligence. All subjects completed a letter n-back task (one-, two-, and three-back), while concentration changes of oxygenated (O(2)Hb) hemoglobin in the prefrontal cortex were measured with functional near-infrared spectroscopy (fNIRS). We found load-associated O(2)Hb increases in the prefrontal and parts of the parietal cortex. Significant load-associated oxygenation differences between the two genotype groups could be shown for the dorsolateral prefrontal cortex and the parietal cortex. Specifically, short allele carriers showed a significantly larger increase in oxygenation in all three n-back tasks. This suggests a potential compensatory mechanism, with task-related brain regions being more active in short allele carriers to compensate for reduced NOS1 expression. Copyright © 2011 Elsevier Inc. All rights reserved.
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Differential patterns of prefrontal MEG activation during verbal & visual encoding and retrieval.
Directory of Open Access Journals (Sweden)
Garreth Prendergast
Full Text Available The spatiotemporal profile of activation of the prefrontal cortex in verbal and non-verbal recognition memory was examined using magnetoencephalography (MEG. Sixteen neurologically healthy right-handed participants were scanned whilst carrying out a modified version of the Doors and People Test of recognition memory. A pattern of significant prefrontal activity was found for non-verbal and verbal encoding and recognition. During the encoding, verbal stimuli activated an area in the left ventromedial prefrontal cortex, and non-verbal stimuli activated an area in the right. A region in the left dorsolateral prefrontal cortex also showed significant activation during the encoding of non-verbal stimuli. Both verbal and non-verbal stimuli significantly activated an area in the right dorsomedial prefrontal cortex and the right anterior prefrontal cortex during successful recognition, however these areas showed temporally distinct activation dependent on material, with non-verbal showing activation earlier than verbal stimuli. Additionally, non-verbal material activated an area in the left anterior prefrontal cortex during recognition. These findings suggest a material-specific laterality in the ventromedial prefrontal cortex during encoding for verbal and non-verbal but also support the HERA model for verbal material. The discovery of two process dependent areas during recognition that showed patterns of temporal activation dependent on material demonstrates the need for the application of more temporally sensitive techniques to the involvement of the prefrontal cortex in recognition memory.
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Directory of Open Access Journals (Sweden)
Qiao J
2016-09-01
Full Text Available Jun Qiao,1,2 Guixing Jin,1,2 Licun Lei,3 Lan Wang,1,2 Yaqiang Du,3 Xueyi Wang1,2 1Institute of Mental Health, The First Hospital of Hebei Medical University, 2Brain Ageing and Cognitive Neuroscience Laboratory, Hebei Medical University, 3Department of Radiology, The First Hospital of Hebei Medical University, Hebei, People’s Republic of China Objective: To explore the effect of right dorsolateral prefrontal cortex (DLPFC repetitive transcranial magnetic stimulation (rTMS on memory, and its correlation with levels of hippocampal brain metabolites detected by proton magnetic resonance spectroscopy (1H-MRS in recently detoxified alcohol-dependent patients. Materials and methods: In this randomized, double-blind sham-controlled trial, alcohol-dependent patients were enrolled and randomized into two groups: the experimental group (rTMS, 10 Hz, on right DLPFC, 20 sessions and the control group (sham stimulation. Memory function was assessed using Hopkins Verbal Learning Test-Revised (HVLT-R and Brief Visuospatial Memory Test-Revised (BVMT-R before and after treatment. 1H-MRS was used to detect the levels of N-acetyl aspartic acid (NAA, choline (Cho, and creatine (Cr in bilateral hippocampi before and after treatment. Results: Thirty-eight patients (18 in the experimental group and 20 in the control group were included in the analyses. The experimental group showed significantly greater changes in HVLT-R, BVMT-R, NAA/Cr, and Cho/Cr after rTMS from baseline than the control group. The percentage change in BVMT-R and HVLT-R correlated with the percentage change in NAA/Cr and Cho/Cr in the right brain. Conclusion: High-frequency right DLPFC rTMS was associated with improvement in memory dysfunction, which is correlated with levels of hippocampal brain metabolites detected by 1H-MRS in recently detoxified alcohol-dependent patients. Keywords: alcohol dependence, memory, repetitive transcranial magnetic stimulation, MR spectroscopy
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Colombo, Barbara; Bartesaghi, Noemi; Simonelli, Luisa; Antonietti, Alessandro
2015-01-01
The role of prefrontal cortex (PFC) in influencing creative thinking has been investigated by many researchers who, while succeeding in proving an effective involvement of PFC, reported suggestive but sometimes conflicting results. In order to better understand the relationships between creative thinking and brain activation in a more specific area of the PFC, we explored the role of dorsolateral PFC (DLPFC). We devised an experimental protocol using transcranial direct-current stimulation (tDCS). The study was based on a 3 (kind of stimulation: anodal vs. cathodal vs. sham) × 2 (priming: divergent vs. convergent) design. Forty-five healthy adults were randomly assigned to one stimulation condition. Participants’ creativity skills were assessed using the Product Improvement subtest from the Torrance Tests of Creative Thinking (TTCT). After 20 min of tDCS stimulation, participants were presented with visual images of common objects. Half of the participants were instructed to visualize themselves using the object in an unusual way (divergent priming), whereas the other half were asked to visualize themselves while using the object in a common way (convergent priming). Priming was aimed at inducing participants to adopt different attitudes toward the creative task. Afterwards, participants were asked to describe all of the possible uses of the objects that were presented. Participants’ physiological activation was recorded using a biofeedback equipment. Results showed a significant effect of anodal stimulation that enhanced creative performance, but only after divergent priming. Participants showed lower skin temperature values after cathodal stimulation, a finding which is coherent with studies reporting that, when a task is not creative or creative thinking is not prompted, people show lower levels of arousal. Differences in individual levels of creativity as assessed by the Product Improvement test were not influential. The involvement of DLPFC in creativity
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Colombo, Barbara; Bartesaghi, Noemi; Simonelli, Luisa; Antonietti, Alessandro
2015-01-01
The role of prefrontal cortex (PFC) in influencing creative thinking has been investigated by many researchers who, while succeeding in proving an effective involvement of PFC, reported suggestive but sometimes conflicting results. In order to better understand the relationships between creative thinking and brain activation in a more specific area of the PFC, we explored the role of dorsolateral PFC (DLPFC). We devised an experimental protocol using transcranial direct-current stimulation (tDCS). The study was based on a 3 (kind of stimulation: anodal vs. cathodal vs. sham) × 2 (priming: divergent vs. convergent) design. Forty-five healthy adults were randomly assigned to one stimulation condition. Participants' creativity skills were assessed using the Product Improvement subtest from the Torrance Tests of Creative Thinking (TTCT). After 20 min of tDCS stimulation, participants were presented with visual images of common objects. Half of the participants were instructed to visualize themselves using the object in an unusual way (divergent priming), whereas the other half were asked to visualize themselves while using the object in a common way (convergent priming). Priming was aimed at inducing participants to adopt different attitudes toward the creative task. Afterwards, participants were asked to describe all of the possible uses of the objects that were presented. Participants' physiological activation was recorded using a biofeedback equipment. Results showed a significant effect of anodal stimulation that enhanced creative performance, but only after divergent priming. Participants showed lower skin temperature values after cathodal stimulation, a finding which is coherent with studies reporting that, when a task is not creative or creative thinking is not prompted, people show lower levels of arousal. Differences in individual levels of creativity as assessed by the Product Improvement test were not influential. The involvement of DLPFC in creativity has
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Pinho, Ana Luísa; de Manzano, Örjan; Fransson, Peter; Eriksson, Helene; Ullén, Fredrik
2014-04-30
Musicians have been used extensively to study neural correlates of long-term practice, but no studies have investigated the specific effects of training musical creativity. Here, we used human functional MRI to measure brain activity during improvisation in a sample of 39 professional pianists with varying backgrounds in classical and jazz piano playing. We found total hours of improvisation experience to be negatively associated with activity in frontoparietal executive cortical areas. In contrast, improvisation training was positively associated with functional connectivity of the bilateral dorsolateral prefrontal cortices, dorsal premotor cortices, and presupplementary areas. The effects were significant when controlling for hours of classical piano practice and age. These results indicate that even neural mechanisms involved in creative behaviors, which require a flexible online generation of novel and meaningful output, can be automated by training. Second, improvisational musical training can influence functional brain properties at a network level. We show that the greater functional connectivity seen in experienced improvisers may reflect a more efficient exchange of information within associative networks of importance for musical creativity.
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Strzelecki, Dominik; Podgórski, Michał; Kałużyńska, Olga; Stefańczyk, Ludomir; Kotlicka-Antczak, Magdalena; Gmitrowicz, Agnieszka; Grzelak, Piotr
2015-10-15
The glutamatergic system is a key point in pathogenesis of schizophrenia. Sarcosine (N-methylglycine) is an exogenous amino acid that acts as a glycine transporter inhibitor. It modulates glutamatergic transmission by increasing glycine concentration around NMDA (N-methyl-d-aspartate) receptors. In patients with schizophrenia, the function of the glutamatergic system in the prefrontal cortex is impaired, which may promote negative and cognitive symptoms. Proton nuclear magnetic resonance (¹H-NMR) spectroscopy is a non-invasive imaging method enabling the evaluation of brain metabolite concentration, which can be applied to assess pharmacologically induced changes. The aim of the study was to evaluate the influence of a six-month course of sarcosine therapy on the concentration of metabolites (NAA, N-acetylaspartate; Glx, complex of glutamate, glutamine and γ-aminobutyric acid (GABA); mI, myo-inositol; Cr, creatine; Cho, choline) in the left dorso-lateral prefrontal cortex (DLPFC) in patients with stable schizophrenia. Fifty patients with schizophrenia, treated with constant antipsychotics doses, in stable clinical condition were randomly assigned to administration of sarcosine (25 patients) or placebo (25 patients) for six months. Metabolite concentrations in DLPFC were assessed with 1.5 Tesla ¹H-NMR spectroscopy. Clinical symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS). The first spectroscopy revealed no differences in metabolite concentrations between groups. After six months, NAA/Cho, mI/Cr and mI/Cho ratios in the left DLPFC were significantly higher in the sarcosine than the placebo group. In the sarcosine group, NAA/Cr, NAA/Cho, mI/Cr, mI/Cho ratios also significantly increased compared to baseline values. In the placebo group, only the NAA/Cr ratio increased. The addition of sarcosine to antipsychotic therapy for six months increased markers of neurons viability (NAA) and neurogilal activity (mI) with simultaneous improvement
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Dominik Strzelecki
2015-10-01
Full Text Available The glutamatergic system is a key point in pathogenesis of schizophrenia. Sarcosine (N-methylglycine is an exogenous amino acid that acts as a glycine transporter inhibitor. It modulates glutamatergic transmission by increasing glycine concentration around NMDA (N-methyl-d-aspartate receptors. In patients with schizophrenia, the function of the glutamatergic system in the prefrontal cortex is impaired, which may promote negative and cognitive symptoms. Proton nuclear magnetic resonance (1H-NMR spectroscopy is a non-invasive imaging method enabling the evaluation of brain metabolite concentration, which can be applied to assess pharmacologically induced changes. The aim of the study was to evaluate the influence of a six-month course of sarcosine therapy on the concentration of metabolites (NAA, N-acetylaspartate; Glx, complex of glutamate, glutamine and γ-aminobutyric acid (GABA; mI, myo-inositol; Cr, creatine; Cho, choline in the left dorso-lateral prefrontal cortex (DLPFC in patients with stable schizophrenia. Fifty patients with schizophrenia, treated with constant antipsychotics doses, in stable clinical condition were randomly assigned to administration of sarcosine (25 patients or placebo (25 patients for six months. Metabolite concentrations in DLPFC were assessed with 1.5 Tesla 1H-NMR spectroscopy. Clinical symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS. The first spectroscopy revealed no differences in metabolite concentrations between groups. After six months, NAA/Cho, mI/Cr and mI/Cho ratios in the left DLPFC were significantly higher in the sarcosine than the placebo group. In the sarcosine group, NAA/Cr, NAA/Cho, mI/Cr, mI/Cho ratios also significantly increased compared to baseline values. In the placebo group, only the NAA/Cr ratio increased. The addition of sarcosine to antipsychotic therapy for six months increased markers of neurons viability (NAA and neurogilal activity (mI with simultaneous
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The Polarity-Dependent Effects of the Bilateral Brain Stimulation on Working Memory
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Fatemeh Keshvari
2013-08-01
Full Text Available Introduction: Working memory plays a critical role in cognitive processes which are central to our daily life. Neuroimaging studies have shown that one of the most important areas corresponding to the working memory is the dorsolateral prefrontal cortex (DLFPC. This study was aimed to assess whether bilateral modulation of the DLPFC using a noninvasive brain stimulation, namely transcranial direct current stimulation (tDCS, modi.es the working memory function in healthy adults.Methods: In a randomized sham-controlled cross-over study, 60 subjects (30 Males received sham and active tDCS in two subgroups (anode left/cathode right and anode right/cathode left of the DLPFC. Subjects were presented working memory n-back task while the reaction time and accuracy were recorded.Results: A repeated measures, mixed design ANOVA indicated a signi.cant difference between the type of stimulation (sham vs. active in anodal stimulation of the left DLPFC with cathodal stimulation of the right DLPFC [F(1,55= 5.29, P=0.019], but not the inverse polarity worsened accuracy in the 2-back working memory task. There were also no statistically signi.cant changes in speed of working memory [F(1,55= 0.458 ,P=0.502] related to type or order of stimulation..Discussion: The results would imply to a polarity dependence of bilateral tDCS of working memory. Left anodal/ right cathodal stimulation of DLPFC could impair working memory, while the reverser stimulation had no effect. Meaning that bilateral stimulation of DLFC would not be a useful procedure to improve working memory. Further studies are required to understand subtle effects of different tDCS stimulation/inhibition electrode positioning on the working memory.
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DRD2/CHRNA5 interaction on prefrontal biology and physiology during working memory.
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Annabella Di Giorgio
Full Text Available BACKGROUND: Prefrontal behavior and activity in humans are heritable. Studies in animals demonstrate an interaction between dopamine D2 receptors and nicotinic acetylcholine receptors on prefrontal behavior but evidence in humans is weak. Therefore, we hypothesize that genetic variation regulating dopamine D2 and nicotinic acetylcholine receptor signaling impact prefrontal cortex activity and related cognition. To test this hypothesis in humans, we explored the interaction between functional genetic variants in the D2 receptor gene (DRD2, rs1076560 and in the nicotinic receptor α5 gene (CHRNA5, rs16969968 on both dorsolateral prefrontal cortex mediated behavior and physiology during working memory and on prefrontal gray matter volume. METHODS: A large sample of healthy subjects was compared for genotypic differences for DRD2 rs1076560 (G>T and CHNRA5 rs16969968 (G>A on prefrontal phenotypes, including cognitive performance at the N-Back task, prefrontal physiology with BOLD fMRI during performance of the 2-Back working memory task, and prefrontal morphometry with structural MRI. RESULTS: We found that DRD2 rs1076560 and CHNRA5 rs16969968 interact to modulate cognitive function, prefrontal physiology during working memory, and prefrontal gray matter volume. More specifically, CHRNA5-AA/DRD2-GT subjects had greater behavioral performance, more efficient prefrontal cortex activity at 2Back working memory task, and greater prefrontal gray matter volume than the other genotype groups. CONCLUSIONS: The present data extend previous studies in animals and enhance our understanding of dopamine and acetylcholine signaling in the human prefrontal cortex, demonstrating interactions elicited by working memory that are modulated by genetic variants in DRD2 and CHRNA5.
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DRD2/CHRNA5 interaction on prefrontal biology and physiology during working memory.
Di Giorgio, Annabella; Smith, Ryan M; Fazio, Leonardo; D'Ambrosio, Enrico; Gelao, Barbara; Tomasicchio, Aldo; Selvaggi, Pierluigi; Taurisano, Paolo; Quarto, Tiziana; Masellis, Rita; Rampino, Antonio; Caforio, Grazia; Popolizio, Teresa; Blasi, Giuseppe; Sadee, Wolfgang; Bertolino, Alessandro
2014-01-01
Prefrontal behavior and activity in humans are heritable. Studies in animals demonstrate an interaction between dopamine D2 receptors and nicotinic acetylcholine receptors on prefrontal behavior but evidence in humans is weak. Therefore, we hypothesize that genetic variation regulating dopamine D2 and nicotinic acetylcholine receptor signaling impact prefrontal cortex activity and related cognition. To test this hypothesis in humans, we explored the interaction between functional genetic variants in the D2 receptor gene (DRD2, rs1076560) and in the nicotinic receptor α5 gene (CHRNA5, rs16969968) on both dorsolateral prefrontal cortex mediated behavior and physiology during working memory and on prefrontal gray matter volume. A large sample of healthy subjects was compared for genotypic differences for DRD2 rs1076560 (G>T) and CHNRA5 rs16969968 (G>A) on prefrontal phenotypes, including cognitive performance at the N-Back task, prefrontal physiology with BOLD fMRI during performance of the 2-Back working memory task, and prefrontal morphometry with structural MRI. We found that DRD2 rs1076560 and CHNRA5 rs16969968 interact to modulate cognitive function, prefrontal physiology during working memory, and prefrontal gray matter volume. More specifically, CHRNA5-AA/DRD2-GT subjects had greater behavioral performance, more efficient prefrontal cortex activity at 2Back working memory task, and greater prefrontal gray matter volume than the other genotype groups. The present data extend previous studies in animals and enhance our understanding of dopamine and acetylcholine signaling in the human prefrontal cortex, demonstrating interactions elicited by working memory that are modulated by genetic variants in DRD2 and CHRNA5.
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Decreased prefrontal cortical dopamine transmission in alcoholism.
Narendran, Rajesh; Mason, Neale Scott; Paris, Jennifer; Himes, Michael L; Douaihy, Antoine B; Frankle, W Gordon
2014-08-01
Basic studies have demonstrated that optimal levels of prefrontal cortical dopamine are critical to various executive functions such as working memory, attention, inhibitory control, and risk/reward decisions, all of which are impaired in addictive disorders such as alcoholism. Based on this and imaging studies of alcoholism that have demonstrated less dopamine in the striatum, the authors hypothesized decreased dopamine transmission in the prefrontal cortex in persons with alcohol dependence. To test this hypothesis, amphetamine and [11C]FLB 457 positron emission tomography were used to measure cortical dopamine transmission in 21 recently abstinent persons with alcohol dependence and 21 matched healthy comparison subjects. [11C]FLB 457 binding potential, specific compared to nondisplaceable uptake (BPND), was measured in subjects with kinetic analysis using the arterial input function both before and after 0.5 mg kg-1 of d-amphetamine. Amphetamine-induced displacement of [11C]FLB 457 binding potential (ΔBPND) was significantly smaller in the cortical regions in the alcohol-dependent group compared with the healthy comparison group. Cortical regions that demonstrated lower dopamine transmission in the alcohol-dependent group included the dorsolateral prefrontal cortex, medial prefrontal cortex, orbital frontal cortex, temporal cortex, and medial temporal lobe. The results of this study, for the first time, unambiguously demonstrate decreased dopamine transmission in the cortex in alcoholism. Further research is necessary to understand the clinical relevance of decreased cortical dopamine as to whether it is related to impaired executive function, relapse, and outcome in alcoholism.
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Prefrontal cortex glutamate correlates with mental perspective-taking.
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Christiane Montag
Full Text Available BACKGROUND: Dysfunctions in theory of mind and empathic abilities have been suggested as core symptoms in major psychiatric disorders including schizophrenia and autism. Since self monitoring, perspective taking and empathy have been linked to prefrontal (PFC and anterior cingulate cortex (ACC function, neurotransmitter variations in these areas may account for normal and pathological variations of these functions. Converging evidence indicates an essential role of glutamatergic neurotransmission in psychiatric diseases with pronounced deficits in empathy. However, the role of the glutamate system for different dimensions of empathy has not been investigated so far. METHODOLOGY/PRINCIPAL FINDINGS: Absolute concentrations of cerebral glutamate in the ACC, left dorsolateral PFC and left hippocampus were determined by 3-tesla proton magnetic resonance spectroscopy (1H-MRS in 17 healthy individuals. Three dimensions of empathy were estimated by a self-rating questionnaire, the Interpersonal Reactivity Index (IRI. Linear regression analysis showed that dorsolateral PFC glutamate concentration was predicted by IRI factor "perspective taking" (T = -2.710, p = 0.018; adjusted alpha-level of 0.017, Bonferroni but not by "empathic concern" or "personal distress". No significant relationship between IRI subscores and the glutamate levels in the ACC or left hippocampus was detected. CONCLUSIONS/SIGNIFICANCE: This is the first study to investigate the role of the glutamate system for dimensions of theory of mind and empathy. Results are in line with recent concepts that executive top-down control of behavior is mediated by prefrontal glutamatergic projections. This is a preliminary finding that needs a replication in an independent sample.
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Ruocco, Anthony C.; Rodrigo, Achala H.; McMain, Shelley F.; Page-Gould, Elizabeth; Ayaz, Hasan; Links, Paul S.
2016-01-01
Self-harm is a potentially lethal symptom of borderline personality disorder (BPD) that often improves with dialectical behavior therapy (DBT). While DBT is effective for reducing self-harm in many patients with BPD, a small but significant number of patients either does not improve in treatment or ends treatment prematurely. Accordingly, it is crucial to identify factors that may prospectively predict which patients are most likely to benefit from and remain in treatment. In the present preliminary study, 29 actively self-harming patients with BPD completed brain-imaging procedures probing activation of the prefrontal cortex (PFC) during impulse control prior to beginning DBT and after 7 months of treatment. Patients that reduced their frequency of self-harm the most over treatment displayed lower levels of neural activation in the bilateral dorsolateral prefrontal cortex (DLPFC) prior to beginning treatment, and they showed the greatest increases in activity within this region after 7 months of treatment. Prior to starting DBT, treatment non-completers demonstrated greater activation than treatment-completers in the medial PFC and right inferior frontal gyrus. Reductions in self-harm over the treatment period were associated with increases in activity in right DLPFC even after accounting for improvements in depression, mania, and BPD symptom severity. These findings suggest that pre-treatment patterns of activation in the PFC underlying impulse control may be prospectively associated with improvements in self-harm and treatment attrition for patients with BPD treated with DBT. PMID:27242484
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Ruocco, Anthony C; Rodrigo, Achala H; McMain, Shelley F; Page-Gould, Elizabeth; Ayaz, Hasan; Links, Paul S
2016-01-01
Self-harm is a potentially lethal symptom of borderline personality disorder (BPD) that often improves with dialectical behavior therapy (DBT). While DBT is effective for reducing self-harm in many patients with BPD, a small but significant number of patients either does not improve in treatment or ends treatment prematurely. Accordingly, it is crucial to identify factors that may prospectively predict which patients are most likely to benefit from and remain in treatment. In the present preliminary study, 29 actively self-harming patients with BPD completed brain-imaging procedures probing activation of the prefrontal cortex (PFC) during impulse control prior to beginning DBT and after 7 months of treatment. Patients that reduced their frequency of self-harm the most over treatment displayed lower levels of neural activation in the bilateral dorsolateral prefrontal cortex (DLPFC) prior to beginning treatment, and they showed the greatest increases in activity within this region after 7 months of treatment. Prior to starting DBT, treatment non-completers demonstrated greater activation than treatment-completers in the medial PFC and right inferior frontal gyrus. Reductions in self-harm over the treatment period were associated with increases in activity in right DLPFC even after accounting for improvements in depression, mania, and BPD symptom severity. These findings suggest that pre-treatment patterns of activation in the PFC underlying impulse control may be prospectively associated with improvements in self-harm and treatment attrition for patients with BPD treated with DBT.
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Cho, Soohyun; Metcalfe, Arron W S; Young, Christina B; Ryali, Srikanth; Geary, David C; Menon, Vinod
2012-09-01
Children's gains in problem-solving skills during the elementary school years are characterized by shifts in the mix of problem-solving approaches, with inefficient procedural strategies being gradually replaced with direct retrieval of domain-relevant facts. We used a well-established procedure for strategy assessment during arithmetic problem solving to investigate the neural basis of this critical transition. We indexed behavioral strategy use by focusing on the retrieval frequency and examined changes in brain activity and connectivity associated with retrieval fluency during arithmetic problem solving in second- and third-grade (7- to 9-year-old) children. Children with higher retrieval fluency showed elevated signal in the right hippocampus, parahippocampal gyrus (PHG), lingual gyrus (LG), fusiform gyrus (FG), left ventrolateral PFC (VLPFC), bilateral dorsolateral PFC (DLPFC), and posterior angular gyrus. Critically, these effects were not confounded by individual differences in problem-solving speed or accuracy. Psychophysiological interaction analysis revealed significant effective connectivity of the right hippocampus with bilateral VLPFC and DLPFC during arithmetic problem solving. Dynamic causal modeling analysis revealed strong bidirectional interactions between the hippocampus and the left VLPFC and DLPFC. Furthermore, causal influences from the left VLPFC to the hippocampus served as the main top-down component, whereas causal influences from the hippocampus to the left DLPFC served as the main bottom-up component of this retrieval network. Our study highlights the contribution of hippocampal-prefrontal circuits to the early development of retrieval fluency in arithmetic problem solving and provides a novel framework for studying dynamic developmental processes that accompany children's development of problem-solving skills.
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No Effects of Bilateral tDCS over Inferior Frontal Gyrus on Response Inhibition and Aggression.
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Franziska Dambacher
Full Text Available Response inhibition is defined as the capacity to adequately withdraw pre-planned responses. It has been shown that individuals with deficits in inhibiting pre-planned responses tend to display more aggressive behaviour. The prefrontal cortex is involved in both, response inhibition and aggression. While response inhibition is mostly associated with predominantly right prefrontal activity, the neural components underlying aggression seem to be left-lateralized. These differences in hemispheric dominance are conceptualized in cortical asymmetry theories on motivational direction, which assign avoidance motivation (relevant to inhibit responses to the right and approach motivation (relevant for aggressive actions to the left prefrontal cortex. The current study aimed to directly address the inverse relationship between response inhibition and aggression by assessing them within one experiment. Sixty-nine healthy participants underwent bilateral transcranial Direct Current Stimulation (tDCS to the inferior frontal cortex. In one group we induced right-hemispheric fronto-cortical dominance by means of a combined right prefrontal anodal and left prefrontal cathodal tDCS montage. In a second group we induced left-hemispheric fronto-cortical dominance by means of a combined left prefrontal anodal and right prefrontal cathodal tDCS montage. A control group received sham stimulation. Response inhibition was assessed with a go/no-go task (GNGT and aggression with the Taylor Aggression Paradigm (TAP. We revealed that participants with poorer performance in the GNGT displayed more aggression during the TAP. No effects of bilateral prefrontal tDCS on either response inhibition or aggression were observed. This is at odds with previous brain stimulation studies applying unilateral protocols. Our results failed to provide evidence in support of the prefrontal cortical asymmetry model in the domain of response inhibition and aggression. The absence of t
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Anilkumar Pillai
Full Text Available BACKGROUND: Current theories on the pathophysiology of schizophrenia suggest altered brain plasticity such as decreased neural proliferation and migration, delayed myelination, and abnormal synaptic modeling, in the brain of subjects with schizophrenia. Though functional alterations in BDNF, which plays important role in neuroplasticity, are implicated in many abnormalities found in schizophrenia, the regulatory mechanism(s involved in the abnormal signaling of BDNF in schizophrenia is not clear. The present study investigated whether Sprouty2, a regulator of growth factor signaling, is abnormally expressed in schizophrenia, and is associated with the changes in BDNF mRNA in this disorder. The potential effect of antipsychotic drugs on Sprouty2 expression was tested in adult rats. METHODS AND FINDINGS: Sprouty2 and BDNF gene expression were analyzed in dorsolateral prefrontal cortex samples from the Stanley Array Collection. Quantitative real-time PCR analysis of RNA in 100 individuals (35 with schizophrenia, 31 with bipolar disorder, and 34 psychiatrically normal controls showed significantly decreased expression of Sprouty2 and BDNF in both schizophrenia and bipolar disorder. Moreover, a significant correlation between these two genes existed in control, schizophrenia and bipolar subjects. Long-term treatment with antipsychotic drugs, haloperidol and olanzapine, showed differential effects on both Sprouty2 and BDNF mRNA and protein levels in the frontal cortex of rats. CONCLUSION: These findings demonstrating decreased expression of Sprouty2 associated with changes in BDNF, suggest the possibility that these decreases are secondary to treatment rather than to factors that are significant in the disease process of either schizophrenia and/or bipolar disorder. Further exploration of Sprouty2-related signal transduction pathways may be helpful to design novel treatment strategies for these disorders.
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de Oliveira, Rogério Adas Ayres; de Andrade, Daniel Ciampi; Mendonça, Melina; Barros, Rafael; Luvisoto, Tatiana; Myczkowski, Martin Luiz; Marcolin, Marco Antonio; Teixeira, Manoel Jacobsen
2014-12-01
Central poststroke pain (CPSP) is caused by an encephalic vascular lesion of the somatosensory pathways and is commonly refractory to current pharmacologic treatments. Repetitive transcranial magnetic stimulation (rTMS) of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) can change thermal pain threshold toward analgesia in healthy subjects and has analgesic effects in acute postoperative pain as well as in fibromyalgia patients. However, its effect on neuropathic pain and in CPSP, in particular, has not been assessed. The aim of this prospective, double-blind, placebo-controlled study was to evaluate the analgesic effect of PMC/DLPFC rTMS in CPSP patients. Patients were randomized into 2 groups, active (a-) rTMS and sham (s-) rTMS, and were treated with 10 daily sessions of rTMS over the left PMC/DLPFC (10 Hz, 1,250 pulses/d). Outcomes were assessed at baseline, during the stimulation phase, and at 1, 2, and 4 weeks after the last stimulation. The main outcome was pain intensity changes measured by the visual analog scale on the last stimulation day compared to baseline. Interim analysis was scheduled when the first half of the patients completed the study. The study was terminated because of a significant lack of efficacy of the active arm after 21 patients completed the whole treatment and follow-up phases. rTMS of the left PMC/DLPFC did not improve pain in CPSP. The aim of this double-blind, placebo-controlled study was to evaluate the analgesic effects of rTMS to the PMC/DLPFC in CPSP patients. An interim analysis showed a consistent lack of analgesic effect, and the study was terminated. rTMS of the PMC/DLPFC is not effective in relieving CPSP. Copyright © 2014 American Pain Society. Published by Elsevier Inc. All rights reserved.
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Boggio, Paulo S; Zaghi, Soroush; Villani, Ana Beatriz; Fecteau, Shirley; Pascual-Leone, Alvaro; Fregni, Felipe
2010-12-01
Cognitive deficits that are reported in heavy marijuana users (attention, memory, affect perception, decision-making) appear to be completely reversible after a prolonged abstinence period of about 28 days. However, it remains unclear whether the reversibility of these cognitive deficits indicates that (1) chronic marijuana use is not associated with long-lasting changes in cortical networks or (2) that such changes occur but the brain adapts to and compensates for the drug-induced changes. Therefore, we examined whether chronic marijuana smokers would demonstrate a differential pattern of response in comparison to healthy volunteers on a decision-making paradigm (Risk Task) while undergoing sham or active transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC). Twenty-five chronic marijuana users who were abstinent for at least 24h were randomly assigned to receive left anodal/right cathodal tDCS of DLPFC (n=8), right anodal/left cathodal tDCS of DLPFC (n=9), or sham stimulation (n=8); results on Risk Task during sham/active tDCS were compared to healthy volunteers from a previously published dataset. Chronic marijuana users demonstrated more conservative (i.e. less risky) decision-making during sham stimulation. While right anodal stimulation of the DLPFC enhanced conservative decision-making in healthy volunteers, both right anodal and left anodal DLPFC stimulation increased the propensity for risk-taking in marijuana users. These findings reveal alterations in the decision-making neural networks among chronic marijuana users. Finally, we also assessed the effects of tDCS on marijuana craving and observed that right anodal/left cathodal tDCS of DLPFC is significantly associated with a diminished craving for marijuana. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
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Sun, Yongan; Yang, Yang; Galvin, Veronica C; Yang, Shengtao; Arnsten, Amy F; Wang, Min
2017-05-24
The primate dorsolateral prefrontal cortex (dlPFC) subserves top-down regulation of attention and working memory abilities. Depletion studies show that the neuromodulator acetylcholine (ACh) is essential to dlPFC working memory functions, but the receptor and cellular bases for cholinergic actions are just beginning to be understood. The current study found that nicotinic receptors comprised of α4 and β2 subunits (α4β2-nAChR) enhance the task-related firing of delay and fixation cells in the dlPFC of monkeys performing a working memory task. Iontophoresis of α4β2-nAChR agonists increased the neuronal firing and enhanced the spatial tuning of delay cells, neurons that represent visual space in the absence of sensory stimulation. These enhancing effects were reversed by coapplication of a α4β2-nAChR antagonist, consistent with actions at α4β2-nAChR. Delay cell firing was reduced when distractors were presented during the delay epoch, whereas stimulation of α4β2-nAChR protected delay cells from these deleterious effects. Iontophoresis of α4β2-nAChR agonists also enhanced the firing of fixation cells, neurons that increase firing when the monkey initiates a trial, and maintain firing until the trial is completed. These neurons are thought to contribute to sustained attention and top-down motor control and have never before been the subject of pharmacological inquiry. These findings begin to build a picture of the cellular actions underlying the beneficial effects of ACh on attention and working memory. The data may also help to explain why genetic insults to α4 subunits are associated with working memory and attentional deficits and why α4β2-nAChR agonists may have therapeutic potential. SIGNIFICANCE STATEMENT The acetylcholine (ACh) arousal system in the brain is needed for robust attention and working memory functions, but the receptor and cellular bases for its beneficial effects are poorly understood in the newly evolved primate brain. The current
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Ondine's Curse in a Patient with Unilateral Medullary and Bilateral Cerebellar Infarctions
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Hui-Tzu Ho
2005-11-01
Full Text Available Central sleep apnea (CSA, also known as Ondine's curse (OC, is a phenomenon characterized by episodes of repeated apnea during sleep due to disorders of the central nervous system. We report a patient with CSA/OC due to right dorsolateral medullary and bilateral cerebellar infarctions that occurred in the clinical setting of right vertebral artery stenosis. Polysomnography (PSG showed repeated episodes of absence of nasal cannula flow accompanying cessation of thoracic and abdominal respiratory movements and a decline in blood oxygen saturation. The duration of apnea was as long as 12 seconds. Brain magnetic resonance (MR images showed acute infarctions involving the right dorsolateral medulla, bilateral cerebellar vermis and paramedian cerebellar hemispheres. MR angiography showed nonvisualization of the right vertebral artery. Transcranial Doppler sonography showed a high resistance flow profile in the right vertebral artery and normal flow patterns in the basilar artery and left vertebral artery. These findings suggest that the medullary and bilateral cerebellar infarcts were caused by stenosis/pseudo-occlusion of the right vertebral artery. Reduced respiratory afferent inputs to the dorsal respiratory group of medullary neurons, the nucleus tractus solitarius and reduced “automatic” components of the respiratory drive may play a role in the development of CSA/OC.
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Thinning of the lateral prefrontal cortex during adolescence predicts emotion regulation in females.
Vijayakumar, Nandita; Whittle, Sarah; Yücel, Murat; Dennison, Meg; Simmons, Julian; Allen, Nicholas B
2014-11-01
Adolescence is a crucial period for the development of adaptive emotion regulation strategies. Despite the fact that structural maturation of the prefrontal cortex during adolescence is often assumed to underlie the maturation of emotion regulation strategies, no longitudinal studies have directly assessed this relationship. This study examined whether use of cognitive reappraisal strategies during late adolescence was predicted by (i) absolute prefrontal cortical thickness during early adolescence and (ii) structural maturation of the prefrontal cortex between early and mid-adolescence. Ninety-two adolescents underwent baseline and follow-up magnetic resonance imaging scans when they were aged approximately 12 and 16 years, respectively. FreeSurfer software was used to obtain cortical thickness estimates for three prefrontal regions [anterior cingulate cortex; dorsolateral prefrontal cortex (dlPFC); ventrolateral prefrontal cortex (vlPFC)]. The Emotion Regulation Questionnaire was completed when adolescents were aged approximately 19 years. Results showed that greater cortical thinning of the left dlPFC and left vlPFC during adolescence was significantly associated with greater use of cognitive reappraisal in females, though no such relationship was evident in males. Furthermore, baseline left dlPFC thickness predicted cognitive reappraisal at trend level. These findings suggest that cortical maturation may play a role in the development of adaptive emotion regulation strategies during adolescence. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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Nagamitsu, Shinichiro; Nagano, Miki; Yamashita, Yushiro; Takashima, Sachio; Matsuishi, Toyojiro
2006-06-01
Video game playing is an attractive form of entertainment among school-age children. Although this activity reportedly has many adverse effects on child development, these effects remain controversial. To investigate the effect of video game playing on regional cerebral blood volume, we measured cerebral hemoglobin concentrations using near-infrared spectroscopy in 12 normal volunteers consisting of six children and six adults. A Hitachi Optical Topography system was used to measure hemoglobin changes. For all subjects, the video game Donkey Kong was played on a Game Boy device. After spectroscopic probes were positioned on the scalp near the target brain regions, the participants were asked to play the game for nine periods of 15s each, with 15-s rest intervals between these task periods. Significant increases in bilateral prefrontal total-hemoglobin concentrations were observed in four of the adults during video game playing. On the other hand, significant decreases in bilateral prefrontal total-hemoglobin concentrations were seen in two of the children. A significant positive correlation between mean oxy-hemoglobin changes in the prefrontal region and those in the bilateral motor cortex area was seen in adults. Playing video games gave rise to dynamic changes in cerebral blood volume in both age groups, while the difference in the prefrontal oxygenation patterns suggested an age-dependent utilization of different neural circuits during video game tasks.
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Mariano, Timothy Y; Van't Wout, Mascha; Garnaat, Sarah L; Rasmussen, Steven A; Greenberg, Benjamin D
2016-04-01
Current chronic pain treatments target nociception rather than affective "suffering" and its associated functional and psychiatric comorbidities. The left dorsolateral prefrontal cortex (DLPFC) has been implicated in affective, cognitive, and attentional aspects of pain and is a primary target of neuromodulation for affective disorders. Transcranial direct current stimulation (tDCS) can non-invasively modulate cortical activity. The present study tests whether anodal tDCS targeting the left DLPFC will increase tolerability of acute painful stimuli vs cathodal tDCS. Forty tDCS-naive healthy volunteers received anodal and cathodal stimulation targeting the left DLPFC in two randomized and counterbalanced sessions. During stimulation, each participant performed cold pressor (CP) and breath holding (BH) tasks. We measured pain intensity with the Defense and Veterans Pain Rating Scale (DVPRS) before and after each task. Mixed ANOVA revealed no main effect of stimulation polarity for mean CP threshold, tolerance, or endurance, or mean BH time (allP > 0.27). However, DVPRS rise associated with CP was significantly smaller with anodal vs cathodal tDCS (P = 0.024). We further observed a significant tDCS polarity × stimulation order interaction (P = 0.042) on CP threshold, suggesting task sensitization. Although our results do not suggest that polarity of tDCS targeting the left DLPFC differentially modulates the tolerability of CP- and BH-related pain distress in healthy volunteers, there was a significant effect on DVPRS pain ratings. This contrasts with our previous findings that tDCS targeting the left dorsal anterior cingulate cortex showed a trend toward higher mean CP tolerance with cathodal vs anodal stimulation. The present results may suggest tDCS-related effects on nociception or DLPFC-mediated attention, or preferential modulation of the affective valence of pain as captured by the DVPRS. Sham-controlled clinical studies are needed. © 2015
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Brennan, Sean; McLoughlin, Declan M; O'Connell, Redmond; Bogue, John; O'Connor, Stephanie; McHugh, Caroline; Glennon, Mark
2017-05-01
Transcranial direct current stimulation (tDCS) can enhance a range of neuropsychological functions but its efficacy in addressing clinically significant emotion recognition deficits associated with depression is largely untested. A randomized crossover placebo controlled study was used to investigate the effects of tDCS over the left dorsolateral prefrontal cortex (L-DLPFC) on a range of neuropsychological variables associated with depression as well as neural activity in the associated brain region. A series of computerized tests was administered to clinical (n = 17) and control groups (n = 20) during sham and anodal (1.5 mA) stimulation. Anodal tDCS led to a significant main effect for overall emotion recognition (p = .02), with a significant improvement in the control group (p = .04). Recognition of disgust was significantly greater in the clinical group (p = .01). Recognition of anger was significantly improved for the clinical group (p = .04) during anodal stimulation. Differences between groups for each of the six emotions at varying levels of expression found that at 40% during anodal stimulation, happy recognition significantly improved for the clinical group (p = .01). Anger recognition at 80% during anodal stimulation significantly improved for the clinical group (p = .02). These improvements were observed in the absence of any change in psychomotor speed or trail making ability during anodal stimulation. Working memory significantly improved during anodal stimulation for the clinical group but not for controls (p = .03). The tentative findings of this study indicate that tDCS can have a neuromodulatory effect on a range of neuropsychological variables. However, it is clear that there was a wide variation in responses to tDCS and that individual difference and different approaches to testing and stimulation have a significant impact on final outcomes. Nonetheless, tDCS remains a promising tool for future neuropsychological research.
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Dedoncker, Josefien; Brunoni, Andre R; Baeken, Chris; Vanderhasselt, Marie-Anne
2016-01-01
Research into the effects of transcranial direct current stimulation of the dorsolateral prefrontal cortex on cognitive functioning is increasing rapidly. However, methodological heterogeneity in prefrontal tDCS research is also increasing, particularly in technical stimulation parameters that might influence tDCS effects. To systematically examine the influence of technical stimulation parameters on DLPFC-tDCS effects. We performed a systematic review and meta-analysis of tDCS studies targeting the DLPFC published from the first data available to February 2016. Only single-session, sham-controlled, within-subject studies reporting the effects of tDCS on cognition in healthy controls and neuropsychiatric patients were included. Evaluation of 61 studies showed that after single-session a-tDCS, but not c-tDCS, participants responded faster and more accurately on cognitive tasks. Sub-analyses specified that following a-tDCS, healthy subjects responded faster, while neuropsychiatric patients responded more accurately. Importantly, different stimulation parameters affected a-tDCS effects, but not c-tDCS effects, on accuracy in healthy samples vs. increased current density and density charge resulted in improved accuracy in healthy samples, most prominently in females; for neuropsychiatric patients, task performance during a-tDCS resulted in stronger increases in accuracy rates compared to task performance following a-tDCS. Healthy participants respond faster, but not more accurate on cognitive tasks after a-tDCS. However, increasing the current density and/or charge might be able to enhance response accuracy, particularly in females. In contrast, online task performance leads to greater increases in response accuracy than offline task performance in neuropsychiatric patients. Possible implications and practical recommendations are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.
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Cattaneo, Zaira; Mattavelli, Giulia; Platania, Elisa; Papagno, Costanza
2011-06-01
Stereotypes associated with gender, race, ethnicity and religion are powerful forces in human social interactions. Previous neuroimaging and neuropsychological studies point to a role of the prefrontal cortex in controlling stereotypical responses. Here we used transcranial magnetic stimulation (TMS) in combination with an Implicit Association Test (IAT) to highlight the possible causal role of the left dorsolateral prefrontal cortex (DLPFC) and the right anterior dorsomedial prefrontal cortex (aDMPFC) in controlling gender-stereotypical responses. Young male and female participants were tested. Our results showed that applying TMS over the left DLPFC and the right aDMPFC increased the gender-stereotypical bias in male participants compared to when TMS was applied to a control site (vertex). This suggests that both the left DLPFC and the right aDMPFC play a direct role in stereotyping. Females did not show a significant gender bias on the IAT; correspondingly their responses were unaffected by TMS. Copyright © 2011 Elsevier Inc. All rights reserved.
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Kimoto, Sohei; Bazmi, H Holly; Lewis, David A
2014-09-01
Cognitive deficits of schizophrenia may be due at least in part to lower expression of the 67-kDa isoform of glutamic acid decarboxylase (GAD67), a key enzyme for GABA synthesis, in the dorsolateral prefrontal cortex of individuals with schizophrenia. However, little is known about the molecular regulation of lower cortical GAD67 levels in schizophrenia. The GAD67 promoter region contains a conserved Zif268 binding site, and Zif268 activation is accompanied by increased GAD67 expression. Thus, altered expression of the immediate early gene Zif268 may contribute to lower levels of GAD67 mRNA in the dorsolateral prefrontal cortex in schizophrenia. The authors used polymerase chain reaction to quantify GAD67 and Zif268 mRNA levels in dorsolateral prefrontal cortex area 9 from 62 matched pairs of schizophrenia and healthy comparison subjects, and in situ hybridization to assess Zif268 expression at laminar and cellular levels of resolution. The effects of potentially confounding variables were assessed in human subjects, and the effects of antipsychotic treatments were tested in antipsychotic-exposed monkeys. The specificity of the Zif268 findings was assessed by quantifying mRNA levels for other immediate early genes. GAD67 and Zif268 mRNA levels were significantly lower and were positively correlated in the schizophrenia subjects. Both Zif268 mRNA-positive neuron density and Zif268 mRNA levels per neuron were significantly lower in the schizophrenia subjects. These findings were robust to the effects of the confounding variables examined and differed from other immediate early genes. Deficient Zif268 mRNA expression may contribute to lower cortical GAD67 levels in schizophrenia, suggesting a potential mechanistic basis for altered cortical GABA synthesis and impaired cognition in schizophrenia.
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Vermeij, Anouk; van Beek, Arenda H E A; Reijs, Babette L R; Claassen, Jurgen A H R; Kessels, Roy P C
2014-01-01
Older adults show more bilateral prefrontal activation during cognitive performance than younger adults, who typically show unilateral activation. This over-recruitment has been interpreted as compensation for declining structure and function of the brain. Here we examined how the relationship between behavioral performance and prefrontal activation is modulated by different levels of working-memory load. Eighteen healthy older adults (70.8 ± 5.0 years; MMSE 29.3 ± 0.9) performed a spatial working-memory task (n-back). Oxygenated ([O2Hb]) and deoxygenated ([HHb]) hemoglobin concentration changes were registered by two functional Near-Infrared Spectroscopy (fNIRS) channels located over the left and right prefrontal cortex. Increased working-memory load resulted in worse performance compared to the control condition. [O2Hb] increased with rising working-memory load in both fNIRS channels. Based on the performance in the high working-memory load condition, the group was divided into low and high performers. A significant interaction effect of performance level and hemisphere on [O2Hb] increase was found, indicating that high performers were better able to keep the right prefrontal cortex engaged under high cognitive demand. Furthermore, in the low performers group, individuals with a larger decline in task performance from the control to the high working-memory load condition had a larger bilateral increase of [O2Hb]. The high performers did not show a correlation between performance decline and working-memory load related prefrontal activation changes. Thus, additional bilateral prefrontal activation in low performers did not necessarily result in better cognitive performance. Our study showed that bilateral prefrontal activation may not always be successfully compensatory. Individual behavioral performance should be taken into account to be able to distinguish successful and unsuccessful compensation or declined neural efficiency.
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Maeoka, Hiroshi; Matsuo, Atsushi; Hiyamizu, Makoto; Morioka, Shu; Ando, Hiroshi
2012-03-14
Pain is a multidimensional experience with sensory-discriminative, cognitive-evaluative and affective-motivational components. Emotional factors such as unpleasantness or anxiety are known to have influence on pain in humans. The aim of this single-blinded, cross over study was to evaluate the effects of transcranial direct current stimulation (tDCS) on emotional aspects of pain in pain alleviation. Fifteen subjects (5 females, 10 males) volunteered to participate in this study. In an oddball paradigm, three categories of 20 pictures (unpleasant, neutral, and pleasant) served as rare target pictures from the International Affective Picture System (IAPS). The power of the delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-25 Hz), and gamma (30-40 Hz) frequency bands in the three categories were measured using electroencephalography during an oddball paradigm at pre- and post-anodal or sham tDCS above the left dorsolateral prefrontal cortex (DLPFC). Results showed that the beta band power was significantly increased, and the alpha band power was significantly decreased during unpleasant pictures after anodal tDCS compared with sham tDCS. Furthermore, regarding unpleasant pictures, subjective reports of Self Assessment Manikin (SAM) for emotional valence after anodal tDCS showed a significant decrease of unpleasantness. Therefore, emotional aspects of pain may be effectively alleviated by tDCS of the left DLPFC as was shown not only by subjective evaluation, but also by objective observation of cerebral neural activity. This processing may be mediated by facilitation of the descending pain inhibitory system through enhancing neural activity of the left DLPFC. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
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Higgins, Daniel M; Peterson, Jordan B; Pihl, Robert O; Lee, Alice G M
2007-08-01
Studies 1 and 2 assessed performance on a battery of dorsolateral prefrontal cognitive ability (D-PFCA) tests, personality, psychometric intelligence, and academic performance (AP) in 2 undergraduate samples. In Studies 1 and 2, AP was correlated with D-PFCA (r=.37, ppersonality. Studies 3 and 4 assessed D-PFCA, personality, and workplace performance among (a) managerial-administrative workers and (b) factory floor workers at a manufacturing company. Prefrontal cognitive ability correlated with supervisor ratings of manager performance at values of r ranging from .42 to .57 (ps<.001), depending on experience, and with factory floor performance at pr=.21 (p=.02), after controlling for experience, age, and education. Conscientiousness correlated with factory floor performance at r=.23.
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Gallo, David A; Kensinger, Elizabeth A; Schacter, Daniel L
2006-01-01
According to the distinctiveness heuristic, subjects rely more on detailed recollections (and less on familiarity) when memory is tested for pictures relative to words, leading to reduced false recognition. If so, then neural regions that have been implicated in effortful postretrieval monitoring (e.g., dorsolateral prefrontal cortex) might be recruited less heavily when trying to remember pictures. We tested this prediction with the criterial recollection task. Subjects studied black words, paired with either the same word in red font or a corresponding colored picture. Red words were repeated at study to equate recognition hits for red words and pictures. During fMRI scanning, alternating red word memory tests and picture memory tests were given, using only white words as test stimuli (say "yes" only if you recollect a corresponding red word or picture, respectively). These tests were designed so that subjects had to rely on memory for the criterial information. Replicating prior behavioral work, we found enhanced rejection of lures on the picture test compared to the red word test, indicating that subjects had used a distinctiveness heuristic. Critically, dorsolateral prefrontal activity was reduced when rejecting familiar lures on the picture test, relative to the red word test. These findings indicate that reducing false recognition via the distinctiveness heuristic is not heavily dependent on frontally mediated postretrieval monitoring processes.
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Li, Yue; Zhang, Lei; Long, Kehong; Gong, Hui; Lei, Hao
2018-02-16
A growing body of literature has suggested that video game playing can induce functional and structural plasticity of the brain. The underlying mechanisms, however, remain poorly understood. In this study, functional near-infrared spectroscopy (fNIRS) was used to record prefrontal activities in 24 experienced game players when they played a massively multiplayer online battle arena video game, League of Legends (LOL), under naturalistic conditions. It was observed that game onset was associated with significant activations in the ventrolateral prefrontal cortex (VLPFC) and concomitant deactivations in the dorsolateral prefrontal cortex (DLPFC) and frontal pole area (FPA). Game events, such as slaying an enemy and being slain by an enemy evoked region-specific time-locked hemodynamic/oxygenation responses in the prefrontal cortex (PFC). It was proposed that the VLPFC activities during LOL playing are likely responses to visuo-motor task load of the game, while the DLPFC/FPA activities may be involved in the constant shifts of attentional states and allocation of cognitive resources required by game playing. The present study demonstrated that it is feasible to use fNIRS to monitor real-time prefrontal activity during online video game playing. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Weissbart, Steven J; Bhavsar, Rupal; Rao, Hengyi; Wein, Alan J; Detre, John A; Arya, Lily A; Smith, Ariana L
2018-04-06
The mechanism of sacral neuromodulation is poorly understood. We compared brain activity during urgency before and after sacral neuromodulation in women with overactive bladder and according to response to treatment. Women with refractory overactive bladder who elected for sacral neuromodulation were invited to undergo a functional magnetic resonance imaging exam before and after treatment. During the imaging exams, the bladder was filled until urgency was experienced. Regions of interest were identified a priori, and brain activity in these regions of interest was compared before and after treatment as well as according to treatment response. A whole brain exploratory analysis with an uncorrected voxel level threshold of pbrain regions that changed after sacral neuromodulation. Among 12 women who underwent a pretreatment functional magnetic resonance imaging exam, seven were successfully treated with sacral neuromodulation and underwent a posttreatment exam. After sacral neuromodulation, brain activity decreased in the left anterior cingulate cortex, bilateral insula, left dorsolateral prefrontal cortex and bilateral orbitofrontal cortex (all pbrain regions with increased activity after sacral neuromodulation. Pretreatment brain activity levels in the bilateral anterior cingulate cortex, right insula, bilateral dorsolateral prefrontal cortex, right orbitofrontal cortex, right supplementary motor area, and right sensorimotor cortex were higher in women who underwent successful treatment (all pBrain activity during urgency changes after successful sacral neuromodulation. Sacral neuromodulation may be more effective in women with higher levels of pretreatment brain activity during urgency. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.
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Albaugh, Matthew D; Ducharme, Simon; Collins, D Louis; Botteron, Kelly N; Althoff, Robert R; Evans, Alan C; Karama, Sherif; Hudziak, James J
2013-05-01
Recent functional connectivity studies have demonstrated that, in resting humans, activity in a dorsally-situated neocortical network is inversely associated with activity in the amygdalae. Similarly, in human neuroimaging studies, aspects of emotion regulation have been associated with increased activity in dorsolateral, dorsomedial, orbital and ventromedial prefrontal regions, as well as concomitant decreases in amygdalar activity. These findings indicate the presence of two countervailing systems in the human brain that are reciprocally related: a dorsally-situated cognitive control network, and a ventrally-situated limbic network. We investigated the extent to which this functional reciprocity between limbic and dorsal neocortical regions is recapitulated from a purely structural standpoint. Specifically, we hypothesized that amygdalar volume would be related to cerebral cortical thickness in cortical regions implicated in aspects of emotion regulation. In 297 typically developing youths (162 females, 135 males; 572 MRIs), the relationship between cortical thickness and amygdalar volume was characterized. Amygdalar volume was found to be inversely associated with thickness in bilateral dorsolateral and dorsomedial prefrontal, inferior parietal, as well as bilateral orbital and ventromedial prefrontal cortices. Our findings are in line with previous work demonstrating that a predominantly dorsally-centered neocortical network is reciprocally related to core limbic structures such as the amygdalae. Future research may benefit from investigating the extent to which such cortical-limbic morphometric relations are qualified by the presence of mood and anxiety psychopathology. Copyright © 2012 Elsevier Inc. All rights reserved.
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Sherwood, Matthew S; Kane, Jessica H; Weisend, Michael P; Parker, Jason G
2016-01-01
Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback can be used to train localized, conscious regulation of blood oxygen level-dependent (BOLD) signals. As a therapeutic technique, rt-fMRI neurofeedback reduces the symptoms of a variety of neurologic disorders. To date, few studies have investigated the use of self-regulation training using rt-fMRI neurofeedback to enhance cognitive performance. This work investigates the utility of rt-fMRI neurofeedback as a tool to enhance human cognition by training healthy individuals to consciously control activity in the left dorsolateral prefrontal cortex (DLPFC). A cohort of 18 healthy participants in the experimental group underwent rt-fMRI neurofeedback from the left DLPFC in five training sessions across two weeks while 7 participants in the control group underwent similar training outside the MRI and without rt-fMRI neurofeedback. Working memory (WM) performance was evaluated on two testing days separated by the five rt-fMRI neurofeedback sessions using two computerized tests. We investigated the ability to control the BOLD signal across training sessions and WM performance across the two testing days. The group with rt-fMRI neurofeedback demonstrated a significant increase in the ability to self-regulate the BOLD signal in the left DLPFC across sessions. WM performance showed differential improvement between testing days one and two across the groups with the highest increases observed in the rt-fMRI neurofeedback group. These results provide evidence that individuals can quickly gain the ability to consciously control the left DLPFC, and this training results in improvements of WM performance beyond that of training alone. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
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A bilateral frontoparietal network underlies visuospatial analogical reasoning.
Watson, Christine E; Chatterjee, Anjan
2012-02-01
Our ability to reason by analogy facilitates problem solving and allows us to communicate ideas efficiently. In this study, we examined the neural correlates of analogical reasoning and, more specifically, the contribution of rostrolateral prefrontal cortex (RLPFC) to reasoning. This area of the brain has been hypothesized to integrate relational information, as in analogy, or the outcomes of subgoals, as in multi-tasking and complex problem solving. Using fMRI, we compared visuospatial analogical reasoning to a control task that was as complex and difficult as the analogies and required the coordination of subgoals but not the integration of relations. We found that analogical reasoning more strongly activated bilateral RLPFC, suggesting that anterior prefrontal cortex is preferentially recruited by the integration of relational knowledge. Consistent with the need for inhibition during analogy, bilateral, and particularly right, inferior frontal gyri were also more active during analogy. Finally, greater activity in bilateral inferior parietal cortex during the analogy task is consistent with recent evidence for the neural basis of spatial relation knowledge. Together, these findings indicate that a network of frontoparietal areas underlies analogical reasoning; we also suggest that hemispheric differences may emerge depending on the visuospatial or verbal/semantic nature of the analogies. Copyright © 2011 Elsevier Inc. All rights reserved.
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Ventromedial prefrontal cortex mediates visual attention during facial emotion recognition.
Wolf, Richard C; Philippi, Carissa L; Motzkin, Julian C; Baskaya, Mustafa K; Koenigs, Michael
2014-06-01
The ventromedial prefrontal cortex is known to play a crucial role in regulating human social and emotional behaviour, yet the precise mechanisms by which it subserves this broad function remain unclear. Whereas previous neuropsychological studies have largely focused on the role of the ventromedial prefrontal cortex in higher-order deliberative processes related to valuation and decision-making, here we test whether ventromedial prefrontal cortex may also be critical for more basic aspects of orienting attention to socially and emotionally meaningful stimuli. Using eye tracking during a test of facial emotion recognition in a sample of lesion patients, we show that bilateral ventromedial prefrontal cortex damage impairs visual attention to the eye regions of faces, particularly for fearful faces. This finding demonstrates a heretofore unrecognized function of the ventromedial prefrontal cortex-the basic attentional process of controlling eye movements to faces expressing emotion. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Transcranial direct current stimulation over prefrontal cortex diminishes degree of risk aversion.
Ye, Hang; Chen, Shu; Huang, Daqiang; Wang, Siqi; Jia, Yongmin; Luo, Jun
2015-06-26
Previous studies have established that transcranial direct current stimulation (tDCS) is a powerful technique for manipulating the activity of the human cerebral cortex. Many studies have found that weighing the risks and benefits in decision-making involves a complex neural network that includes the dorsolateral prefrontal cortex (DLPFC). We studied whether participants change the balance of risky and safe responses after receiving tDCS applied over the right and left prefrontal cortex. A total of 60 healthy volunteers performed a risk task while they received either anodal tDCS over the right prefrontal cortex, with cathodal over the left; anodal tDCS over the left prefrontal cortex, with cathodal over the right; or sham stimulation. The participants tended to choose less risky options after receiving sham stimulation, demonstrating that the task might be highly influenced by the "wealth effect". There was no statistically significant change after either right anodal/left cathodal or left anodal/right cathodal tDCS, indicating that both types of tDCS impact the participants' degrees of risk aversion, and therefore, counteract the wealth effect. We also found gender differences in the participants' choices. These findings extend the notion that DLPFC activity is critical for risk decision-making. Application of tDCS to the right/left DLPFC may impact a person's attitude to taking risks. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
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Lewis, David A.; Hashimoto, Takanori; Morris, Harvey M.
2008-01-01
Impairments in cognitive control, such as those involved in working memory, are associated with dysfunction of the dorsolateral prefrontal cortex (DLPFC) in individuals with schizophrenia. This dysfunction appears to result, at least in part, from abnormalities in GABA-mediated neurotransmission. In this paper, we review recent findings indicating that the altered DLPFC circuitry in subjects with schizophrenia reflects changes in the expression of genes that encode selective presynaptic and p...
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Directory of Open Access Journals (Sweden)
Alexandre Heeren
Full Text Available People with anxiety disorders show an attentional bias for threat (AB, and Attention Bias Modification (ABM procedures have been found to reduce this bias. However, the underlying processes accounting for this effect remain poorly understood. One explanation suggests that ABM requires the modification of attention control, driven by the recruitment of the dorsolateral prefrontal cortex (DLPFC. In the present double-blind study, we examined whether modifying left DLPFC activation influences the effect of ABM on AB. We used transcranial direct current stimulation (tDCS to directly modulate cortical excitability of the left DLPFC during an ABM procedure designed to reduce AB to threat. Anodal tDCS increases excitability, whereas cathodal tDCS decreases it. We randomly assigned highly trait-anxious individuals to one of three conditions: 1 ABM combined with cathodal tDCS, 2 ABM combined with anodal tDCS, or 3 ABM combined with sham tDCS. We assessed the effects of these manipulations on both reaction times and eye-movements on a task indexing AB. Results indicate that combining ABM and anodal tDCS over the left DLPFC reduces the total duration that participants' gaze remains fixated on threat, as assessed using eye-tracking measurement. However, in contrast to previous studies, there were no changes in AB from baseline to post-training for participants that received ABM without tDCS. As the tendency to maintain attention to threat is known to play an important role in the maintenance of anxiety, the present findings suggest that anodal tDCS over the left DLPFC may be considered as a promising tool to reduce the maintenance of gaze to threat. Implications for future translational research combining ABM and tDCS are discussed.
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Hamidi, Massihullah; Tononi, Giulio; Postle, Bradley R.
2008-01-01
The dorsolateral prefrontal cortex (dlPFC) plays an important role in working memory, including the control of memory-guided response. In this study, with 24 subjects, we used high frequency repetitive transcranial magnetic stimulation (rTMS) to evaluate the role of the dlPFC in memory-guided response to two different types of spatial working memory tasks: one requiring a recognition decision about a probe stimulus (operationalized with a yes/no button press), another requiring direct recall ...
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Prefrontal Cortex Structure Predicts Training-Induced Improvements in Multitasking Performance.
Verghese, Ashika; Garner, K G; Mattingley, Jason B; Dux, Paul E
2016-03-02
The ability to perform multiple, concurrent tasks efficiently is a much-desired cognitive skill, but one that remains elusive due to the brain's inherent information-processing limitations. Multitasking performance can, however, be greatly improved through cognitive training (Van Selst et al., 1999, Dux et al., 2009). Previous studies have examined how patterns of brain activity change following training (for review, see Kelly and Garavan, 2005). Here, in a large-scale human behavioral and imaging study of 100 healthy adults, we tested whether multitasking training benefits, assessed using a standard dual-task paradigm, are associated with variability in brain structure. We found that the volume of the rostral part of the left dorsolateral prefrontal cortex (DLPFC) predicted an individual's response to training. Critically, this association was observed exclusively in a task-specific training group, and not in an active-training control group. Our findings reveal a link between DLPFC structure and an individual's propensity to gain from training on a task that taps the limits of cognitive control. Cognitive "brain" training is a rapidly growing, multibillion dollar industry (Hayden, 2012) that has been touted as the panacea for a variety of disorders that result in cognitive decline. A key process targeted by such training is "cognitive control." Here, we combined an established cognitive control measure, multitasking ability, with structural brain imaging in a sample of 100 participants. Our goal was to determine whether individual differences in brain structure predict the extent to which people derive measurable benefits from a cognitive training regime. Ours is the first study to identify a structural brain marker-volume of left hemisphere dorsolateral prefrontal cortex-associated with the magnitude of multitasking performance benefits induced by training at an individual level. Copyright © 2016 the authors 0270-6474/16/362638-08$15.00/0.
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Reward-dependent modulation of working memory in lateral prefrontal cortex.
Kennerley, Steven W; Wallis, Jonathan D
2009-03-11
Although research implicates lateral prefrontal cortex (PFC) in executive control and goal-directed behavior, it remains unclear how goals influence executive processes. One possibility is that goal-relevant information, such as expected rewards, could modulate the representation of information relating to executive control, thereby ensuring the efficient allocation of cognitive resources. To investigate this, we examined how reward modulated spatial working memory. Past studies investigating spatial working memory have focused on dorsolateral PFC, but this area only weakly connects with areas processing reward. Ventrolateral PFC has better connections in this regard. Thus, we contrasted the functional properties of single neurons in ventrolateral and dorsolateral PFC as two subjects performed a task that required them to hold spatial information in working memory under different expectancies of reward for correct performance. We balanced the order of presentation of spatial and reward information so we could assess the neuronal encoding of the two pieces of information independently and conjointly. Neurons in ventrolateral PFC encoded both spatial and reward information earlier, stronger and in a more sustained manner than neurons in dorsolateral PFC. Within ventrolateral PFC, spatial selectivity was more prevalent on the inferior convexity than within the principal sulcus. Finally, when reward increased spatial selectivity, behavioral performance improved, whereas when reward decreased spatial selectivity, behavioral performance deteriorated. These results suggest that ventrolateral PFC may be a locus whereby information about expected rewards can modulate information in working memory. The pattern of results is consistent with a role for ventrolateral PFC in attentional control.
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Directory of Open Access Journals (Sweden)
Karina Karis
2018-01-01
Full Text Available Neural adhesion proteins are crucial in the development and maintenance of functional neural connectivity. Growing evidence suggests that the IgLON family of neural adhesion molecules LSAMP, NTM, NEGR1, and OPCML are important candidates in forming the susceptibility to schizophrenia (SCZ. IgLON proteins have been shown to be involved in neurite outgrowth, synaptic plasticity and neuronal connectivity, all of which have been shown to be altered in the brains of patients with the diagnosis of schizophrenia. Here we optimized custom 5′-isoform-specific TaqMan gene-expression analysis for the transcripts of human IgLON genes to study the expression of IgLONs in the dorsolateral prefrontal cortex (DLPFC of schizophrenic patients (n = 36 and control subjects (n = 36. Uniform 5′-region and a single promoter was confirmed for the human NEGR1 gene by in silico analysis. IgLON5, a recently described family member, was also included in the study. We detected significantly elevated levels of the NEGR1 transcript (1.33-fold increase and the NTM 1b isoform transcript (1.47-fold increase in the DLPFC of schizophrenia patients compared to healthy controls. Consequent protein analysis performed in male subjects confirmed the increase in NEGR1 protein content both in patients with the paranoid subtype and in patients with other subtypes. In-group analysis of patients revealed that lower expression of certain IgLON transcripts, mostly LSAMP 1a and 1b, could be related with concurrent depressive endophenotype in schizophrenic patients. Additionally, our study cohort provides further evidence that cannabis use may be a relevant risk factor associated with suicidal behaviors in psychotic patients. In conclusion, we provide clinical evidence of increased expression levels of particular IgLON family members in the DLPFC of schizophrenic patients. We propose that alterations in the expression profile of IgLON neural adhesion molecules are associated with brain
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Impaired prefrontal hemodynamic maturation in autism and unaffected siblings.
Directory of Open Access Journals (Sweden)
Yuki Kawakubo
Full Text Available BACKGROUND: Dysfunctions of the prefrontal cortex have been previously reported in individuals with autism spectrum disorders (ASD. Previous studies reported that first-degree relatives of individuals with ASD show atypical brain activity during tasks associated with social function. However, developmental changes in prefrontal dysfunction in ASD and genetic influences on the phenomena remain unclear. In the present study, we investigated the change in hemoglobin concentration in the prefrontal cortex as measured with near-infrared spectroscopy, in children and adults with ASD during the letter fluency test. Moreover, to clarify the genetic influences on developmental changes in the prefrontal dysfunction in ASD, unaffected siblings of the ASD participants were also assessed. METHODOLOGY/PRINCIPAL FINDINGS: Study participants included 27 individuals with high-functioning ASD, age- and IQ-matched 24 healthy non-affected siblings, and 27 unrelated healthy controls aged 5 to 39 years. The relative concentration of hemoglobin ([Hb] in the prefrontal cortex was measured during the letter fluency task. For children, neither the [oxy-Hb] change during the task nor task performances differed significantly among three groups. For adults, the [oxy-Hb] increases during the task were significantly smaller in the bilateral prefrontal cortex in ASD than those in control subjects, although task performances were similar. In the adult siblings the [oxy-Hb] change was intermediate between those in controls and ASDs. CONCLUSION/SIGNIFICANCE: Although indirectly due to a cross-sectional design, the results of this study indicate altered age-related change of prefrontal activity during executive processing in ASD. This is a first near-infrared spectroscopy study that implies alteration in the age-related changes of prefrontal activity in ASD and genetic influences on the phenomena.
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Levitt, James J; Nestor, Paul G; Levin, Laura; Pelavin, Paula; Lin, Pan; Kubicki, Marek; McCarley, Robert W; Shenton, Martha E; Rathi, Yogesh
2017-11-01
The striatum receives segregated and integrative white matter tracts from the cortex facilitating information processing in the cortico-basal ganglia network. The authors examined both types of input tracts in the striatal associative loop in chronic schizophrenia patients and healthy control subjects. Structural and diffusion MRI scans were acquired on a 3-T system from 26 chronic schizophrenia patients and 26 matched healthy control subjects. Using FreeSurfer, the associative cortex was parcellated into ventrolateral prefrontal cortex and dorsolateral prefrontal cortex subregions. The striatum was manually parcellated into its associative and sensorimotor functional subregions. Fractional anisotropy and normalized streamlines, an estimate of fiber counts, were assessed in four frontostriatal tracts (dorsolateral prefrontal cortex-associative striatum, dorsolateral prefrontal cortex-sensorimotor striatum, ventrolateral prefrontal cortex-associative striatum, and ventrolateral prefrontal cortex-sensorimotor striatum). Furthermore, these measures were correlated with a measure of cognitive control, the Trail-Making Test, Part B. Results showed reduced fractional anisotropy and fewer streamlines in chronic schizophrenia patients for all four tracts, both segregated and integrative. Post hoc t tests showed reduced fractional anisotropy in the left ventrolateral prefrontal cortex-associative striatum and left ventrolateral prefrontal cortex-sensorimotor striatum and fewer normalized streamlines in the right dorsolateral prefrontal cortex-sensorimotor striatum and in the left and right ventrolateral prefrontal cortex-sensorimotor striatum in chronic schizophrenia patients. Furthermore, normalized streamlines in the right dorsolateral prefrontal cortex-sensorimotor striatum negatively correlated with Trail-Making Test, Part B, time spent in healthy control subjects but not in chronic schizophrenia patients. These findings demonstrated that structural connectivity is
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Directory of Open Access Journals (Sweden)
Manish S Dalwani
Full Text Available Structural neuroimaging studies have demonstrated lower regional gray matter volume in adolescents with severe substance and conduct problems. These research studies, including ours, have generally focused on male-only or mixed-sex samples of adolescents with conduct and/or substance problems. Here we compare gray matter volume between female adolescents with severe substance and conduct problems and female healthy controls of similar ages.Female adolescents with severe substance and conduct problems will show significantly less gray matter volume in frontal regions critical to inhibition (i.e. dorsolateral prefrontal cortex and ventrolateral prefrontal cortex, conflict processing (i.e., anterior cingulate, valuation of expected outcomes (i.e., medial orbitofrontal cortex and the dopamine reward system (i.e. striatum.We conducted whole-brain voxel-based morphometric comparison of structural MR images of 22 patients (14-18 years with severe substance and conduct problems and 21 controls of similar age using statistical parametric mapping (SPM and voxel-based morphometric (VBM8 toolbox. We tested group differences in regional gray matter volume with analyses of covariance, adjusting for age and IQ at p<0.05, corrected for multiple comparisons at whole-brain cluster-level threshold.Female adolescents with severe substance and conduct problems compared to controls showed significantly less gray matter volume in right dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, medial orbitofrontal cortex, anterior cingulate, bilateral somatosensory cortex, left supramarginal gyrus, and bilateral angular gyrus. Considering the entire brain, patients had 9.5% less overall gray matter volume compared to controls.Female adolescents with severe substance and conduct problems in comparison to similarly aged female healthy controls showed substantially lower gray matter volume in brain regions involved in inhibition, conflict processing, valuation
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Lyoo, In Kyoon; Kim, Jieun E; Yoon, Sujung J; Hwang, Jaeuk; Bae, Sujin; Kim, Dajung J
2011-07-01
A multiwave longitudinal neuroimaging study in a cohort of direct survivors of a South Korean subway disaster, most of whom recovered from posttraumatic stress disorder 5 years after trauma, provided a unique opportunity to investigate the brain correlates of recovery from a severe psychological trauma. To investigate region-specific brain mobilization during successful recovery from posttraumatic stress disorder by assessing cortical thickness multiple times from early after trauma to recovery, and to examine whether a brain-derived neurotrophic factor gene polymorphism was associated with this brain mobilization. Five-year follow-up case-control study conducted from 2003-2007. Seoul National University and Hospital. Thirty psychologically traumatized disaster survivors and 36 age- and sex-matched control group members recruited from the disaster registry and local community, respectively, who contributed 156 high-resolution brain magnetic resonance images during 3 waves of assessments. Cerebral cortical thickness measured in high-resolution anatomic magnetic resonance images using a validated cortical thickness analysis tool and its prospective changes from early after trauma to recovery in trauma-exposed individuals and controls. Trauma-exposed individuals had greater dorsolateral prefrontal cortical (DLPFC) thickness 1.42 years after trauma (right DLPFC, 5.4%; left superior frontal cortex, 5.8%; and left inferior frontal cortex, 5.3% [all clusters, P ≤ .01]) relative to controls. Thicknesses gradually normalized over time during recovery. We found a positive linear trend, with trauma-exposed individuals with a valine/valine genotype having the greatest DLPFC cortical thickness, followed by those with a methionine genotype and controls (P < .001 for trend). Greater DLPFC thickness was associated with greater posttraumatic stress disorder symptom reductions and better recovery. The DLPFC region might play an important role in psychological recovery from a
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Disrupted nodal and hub organization account for brain network abnormalities in Parkinson’s disease
Directory of Open Access Journals (Sweden)
Yuko Koshimori
2016-11-01
Full Text Available The recent application of graph theory to brain networks promises to shed light on complex diseases such as Parkinson’s disease. This study aimed to investigate functional changes in sensorimotor and cognitive networks in parkinsonian patients, with a focus on inter- and intra-connectivity organization in the disease-associated nodal and hub regions using the graph theoretical analyses. Resting-state functional MRI data of a total of 65 participants, including 23 healthy controls and 42 patients, were investigated in 120 nodes for local efficiency, betweenness centrality, and degree. Hub regions were identified in the healthy control and patient groups. We found nodal and hub changes in patients compared with healthy controls, including the right pre-supplementary motor area, left anterior insula, bilateral mid-insula, bilateral dorsolateral prefrontal cortex, and right caudate nucleus. In general, nodal regions within the sensorimotor network (i.e. right pre-supplementary motor area and right mid-insula displayed weakened connectivity, with the former node associated with more severe bradykinesia, and impaired integration with default mode network regions. The left mid-insula also lost its hub properties in patients. Within the executive networks, the left anterior insular cortex lost its hub properties in patients, while a new hub region was identified in the right caudate nucleus, paralleled by an increased level of inter- and intra-connectivity in the bilateral dorsolateral prefrontal cortex possibly representing compensatory mechanisms. These findings highlight the diffuse changes in nodal organization and regional hub disruption accounting for the distributed abnormalities across brain networks and the clinical manifestations of Parkinson’s disease.
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Arbula, Sandra; Pacella, Valentina; De Pellegrin, Serena; Rossetto, Marta; Denaro, Luca; D'Avella, Domenico; Della Puppa, Alessandro; Vallesi, Antonino
2017-06-01
The diverging evidence for functional localization of response inhibition within the prefrontal cortex might be justified by the still unclear involvement of other intrinsically related cognitive processes like response selection and sustained attention. In this study, the main aim was to understand whether inhibitory impairments, previously found in patients with both left and right frontal lesions, could be better accounted for by assessing these potentially related cognitive processes. We tested 37 brain tumor patients with left prefrontal, right prefrontal and non-prefrontal lesions and a healthy control group on Go/No-Go and Foreperiod tasks. In both types of tasks inhibitory impairments are likely to cause false alarms, although additionally the former task requires response selection and the latter target detection abilities. Irrespective of the task context, patients with right prefrontal damage showed frequent Go and target omissions, probably due to sustained attention lapses. Left prefrontal patients, on the other hand, showed both Go and target omissions and high false alarm rates to No-Go and warning stimuli, suggesting a decisional rather than an inhibitory impairment. An exploratory whole-brain voxel-based lesion-symptom mapping analysis confirmed the association of left ventrolateral and dorsolateral prefrontal lesions with target discrimination failure, and right ventrolateral and medial prefrontal lesions with target detection failure. Results from this study show how left and right prefrontal areas, which previous research has linked to response inhibition, underlie broader cognitive control processes, particularly involved in response selection and target detection. Based on these findings, we suggest that successful inhibitory control relies on more than one functionally distinct process which, if assessed appropriately, might help us to better understand inhibitory impairments across different pathologies. Copyright © 2017 The Authors
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Ferreri, Laura; Bigand, Emmanuel; Perrey, Stephane; Muthalib, Makii; Bard, Patrick; Bugaiska, Aurélia
2014-01-01
Several neuroimaging studies of cognitive aging revealed deficits in episodic memory abilities as a result of prefrontal cortex (PFC) limitations. Improving episodic memory performance despite PFC deficits is thus a critical issue in aging research. Listening to music stimulates cognitive performance in several non-purely musical activities (e.g., language and memory). Thus, music could represent a rich and helpful source during verbal encoding and therefore help subsequent retrieval. Furthermore, such benefit could be reflected in less demand of PFC, which is known to be crucial for encoding processes. This study aimed to investigate whether music may improve episodic memory in older adults while decreasing the PFC activity. Sixteen healthy older adults (μ = 64.5 years) encoded lists of words presented with or without a musical background while their dorsolateral prefrontal cortex (DLPFC) activity was monitored using a eight-channel continuous-wave near-infrared spectroscopy (NIRS) system (Oxymon Mk III, Artinis, The Netherlands). Behavioral results indicated a better source-memory performance for words encoded with music compared to words encoded with silence (p < 0.05). Functional NIRS data revealed bilateral decrease of oxyhemoglobin values in the music encoding condition compared to the silence condition (p < 0.05), suggesting that music modulates the activity of the DLPFC during encoding in a less-demanding direction. Taken together, our results indicate that music can help older adults in memory performances by decreasing their PFC activity. These findings open new perspectives about music as tool for episodic memory rehabilitation on special populations with memory deficits due to frontal lobe damage such as Alzheimer's patients.
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Directory of Open Access Journals (Sweden)
Felicitas Grundeis
2017-06-01
Full Text Available Background/Objectives: Previous studies suggest that non-invasive transcranial direct current stimulation (tDCS applied to the prefrontal cortex modulates food choices and calorie intake in obese humans.Participants/Methods: In the present fully randomized, placebo-controlled, within-subject and double-blinded study, we applied single sessions of anodal, cathodal, and sham tDCS to the left dorsolateral prefrontal cortex (DLPFC and contralateral frontal operculum in 25 hungry obese women and investigated possible influences on food reappraisal abilities as well as calorie intake. We hypothesized that tDCS, (i improves the ability to regulate the desire for visually presented foods and, (ii reduces their consumption.Results: We could not confirm an effect of anodal or cathodal tDCS, neither on the ability to modulate the desire for visually presented foods, nor on calorie consumption.Conclusions: The present findings do not support the notion of prefrontal/frontal tDCS as a promising treatment option for obesity.
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Goldstein, Kim E; Hazlett, Erin A; Savage, Kimberley R; Berlin, Heather A; Hamilton, Holly K; Zelmanova, Yuliya; Look, Amy E; Koenigsberg, Harold W; Mitsis, Effie M; Tang, Cheuk Y; McNamara, Margaret; Siever, Larry J; Cohen, Barry H; New, Antonia S
2011-04-15
Schizotypal personality disorder (SPD) individuals and borderline personality disorder (BPD) individuals have been reported to show neuropsychological impairments and abnormalities in brain structure. However, relationships between neuropsychological function and brain structure in these groups are not well understood. This study compared visual-spatial working memory (SWM) and its associations with dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC) gray matter volume in 18 unmedicated SPD patients with no BPD traits, 18 unmedicated BPD patients with no SPD traits, and 16 healthy controls (HC). Results showed impaired SWM in SPD but not BPD, compared with HC. Moreover, among the HC group, but not SPD patients, better SWM performance was associated with larger VLPFC (BA44/45) gray matter volume (Fisher's Z p-values <0.05). Findings suggest spatial working memory impairments may be a core neuropsychological deficit specific to SPD patients and highlight the role of VLPFC subcomponents in normal and dysfunctional memory performance. Published by Elsevier B.V.
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Amodal processing in human prefrontal cortex.
Tamber-Rosenau, Benjamin J; Dux, Paul E; Tombu, Michael N; Asplund, Christopher L; Marois, René
2013-07-10
Information enters the cortex via modality-specific sensory regions, whereas actions are produced by modality-specific motor regions. Intervening central stages of information processing map sensation to behavior. Humans perform this central processing in a flexible, abstract manner such that sensory information in any modality can lead to response via any motor system. Cognitive theories account for such flexible behavior by positing amodal central information processing (e.g., "central executive," Baddeley and Hitch, 1974; "supervisory attentional system," Norman and Shallice, 1986; "response selection bottleneck," Pashler, 1994). However, the extent to which brain regions embodying central mechanisms of information processing are amodal remains unclear. Here we apply multivariate pattern analysis to functional magnetic resonance imaging (fMRI) data to compare response selection, a cognitive process widely believed to recruit an amodal central resource across sensory and motor modalities. We show that most frontal and parietal cortical areas known to activate across a wide variety of tasks code modality, casting doubt on the notion that these regions embody a central processor devoid of modality representation. Importantly, regions of anterior insula and dorsolateral prefrontal cortex consistently failed to code modality across four experiments. However, these areas code at least one other task dimension, process (instantiated as response selection vs response execution), ensuring that failure to find coding of modality is not driven by insensitivity of multivariate pattern analysis in these regions. We conclude that abstract encoding of information modality is primarily a property of subregions of the prefrontal cortex.
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Energy Technology Data Exchange (ETDEWEB)
Shin, Na-Young [The Catholic University of Korea, Department of Radiology, College of Medicine, Seoul (Korea, Republic of); Hong, Jinwoo; Yoon, Uicheul [Catholic University of Daegu, Department of Biomedical Engineering, College of Health and Medical Science, Gyeongsan-si, Gyeongbuk (Korea, Republic of); Choi, Jun Yong [Yonsei University College of Medicine, Department of Internal Medicine and AIDS Research Institute, Seoul (Korea, Republic of); Lee, Seung-Koo [Yonsei University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Lim, Soo Mee [Ewha Womans University, School of Medicine, Department of Radiology, Seoul (Korea, Republic of)
2017-11-15
To identify brain cortical regions relevant to HIV-associated neurocognitive disorder (HAND) in HIV patients. HIV patients with HAND (n = 10), those with intact cognition (HIV-IC; n = 12), and age-matched, seronegative controls (n = 11) were recruited. All participants were male and underwent 3-dimensional T1-weighted imaging. Both vertex-wise and region of interest (ROI) analyses were performed to analyse cortical thickness. Compared to controls, both HIV-IC and HAND showed decreased cortical thickness mainly in the bilateral primary sensorimotor areas, extending to the prefrontal and parietal cortices. When directly comparing HIV-IC and HAND, HAND showed cortical thinning in the left retrosplenial cortex, left dorsolateral prefrontal cortex, left inferior parietal lobule, bilateral superior medial prefrontal cortices, right temporoparietal junction and left hippocampus, and cortical thickening in the left middle occipital cortex. Left retrosplenial cortical thinning showed significant correlation with slower information processing, declined verbal memory and executive function, and impaired fine motor skills. This study supports previous research suggesting the selective vulnerability of the primary sensorimotor cortices and associations between cortical thinning in the prefrontal and parietal cortices and cognitive impairment in HIV-infected patients. Furthermore, for the first time, we propose retrosplenial cortical thinning as a possible major contributor to HIV-associated cognitive impairment. (orig.)
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International Nuclear Information System (INIS)
Shin, Na-Young; Hong, Jinwoo; Yoon, Uicheul; Choi, Jun Yong; Lee, Seung-Koo; Lim, Soo Mee
2017-01-01
To identify brain cortical regions relevant to HIV-associated neurocognitive disorder (HAND) in HIV patients. HIV patients with HAND (n = 10), those with intact cognition (HIV-IC; n = 12), and age-matched, seronegative controls (n = 11) were recruited. All participants were male and underwent 3-dimensional T1-weighted imaging. Both vertex-wise and region of interest (ROI) analyses were performed to analyse cortical thickness. Compared to controls, both HIV-IC and HAND showed decreased cortical thickness mainly in the bilateral primary sensorimotor areas, extending to the prefrontal and parietal cortices. When directly comparing HIV-IC and HAND, HAND showed cortical thinning in the left retrosplenial cortex, left dorsolateral prefrontal cortex, left inferior parietal lobule, bilateral superior medial prefrontal cortices, right temporoparietal junction and left hippocampus, and cortical thickening in the left middle occipital cortex. Left retrosplenial cortical thinning showed significant correlation with slower information processing, declined verbal memory and executive function, and impaired fine motor skills. This study supports previous research suggesting the selective vulnerability of the primary sensorimotor cortices and associations between cortical thinning in the prefrontal and parietal cortices and cognitive impairment in HIV-infected patients. Furthermore, for the first time, we propose retrosplenial cortical thinning as a possible major contributor to HIV-associated cognitive impairment. (orig.)
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Ferreri, Laura; Bigand, Emmanuel; Bard, Patrick; Bugaiska, Aurélia
2015-01-01
Music can be thought of as a complex stimulus able to enrich the encoding of an event thus boosting its subsequent retrieval. However, several findings suggest that music can also interfere with memory performance. A better understanding of the behavioral and neural processes involved can substantially improve knowledge and shed new light on the most efficient music-based interventions. Based on fNIRS studies on music, episodic encoding, and the dorsolateral prefrontal cortex (PFC), this work...
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Jäncke, Lutz; Brunner, Béatrice; Esslen, Michaela
2008-07-16
Little is currently known about the neural underpinnings of the cognitive control of driving behavior in realistic situations and of the driver's speeding behavior in particular. In this study, participants drove in realistic scenarios presented in a high-end driving simulator. Scalp-recorded EEG oscillations in the alpha-band (8-13 Hz) with a 30-electrode montage were recorded while the participants drove under different conditions: (i) excessively fast (Fast), (ii) in a controlled manner at a safe speed (Correct), and (iii) impatiently in the context of testing traffic conditions (Impatient). Intracerebral sources of alpha-band activation were estimated using low resolution electrical tomography. Given that previous studies have shown a strong negative correlation between the Bold response in the frontal cortex and the alpha-band power, we used alpha-band-related activity as an estimation of frontal activation. Statistical analysis revealed more alpha-band-related activity (i.e. less neuronal activation) in the right lateral prefrontal cortex, including the dorsolateral prefrontal cortex, during fast driving. Those participants who speeded most and exhibited greater risk-taking behavior demonstrated stronger alpha-related activity (i.e. less neuronal activation) in the left anterior lateral prefrontal cortex. These findings are discussed in the context of current theories about the role of the lateral prefrontal cortex in controlling risk-taking behavior, task switching, and multitasking.
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Roberts, C A; Wetherell, M A; Fisk, J E; Montgomery, C
2015-01-01
Cognitive deficits are well documented in ecstasy (3,4-methylenedioxymethamphetamine; MDMA) users, with such deficits being taken as evidence of dysregulation of the serotonin (5-hydroxytryptamine; 5-HT) system. More recently neuroimaging has been used to corroborate these deficits. The present study aimed to assess multitasking performance in ecstasy polydrug users, polydrug users and drug-naive individuals. It was predicted that ecstasy polydrug users would perform worse than non-users on the behavioural measure and this would be supported by differences in cortical blood oxygenation. In the study, 20 ecstasy-polydrug users, 17 polydrug users and 19 drug-naive individuals took part. On day 1, drug use history was taken and questionnaire measures were completed. On day 2, participants completed a 20-min multitasking stressor while brain blood oxygenation was measured using functional near infrared spectroscopy (fNIRS). There were no significant differences between the three groups on the subscales of the multitasking stressor. In addition, there were no significant differences on self-report measures of perceived workload (NASA Task Load Index). In terms of mood, ecstasy users were significantly less calm and less relaxed compared with drug-naive controls. There were also significant differences at three voxels on the fNIRS, indicating decreased blood oxygenation in ecstasy users compared with drug-naive controls at voxel 2 (left dorsolateral prefrontal cortex), voxel 14 and voxel 16 (right dorsolateral prefrontal cortex), and compared with polydrug controls at V14. The results of the present study provide support for changes in brain activation during performance of demanding tasks in ecstasy polydrug users, which could be related to cerebral vasoconstriction.
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Walter, Martin; Witzel, Joachim; Wiebking, Christine; Gubka, Udo; Rotte, Michael; Schiltz, Kolja; Bermpohl, Felix; Tempelmann, Claus; Bogerts, Bernhard; Heinze, Hans Jochen; Northoff, Georg
2007-09-15
Although pedophilia is of high public concern, little is known about underlying neural mechanisms. Although pedophilic patients are sexually attracted to prepubescent children, they show no sexual interest toward adults. This study aimed to investigate the neural correlates of deficits of sexual and emotional arousal in pedophiles. Thirteen pedophilic patients and 14 healthy control subjects were tested for differential neural activity during visual stimulation with emotional and erotic pictures with functional magnetic resonance imaging. Regions showing differential activations during the erotic condition comprised the hypothalamus, the periaqueductal gray, and dorsolateral prefrontal cortex, the latter correlating with a clinical measure. Alterations of emotional processing concerned the amygdala-hippocampus and dorsomedial prefrontal cortex. Hypothesized regions relevant for processing of erotic stimuli in healthy individuals showed reduced activations during visual erotic stimulation in pedophilic patients. This suggests an impaired recruitment of key structures that might contribute to an altered sexual interest of these patients toward adults.
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Directory of Open Access Journals (Sweden)
Michael A. Nitsche
2012-06-01
Full Text Available The prefrontal cortex is involved in mood and emotional processing. In patients suffering from depression, the left dorsolateral prefrontal cortex is hypoactive, while activity of the right dorsolateral prefrontal cortex is enhanced. Counterbalancing these pathological excitability alterations by repetitive transcranial magnetic stimulation (rTMS or transcranial direct current stimulation (tDCS improves mood in these patients. In healthy subjects, however, rTMS of the same areas has no major effect, and the effects of tDCS are mixed. We aimed to evaluate the effects of prefrontal tDCS on mood and mood-related cognitive processing in healthy humans. In a first study, we administered excitability-enhancing anodal, excitability-diminishing cathodal and placebo tDCS to the left dorsolateral prefrontal cortex, combined with antagonistic stimulation of the right frontopolar cortex, and tested acute mood changes by an adjective checklist. Subjective mood was not influenced by tDCS. Emotional face identification, however, which was explored in a second experiment, was subtly improved by a tDCS-driven excitability modulation of the prefrontal cortex, markedly by anodal tDCS of the left dorsolateral prefrontal cortex for positive emotional content. We conclude that tDCS of the prefrontal cortex improves mood processing in healthy subjects, but does not influence subjective mood state.
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Ćurčić-Blake, Branislava; Bais, Leonie; Sibeijn-Kuiper, Anita; Pijnenborg, Hendrika Maria; Knegtering, Henderikus; Liemburg, Edith; Aleman, André
2017-08-01
Glutamatergic models of psychosis propose that dysfunction of N-methyl-d-aspartate (NMDA) receptors, and associated excess of glutamate, may underlie psychotic experiences in people with schizophrenia. However, little is known about the specific relation between glutamate and auditory verbal hallucinations (AVH) in patients with psychosis. In this study, levels of glutamate+glutamine (Glx) in the left lateral prefrontal lobe were determined using proton magnetic resonance spectroscopy ( 1 H MRS) to calculate their association with AVH. Sixty-seven patients with schizophrenia and thirty healthy control participants (HC) underwent magnetic resonance spectroscopy (MRS) to estimate levels of Glx in the white matter of the left prefrontal lobe. The spectrum was estimated from an 8mm 3 voxel placed in the left lateral prefrontal region, belonging to both the cingulum and forceps minor. Patients with lifetime AVH (AVH group; n=45) and patients without lifetime AVH were compared (NoAVH group; n=22) to control participants. Levels of Glx were significantly different between the groups (F(2,94)=5.27, p=0.007). Planned comparisons showed that higher Glx levels were found in control participants than in the total patient group (p=0.010). However, patients with lifetime AVH had higher levels of Glx compared to patients without lifetime AVH (p=0.019). Creatin levels were similar in all three groups. We found no association between Glx and the severity of symptoms (item P3 of the PANSS or PANSS positive subscale). The higher Glx levels in patients with lifetime AVH as compared to patients without lifetime AVH suggest a mediating role for Glx in AVH. Our results are consistent with a previous study that found similar decreased levels of Glx in patients with schizophrenia, and increased levels in an AVH group as compared to a NoAVH group. The role of the glutamatergic system deserves further investigation, for example in different brain regions and in relation to clinical variables
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Inactivation of Primate Prefrontal Cortex Impairs Auditory and Audiovisual Working Memory.
Plakke, Bethany; Hwang, Jaewon; Romanski, Lizabeth M
2015-07-01
The prefrontal cortex is associated with cognitive functions that include planning, reasoning, decision-making, working memory, and communication. Neurophysiology and neuropsychology studies have established that dorsolateral prefrontal cortex is essential in spatial working memory while the ventral frontal lobe processes language and communication signals. Single-unit recordings in nonhuman primates has shown that ventral prefrontal (VLPFC) neurons integrate face and vocal information and are active during audiovisual working memory. However, whether VLPFC is essential in remembering face and voice information is unknown. We therefore trained nonhuman primates in an audiovisual working memory paradigm using naturalistic face-vocalization movies as memoranda. We inactivated VLPFC, with reversible cortical cooling, and examined performance when faces, vocalizations or both faces and vocalization had to be remembered. We found that VLPFC inactivation impaired subjects' performance in audiovisual and auditory-alone versions of the task. In contrast, VLPFC inactivation did not disrupt visual working memory. Our studies demonstrate the importance of VLPFC in auditory and audiovisual working memory for social stimuli but suggest a different role for VLPFC in unimodal visual processing. The ventral frontal lobe, or inferior frontal gyrus, plays an important role in audiovisual communication in the human brain. Studies with nonhuman primates have found that neurons within ventral prefrontal cortex (VLPFC) encode both faces and vocalizations and that VLPFC is active when animals need to remember these social stimuli. In the present study, we temporarily inactivated VLPFC by cooling the cortex while nonhuman primates performed a working memory task. This impaired the ability of subjects to remember a face and vocalization pair or just the vocalization alone. Our work highlights the importance of the primate VLPFC in the processing of faces and vocalizations in a manner that
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Anderson, Afrouz A; Parsa, Kian; Geiger, Sydney; Zaragoza, Rachel; Kermanian, Riley; Miguel, Helga; Dashtestani, Hadis; Chowdhry, Fatima A; Smith, Elizabeth; Aram, Siamak; Gandjbakhche, Amir H
2018-01-01
Existing literature outlines the quality and location of activation in the prefrontal cortex (PFC) during working memory (WM) tasks. However, the effects of individual differences on the underlying neural process of WM tasks are still unclear. In this functional near infrared spectroscopy study, we administered a visual and auditory n-back task to examine activation in the PFC while considering the influences of task performance, and preferred learning strategy (VARK score). While controlling for age, results indicated that high performance (HP) subjects (accuracy > 90%) showed task dependent lower activation compared to normal performance subjects in PFC region Specifically HP groups showed lower activation in left dorsolateral PFC (DLPFC) region during performance of auditory task whereas during visual task they showed lower activation in the right DLPFC. After accounting for learning style, we found a correlation between visual and aural VARK score and level of activation in the PFC. Subjects with higher visual VARK scores displayed lower activation during auditory task in left DLPFC, while those with higher visual scores exhibited higher activation during visual task in bilateral DLPFC. During performance of auditory task, HP subjects had higher visual VARK scores compared to NP subjects indicating an effect of learning style on the task performance and activation. The results of this study show that learning style and task performance can influence PFC activation, with applications toward neurological implications of learning style and populations with deficits in auditory or visual processing.
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Soutschek, Alexander; Sauter, Marian; Schubert, Torsten
2015-12-01
Previous functional imaging studies investigating the neural basis of strategic decision making in the prisoner's dilemma reported a correlation between cooperative behavior and dorsolateral prefrontal cortex (DLPFC) activity; however, the precise function of the DLPFC in establishing cooperation remains unclear so far. The present study investigated the causal role of the DLPFC in an iterative prisoner's dilemma game with transcranial magnetic stimulation (TMS). We discovered that disrupting the DLPFC with TMS decreased cooperation rates in comparison to control conditions, with this effect being most pronounced when the partner had defected previously. Thus, the current results suggest that the DLPFC contributes to strategic decision making in the prisoner's dilemma game.
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Remembering the time: a continuous clock.
Lewis, Penelope A; Miall, R Chris
2006-09-01
The neural mechanisms for time measurement are currently a subject of much debate. This article argues that our brains can measure time using the same dorsolateral prefrontal cells that are known to be involved in working memory. Evidence for this is: (1) the dorsolateral prefrontal cortex is integral to both cognitive timing and working memory; (2) both behavioural processes are modulated by dopamine and disrupted by manipulation of dopaminergic projections to the dorsolateral prefrontal cortex; (3) the neurons in question ramp their activity in a temporally predictable way during both types of processing; and (4) this ramping activity is modulated by dopamine. The dual involvement of these prefrontal neurons in working memory and cognitive timing supports a view of the prefrontal cortex as a multipurpose processor recruited by a wide variety of tasks.
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Shiozawa, Pedro; Gomes, July Silveira; Ducos, Daniella Valverde; Akiba, Henrique Teruo; Dias, Álvaro Machado; Trevizol, Alisson Paulino; Uchida, Ricardo R.; Orlov, Natasza; Cordeiro, Quirino
2016-01-01
Abstract Introduction: We report a transcranial direct current stimulation (tDCS) protocol over the dorsolateral prefrontal cortex (DLPFC) combined with cognitive training in schizophrenia. Method: We assessed psychotic symptoms in nine patients using the Positive and Negative Syndrome Scale (PANSS). All evaluations were scored at baseline, at the end of the intervention protocol, and during a 4-week follow-up. The tDCS protocol consisted of 10 consecutive sessions over 5-day periods. We pl...
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Bilateral theta-burst magnetic stimulation influence on event-related brain potentials.
Pinto, Nuno; Duarte, Marta; Gonçalves, Helena; Silva, Ricardo; Gama, Jorge; Pato, Maria Vaz
2018-01-01
Theta-burst stimulation (TBS) can be a non-invasive technique to modulate cognitive functions, with promising therapeutic potential, but with some contradictory results. Event related potentials are used as a marker of brain deterioration and can be used to evaluate TBS-related cognitive performance, but its use remains scant. This study aimed to study bilateral inhibitory and excitatory TBS effects upon neurocognitive performance of young healthy volunteers, using the auditory P300' results. Using a double-blind sham-controlled study, 51 healthy volunteers were randomly assigned to five different groups, two submitted to either excitatory (iTBS) or inhibitory (cTBS) stimulation over the left dorsolateral pre-frontal cortex (DLPFC), two other actively stimulated the right DLPFC and finally a sham stimulation group. An oddball based auditory P300 was performed just before a single session of iTBS, cTBS or sham stimulation and repeated immediately after. P300 mean latency comparison between the pre- and post-TBS stimulation stages revealed significantly faster post stimulation latencies only when iTBS was performed on the left hemisphere (p = 0.003). Right and left hemisphere cTBS significantly delayed P300 latency (right p = 0.026; left p = 0.000). Multiple comparisons for N200 showed slower latencies after iTBS over the right hemisphere. No significant difference was found in amplitude variation. TBS appears to effectively influence neural networking involved in P300 formation, but effects seem distinct for iTBS vs cTBS and for the right or the left hemisphere. P300 evoked potentials can be an effective and practical tool to evaluate transcranial magnetic stimulation related outcomes.
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Szabó, Ádám György; Farkas, Kinga; Marosi, Csilla; Kozák, Lajos R; Rudas, Gábor; Réthelyi, János; Csukly, Gábor
2017-12-08
Schizophrenia has a negative effect on the activity of the temporal and prefrontal cortices in the processing of emotional facial expressions. However no previous research focused on the evaluation of mixed emotions in schizophrenia, albeit they are frequently expressed in everyday situations and negative emotions are frequently expressed by mixed facial expressions. Altogether 37 subjects, 19 patients with schizophrenia and 18 healthy control subjects were enrolled in the study. The two study groups did not differ in age and education. The stimulus set consisted of 10 fearful (100%), 10 happy (100%), 10 mixed fear (70% fear and 30% happy) and 10 mixed happy facial expressions. During the fMRI acquisition pictures were presented in a randomized order and subjects had to categorize expressions by button press. A decreased activation was found in the patient group during fear, mixed fear and mixed happy processing in the right ventrolateral prefrontal cortex (VLPFC) and the right anterior insula (RAI) at voxel and cluster level after familywise error correction. No difference was found between study groups in activations to happy facial condition. Patients with schizophrenia did not show a differential activation between mixed happy and happy facial expression similar to controls in the right dorsolateral prefrontal cortex (DLPFC). Patients with schizophrenia showed decreased functioning in right prefrontal regions responsible for salience signaling and valence evaluation during emotion recognition. Our results indicate that fear and mixed happy/fear processing are impaired in schizophrenia, while happy facial expression processing is relatively intact.
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Increased contextual cue utilization with tDCS over the prefrontal cortex during a recognition task
Pergolizzi, Denise; Chua, Elizabeth F.
2016-01-01
The precise role of the prefrontal and posterior parietal cortices in recognition performance remains controversial, with questions about whether these regions contribute to recognition via the availability of mnemonic evidence or via decision biases and retrieval orientation. Here we used an explicit memory cueing paradigm, whereby external cues probabilistically predict upcoming memoranda as old or new, in our case with 75% validity, and these cues affect recognition decision biases in the direction of the cue. The present study applied bilateral transcranial direct current stimulation (tDCS) over prefrontal or posterior parietal cortex, or sham tDCS, to test the causal role of these regions in recognition accuracy or decision biasing. Participants who received tDCS over prefrontal cortex showed increased cue utilization compared to tDCS over posterior parietal cortex and sham tDCS, suggesting that the prefrontal cortex is involved in processes that contribute to decision biases in memory. PMID:27845032
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Reduced prefrontal cortical gray matter volume in young adults exposed to harsh corporal punishment.
Tomoda, Akemi; Suzuki, Hanako; Rabi, Keren; Sheu, Yi-Shin; Polcari, Ann; Teicher, Martin H
2009-08-01
Harsh corporal punishment (HCP) during childhood is a chronic, developmental stressor associated with depression, aggression and addictive behaviors. Exposure to traumatic stressors, such as sexual abuse, is associated with alteration in brain structure, but nothing is known about the potential neurobiological consequences of HCP. The aim of this study was to investigate whether HCP was associated with discernible alterations in gray matter volume (GMV) using voxel-based morphometry (VBM). 1455 young adults (18-25 years) were screened to identify 23 with exposure to HCP (minimum 3 years duration, 12 episodes per year, frequently involving objects) and 22 healthy controls. High-resolution T1-weighted MRI datasets were obtained using Siemens 3 T trio scanner. GMV was reduced by 19.1% in the right medial frontal gyrus (medial prefrontal cortex; MPFC, BA10) (P=0.037, corrected cluster level), by 14.5% in the left medial frontal gyrus (dorsolateral prefrontal cortex; DLPFC, BA9) (P=0.015, uncorrected cluster level) and by 16.9% in the right anterior cingulate gyrus (BA24) (P<0.001, uncorrected cluster level) of HCP subjects. There were significant correlations between GMV in these identified regions and performance IQ on the WAIS-III. Exposing children to harsh HCP may have detrimental effects on trajectories of brain development. However, it is also conceivable that differences in prefrontal cortical development may increase risk of exposure to HCP.
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Dlabac-de Lange, Jozarni J.; Liemburg, Edith J.; Bais, Leonie; van de Poel-Mustafayeva, Aida T.; de Lange-de Klerk, Elly S. M.; Knegtering, Henderikus; Aleman, Andre
2017-01-01
Background: Prefrontal repetitive Transcranial Magnetic Stimulation (rTMS) may improve negative symptoms in patients with schizophrenia, but few studies have investigated the underlying neural mechanism. Objective: This study aims to investigate changes in the levels of glutamate and glutamine (Glx,
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Schreiber, Shaul; Dannon, Pinhas N; Goshen, Elinor; Amiaz, Revital; Zwas, Tzila S; Grunhaus, Leon
2002-11-30
Auditory command hallucinations probably arise from the patient's failure to monitor his/her own 'inner speech', which is connected to activation of speech perception areas of the left cerebral cortex and to various degrees of dysfunction of cortical circuits involved in schizophrenia as supported by functional brain imaging. We hypothesized that rapid transcranial magnetic stimulation (rTMS), by increasing cortical activation of the right prefrontal brain region, would bring about a reduction of the hallucinations. We report our first schizophrenic patient affected with refractory command hallucinations treated with 10 Hz rTMS. Treatment was performed over the right dorsolateral prefrontal cortex, with 1200 magnetic stimulations administered daily for 20 days at 90% motor threshold. Regional cerebral blood flow changes were monitored with neuroSPECT. Clinical evaluation and scores on the Positive and Negative Symptoms Scale and the Brief Psychiatric Rating Scale demonstrated a global improvement in the patient's condition, with no change in the intensity and frequency of the hallucinations. NeuroSPECT performed at intervals during and after treatment indicated a general improvement in cerebral perfusion. We conclude that right prefrontal rTMS may induce a general clinical improvement of schizophrenic brain function, without directly influencing the mechanism involved in auditory command hallucinations.
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Guo, Heng; Zhang, Zhuoran; Da, Shu; Sheng, Xiaotian; Zhang, Xichao
2018-02-01
Studies on risk preferences have long been of great concern and have examined the neural basis underlying risk-based decision making. However, studies using conventional transcranial direct current stimulation (tDCS) revealed that bilateral stimulation could change risk propensity with limited evidence of precisely focalized unilateral high-definition transcranial direct current stimulation (HD-tDCS). The aim of this experiment was to investigate the effect of HD-tDCS focalizing the left dorsal lateral prefrontal cortex (DLPFC) on risk-taking behavior during the Balloon Analogue Risk Task (BART). This study was designed as a between-subject, single-blind, sham-controlled experiment. University students were randomly assigned to three groups: the anodal group (F3 anode, AF3, F1, F5, FC3 returned), the cathodal group (F3 cathodal, AF3, F1, F5, FC3 returned) and the sham group. Subsequently, 1.5-mA 20-min HD-tDCS was applied during the BART, and the Positive Affect and Negative Affect Scale (PANAS), the Sensation Seeking Scale-5 (SSS-5), and the Behavioral Inhibition System and Behavioral Approach System scale (BIS/BAS) were measured as control variables. The cathodal group earned less total money than the sham group, and no significant difference was observed between the anodal group and the sham group. These results showed that, to some extent, focalized unilateral cathodal HD-tDCS on left DLPFC could change performance during risky tasks and diminish risky decision making. Further studies are needed to investigate the dose effect and electrode distribution of HD-tDCS during risky tasks and examine synchronous brain activity to show the neural basis.
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Directory of Open Access Journals (Sweden)
Vadim Zotev
Full Text Available We observed in a previous study (PLoS ONE 6:e24522 that the self-regulation of amygdala activity via real-time fMRI neurofeedback (rtfMRI-nf with positive emotion induction was associated, in healthy participants, with an enhancement in the functional connectivity between the left amygdala (LA and six regions of the prefrontal cortex. These regions included the left rostral anterior cingulate cortex (rACC, bilateral dorsomedial prefrontal cortex (DMPFC, bilateral superior frontal gyrus (SFG, and right medial frontopolar cortex (MFPC. Together with the LA, these six prefrontal regions thus formed the functional neuroanatomical network engaged during the rtfMRI-nf procedure. Here we perform a structural vector autoregression (SVAR analysis of the effective connectivity for this network. The SVAR analysis demonstrates that the left rACC plays an important role during the rtfMRI-nf training, modulating the LA and the other network regions. According to the analysis, the rtfMRI-nf training leads to a significant enhancement in the time-lagged effect of the left rACC on the LA, potentially consistent with the ipsilateral distribution of the monosynaptic projections between these regions. The training is also accompanied by significant increases in the instantaneous (contemporaneous effects of the left rACC on four other regions - the bilateral DMPFC, the right MFPC, and the left SFG. The instantaneous effects of the LA on the bilateral DMPFC are also significantly enhanced. Our results are consistent with a broad literature supporting the role of the rACC in emotion processing and regulation. Our exploratory analysis provides, for the first time, insights into the causal relationships within the network of regions engaged during the rtfMRI-nf procedure targeting the amygdala. It suggests that the rACC may constitute a promising target for rtfMRI-nf training along with the amygdala in patients with affective disorders, particularly posttraumatic stress
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Versace, Amelia; Sharma, Vinod; Bertocci, Michele A; Bebko, Genna; Iyengar, Satish; Dwojak, Amanda; Bonar, Lisa; Perlman, Susan B; Schirda, Claudiu; Travis, Michael; Gill, Mary Kay; Diwadkar, Vaibhav A; Sunshine, Jeffrey L; Holland, Scott K; Kowatch, Robert A; Birmaher, Boris; Axelson, David; Frazier, Thomas W; Arnold, L Eugene; Fristad, Mary A; Youngstrom, Eric A; Horwitz, Sarah M; Findling, Robert L; Phillips, Mary L
2017-01-01
Difficulty regulating positive mood and energy is a feature that cuts across different pediatric psychiatric disorders. Yet, little is known regarding the neural mechanisms underlying different developmental trajectories of positive mood and energy regulation in youth. Recent studies indicate that machine learning techniques can help elucidate the role of neuroimaging measures in classifying individual subjects by specific symptom trajectory. Cortical thickness measures were extracted in sixty-eight anatomical regions covering the entire brain in 115 participants from the Longitudinal Assessment of Manic Symptoms (LAMS) study and 31 healthy comparison youth (12.5 y/o;-Male/Female = 15/16;-IQ = 104;-Right/Left handedness = 24/5). Using a combination of trajectories analyses, surface reconstruction, and machine learning techniques, the present study aims to identify the extent to which measures of cortical thickness can accurately distinguish youth with higher (n = 18) from those with lower (n = 34) trajectories of manic-like behaviors in a large sample of LAMS youth (n = 115; 13.6 y/o; M/F = 68/47, IQ = 100.1, R/L = 108/7). Machine learning analyses revealed that widespread cortical thickening in portions of the left dorsolateral prefrontal cortex, right inferior and middle temporal gyrus, bilateral precuneus, and bilateral paracentral gyri and cortical thinning in portions of the right dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, and right parahippocampal gyrus accurately differentiate (Area Under Curve = 0.89;p = 0.03) youth with different (higher vs lower) trajectories of positive mood and energy dysregulation over a period up to 5years, as measured by the Parent General Behavior Inventory-10 Item Mania Scale. Our findings suggest that specific patterns of cortical thickness may reflect transdiagnostic neural mechanisms associated with different temporal trajectories of positive mood and energy dysregulation in youth. This approach has
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Directory of Open Access Journals (Sweden)
Amelia Versace
Full Text Available Difficulty regulating positive mood and energy is a feature that cuts across different pediatric psychiatric disorders. Yet, little is known regarding the neural mechanisms underlying different developmental trajectories of positive mood and energy regulation in youth. Recent studies indicate that machine learning techniques can help elucidate the role of neuroimaging measures in classifying individual subjects by specific symptom trajectory. Cortical thickness measures were extracted in sixty-eight anatomical regions covering the entire brain in 115 participants from the Longitudinal Assessment of Manic Symptoms (LAMS study and 31 healthy comparison youth (12.5 y/o;-Male/Female = 15/16;-IQ = 104;-Right/Left handedness = 24/5. Using a combination of trajectories analyses, surface reconstruction, and machine learning techniques, the present study aims to identify the extent to which measures of cortical thickness can accurately distinguish youth with higher (n = 18 from those with lower (n = 34 trajectories of manic-like behaviors in a large sample of LAMS youth (n = 115; 13.6 y/o; M/F = 68/47, IQ = 100.1, R/L = 108/7. Machine learning analyses revealed that widespread cortical thickening in portions of the left dorsolateral prefrontal cortex, right inferior and middle temporal gyrus, bilateral precuneus, and bilateral paracentral gyri and cortical thinning in portions of the right dorsolateral prefrontal cortex, left ventrolateral prefrontal cortex, and right parahippocampal gyrus accurately differentiate (Area Under Curve = 0.89;p = 0.03 youth with different (higher vs lower trajectories of positive mood and energy dysregulation over a period up to 5years, as measured by the Parent General Behavior Inventory-10 Item Mania Scale. Our findings suggest that specific patterns of cortical thickness may reflect transdiagnostic neural mechanisms associated with different temporal trajectories of positive mood and energy dysregulation in youth. This
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Araneda, Rodrigo; Renier, Laurent; Dricot, Laurence; Decat, Monique; Ebner-Karestinos, Daniela; Deggouj, Naïma; De Volder, Anne G
2018-01-01
Since we recently showed in behavioural tasks that the top-down cognitive control was specifically altered in tinnitus sufferers, here we wanted to establish the link between this impaired executive function and brain alterations in the frontal cortex in tinnitus patients. Using functional magnetic resonance imaging (fMRI), we monitored the brain activity changes in sixteen tinnitus patients (TP) and their control subjects (CS) while they were performing a spatial Stroop task, both in audition and vision. We observed that TP differed from CS in their functional recruitment of the dorsolateral prefrontal cortex (dlPFC, BA46), the cingulate gyrus and the ventromedial prefrontal cortex (vmPFC, BA10). This recruitment was higher during interference conditions in tinnitus participants than in controls, whatever the sensory modality. Furthermore, the brain activity level in the right dlPFC and vmPFC correlated with the performance in the Stroop task in TP. Due to the direct link between poor executive functions and prefrontal cortex alterations in TP, we postulate that a lack of inhibitory modulation following an impaired top-down cognitive control may maintain tinnitus by hampering habituation mechanisms. This deficit in executive functions caused by prefrontal cortex alterations would be a key-factor in the generation and persistence of tinnitus.
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Directory of Open Access Journals (Sweden)
Long-Biao eCui
2015-11-01
Full Text Available Understanding the neural basis of schizophrenia (SZ is important for shedding light on the neurobiological mechanisms underlying this mental disorder. Structural and functional alterations in the anterior cingulate cortex (ACC, dorsolateral prefrontal cortex (DLPFC, hippocampus, and medial prefrontal cortex (MPFC have been implicated in the neurobiology of SZ. However, the effective connectivity among them in SZ remains unclear. The current study investigated how neuronal pathways involving these regions were affected in first-episode SZ using functional magnetic resonance imaging (fMRI. Forty-nine patients with a first-episode of psychosis and diagnosis of SZ—according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision—were studied. Fifty healthy controls (HCs were included for comparison. All subjects underwent resting state fMRI. We used spectral dynamic causal modeling (DCM to estimate directed connections among the bilateral ACC, DLPFC, hippocampus, and MPFC. We characterized the differences using Bayesian parameter averaging (BPA in addition to classical inference (t-test. In addition to common effective connectivity in these two groups, HCs displayed widespread significant connections predominantly involved in ACC not detected in SZ patients, but SZ showed few connections. Based on BPA results, SZ patients exhibited anterior cingulate cortico-prefrontal-hippocampal hyperconnectivity, as well as ACC-related and hippocampal-dorsolateral prefrontal-medial prefrontal hypoconnectivity. In summary, sDCM revealed the pattern of effective connectivity involving ACC in patients with first-episode SZ. This study provides a potential link between SZ and dysfunction of ACC, creating an ideal situation to associate mechanisms behind SZ with aberrant connectivity among these cognition and emotion-related regions.
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Shalini, Suku-Maran; Herr, Deron R; Ong, Wei-Yi
2017-10-01
Pain and anxiety have a complex relationship and pain is known to share neurobiological pathways and neurotransmitters with anxiety. Top-down modulatory pathways of pain have been shown to originate from cortical and subcortical regions, including the dorsolateral prefrontal cortex. In this study, a novel docosahexaenoic acid (DHA)-containing nutraceutical, Souvenaid, was administered to mice with infraorbital nerve ligation-induced neuropathic pain and behavioral responses recorded. Infraorbital nerve ligation resulted in increased face wash strokes of the face upon von Frey hair stimulation, indicating increased nociception. Part of this response involves general pain sensitization that is dependent on the CNS, since increased nociception was also found in the paws during the hot plate test. Mice receiving oral gavage of Souvenaid, a nutraceutical containing DHA; choline; and other cell membrane components, showed significantly reduced pain sensitization. The mechanism of Souvenaid's activity involves supraspinal antinociception, originating in the prefrontal cortex, since inhibition of the DHA-metabolizing enzyme 15-lipoxygenase (Alox15) in the prefrontal cortex attenuated the antinociceptive effect of Souvenaid. Alox15 inhibition also modulated anxiety behavior associated with pain after infraorbital nerve ligation. The effects of Souvenaid components and Alox15 on reducing central sensitization of pain may be due to strengthening of a known supraspinal antinociceptive pathway from the prefrontal cortex to the periaqueductal gray. Together, results indicate the importance of the prefrontal cortex and DHA/Alox15 in central antinociceptive pathways and suggest that Souvenaid may be a novel therapeutic for neuropathic pain.
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Halari, R; Kumari, V
2005-03-07
Men are hypothesised to perform better than women at tasks requiring cognitive inhibition. The present study applied whole-brain functional magnetic resonance imaging to investigate the neural correlates of cognitive inhibition using a novel task, requiring detection of numbers decreasing in numerical order, in relation to sex. The study involved 19 young healthy subjects (9 men, 10 women). Behavioural sex differences favouring men were found on the inhibition, but not on the automatization (i.e. detection of numbers increasing in numerical order), condition of the task. Significant areas of activation associated with cognitive inhibition included the right inferior prefrontal and bilateral dorsolateral prefrontal cortices, left inferior and superior parietal lobes, and bilateral temporal regions across men and women. No brain region was significantly differently activated in men and women. Our findings demonstrate that (a) cognitive inhibition is dependent on intact processes within frontal and parietal regions, and (b) women show inferior cognitive inhibition despite of comparable activation to men in relevant regions. Equated behavioural performance may elicit sex differences in brain activation.
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Bi-Hemispheric Engagement in the Retrieval of Autobiographical Episodes
Directory of Open Access Journals (Sweden)
Marie M. P. Vandekerckhove
2005-01-01
Full Text Available Functional magnetic resonance imaging (fMRI was used to study the neural correlates of neutral, stressful, negative and positive autobiographical memories. The brain activity produced by these different kinds of episodic memory did not differ significantly, but a common pattern of activation for different kinds of autobiographical memory was revealed that included (1 largely bilateral portions of the medial and superior temporal lobes, hippocampus and parahippocampus, (2 portions of the ventral, medial, superior and dorsolateral prefrontal cortex, (3 the anterior and posterior cingulate, including the retrosplenial, cortex, (4 the parietal cortex, and (5 portions of the cerebellum. The brain regions that were mainly activated constituted an interactive network of temporal and prefrontal areas associated with structures of the extended limbic system. The main bilateral activations with left-sided preponderance probably reflected reactivation of complex semantic and episodic self-related information representations that included previously experienced contexts. In conclusion, the earlier view of a strict left versus right prefrontal laterality in the retrieval of semantic as opposed to episodic autobiographical memory, may have to be modified by considering contextual variables such as task demands and subject variables. Consequently, autobiographical memory integration should be viewed as based on distributed bi-hemispheric neural networks supporting multi-modal, emotionally coloured components of personal episodes.
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Manning, Joshua; Reynolds, Gretchen; Saygin, Zeynep M; Hofmann, Stefan G; Pollack, Mark; Gabrieli, John D E; Whitfield-Gabrieli, Susan
2015-01-01
We investigated differences in the intrinsic functional brain organization (functional connectivity) of the human reward system between healthy control participants and patients with social anxiety disorder. Functional connectivity was measured in the resting-state via functional magnetic resonance imaging (fMRI). 53 patients with social anxiety disorder and 33 healthy control participants underwent a 6-minute resting-state fMRI scan. Functional connectivity of the reward system was analyzed by calculating whole-brain temporal correlations with a bilateral nucleus accumbens seed and a ventromedial prefrontal cortex seed. Patients with social anxiety disorder, relative to the control group, had (1) decreased functional connectivity between the nucleus accumbens seed and other regions associated with reward, including ventromedial prefrontal cortex; (2) decreased functional connectivity between the ventromedial prefrontal cortex seed and lateral prefrontal regions, including the anterior and dorsolateral prefrontal cortices; and (3) increased functional connectivity between both the nucleus accumbens seed and the ventromedial prefrontal cortex seed with more posterior brain regions, including anterior cingulate cortex. Social anxiety disorder appears to be associated with widespread differences in the functional connectivity of the reward system, including markedly decreased functional connectivity between reward regions and between reward regions and lateral prefrontal cortices, and markedly increased functional connectivity between reward regions and posterior brain regions.
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Prefrontal-Amygdala Connectivity and State Anxiety during Fear Extinction Recall in Adolescents
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Despina E. Ganella
2017-12-01
Full Text Available While deficits in fear extinction recall have been suggested to underlie vulnerability to anxiety disorders in adolescents, the neurobiology of these deficits remain underexplored. Here we investigate the functional connectivity (FC of the ventromedial prefrontal cortex (vmPFC and dorsolateral PFC (dlPFC underlying extinction recall in healthy adolescents, and assess associations between FC and state/trait anxiety. Adolescents (17 and adults (14, for comparison completed a fear-learning paradigm involving extinction and extinction recall during a functional magnetic resonance imaging session, in which skin conductance response (SCR was recorded. Psychophysiological interaction analyses revealed that during extinction recall there was significant negative connectivity between the vmPFC and amygdala in adults, but not adolescents. vmPFC-amygdala connectivity was positively correlated with SCR. Adolescents showed significant negative FC between the dlPFC and the left and right hippocampus, and the amygdala, which was positively correlated with state anxiety. Recall was also associated with negative connectivity between the dlPFC and thalamus, posterior cingulate cortex, fusiform gyrus, and pallidum in adolescents. These results demonstrate that fear extinction recall in healthy adolescents is associated with FC between prefrontal and limbic brain regions, and suggest that alterations in connectivity may be associated with vulnerability to anxiety in adolescence.
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Prefrontal mediation of emotion regulation in social anxiety disorder during laughter perception.
Kreifelts, Benjamin; Brück, Carolin; Ethofer, Thomas; Ritter, Jan; Weigel, Lena; Erb, Michael; Wildgruber, Dirk
2017-02-01
Social anxiety disorder (SAD) is characterized by negatively biased perception of social cues and deficits in emotion regulation. While negatively biased perception is thought to maintain social anxiety, emotion regulation represents an ability necessary to overcome both biased perception and social anxiety. Here, we used laughter as a social threat in a functional magnetic resonance imaging (fMRI) study to identify cerebral mediators linking SAD with attention and interpretation biases and their modification through cognitive emotion regulation in the form of reappraisal. We found that reappraisal abolished the negative laughter interpretation bias in SAD and that this process was directly mediated through activation patterns of the left dorsolateral prefrontal cortex (DLPFC) serving as a cerebral pivot between biased social perception and its normalization through reappraisal. Connectivity analyses revealed reduced prefrontal control over threat-processing sensory cortices (here: the temporal voice area) during cognitive emotion regulation in SAD. Our results indicate a central role for the left DLPFC in SAD which might represent a valuable target for future research on interventions either aiming to directly modulate cognitive emotion regulation in SAD or to evaluate its potential as physiological marker for psychotherapeutic interventions relying on emotion regulation. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Croarkin, Paul E; Nakonezny, Paul A; Wall, Christopher A; Murphy, Lauren L; Sampson, Shirlene M; Frye, Mark A; Port, John D
2016-01-30
Abnormalities in glutamate neurotransmission may have a role in the pathophysiology of adolescent depression. The present pilot study examined changes in cortical glutamine/glutamate ratios in depressed adolescents receiving high-frequency repetitive transcranial magnetic stimulation. Ten adolescents with treatment-refractory major depressive disorder received up to 30 sessions of 10-Hz repetitive transcranial magnetic stimulation at 120% motor threshold with 3000 pulses per session applied to the left dorsolateral prefrontal cortex. Baseline, posttreatment, and 6-month follow-up proton magnetic resonance spectroscopy scans of the anterior cingulate cortex and left dorsolateral prefrontal cortex were collected at 3T with 8-cm(3) voxels. Glutamate metabolites were quantified with 2 distinct proton magnetic resonance spectroscopy sequences in each brain region. After repetitive transcranial magnetic stimulation and at 6 months of follow-up, glutamine/glutamate ratios increased in the anterior cingulate cortex and left dorsolateral prefrontal cortex with both measurements. The increase in the glutamine/glutamate ratio reached statistical significance with the TE-optimized PRESS sequence in the anterior cingulate cortex. Glutamine/glutamate ratios increased in conjunction with depressive symptom improvement. This reached statistical significance with the TE-optimized PRESS sequence in the left dorsolateral prefrontal cortex. High-frequency repetitive transcranial magnetic stimulation applied to the left dorsolateral prefrontal cortex may modulate glutamate neurochemistry in depressed adolescents. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
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Prefrontal control of attention to threat
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Polly V Peers
2013-02-01
Full Text Available Attentional control refers to the regulatory processes that ensure that our actions are in accordance with our goals. Dual-system accounts view temperament as consisting of both individual variation in emotionality (e.g. trait anxiety and variation in regulatory attentional mechanisms that act to modulate emotionality. Increasing evidence links trait variation in attentional control to clinical mood and anxiety disorder symptoms, independent of trait emotionality. Attentional biases to threat have been robustly linked to mood and anxiety disorders. However, the role of variation in attentional control in influencing such biases, and the neural underpinnings of trait variation in attentional control, are unknown. Here, we show, that individual differences in trait attentional control, even when accounting for trait and state anxiety, are related to the magnitude of an attentional blink following threat-related targets. Moreover, we demonstrate that activity in dorsolateral prefrontal cortex, is observed specifically in relation to control of attention over threatening stimuli, in line with neural theories of attentional control, such as guided activation theory. These results have key implications for neurocognitive theories of attentional bias and emotional resilience.
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The dorso-lateral recess of the hypothalamic ventricle in neonatal rats.
Menéndez, A; Alvarez-Uría, M
1987-10-01
Light and electron microscopy of the hypothalamic ventricle in neonatal rats demonstrate morphological specializations of the ventricular wall at the level of the premammillary region of the third ventricle. The morphological features are: (1) A ventricular recess that we have called the "hypothalamic dorso-lateral recess" (HDR). (2) The presence of intraventricular capillaries near the dorso-lateral recess. (3) The HDR possessing a specialized ependymal lining; this consists of non-ciliated cells with short microvilli and bleb-like processes. (4) The existence of cerebrospinal fluid-contacting neurons within the HDR. (5) The presence of numerous phagocytic supraependymal cells. The HDR is not found in adult rats. This indicates that the dorso-lateral recess may play a physiological role during development.
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Directory of Open Access Journals (Sweden)
Karolina M. Lukasik
2018-01-01
Full Text Available The effects of transcranial direct current stimulation (tDCS on dorsolateral prefrontal cortex functions, such as working memory (WM, have been examined in a number of studies. However, much less is known about the behavioral effects of tDCS over other important WM-related brain regions, such as the ventrolateral prefrontal cortex (VLPFC. In a counterbalanced within-subjects design with 33 young healthy participants, we examined whether online and offline single-session tDCS over VLPFC affects WM updating performance as measured by a digit 3-back task. We compared three conditions: anodal, cathodal and sham. We observed no significant tDCS effects on participants' accuracy or reaction times during or after the stimulation. Neither did we find any differences between anodal and cathodal stimulation. Largely similar results were obtained when comparing subgroups of high- and low-performing participants. Possible reasons for the lack of effects, including individual differences in responsiveness to tDCS, features of montage, task and sample characteristics, and the role of VLPFC in WM, are discussed.
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Premenstrual dysphoric disorder and prefrontal reactivity during anticipation of emotional stimuli.
Gingnell, Malin; Bannbers, Elin; Wikström, Johan; Fredrikson, Mats; Sundström-Poromaa, Inger
2013-11-01
Premenstrual disorder (PMDD) affects around 5% of women in childbearing ages. An increased sensitivity in emotion processing areas of the brain to variations in ovarian steroid levels has been suggested as part of the pathophysiology in PMDD, but prior neuroimaging studies of emotion processing are yet inconclusive. Previous behavioral studies of women with PMDD have, however, reported enhanced luteal phase startle responsivity during emotional anticipation. Here we used functional magnetic resonance imaging (fMRI) to investigate central neural circuitry activity during anticipation of, and exposure to, emotional stimuli across the menstrual cycle in women with and without PMDD. As compared to healthy controls, women with PMDD displayed significantly enhanced reactivity in the prefrontal cortex during anticipation of, but not exposure to, negative emotional stimuli during the luteal phase. In PMDD patients, BOLD reactivity during anticipation or viewing of negative emotional stimuli was not dependent on absolute levels of estradiol or progesterone. However, progesterone levels were positively correlated with emotion-induced reactivity in the dorsolateral prefrontal cortex to positive emotional stimuli. These findings suggest that cortical emotional circuitry reactivity during anticipation is altered in PMDD during the luteal phase, which might be part of the pathophysiology behind the emotional symptoms or lack of emotional control reported by women with PMDD. © 2013 Elsevier B.V. and ECNP. All rights reserved.
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Disrupting the right prefrontal cortex alters moral judgement.
Tassy, Sébastien; Oullier, Olivier; Duclos, Yann; Coulon, Olivier; Mancini, Julien; Deruelle, Christine; Attarian, Sharam; Felician, Olivier; Wicker, Bruno
2012-03-01
Humans daily face social situations involving conflicts between competing moral decision. Despite a substantial amount of studies published over the past 10 years, the respective role of emotions and reason, their possible interaction, and their behavioural expression during moral evaluation remains an unresolved issue. A dualistic approach to moral evaluation proposes that the right dorsolateral prefrontal cortex (rDLPFc) controls emotional impulses. However, recent findings raise the possibility that the right DLPFc processes emotional information during moral decision making. We used repetitive transcranial magnetic stimulation (rTMS) to transiently disrupt rDLPFc activity before measuring decision making in the context of moral dilemmas. Results reveal an increase of the probability of utilitarian responses during objective evaluation of moral dilemmas in the rTMS group (compared to a SHAM one). This suggests that the right DLPFc function not only participates to a rational cognitive control process, but also integrates emotions generated by contextual information appraisal, which are decisive for response selection in moral judgements. © The Author (2011). Published by Oxford University Press.
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International Nuclear Information System (INIS)
Park, Hyun Soo; Bang, Soong Ae; Yoon, Eun Jin; Cho, Sang Soo; Kim, Sang Hee; Kim, Yu Kyeong; Kim, Sang Eun
2007-01-01
Internet Game Addiction (IGA) is known to be associated with poor decision-making and diminished impulse control; however, the underlying neural substrates of IGA have not been identified. To investigate the neural substrates of IGA, we compared regional cerebral glucose metabolism between adults with and without IGA, primarily in the prefrontal brain regions, which have been implicated in inhibitory control. We studied 10 right-handed participants (5 controls: male, 23.8±0.75 y, 5 IGAs: male, 22.6±2.42 y) with FDG PET. A standardized questionnaire was used to assess the severity of IGA. Before scanning, all subjects carried out a computerized version of the Iowa Gambling Task (IGT) and the Balloon Analogue Risk Task (BART), as measures of behavioral inhibitory control. Statistical Parametric Mapping 2 (SPM2) was used to analyze differences in regional brain glucose metabolism between adults with and without IGA. Consistent with our predictions, compared to controls, significant reductions in FDG uptake in individuals with IGA were found in the bilateral orbitofrontal gyrus (BA 11, 47), bilateral inferior frontal gyrus (BA 44, 48), cingulate cortex (BA 24), and bilateral supplementary motor area (SMA) (BA 6); whereas increases were found in the bilateral hippocampus. Correlation analyses within the IGA group further showed that the level of glucose metabolism in the right orbitofrontal gyrus was marginally positively correlated with task scores in BART. Our results showed that IGA is associated with reduced glucose metabolism in the prefrontal regions involved in inhibitory control. This finding highlights dysfunctional inhibitory brain systems in individuals with IGA and offers implications for the development for therapeutic paradigms for IGA
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Baxter, Mark G; Gaffan, David; Kyriazis, Diana A; Mitchell, Anna S
2007-10-17
The orbital prefrontal cortex is thought to be involved in behavioral flexibility in primates, and human neuroimaging studies have identified orbital prefrontal activation during episodic memory encoding. The goal of the present study was to ascertain whether deficits in strategy implementation and episodic memory that occur after ablation of the entire prefrontal cortex can be ascribed to damage to the orbital prefrontal cortex. Rhesus monkeys were preoperatively trained on two behavioral tasks, the performance of both of which is severely impaired by the disconnection of frontal cortex from inferotemporal cortex. In the strategy implementation task, monkeys were required to learn about two categories of objects, each associated with a different strategy that had to be performed to obtain food reward. The different strategies had to be applied flexibly to optimize the rate of reward delivery. In the scene memory task, monkeys learned 20 new object-in-place discrimination problems in each session. Monkeys were tested on both tasks before and after bilateral ablation of orbital prefrontal cortex. These lesions impaired new scene learning but had no effect on strategy implementation. This finding supports a role for the orbital prefrontal cortex in memory but places limits on the involvement of orbital prefrontal cortex in the representation and implementation of behavioral goals and strategies.
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Hori, Hiroaki; Nagamine, Mitsue; Soshi, Takahiro; Okabe, Shigeo; Kim, Yoshiharu; Kunugi, Hiroshi
2008-01-01
Previous functional neuroimaging studies have reported that patients with schizophrenia show reduced prefrontal activation during cognitive tasks whereas patients with schizotypal personality disorder (SPD) show preserved or even increased right prefrontal activation, compared to healthy controls; on the other hand, reduced hemispheric laterality is considered to be common to these two disorders. The aim of this study was to examine the possible association between schizotypal traits at a nonclinical level and prefrontal activation patterns during a letter version of the verbal fluency task (VFT). We examined the relationships of schizotypal traits as measured by the Schizotypal Personality Questionnaire (SPQ) in a nonclinical female population with prefrontal activation patterns during the VFT, using near-infrared spectroscopy. Twenty-seven healthy participants were divided into high (n = 14) and low (n = 13) SPQ groups by the median split of the total SPQ score. Compared to the low SPQ group, the high SPQ group showed significantly larger right prefrontal activation during the performance of the VFT, leading to more bilateral activation. Our results suggest that schizotypal traits at a nonclinical level may be related to relative right prefrontal laterality with overall prefrontal activation being preserved, consistent with previous findings obtained by studies of patients with SPD. 2008 S. Karger AG, Basel.
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Must, Anita; Horváth, Szatmár; Janka, Zoltán
2008-05-30
Patients with major depressive disorder (MDD) show neuropsychological impairments, including deficient executive functions and suboptimal decision-making strategies, which are mediated by several brain regions. In the development of these symptoms the pathology of the prefrontal cortex (PFC), including the dorsolateral, ventromedial and orbitofrontal regions, may also play an important role. Neuropsychological assessment is a useful tool in detecting and measuring these deficiencies, showing that patients with MDD exhibit altered sensitivity to reward and punishment. However, impairment of emotional decision-making strategies in MDD is influenced by genetic variations (5-HTTLPR polymorphism) and personality traits, which seem to have a higher predictive value on decision making performance than the clinical symptoms.
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Directory of Open Access Journals (Sweden)
Guilhem Carle
2017-05-01
Full Text Available The potential of repetitive transcranial magnetic stimulation (rTMS to treat numerous neurological and psychiatric disorders has been thoroughly studied for the last two decades. Here, we report for the first time, the case of a 65-year-old woman suffering from treatment-resistant depression who developed an acute frontal lobe syndrome following eight sessions of low-frequency rTMS (LF-rTMS to the right dorsolateral prefrontal cortex while also treated with sertraline and mianserin. The pathophysiological mechanisms underlying such an unexpected acute frontal lobe dysfunction are discussed in relation to the therapeutic use of LF-rTMS in combination with pharmacotherapy in depressed patients.
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Schulz, Kurt P; Clerkin, Suzanne M; Fan, Jin; Halperin, Jeffrey M; Newcorn, Jeffrey H
2013-03-01
Functional interactions between limbic regions that process emotions and frontal networks that guide response functions provide a substrate for emotional cues to influence behavior. Stimulation of postsynaptic α₂ adrenoceptors enhances the function of prefrontal regions in these networks. However, the impact of this stimulation on the emotional biasing of behavior has not been established. This study tested the effect of the postsynaptic α₂ adrenoceptor agonist guanfacine on the emotional biasing of response execution and inhibition in prefrontal cortex. Fifteen healthy young adults were scanned twice with functional magnetic resonance imaging while performing a face emotion go/no-go task following counterbalanced administration of single doses of oral guanfacine (1 mg) and placebo in a double-blind, cross-over design. Lower perceptual sensitivity and less response bias for sad faces resulted in fewer correct responses compared to happy and neutral faces but had no effect on correct inhibitions. Guanfacine increased the sensitivity and bias selectively for sad faces, resulting in response accuracy comparable to happy and neutral faces, and reversed the valence-dependent variation in response-related activation in left dorsolateral prefrontal cortex (DLPFC), resulting in enhanced activation for response execution cued by sad faces relative to happy and neutral faces, in line with other frontoparietal regions. These results provide evidence that guanfacine stimulation of postsynaptic α₂ adrenoceptors moderates DLPFC activation associated with the emotional biasing of response execution processes. The findings have implications for the α₂ adrenoceptor agonist treatment of attention-deficit hyperactivity disorder.
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Zhou, Zhe Charles; Yu, Chunxiu; Sellers, Kristin K; Fröhlich, Flavio
2016-03-30
Visual discrimination requires sensory processing followed by a perceptual decision. Despite a growing understanding of visual areas in this behavior, it is unclear what role top-down signals from prefrontal cortex play, in particular as a function of perceptual difficulty. To address this gap, we investigated how neurons in dorso-lateral frontal cortex (dl-FC) of freely-moving ferrets encode task variables in a two-alternative forced choice visual discrimination task with high- and low-contrast visual input. About two-thirds of all recorded neurons in dl-FC were modulated by at least one of the two task variables, task difficulty and target location. More neurons in dl-FC preferred the hard trials; no such preference bias was found for target location. In individual neurons, this preference for specific task types was limited to brief epochs. Finally, optogenetic stimulation confirmed the functional role of the activity in dl-FC before target touch; suppression of activity in pyramidal neurons with the ArchT silencing opsin resulted in a decrease in reaction time to touch the target but not to retrieve reward. In conclusion, dl-FC activity is differentially recruited for high perceptual difficulty in the freely-moving ferret and the resulting signal may provide top-down behavioral inhibition.
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Deppe, Michael; Schwindt, Wolfram; Kugel, Harald; Plassmann, Hilke; Kenning, Peter
2005-04-01
The authors used functional magnetic resonance imaging (fMRI) to investigate how individual economic decisions are influenced by implicit memory contributions. Twenty-two participants were asked to make binary decisions between different brands of sensorily nearly undistinguishable consumer goods. Changes of brain activity comparing decisions in the presence or absence of a specific target brand were detected by fMRI. Only when the tar get brand was the participant's favorite one did the authors find reduced activation in the dorsolateral prefrontal, posterior parietal, and occipital cortices and the left premotor area (Brodmann areas [BA] 9, 46, 7/19, and 6). Simultaneously, activity was increased in the inferior precuneus and posterior cingulate (BA 7), right superior frontal gyrus (BA 10), right supramarginal gyrus (BA 40), and, most pronounced, in the ventromedial prefrontal cortex (BA 10). For products mainly distinguishable by brand information, the authors revealed a nonlinear winner-take-all effect for a participant's favorite brand characterized, on one hand, by reduced activation in brain areas associated with working memory and reasoning and, on the other hand, increased activation in areas involved in processing of emotions and self-reflections during decision making.
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Byun, Kyeongho; Hyodo, Kazuki; Suwabe, Kazuya; Ochi, Genta; Sakairi, Yosuke; Kato, Morimasa; Dan, Ippeita; Soya, Hideaki
2014-09-01
Despite the practical implication of mild exercise, little is known about its influence on executive function and its neural substrates. To address these issues, the present study examined the effect of an acute bout of mild exercise on executive function and attempted to identify potential neural substrates using non-invasive functional near-infrared spectroscopy (fNIRS). Twenty-five young individuals performed a color-word matching Stroop task (CWST) and a two-dimensional scale to measure changes of psychological mood states both before and after a 10-minute exercise session on a cycle ergometer at light intensity (30% v(·)o2peak) and, for the control session, without exercise. Cortical hemodynamic changes in the prefrontal area were monitored with fNIRS during the CWST in both sessions. The acute bout of mild exercise led to improved Stroop performance, which was positively correlated with increased arousal levels. It also evoked cortical activations regarding Stroop interference on the left dorsolateral prefrontal cortex and frontopolar area. These activations significantly corresponded with both improved cognitive performance and increased arousal levels. Concurrently, this study provides empirical evidence that an acute bout of mild exercise improves executive function mediated by the exercise-induced arousal system, which intensifies cortical activation in task-related prefrontal sub-regions. Copyright © 2014 Elsevier Inc. All rights reserved.
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Imburgio, Michael J; Orr, Joseph M
2018-05-01
A meta-analysis of studies using single-session transcranial direct current stimulation (tDCS) to target the dorsolateral prefrontal cortex (DLPFC) was undertaken to examine the effect of stimulation on executive function (EF) in healthy samples. 27 studies were included in analyses, yielding 71 effect sizes. The most relevant measure for each task was determined a priori and used to calculate Hedge's g. Methodological characteristics of each study were examined individually as potential moderators of effect size. Stimulation effects on three domains of EF (inhibition of prepotent responses, mental set shifting, and information updating and monitoring) were analyzed separately. In line with previous work, the current study found no significant effect of anodal unilateral tDCS, cathodal unilateral tDCS, or bilateral tDCS on EF. Further moderator and subgroup analyses were only carried out for anodal unilateral montages due to the small number of studies using other montages. Subgroup analyses revealed a significant effect of anodal unilateral tDCS on updating tasks, but not on inhibition or set-shifting tasks. Cathode location significantly moderated the effect of anodal unilateral tDCS. Extracranial cathodes yielded a significant effect on EF while cranial cathodes yielded no effect. Anode size also significantly moderated effect of anodal unilateral tDCS, with smaller anodes being more effective than larger anodes. In summary, anodal DLPFC stimulation is more effective at improving updating ability than inhibition and set-shifting ability, but anodal stimulation can significantly improve general executive function when extracranial cathodes or small anodes are used. Future meta-analyses may examine how stimulation's effects on specific behavioral tasks, rather than broader domains, might be affected by methodological moderators. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Park, Hyun Soo; Bang, Soong Ae; Yoon, Eun Jin; Cho, Sang Soo; Kim, Sang Hee; Kim, Yu Kyeong; Kim, Sang Eun [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)
2007-07-01
Internet Game Addiction (IGA) is known to be associated with poor decision-making and diminished impulse control; however, the underlying neural substrates of IGA have not been identified. To investigate the neural substrates of IGA, we compared regional cerebral glucose metabolism between adults with and without IGA, primarily in the prefrontal brain regions, which have been implicated in inhibitory control. We studied 10 right-handed participants (5 controls: male, 23.8{+-}0.75 y, 5 IGAs: male, 22.6{+-}2.42 y) with FDG PET. A standardized questionnaire was used to assess the severity of IGA. Before scanning, all subjects carried out a computerized version of the Iowa Gambling Task (IGT) and the Balloon Analogue Risk Task (BART), as measures of behavioral inhibitory control. Statistical Parametric Mapping 2 (SPM2) was used to analyze differences in regional brain glucose metabolism between adults with and without IGA. Consistent with our predictions, compared to controls, significant reductions in FDG uptake in individuals with IGA were found in the bilateral orbitofrontal gyrus (BA 11, 47), bilateral inferior frontal gyrus (BA 44, 48), cingulate cortex (BA 24), and bilateral supplementary motor area (SMA) (BA 6); whereas increases were found in the bilateral hippocampus. Correlation analyses within the IGA group further showed that the level of glucose metabolism in the right orbitofrontal gyrus was marginally positively correlated with task scores in BART. Our results showed that IGA is associated with reduced glucose metabolism in the prefrontal regions involved in inhibitory control. This finding highlights dysfunctional inhibitory brain systems in individuals with IGA and offers implications for the development for therapeutic paradigms for IGA.
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The role of the dorsolateral tegmentum in the control of male sexual behavior: a reevaluation.
Romero-Carbente, J C; Camacho, F J; Paredes, R G
2006-06-30
The medial preoptic area/anterior hypothalamus (MPOA/AH) plays a key role in the control of male sexual behavior. Independently of the type, MPOA/AH lesions permanently eliminate male sexual behavior in the rat. The MPOA/AH projects among other structures to the dorsolateral tegmentum (DLT). Bilateral electrolytic lesions of the DLT or the unilateral electrolytic destruction of the MPOA/HA combined with a contralateral electrolytic lesion of the DLT eliminate male sexual behavior. In the present experiment, we evaluated if neurotoxic lesions of the DLT produce the same behavioral deficits as those observed after electrolytic lesions. This would allow us to evaluate if neurons of the DLT or the fibers passing through this area are important in the control of male sexual behavior. To this aim, sexually experience male rats were tested for socio-sexual behavior, partner preference and motor execution in order to determine if the possible behavioral changes could be attributed to alterations in sexual motivation or motor execution. One week after the bilateral DLT lesions the animals were evaluated in the same behavioral tests. The lesions were identified by glial fibrillary acidic protein (GFAP) and neuronal nuclear protein (Neu-N) immunohistochemistry. No significant consistent effects upon sexual behavior were observed in any of the groups, including the group with clear bilateral damage of the DLT. A reduction in the percentage of males displaying ejaculation in the first post-lesion test was observed for all groups injected with quinolinic acid. No effects upon partner preference or motor coordination were observed after the lesion in any of the groups. The lack of effect of DLT neurotoxic lesions upon mating suggests that neurons of this structure are not involved in the control of male sexual behavior.
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Directory of Open Access Journals (Sweden)
Stefania Balzarotti
Full Text Available The dorsolateral prefrontal cortex (DLPFC is generally thought to be involved in affect and emotional processing; however, the specific contribution of each hemisphere continues to be debated. In the present study, we employed unilateral tDCS to test the unique contribution of left DLPFC in the encoding and retrieval of emotional stimuli in healthy subjects. Forty-two right handed undergraduate students received either anodal, cathodal or sham stimulation of left DLPFC while viewing neutral, pleasant, and unpleasant pictures. After completing a filler task, participants were asked to remember as many pictures as possible. Results showed that participants were able to remember a larger amount of emotional (both pleasant and unpleasant pictures than of neutral ones, regardless of the type of tDCS condition. Participants who received anodal stimulation recalled a significantly higher number of pleasant images than participants in the sham and cathodal conditions, while no differences emerged in the recall of neutral and unpleasant pictures. We conclude that our results provide some support to the role of left prefrontal cortex in the encoding and retrieval of pleasant stimuli.
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Balzarotti, Stefania; Colombo, Barbara
2016-01-01
The dorsolateral prefrontal cortex (DLPFC) is generally thought to be involved in affect and emotional processing; however, the specific contribution of each hemisphere continues to be debated. In the present study, we employed unilateral tDCS to test the unique contribution of left DLPFC in the encoding and retrieval of emotional stimuli in healthy subjects. Forty-two right handed undergraduate students received either anodal, cathodal or sham stimulation of left DLPFC while viewing neutral, pleasant, and unpleasant pictures. After completing a filler task, participants were asked to remember as many pictures as possible. Results showed that participants were able to remember a larger amount of emotional (both pleasant and unpleasant) pictures than of neutral ones, regardless of the type of tDCS condition. Participants who received anodal stimulation recalled a significantly higher number of pleasant images than participants in the sham and cathodal conditions, while no differences emerged in the recall of neutral and unpleasant pictures. We conclude that our results provide some support to the role of left prefrontal cortex in the encoding and retrieval of pleasant stimuli.
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Giordano, Giulia Maria; Stanziano, Mario; Papa, Michele; Mucci, Armida; Prinster, Anna; Soricelli, Andrea; Galderisi, Silvana
2018-04-10
Avolition, a deficit in goal-directed behavior, is a key aspect of negative symptoms. It is highly prevalent in schizophrenia and is associated to poor functional outcome and to measures of real life motivation, indicating that central to the concept is the lack of interest and motivation. In this study we tested the hypothesis that avolition is related to altered connectivity within dopaminergic cortico-striatal circuits involved in motivation processes. Since dopamine input to these circuits derives mostly from the ventro-tegmental area (VTA), we investigated the relationships between the resting-state functional connectivity (RS-FC) of the VTA and avolition in twenty-six subjects with schizophrenia (SCZ), treated with second-generation antipsychotics only, compared to twenty-two healthy controls (HC). SCZ, in comparison to HC, showed significantly reduced RS-FC of the VTA with bilateral ventro-lateral prefrontal cortex (VLPFC), bilateral insular cortex (IC) and right (R) lateral occipital complex (LOC) and increased RS-FC of the VTA with bilateral dorso-lateral prefrontal cortex (DLPFC). Significant negative correlations were found between avolition and RS-FC of the VTA with the bilateral IC, R VLPFC and R LOC. According to our findings, avolition is linked to a disconnectivity of the VTA from several key cortical regions involved in the integration of value information with action selection. These findings are in line with translational animal models of "auto-activation apathy". Copyright © 2018 Elsevier B.V. and ECNP. All rights reserved.
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Directory of Open Access Journals (Sweden)
Glen eAcosta
2012-01-01
Full Text Available Functional impairment of the orbital and medial prefrontal cortex underlies deficits in executive control that characterize addictive disorders, including alcohol addiction. Previous studies indicate that alcohol alters glutamate neurotransmission and one substrate of these effects may be through the reconfiguration of the subunits constituting ionotropic glutamate receptor (iGluR complexes. Glutamatergic transmission is integral to cortico-cortical and cortico-subcortical communication and alcohol-induced changes in the abundance of the receptor subunits and/or their splice variants may result in critical functional impairments of prefrontal cortex in alcohol dependence. To this end, the effects of chronic ethanol self-administration on glutamate receptor ionotropic AMPA (GRIA subunit variant and kainate (GRIK subunit mRNA expression were studied in the orbitofrontal cortex (OFC, dorsolateral prefrontal cortex (DLPFC and anterior cingulate cortex (ACC of male cynomolgus monkeys. In DLPFC, total AMPA splice variant expression and total kainate receptor subunit expression were significantly decreased in alcohol drinking monkeys. Expression levels of GRIA3 flip and flop and GRIA4 flop mRNAs in this region were positively correlated with daily ethanol intake and blood ethanol concentrations averaged over the six months prior to necropsy. In OFC, AMPA subunit splice variant expression was reduced in the alcohol treated group. GRIA2 flop mRNA levels in this region were positively correlated with daily ethanol intake and blood ethanol concentrations averaged over the six months prior to necropsy. Results from these studies provide further evidence of transcriptional regulation of iGluR subunits in the primate brain following chronic alcohol self-administration. Additional studies examining the cellular localization of such effects in the framework of primate prefrontal cortical circuitry are warranted.
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Kekic, Maria; McClelland, Jessica; Campbell, Iain; Nestler, Steffen; Rubia, Katya; David, Anthony S; Schmidt, Ulrike
2014-07-01
Bulimia nervosa, binge-eating disorder, and some forms of obesity are characterised by compulsive overeating that is often precipitated by food craving. Transcranial direct current stimulation (tDCS) has been used to suppress food cravings, but there is insufficient evidence to support its application in clinical practice. Furthermore, the potential moderating role of impulsivity has not been considered. This study used a randomised within-subjects crossover design to examine whether a 20-minute session of sham-controlled bilateral tDCS to the dorsolateral prefrontal cortex (anode right/cathode left) would transiently modify food cravings and temporal discounting (TD; a measure of choice impulsivity) in 17 healthy women with frequent food cravings. Whether the effects of tDCS on food craving were moderated by individual differences in TD behaviour was also explored. Participants were exposed to food and a film of people eating, and food cravings and TD were assessed before and after active and sham stimulation. Craving for sweet but not savoury foods was reduced following real tDCS. Participants that exhibited more reflective choice behaviour were more susceptible to the anti-craving effects of tDCS than those that displayed more impulsive choice behaviour. No differences were seen in TD or food consumption after real versus sham tDCS. These findings support the efficacy of tDCS in temporarily lowering food cravings and identify the moderating role of TD behaviour. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
Saskia Deppermann
2014-01-01
Full Text Available Objectives. Neurobiologically, panic disorder (PD is supposed to be characterised by cerebral hypofrontality. Via functional near-infrared spectroscopy (fNIRS, we investigated whether prefrontal hypoactivity during cognitive tasks in PD-patients compared to healthy controls (HC could be replicated. As intermittent theta burst stimulation (iTBS modulates cortical activity, we furthermore investigated its ability to normalise prefrontal activation. Methods. Forty-four PD-patients, randomised to sham or verum group, received 15 iTBS-sessions above the left dorsolateral prefrontal cortex (DLPFC in addition to psychoeducation. Before first and after last iTBS-treatment, cortical activity during a verbal fluency task was assessed via fNIRS and compared to the results of 23 HC. Results. At baseline, PD-patients showed hypofrontality including the DLPFC, which differed significantly from activation patterns of HC. However, verum iTBS did not augment prefrontal fNIRS activation. Solely after sham iTBS, a significant increase of measured fNIRS activation in the left inferior frontal gyrus (IFG during the phonological task was found. Conclusion. Our results support findings that PD is characterised by prefrontal hypoactivation during cognitive performance. However, verum iTBS as an “add-on” to psychoeducation did not augment prefrontal activity. Instead we only found increased fNIRS activation in the left IFG after sham iTBS application. Possible reasons including task-related psychophysiological arousal are discussed.
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Deppermann, Saskia; Vennewald, Nadja; Diemer, Julia; Sickinger, Stephanie; Haeussinger, Florian B; Notzon, Swantje; Laeger, Inga; Arolt, Volker; Ehlis, Ann-Christine; Zwanzger, Peter; Fallgatter, Andreas J
2014-01-01
Neurobiologically, panic disorder (PD) is supposed to be characterised by cerebral hypofrontality. Via functional near-infrared spectroscopy (fNIRS), we investigated whether prefrontal hypoactivity during cognitive tasks in PD-patients compared to healthy controls (HC) could be replicated. As intermittent theta burst stimulation (iTBS) modulates cortical activity, we furthermore investigated its ability to normalise prefrontal activation. Forty-four PD-patients, randomised to sham or verum group, received 15 iTBS-sessions above the left dorsolateral prefrontal cortex (DLPFC) in addition to psychoeducation. Before first and after last iTBS-treatment, cortical activity during a verbal fluency task was assessed via fNIRS and compared to the results of 23 HC. At baseline, PD-patients showed hypofrontality including the DLPFC, which differed significantly from activation patterns of HC. However, verum iTBS did not augment prefrontal fNIRS activation. Solely after sham iTBS, a significant increase of measured fNIRS activation in the left inferior frontal gyrus (IFG) during the phonological task was found. Our results support findings that PD is characterised by prefrontal hypoactivation during cognitive performance. However, verum iTBS as an "add-on" to psychoeducation did not augment prefrontal activity. Instead we only found increased fNIRS activation in the left IFG after sham iTBS application. Possible reasons including task-related psychophysiological arousal are discussed.
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Lumma, Anna-Lena; Valk, Sofie L; Böckler, Anne; Vrtička, Pascal; Singer, Tania
2018-04-01
Self-referential processing is a key component of the emotional self-concept. Previous studies have shown that emotional self-referential processing is related to structure and function of cortical midline areas such as medial prefrontal cortex (mPFC), and that it can be altered on a behavioral level by specific mental training practices. However, it remains unknown how behavioral training-related change in emotional self-concept content relates to structural plasticity. To address this issue, we examined the relationship between training-induced change in participant's emotional self-concept measured through emotional word use in the Twenty Statement Test and change in cortical thickness in the context of a large-scale longitudinal mental training study called the ReSource Project . Based on prior behavioral findings showing increased emotional word use particularly after socio-cognitive training targeting perspective-taking capacities, this study extended these results by revealing that individual differences in the degree to which participants changed their emotional self-concept after training was positively related to cortical thickness change in right mPFC extending to dorsolateral PFC (dlPFC). Furthermore, increased self-related negative emotional word use after training was positively associated with cortical thickness change in left pars orbitalis and bilateral dlPFC. Our findings reveal training-related structural brain change in regions known to be involved in self-referential processing and cognitive control, and could indicate a relationship between restructuring of the emotional self-concept content as well as reappraisal of negative aspects and cortical thickness change. As such, our findings can guide the development of psychological interventions targeted to alter specific facets of the self-concept.
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LENUS (Irish Health Repository)
Behan, A T
2009-06-01
The dorsolateral prefrontal cortex (dlpfc) is strongly implicated in the pathogenesis of schizophrenia (SCZ) and bipolar disorder (BPD) and, within this region, abnormalities in glutamatergic neurotransmission and synaptic function have been described. Proteins associated with these functions are enriched in membrane microdomains (MM). In the current study, we used two complementary proteomic methods, two-dimensional difference gel electrophoresis and one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis followed by reverse phase-liquid chromatography-tandem mass spectrometry (RP-LC-MS\\/MS) (gel separation liquid chromatography-tandem mass spectrometry (GeLC-MS\\/MS)) to assess protein expression in MM in pooled samples of dlpfc from SCZ, BPD and control cases (n=10 per group) from the Stanley Foundation Brain series. We identified 16 proteins altered in one\\/both disorders using proteomic methods. We selected three proteins with roles in synaptic function (syntaxin-binding protein 1 (STXBP1), brain abundant membrane-attached signal protein 1 (BASP1) and limbic system-associated membrane protein (LAMP)) for validation by western blotting. This revealed significantly increased expression of these proteins in SCZ (STXBP1 (24% difference; P<0.001), BASP1 (40% difference; P<0.05) and LAMP (22% difference; P<0.01)) and BPD (STXBP1 (31% difference; P<0.001), BASP1 (23% difference; P<0.01) and LAMP (20% difference; P<0.01)) in the Stanley brain series (n=20 per group). Further validation in dlpfc from the Harvard brain subseries (n=10 per group) confirmed increased protein expression in SCZ of STXBP1 (18% difference; P<0.0001), BASP1 (14% difference; P<0.0001) but not LAMP (20% difference; P=0.14). No significant differences in STXBP1, BASP1 or LAMP protein expression in BPD dlpfc were observed. This study, through proteomic assessments of MM in dlpfc and validation in two brain series, strongly implicates LAMP, STXBP1 and BASP1 in SCZ and supports
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Balconi, M; Cobelli, C
2015-02-26
The present research explored the cortical correlates of emotional memories in response to words and pictures. Subjects' performance (Accuracy Index, AI; response times, RTs; RTs/AI) was considered when a repetitive Transcranial Magnetic Stimulation (rTMS) was applied on the left dorsolateral prefrontal cortex (LDLPFC). Specifically, the role of LDLPFC was tested by performing a memory task, in which old (previously encoded targets) and new (previously not encoded distractors) emotional pictures/words had to be recognized. Valence (positive vs. negative) and arousing power (high vs. low) of stimuli were also modulated. Moreover, subjective evaluation of emotional stimuli in terms of valence/arousal was explored. We found significant performance improving (higher AI, reduced RTs, improved general performance) in response to rTMS. This "better recognition effect" was only related to specific emotional features, that is positive high arousal pictures or words. Moreover no significant differences were found between stimulus categories. A direct relationship was also observed between subjective evaluation of emotional cues and memory performance when rTMS was applied to LDLPFC. Supported by valence and approach model of emotions, we supposed that a left lateralized prefrontal system may induce a better recognition of positive high arousal words, and that evaluation of emotional cue is related to prefrontal activation, affecting the recognition memories of emotions. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.
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Directory of Open Access Journals (Sweden)
John M Wang
2012-10-01
Full Text Available Previous functional MRI (fMRI studies have shown that fragile X mental retardation 1 (FMR1 premutation allele carriers (FXPCs exhibit decreased hippocampal activation during a recall task and lower inferior frontal activation during a working memory task compared to matched controls. The molecular characteristics of FXPCs includes 55 to 200 CGG trinucleoutide expansions, increased FMR1 mRNA levels, and decreased FMRP levels especially at higher repeat sizes. In the current study, we utilized MRI to examine differences in hippocampal volume and function during an encoding task in young male FXPCs. While no decreases in either hippocampal volume or hippocampal activity were observed during the encoding task in FXPCs, FMRP level (measured in blood correlated with decreases in parahippocampal activation. In addition, activity in the right dorsolateral prefrontal cortex during correctly encoded trials correlated negatively with mRNA levels. These results, as well as the established biological effects associated with elevated mRNA levels and decreased FMRP levels on dendritic maturation and axonal growth, prompted us to explore functional connectivity between the hippocampus, prefrontal cortex, and parahippocampal gyrus using a psychophysiological interaction analysis. In FXPCs, the right hippocampus evinced significantly lower connectivity with right ventrolateral prefrontal cortex (VLPFC and right parahippocampal gyrus. Furthermore, the weaker connectivity between the right hippocampus and VLPFC was associated with reduced FMRP in the FXPC group. These results suggest that while FXPCs show relatively typical brain response during encoding, faulty connectivity between frontal and hippocampal regions may have subsequent effects on recall and working memory.
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Altered thalamo-cortical resting state functional connectivity in smokers.
Wang, Chaoyan; Bai, Jie; Wang, Caihong; von Deneen, Karen M; Yuan, Kai; Cheng, Jingliang
2017-07-13
The thalamus has widespread connections with the prefrontal cortex (PFC) and modulates communication between the striatum and PFC, which is crucial to the neural mechanisms of smoking. However, relatively few studies focused on the thalamic resting state functional connectivity (RSFC) patterns and their association with smoking behaviors in smokers. 24 young male smokers and 24 non-smokers were enrolled in our study. Fagerström Test for Nicotine Dependence (FTND) was used to assess the nicotine dependence level. The bilateral thalamic RSFC patterns were compared between smokers and non-smokers. The relationship between neuroimaging findings and smoking behaviors (FTND and pack-years) were also investigated in smokers. Relative to nonsmokers, smokers showed reduced RSFC strength between the left thalamus and several brain regions, i.e. the right dorsolateral prefrontal cortex (dlPFC), the anterior cingulate cortex (ACC) and the bilateral caudate. In addition, the right thalamus showed reduced RSFC with the right dlPFC as well as the bilateral insula in smokers. Therefore, the findings in the current study revealed the reduced RSFC of the thalamus with the dlPFC, the ACC, the insula and the caudate in smokers, which provided new insights into the roles of the thalamus in nicotine addiction from a function integration perspective. Copyright © 2017 Elsevier B.V. All rights reserved.
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Girardi, Paolo; Rapinesi, Chiara; Chiarotti, Flavia; Kotzalidis, Georgios D; Piacentino, Daria; Serata, Daniele; Del Casale, Antonio; Scatena, Paola; Mascioli, Flavia; Raccah, Ruggero N; Brugnoli, Roberto; Digiacomantonio, Vittorio; Ferri, Vittoria Rachele; Ferracuti, Stefano; Zangen, Abraham; Angeletti, Gloria
2015-01-01
Dorsolateral prefrontal cortex (DLPFC) is dysfunctional in mood and substance use disorders. We predicted higher efficacy for add-on bilateral prefrontal high-frequency deep transcranial magnetic stimulation (dTMS), compared with standard drug treatment (SDT) in patients with dysthymic disorder (DD)/alcohol use disorder (AUD) comorbidity. We carried-out a 6-month open-label study involving 20 abstinent patients with DSM-IV-TR AUD comorbid with previously developed DD. Ten patients received SDT for AUD with add-on bilateral dTMS (dTMS-AO) over the DLPFC, while another 10 received SDT alone. We rated alcohol craving with the Obsessive Compulsive Drinking Scale (OCDS), depression with the Hamilton Depression Rating Scale (HDRS), clinical status with the Clinical Global Impressions scale (CGI), and global functioning with the Global Assessment of Functioning (GAF). At the end of the 20-session dTMS period (or an equivalent period in the SDT group), craving scores and depressive symptoms in the dTMS-AO group dropped significantly more than in the SDT group (P < 0.001 and P < 0.02, respectively). High frequency bilateral DLPFC dTMS with left preference was well tolerated and found to be effective as add-on in AUD. The potential of dTMS for reducing craving in substance use disorder patients deserves to be further investigated.
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Prefrontal involvement in imitation learning of hand actions: effects of practice and expertise.
Vogt, Stefan; Buccino, Giovanni; Wohlschläger, Afra M; Canessa, Nicola; Shah, N Jon; Zilles, Karl; Eickhoff, Simon B; Freund, Hans-Joachim; Rizzolatti, Giacomo; Fink, Gereon R
2007-10-01
In this event-related fMRI study, we demonstrate the effects of a single session of practising configural hand actions (guitar chords) on cortical activations during observation, motor preparation and imitative execution. During the observation of non-practised actions, the mirror neuron system (MNS), consisting of inferior parietal and ventral premotor areas, was more strongly activated than for the practised actions. This finding indicates a strong role of the MNS in the early stages of imitation learning. In addition, the left dorsolateral prefrontal cortex (DLPFC) was selectively involved during observation and motor preparation of the non-practised chords. This finding confirms Buccino et al.'s [Buccino, G., Vogt, S., Ritzl, A., Fink, G.R., Zilles, K., Freund, H.-J., Rizzolatti, G., 2004a. Neural circuits underlying imitation learning of hand actions: an event-related fMRI study. Neuron 42, 323-334] model of imitation learning: for actions that are not yet part of the observer's motor repertoire, DLPFC engages in operations of selection and combination of existing, elementary representations in the MNS. The pattern of prefrontal activations further supports Shallice's [Shallice, T., 2004. The fractionation of supervisory control. In: Gazzaniga, M.S. (Ed.), The Cognitive Neurosciences, Third edition. MIT Press, Cambridge, MA, pp. 943-956] proposal of a dominant role of the left DLPFC in modulating lower level systems and of a dominant role of the right DLPFC in monitoring operations.
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Ott, Derek V M; Ullsperger, Markus; Jocham, Gerhard; Neumann, Jane; Klein, Tilmann A
2011-07-15
The prefrontal cortex is known to play a key role in higher-order cognitive functions. Recently, we showed that this brain region is active in reinforcement learning, during which subjects constantly have to integrate trial outcomes in order to optimize performance. To further elucidate the role of the dorsolateral prefrontal cortex (DLPFC) in reinforcement learning, we applied continuous theta-burst stimulation (cTBS) either to the left or right DLPFC, or to the vertex as a control region, respectively, prior to the performance of a probabilistic learning task in an fMRI environment. While there was no influence of cTBS on learning performance per se, we observed a stimulation-dependent modulation of reward vs. punishment sensitivity: Left-hemispherical DLPFC stimulation led to a more reward-guided performance, while right-hemispherical cTBS induced a more avoidance-guided behavior. FMRI results showed enhanced prediction error coding in the ventral striatum in subjects stimulated over the left as compared to the right DLPFC. Both behavioral and imaging results are in line with recent findings that left, but not right-hemispherical stimulation can trigger a release of dopamine in the ventral striatum, which has been suggested to increase the relative impact of rewards rather than punishment on behavior. Copyright © 2011 Elsevier Inc. All rights reserved.
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Directory of Open Access Journals (Sweden)
Erica A. Boschin
2015-10-01
Full Text Available The ability to maintain and manipulate information across temporal delays is a fundamental requirement to bridge the gap between perception and action. In the case of higher-order behavior, the maintenance of rules and strategies is particularly helpful in bridging this gap. The prefrontal cortex (PFC has long been considered critical for such processes, and research has focused on different subdivisions of PFC to gain an insight into their diverse contributions to these mechanisms. Substantial evidence indicates that dorsolateral PFC (dlPFC is an important structure for maintaining information across delays, with cells actively firing across delays and lesions to this region causing deficits in tasks involving delayed responses and maintenance of rules online. Frontopolar cortex (FP, on the other hand, appears to show the opposite pattern of results, with cells not firing across delays and lesions to this region not affecting the same rule-based, delayed response tasks that are impaired following dlPFC lesions. The body of evidence therefore suggests that dlPFC and FP’s contributions to working memory differ. In this article, we will provide a perspective on how these regions might implement distinct but complementary and interactive functions that contribute to more general temporally-extended processes and support flexible, dynamic behavior.
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Matheus, Filipe C; Rial, Daniel; Real, Joana I; Lemos, Cristina; Ben, Juliana; Guaita, Gisele O; Pita, Inês R; Sequeira, Ana C; Pereira, Frederico C; Walz, Roger; Takahashi, Reinaldo N; Bertoglio, Leandro J; Da Cunha, Cláudio; Cunha, Rodrigo A; Prediger, Rui D
2016-03-15
Parkinson's disease (PD) is characterized by motor dysfunction associated with dopaminergic degeneration in the dorsolateral striatum (DLS). However, motor symptoms in PD are often preceded by short-term memory deficits, which have been argued to involve deregulation of medial prefrontal cortex (mPFC). We now used a 6-hydroxydopamine (6-OHDA) rat PD model to explore if alterations of synaptic plasticity in DLS and mPFC underlie short-term memory impairments in PD prodrome. The bilateral injection of 6-OHDA (20μg/hemisphere) in the DLS caused a marked loss of dopaminergic neurons in the substantia nigra (>80%) and decreased monoamine levels in the striatum and PFC, accompanied by motor deficits evaluated after 21 days in the open field and accelerated rotarod. A lower dose of 6-OHDA (10μg/hemisphere) only induced a partial degeneration (about 60%) of dopaminergic neurons in the substantia nigra with no gross motor impairments, thus mimicking an early premotor stage of PD. Notably, 6-OHDA (10μg)-lesioned rats displayed decreased monoamine levels in the PFC as well as short-term memory deficits evaluated in the novel object discrimination and in the modified Y-maze tasks; this was accompanied by a selective decrease in the amplitude of long-term potentiation in the mPFC, but not in DLS, without changes of synaptic transmission in either brain regions. These results indicate that the short-term memory dysfunction predating the motor alterations in the 6-OHDA model of PD is associated with selective changes of information processing in PFC circuits, typified by persistent changes of synaptic plasticity. Copyright © 2015 Elsevier B.V. All rights reserved.
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Shajahan, Polash M; Glabus, Mike F; Steele, J Douglas; Doris, Alan B; Anderson, Kay; Jenkins, Jenny A; Gooding, Patricia A; Ebmeier, Klaus P
2002-06-01
Transcranial magnetic stimulation (TMS) has been used for over a decade to investigate cortical function. More recently, it has been employed to treat conditions such as major depression. This study was designed to explore the effects of differential treatment parameters, such as stimulation frequency. In addition, the data were examined to determine whether a change in connectivity occurred following TMS. Fifteen patients with major depression were entered into a combined imaging and treatment experiment with single photon emission computed tomography (SPECT) and repetitive transcranial magnetic stimulation (rTMS) over left dorso-lateral prefrontal cortex (DLPFC). Brain perfusion during a verbal fluency task was compared between pre- and poststimulation conditions. Patients were then treated with 80% of motor threshold for a total of 10 days, using 5000 stimuli at 5, 10 or 20 Hz. Tests of cortical excitability and neuropsychological tests were done throughout the trial. Patients generally improved with treatment. There was no perceptible difference between stimulation frequencies, which may have reflected low study power. An increase in rostral anterior cingulate activation after the treatment day was associated with increased functional connectivity in the dorso-lateral frontal loop on the left and the limbic loop on both sides. No noticeable deterioration in neuropsychological function was observed. TMS at the stimulation frequencies used seems to be safe over a course of 5000 stimuli. It appears to have an activating effect in anterior limbic structures and increase functional connectivity in the neuroanatomical networks under the stimulation coil within an hour of stimulation.
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Shirayama, Yukihiko; Hashimoto, Kenji
2017-03-01
Effects of a single bilateral infusion of R-enantiomer of ketamine in rat brain regions of learned helplessness model of depression were examined. A single bilateral infusion of R-ketamine into infralimbic (IL) portion of medial prefrontal cortex (mPFC), CA3 and dentate gyrus (DG) of the hippocampus showed antidepressant effects. By contrast, a single bilateral infusion of R-ketamine into prelimbic (PL) portion of mPFC, shell and core of nucleus accumbens, basolateral amygdala and central nucleus of the amygdala had no effect. This study suggests that IL of mPFC, CA3 and DG of hippocampus might be involved in the antidepressant actions of R-ketamine.
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From Blame to Punishment: Disrupting Prefrontal Cortex Activity Reveals Norm Enforcement Mechanisms.
Buckholtz, Joshua W; Martin, Justin W; Treadway, Michael T; Jan, Katherine; Zald, David H; Jones, Owen; Marois, René
2015-09-23
The social welfare provided by cooperation depends on the enforcement of social norms. Determining blameworthiness and assigning a deserved punishment are two cognitive cornerstones of norm enforcement. Although prior work has implicated the dorsolateral prefrontal cortex (DLPFC) in norm-based judgments, the relative contribution of this region to blameworthiness and punishment decisions remains poorly understood. Here, we used repetitive transcranial magnetic stimulation (rTMS) and fMRI to determine the specific role of DLPFC function in norm-enforcement behavior. DLPFC rTMS reduced punishment for wrongful acts without affecting blameworthiness ratings, and fMRI revealed punishment-selective DLPFC recruitment, suggesting that these two facets of norm-based decision making are neurobiologically dissociable. Finally, we show that DLPFC rTMS affects punishment decision making by altering the integration of information about culpability and harm. Together, these findings reveal a selective, causal role for DLPFC in norm enforcement: representational integration of the distinct information streams used to make punishment decisions. Copyright © 2015 Elsevier Inc. All rights reserved.
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Müller-Vahl, Kirsten R; Grosskreutz, Julian; Prell, Tino; Kaufmann, Jörn; Bodammer, Nils; Peschel, Thomas
2014-01-07
Despite strong evidence that the pathophysiology of Tourette syndrome (TS) involves structural and functional disturbances of the basal ganglia and cortical frontal areas, findings from in vivo imaging studies have provided conflicting results. In this study we used whole brain diffusion tensor imaging (DTI) to investigate the microstructural integrity of white matter pathways and brain tissue in 19 unmedicated, adult, male patients with TS "only" (without comorbid psychiatric disorders) and 20 age- and sex-matched control subjects. Compared to normal controls, TS patients showed a decrease in the fractional anisotropy index (FA) bilaterally in the medial frontal gyrus, the pars opercularis of the left inferior frontal gyrus, the middle occipital gyrus, the right cingulate gyrus, and the medial premotor cortex. Increased apparent diffusion coefficient (ADC) maps were detected in the left cingulate gyrus, prefrontal areas, left precentral gyrus, and left putamen. There was a negative correlation between tic severity and FA values in the left superior frontal gyrus, medial frontal gyrus bilaterally, cingulate gyrus bilaterally, and ventral posterior lateral nucleus of the right thalamus, and a positive correlation in the body of the corpus callosum, left thalamus, right superior temporal gyrus, and left parahippocampal gyrus. There was also a positive correlation between regional ADC values and tic severity in the left cingulate gyrus, putamen bilaterally, medial frontal gyrus bilaterally, left precentral gyrus, and ventral anterior nucleus of the left thalamus. Our results confirm prior studies suggesting that tics are caused by alterations in prefrontal areas, thalamus and putamen, while changes in the cingulate gyrus seem to reflect secondary compensatory mechanisms. Due to the study design, influences from comorbidities, gender, medication and age can be excluded.
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Directory of Open Access Journals (Sweden)
Nandita Vijayakumar
2014-07-01
Full Text Available This study investigated the relationship between the development of effortful control (EC, a temperamental measure of self-regulation, and concurrent development of three regions of the prefrontal cortex (anterior cingulate cortex, ACC; dorsolateral prefrontal cortex, dlPFC; ventrolateral prefrontal cortex, vlPFC between early- and mid-adolescence. It also examined whether development of EC mediated the relationship between cortical maturation and emotional and behavioral symptoms. Ninety-two adolescents underwent baseline assessments when they were approximately 12 years old and follow-up assessments approximately 4 years later. At each assessment, participants had MRI scans and completed the Early Adolescent Temperament Questionnaire-Revised, as well as measures of depressive and anxious symptoms, and aggressive and risk taking behavior. Cortical thicknesses of the ACC, dlPFC and vlPFC, estimated using the FreeSurfer software, were found to decrease over time. EC also decreased over time in females. Greater thinning of the left ACC was associated with less reduction in EC. Furthermore, change in effortful control mediated the relationship between greater thinning of the left ACC and improvements in socioemotional functioning, including reductions in psychopathological symptoms. These findings highlight the dynamic association between EC and the maturation of the anterior cingulate cortex, and the importance of this relationship for socioemotional functioning during adolescence.
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Cocaine exposure shifts the balance of associative encoding from ventral to dorsolateral striatum
Directory of Open Access Journals (Sweden)
Yuji Takahashi
2007-12-01
Full Text Available Both dorsal and ventral striatum are implicated in the "habitization" of behavior that occurs in addiction. Here we examined the effect of cocaine exposure on associative encoding in these two regions. Neural activity was recorded during go/no-go discrimination learning and reversal. Activity in ventral striatum developed and reversed rapidly, tracking the valence of the predicted outcome, whereas activity in dorsolateral striatum developed and reversed more slowly, tracking discriminative responding. This difference is consistent with the putative roles of these two areas in promoting habit-like behavior. Dorsolateral striatum has been directly implicated in habit or stimulus response learning, whereas ventral striatum appears to be involved indirectly by allowing cues associated with reward to exert a general motivational influence on responding. Interestingly cocaine exposure did not uniformly enhance processing across both regions. Instead cocaine reduced the degree and flexibility of cue-evoked firing in ventral striatum while marginally enhanced cue-selective firing in dorsolateral striatum. Thus cocaine exposure causes regionally specific effects on neural processing in striatum; these effects may promote the habitization of behavior by shifting control from ventral to dorsolateral regions.
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Asahara, Ryota; Matsukawa, Kanji; Ishii, Kei; Liang, Nan; Endo, Kana
2016-11-01
When performing exercise arbitrarily, activation of central command should start before the onset of exercise, but when exercise is forced to start with cue, activation of central command should be delayed. We examined whether the in-advance activation of central command influenced the ventilatory response and reflected in the prefrontal oxygenation, by comparing the responses during exercise with arbitrary and cued start. The breath-by-breath respiratory variables and the prefrontal oxygenated-hemoglobin concentration (Oxy-Hb) were measured during one-legged cycling. Minute ventilation (V̇e) at the onset of arbitrary one-legged cycling was augmented to a greater extent than cued cycling, while end-tidal carbon dioxide tension (ETco 2 ) decreased irrespective of arbitrary or cued start. Symmetric increase in the bilateral prefrontal Oxy-Hb occurred before and at the onset of arbitrary one-legged cycling, whereas such an increase was absent with cued start. The time course and magnitude of the increased prefrontal oxygenation were not influenced by the extent of subjective rating of perceived exertion and were the same as those of the prefrontal oxygenation during two-legged cycling previously reported. Mental imagery or passive performance of the one-legged cycling increased V̇e and decreased ETco 2 Neither intervention, however, augmented the prefrontal Oxy-Hb. The changes in ETco 2 could not explain the prefrontal oxygenation response during voluntary or passive one-legged cycling. Taken together, it is likely that the in-advance activation of central command influenced the ventilatory response by enhancing minute ventilation at the onset of one-legged cycling exercise and reflected in the preexercise increase in the prefrontal oxygenation. Copyright © 2016 the American Physiological Society.
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Differential neural responses to food images in women with bulimia versus anorexia nervosa.
Brooks, Samantha J; O'Daly, Owen G; Uher, Rudolf; Friederich, Hans-Christoph; Giampietro, Vincent; Brammer, Michael; Williams, Steven C R; Schiöth, Helgi B; Treasure, Janet; Campbell, Iain C
2011-01-01
Previous fMRI studies show that women with eating disorders (ED) have differential neural activation to viewing food images. However, despite clinical differences in their responses to food, differential neural activation to thinking about eating food, between women with anorexia nervosa (AN) and bulimia nervosa (BN) is not known. We compare 50 women (8 with BN, 18 with AN and 24 age-matched healthy controls [HC]) while they view food images during functional Magnetic Resonance Imaging (fMRI). In response to food (vs non-food) images, women with BN showed greater neural activation in the visual cortex, right dorsolateral prefrontal cortex, right insular cortex and precentral gyrus, women with AN showed greater activation in the right dorsolateral prefrontal cortex, cerebellum and right precuneus. HC women activated the cerebellum, right insular cortex, right medial temporal lobe and left caudate. Direct comparisons revealed that compared to HC, the BN group showed relative deactivation in the bilateral superior temporal gyrus/insula, and visual cortex, and compared to AN had relative deactivation in the parietal lobe and dorsal posterior cingulate cortex, but greater activation in the caudate, superior temporal gyrus, right insula and supplementary motor area. Women with AN and BN activate top-down cognitive control in response to food images, yet women with BN have increased activation in reward and somatosensory regions, which might impinge on cognitive control over food consumption and binge eating.
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Paik, Seung-ho; Kim, Beop-Min
2016-03-01
fNIRS is a neuroimaging technique which uses near-infrared light source in the 700-1000 nm range and enables to detect hemodynamic changes (i.e., oxygenated hemoglobin, deoxygenated hemoglobin, blood volume) as a response to various brain processes. In this study, we developed a new, portable, prefrontal fNIRS system which has 12 light sources, 15 detectors and 108 channels with a sampling rate of 2 Hz. The wavelengths of light source are 780nm and 850nm. ATxmega128A1, 8bit of Micro controller unit (MCU) with 200~4095 resolution along with MatLab data acquisition algorithm was utilized. We performed a simple left and right finger movement imagery tasks which produced statistically significant changes of oxyhemoglobin concentrations in the dorsolateral prefrontal cortex (dlPFC) areas. We observed that the accuracy of the imagery tasks can be improved by carrying out neurofeedback training, during which a real-time feedback signal is provided to a participating subject. The effects of the neurofeedback training was later visually verified using the 3D NIRfast imaging. Our portable fNIRS system may be useful in non-constraint environment for various clinical diagnoses.
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Directory of Open Access Journals (Sweden)
Ibai Diez
2017-06-01
Full Text Available Traumatic brain injury (TBI affects structural connectivity, triggering the reorganization of structural–functional circuits in a manner that remains poorly understood. We focus here on brain network reorganization in relation to postural control deficits after TBI. We enrolled young participants who had suffered moderate to severe TBI, comparing them to young, typically developing control participants. TBI patients (but not controls recruited prefrontal regions to interact with two separated networks: (1 a subcortical network, including parts of the motor network, basal ganglia, cerebellum, hippocampus, amygdala, posterior cingulate gyrus, and precuneus; and (2 a task-positive network, involving regions of the dorsal attention system, together with dorsolateral and ventrolateral prefrontal regions. We also found that the increased prefrontal connectivity in TBI patients was correlated with some postural control indices, such as the amount of body sway, whereby patients with worse balance increased their connectivity in frontal regions more strongly. The increased prefrontal connectivity found in TBI patients may provide the structural scaffolding for stronger cognitive control of certain behavioral functions, consistent with the observations that various motor tasks are performed less automatically following TBI and that more cognitive control is associated with such actions. Using a new hierarchical atlas whose modules are relevant for both structure and function, we found increased structural and functional connectivity in prefrontal regions in TBI patients as compared to controls, in addition to a general pattern of overall decreased connectivity across the TBI brain. Although this increased prefrontal connectivity reflected interactions between brain areas when participants were at rest, the enhanced connectivity was found to be negatively correlated with active behavior such as postural control performance. Thus our findings, obtained
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Keightley, Michelle L; Saluja, Rajeet Singh; Chen, Jen-Kai; Gagnon, Isabelle; Leonard, Gabriel; Petrides, Michael; Ptito, Alain
2014-03-01
Abstract In children, the importance of detecting deficits after mild traumatic brain injury (mTBI) or concussion has grown with the increasing popularity of leisure physical activities and contact sports. Whereas most postconcussive symptoms (PCS) are similar for children and adults, the breadth of consequences to children remains largely unknown. To investigate the effect of mTBI on brain function, we compared working memory performance and related brain activity using blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in 15 concussed youths and 15 healthy age-matched control subjects. Neuropsychological tests, self-perceived PCS, and levels of anxiety and depression were also assessed. Our results showed that, behaviorally, concussed youths had significantly worse performances on the working memory tasks, as well as on the Rey figure delayed recall and verbal fluency. fMRI results revealed that, compared to healthy children, concussed youths had significantly reduced task-related activity in bilateral dorsolateral prefrontal cortex, left premotor cortex, supplementary motor area, and left superior parietal lobule during performance of verbal and nonverbal working memory tasks. Additionally, concussed youths also showed less activation than healthy controls in the dorsal anterior cingulate cortex, left thalamus, and left caudate nucleus during the nonverbal task. Regression analysis indicated that BOLD signal changes in bilateral dorsolateral prefrontal cortex were significantly correlated with performance such that greater activities in these regions, relative to the control condition, were associated with greater accuracy. Our findings confirmed functional alterations in brain activity after concussion in youths, a result similar to that observed in adults. However, significant differences were noted. In particular, the observation of reduced working memory accuracy suggests that youths may be unable to engage compensatory
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2014-01-01
Background Despite strong evidence that the pathophysiology of Tourette syndrome (TS) involves structural and functional disturbances of the basal ganglia and cortical frontal areas, findings from in vivo imaging studies have provided conflicting results. In this study we used whole brain diffusion tensor imaging (DTI) to investigate the microstructural integrity of white matter pathways and brain tissue in 19 unmedicated, adult, male patients with TS “only” (without comorbid psychiatric disorders) and 20 age- and sex-matched control subjects. Results Compared to normal controls, TS patients showed a decrease in the fractional anisotropy index (FA) bilaterally in the medial frontal gyrus, the pars opercularis of the left inferior frontal gyrus, the middle occipital gyrus, the right cingulate gyrus, and the medial premotor cortex. Increased apparent diffusion coefficient (ADC) maps were detected in the left cingulate gyrus, prefrontal areas, left precentral gyrus, and left putamen. There was a negative correlation between tic severity and FA values in the left superior frontal gyrus, medial frontal gyrus bilaterally, cingulate gyrus bilaterally, and ventral posterior lateral nucleus of the right thalamus, and a positive correlation in the body of the corpus callosum, left thalamus, right superior temporal gyrus, and left parahippocampal gyrus. There was also a positive correlation between regional ADC values and tic severity in the left cingulate gyrus, putamen bilaterally, medial frontal gyrus bilaterally, left precentral gyrus, and ventral anterior nucleus of the left thalamus. Conclusions Our results confirm prior studies suggesting that tics are caused by alterations in prefrontal areas, thalamus and putamen, while changes in the cingulate gyrus seem to reflect secondary compensatory mechanisms. Due to the study design, influences from comorbidities, gender, medication and age can be excluded. PMID:24397347
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Acting on social exclusion: neural correlates of punishment and forgiveness of excluders.
Will, Geert-Jan; Crone, Eveline A; Güroğlu, Berna
2015-02-01
This functional magnetic resonance imaging study examined the neural correlates of punishment and forgiveness of initiators of social exclusion (i.e. 'excluders'). Participants divided money in a modified Dictator Game between themselves and people who previously either included or excluded them during a virtual ball-tossing game (Cyberball). Participants selectively punished the excluders by decreasing their outcomes; even when this required participants to give up monetary rewards. Punishment of excluders was associated with increased activation in the pre-supplementary motor area (pre-SMA) and bilateral anterior insula. Costly punishment was accompanied by higher activity in the pre-SMA compared with punishment that resulted in gains or was non-costly. Refraining from punishment (i.e. forgiveness) was associated with self-reported perspective-taking and increased activation in the bilateral temporoparietal junction, dorsomedial prefrontal cortex, dorsal anterior cingulate cortex, and ventrolateral and dorsolateral prefrontal cortex. These findings show that social exclusion can result in punishment as well as forgiveness of excluders and that separable neural networks implicated in social cognition and cognitive control are recruited when people choose either to punish or to forgive those who excluded them. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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Satterthwaite, T D; Cook, P A; Bruce, S E; Conway, C; Mikkelsen, E; Satchell, E; Vandekar, S N; Durbin, T; Shinohara, R T; Sheline, Y I
2016-07-01
Depressive symptoms are common in multiple psychiatric disorders and are frequent sequelae of trauma. A dimensional conceptualization of depression suggests that symptoms should be associated with a continuum of deficits in specific neural circuits. However, most prior investigations of abnormalities in functional connectivity have typically focused on a single diagnostic category using hypothesis-driven seed-based analyses. Here, using a sample of 105 adult female participants from three diagnostic groups (healthy controls, n=17; major depression, n=38; and post-traumatic stress disorder, n=50), we examine the dimensional relationship between resting-state functional dysconnectivity and severity of depressive symptoms across diagnostic categories using a data-driven analysis (multivariate distance-based matrix regression). This connectome-wide analysis identified foci of dysconnectivity associated with depression severity in the bilateral amygdala. Follow-up seed analyses using subject-specific amygdala segmentations revealed that depression severity was associated with amygdalo-frontal hypo-connectivity in a network of regions including bilateral dorsolateral prefrontal cortex, anterior cingulate and anterior insula. In contrast, anxiety was associated with elevated connectivity between the amygdala and the ventromedial prefrontal cortex. Taken together, these results emphasize the centrality of the amygdala in the pathophysiology of depressive symptoms, and suggest that dissociable patterns of amygdalo-frontal dysconnectivity are a critical neurobiological feature across clinical diagnostic categories.
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International Nuclear Information System (INIS)
Sun Jinyan; Zhai Jiahuan; Gong Hui; Song Ranran; Zou Li
2011-01-01
Behavioral studies have investigated the performance of children with developmental dyslexia in conflict resolution, a function connected with the prefrontal cortex (PFC) closely. However, little is known about the prefrontal activation in conflict resolution for dyslexic children. In the present study, the involvement of the PFC in resolving conflict was evaluated for Chinese dyslexic children by means of near-infrared spectroscopy (NIRS). The NIRS instrument is a portable, continuous-wave system and can measure concentration changes of hemodynamic parameters (including oxy-, deoxy-, and total hemoglobin). Considering better sensitivity, the oxy-hemoglobin (oxy-Hb) was chosen to indicate the prefrontal activation. Ten dyslexic children and 11 normal children were recruited to perform the Chinese-character color-word Stroop task, which included the neutral and color (incongruent) tasks. In behavioral performance, both groups showed significant Stroop effect, longer response time or higher error rate for the color task. In particular, the Stroop interference effect was marginally larger for dyslexic children than normal children in response time. What's more, the two groups showed distinct pattern of oxy-Hb activation during the Stroop tasks. The normal group recruited the bilateral PFC to perform the tasks, while the dyslexic group couldn't activate the bilateral PFC in the difficult color task. Moreover, significantly less color Stroop effect was found in the left PFC for the dyslexic group, showing their disability in coping with the Stroop interference. These findings suggest that the PFC is dysfunctional in conflict resolution for Chinese dyslexic children and that NIRS can be an effective tool in neurological research and clinical application.
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Energy Technology Data Exchange (ETDEWEB)
Sun Jinyan; Zhai Jiahuan; Gong Hui [Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology, Wuhan 430074 (China); Song Ranran; Zou Li, E-mail: huigong@mail.hust.edu.cn [Department of Child and Adolescent Health and Maternal Care, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430074 (China)
2011-01-01
Behavioral studies have investigated the performance of children with developmental dyslexia in conflict resolution, a function connected with the prefrontal cortex (PFC) closely. However, little is known about the prefrontal activation in conflict resolution for dyslexic children. In the present study, the involvement of the PFC in resolving conflict was evaluated for Chinese dyslexic children by means of near-infrared spectroscopy (NIRS). The NIRS instrument is a portable, continuous-wave system and can measure concentration changes of hemodynamic parameters (including oxy-, deoxy-, and total hemoglobin). Considering better sensitivity, the oxy-hemoglobin (oxy-Hb) was chosen to indicate the prefrontal activation. Ten dyslexic children and 11 normal children were recruited to perform the Chinese-character color-word Stroop task, which included the neutral and color (incongruent) tasks. In behavioral performance, both groups showed significant Stroop effect, longer response time or higher error rate for the color task. In particular, the Stroop interference effect was marginally larger for dyslexic children than normal children in response time. What's more, the two groups showed distinct pattern of oxy-Hb activation during the Stroop tasks. The normal group recruited the bilateral PFC to perform the tasks, while the dyslexic group couldn't activate the bilateral PFC in the difficult color task. Moreover, significantly less color Stroop effect was found in the left PFC for the dyslexic group, showing their disability in coping with the Stroop interference. These findings suggest that the PFC is dysfunctional in conflict resolution for Chinese dyslexic children and that NIRS can be an effective tool in neurological research and clinical application.
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International Nuclear Information System (INIS)
Lu Youran; Geng Daoying; Feng Xiaoyuan; Du Yasong; Zhao Zhimin
2006-01-01
Objective: To study the verbal working memory of children with attention deficit hyperactivity disorder (ADHD) as well as to explore the characteristics of functional areas of verbal working memory with blood oxygenation level dependent functional magnetic resonance imaging (fMRI). Method: Eighteen children were selected in the study. There were 9 ADHD children with inattention subtype and 9 healthy subjects. All patients and healthy subjects completed the cognitive examination and the block- designed N-block verbal working memory task using a GE 3.0 T MR. Data were analyzed by AFNI software. Result: The neural activations of ADHD's children are lower than that of control under verbal working memory. Especially in the areas of bilateral middle frontal gyri and inferior frontal gyri, bilateral superior parietal lobules and inferior parietal lobules, right basal ganglia in the 1-BACK task. And bilateral middle frontal gyri and inferior frontal gyri, bilateral superior parietal lobules, left cortex inferior parietallobule, right basal ganglia, anterior cingulatecortex in the 2-BACK task. Conclusion: The hypofunctional areas of verbal working memory (including bilateral dorsolateral prefrontal cortex and parietal cortex) can be seen in the ADHD children especially who also has lower activation of anterior cingulate cortex under 2-BACK task. (authors)
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Lee, Jun Ho; Byun, Min Soo; Sohn, Bo Kyung; Choe, Young Min; Yi, Dahyun; Han, Ji Young; Choi, Hyo Jung; Baek, Hyewon; Woo, Jong Inn; Lee, Dong Young
2015-09-01
We aimed to elucidate the functional neuroanatomical correlates of Frontal Assessment Battery (FAB) performances by applying [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) to a large population of patients with Alzheimer disease (AD). The FAB was administered to 177 patients with AD, and regional cerebral glucose metabolism (rCMglc) was measured by FDG-PET scan. Correlations between FAB scores and rCMglc were explored using both region-of-interest-based (ROI-based) and voxel-based approaches. The ROI-based analysis showed that FAB scores correlated with the rCMglc of the dorsolateral prefrontal cortices. Voxel-based approach revealed significant positive correlations between FAB scores and rCMglc which were in various cortical regions including the temporal and parietal cortices as well as frontal regions, independent of age, gender, and education. After controlling the effect of global disease severity with Mini-Mental State Examination score, significant positive correlation was found only in the bilateral prefrontal regions. Although FAB scores are influenced by temporoparietal dysfunction due to the overall progression of AD, it likely reflects prefrontal dysfunction specifically regardless of global cognitive state or disease severity in patients with AD. © The Author(s) 2015.
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No significant effect of prefrontal tDCS on working memory performance in older adults
Directory of Open Access Journals (Sweden)
Jonna eNilsson
2015-12-01
Full Text Available Transcranial direct current stimulation (tDCS has been put forward as a non-pharmacological alternative for alleviating cognitive decline in old age. Although results have shown some promise, little is known about the optimal stimulation parameters for modulation in the cognitive domain. In this study, the effects of tDCS over the dorsolateral prefrontal cortex (dlPFC on working memory performance were investigated in thirty older adults. An N-back task assessed working memory before, during and after anodal tDCS at a current strength of 1mA and 2mA, in addition to sham stimulation. The study used a single-blind, cross-over design. The results revealed no significant effect of tDCS on accuracy or response times during or after stimulation, for any of the current strengths. These results suggest that a single session of tDCS over the dlPFC is unlikely to improve working memory, as assessed by an N-back task, in old age.
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Testing the involvement of the prefrontal cortex in lucid dreaming: a tDCS study.
Stumbrys, Tadas; Erlacher, Daniel; Schredl, Michael
2013-12-01
Recent studies suggest that lucid dreaming (awareness of dreaming while dreaming) might be associated with increased brain activity over frontal regions during rapid eye movement (REM) sleep. By applying transcranial direct current stimulation (tDCS), we aimed to manipulate the activation of the dorsolateral prefrontal cortex (DLPFC) during REM sleep to increase dream lucidity. Nineteen participants spent three consecutive nights in a sleep laboratory. On the second and third nights they randomly received either 1 mA tDCS for 10 min or sham stimulation during each REM period starting with the second one. According to the participants' self-ratings, tDCS over the DLPFC during REM sleep increased lucidity in dreams. The effects, however, were not strong and found only in frequent lucid dreamers. While this indicates some preliminary support for the involvement of the DLPFC in lucid dreaming, further research, controlling for indirect effects of stimulation and including other brain regions, is needed. Copyright © 2013 Elsevier Inc. All rights reserved.
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Context-dependent representation of response-outcome in monkey prefrontal neurons.
Tsujimoto, Satoshi; Sawaguchi, Toshiyuki
2005-07-01
For behaviour to be purposeful, it is important to monitor the preceding behavioural context, particularly for factors regarding stimulus, response and outcome. The dorsolateral prefrontal cortex (DLPFC) appears to play a major role in such a context-dependent, flexible behavioural control system, and this area is likely to have a neuronal mechanism for such retrospective coding, which associates response-outcome with the information and/or neural systems that guided the response. To address this hypothesis, we recorded neuronal activity from the DLPFC of monkeys performing memory- and sensory-guided saccade tasks, each of which had two conditions with reward contingencies. We found that post-response activity of a subset of DLPFC neurons was modulated by three factors relating to earlier events: the direction of the immediately preceding response, its outcome (reward or non-reward) and the information type (memory or sensory) that guided the response. Such neuronal coding should play a role in associating response-outcome with information and/or neural systems used to guide behaviour - that is, 'retrospective monitoring' of behavioural context and/or neural systems used for guiding behaviour - thereby contributing to context-dependent, flexible control of behaviours.
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tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.
Vanderhasselt, Marie-Anne; De Raedt, Rudi; Brunoni, Andre R; Campanhã, Camila; Baeken, Chris; Remue, Jonathan; Boggio, Paulo S
2013-01-01
Transcranial Direct Current Stimulation (tDCS) is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP) as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC) would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation), we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right) prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.
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A face to remember: emotional expression modulates prefrontal activity during memory formation.
Sergerie, Karine; Lepage, Martin; Armony, Jorge L
2005-01-15
Emotion can exert a modulatory role on episodic memory. Several studies have shown that negative stimuli (e.g., words, pictures) are better remembered than neutral ones. Although facial expressions are powerful emotional stimuli and have been shown to influence perception and attention processes, little is known about their effect on memory. We used functional magnetic resonance imaging (fMRI) in humans to investigate the effects of expression (happy, neutral, and fearful) on prefrontal cortex (PFC) activity during the encoding of faces, using a subsequent memory effect paradigm. Our results show that activity in right PFC predicted memory for faces, regardless of expression, while a homotopic region in the left hemisphere was associated with successful encoding only for faces with an emotional expression. These findings are consistent with the proposed role of right dorsolateral PFC in successful encoding of nonverbal material, but also suggest that left DLPFC may be a site where integration of memory and emotional processes occurs. This study sheds new light on the current controversy regarding the hemispheric lateralization of PFC in memory encoding.
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Energy Technology Data Exchange (ETDEWEB)
Peng Jing, E-mail: ppengjjing@sina.com.cn [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); Liu Jiangtao, E-mail: Liujiangtao813@sina.com [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China); Nie Binbin, E-mail: niebb@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Li Yang, E-mail: Liyang2007428@hotmail.com [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Shan Baoci, E-mail: shanbc@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Yu-Quan St, Shijingshan District, Beijing 100049 (China); Wang Gang, E-mail: gangwang@gmail.com [Department of Psychiatry, Anding Hospital of Capital Medical University, No. 5, An Kang Hutong, Deshengmen wai, Xicheng District, Beijing 100088 (China); Li Kuncheng, E-mail: likuncheng1955@yahoo.com.cn [Department of Radiology, Xuanwu Hospital of Capital Medical University, No. 45, Chang-Chun St, Xuanwu District, Beijing 100053 (China)
2011-11-15
Purpose: To investigate cerebral and cerebellar gray matter abnormalities in patients with first-episode major depressive disorder (MDD). Materials and methods: We examined the structural difference in regional gray matter density (GMD) between 22 first-episode MDD patients and 30 age-, gender- and education-matched healthy controls by optimized voxel-based morphometry (VBM) based on magnetic resonance imaging. Results: Compared with healthy controls, MDD patients showed decreased GMD in the right medial and left lateral orbitofrontal cortex, right dorsolateral prefrontal cortex (DLPFC), bilateral temporal pole, right superior temporal gyrus, bilateral anterior insular cortex, left parahippocampal gyrus, and left cerebellum. In addition, in MDD patients, there was a negative correlation between GMD values of the right DLPFC and the score of the depression rating scale. Conclusions: Our findings provided additional support for the involvement of limbic-cortical circuits in the pathophysiology of MDD and preliminary evidence that a defect involving the cerebellum may also be implicated.
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International Nuclear Information System (INIS)
Peng Jing; Liu Jiangtao; Nie Binbin; Li Yang; Shan Baoci; Wang Gang; Li Kuncheng
2011-01-01
Purpose: To investigate cerebral and cerebellar gray matter abnormalities in patients with first-episode major depressive disorder (MDD). Materials and methods: We examined the structural difference in regional gray matter density (GMD) between 22 first-episode MDD patients and 30 age-, gender- and education-matched healthy controls by optimized voxel-based morphometry (VBM) based on magnetic resonance imaging. Results: Compared with healthy controls, MDD patients showed decreased GMD in the right medial and left lateral orbitofrontal cortex, right dorsolateral prefrontal cortex (DLPFC), bilateral temporal pole, right superior temporal gyrus, bilateral anterior insular cortex, left parahippocampal gyrus, and left cerebellum. In addition, in MDD patients, there was a negative correlation between GMD values of the right DLPFC and the score of the depression rating scale. Conclusions: Our findings provided additional support for the involvement of limbic-cortical circuits in the pathophysiology of MDD and preliminary evidence that a defect involving the cerebellum may also be implicated.
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Sankarasubramanian, Vishwanath; Cunningham, David A; Potter-Baker, Kelsey A; Beall, Erik B; Roelle, Sarah M; Varnerin, Nicole M; Machado, Andre G; Jones, Stephen E; Lowe, Mark J; Plow, Ela B
2017-04-01
The pain matrix is comprised of an extensive network of brain structures involved in sensory and/or affective information processing. The thalamus is a key structure constituting the pain matrix. The thalamus serves as a relay center receiving information from multiple ascending pathways and relating information to and from multiple cortical areas. However, it is unknown how thalamocortical networks specific to sensory-affective information processing are functionally integrated. Here, in a proof-of-concept study in healthy humans, we aimed to understand this connectivity using transcranial direct current stimulation (tDCS) targeting primary motor (M1) or dorsolateral prefrontal cortices (DLPFC). We compared changes in functional connectivity (FC) with DLPFC tDCS to changes in FC with M1 tDCS. FC changes were also compared to further investigate its relation with individual's baseline experience of pain. We hypothesized that resting-state FC would change based on tDCS location and would represent known thalamocortical networks. Ten right-handed individuals received a single application of anodal tDCS (1 mA, 20 min) to right M1 and DLPFC in a single-blind, sham-controlled crossover study. FC changes were studied between ventroposterolateral (VPL), the sensory nucleus of thalamus, and cortical areas involved in sensory information processing and between medial dorsal (MD), the affective nucleus, and cortical areas involved in affective information processing. Individual's perception of pain at baseline was assessed using cutaneous heat pain stimuli. We found that anodal M1 tDCS and anodal DLPFC tDCS both increased FC between VPL and sensorimotor cortices, although FC effects were greater with M1 tDCS. Similarly, anodal M1 tDCS and anodal DLPFC tDCS both increased FC between MD and motor cortices, but only DLPFC tDCS modulated FC between MD and affective cortices, like DLPFC. Our findings suggest that M1 stimulation primarily modulates FC of sensory networks
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Differential Neural Responses to Food Images in Women with Bulimia versus Anorexia Nervosa
Brooks, Samantha J.; O′Daly, Owen G.; Uher, Rudolf; Friederich, Hans-Christoph; Giampietro, Vincent; Brammer, Michael; Williams, Steven C. R.; Schiöth, Helgi B.; Treasure, Janet; Campbell, Iain C.
2011-01-01
Background Previous fMRI studies show that women with eating disorders (ED) have differential neural activation to viewing food images. However, despite clinical differences in their responses to food, differential neural activation to thinking about eating food, between women with anorexia nervosa (AN) and bulimia nervosa (BN) is not known. Methods We compare 50 women (8 with BN, 18 with AN and 24 age-matched healthy controls [HC]) while they view food images during functional Magnetic Resonance Imaging (fMRI). Results In response to food (vs non-food) images, women with BN showed greater neural activation in the visual cortex, right dorsolateral prefrontal cortex, right insular cortex and precentral gyrus, women with AN showed greater activation in the right dorsolateral prefrontal cortex, cerebellum and right precuneus. HC women activated the cerebellum, right insular cortex, right medial temporal lobe and left caudate. Direct comparisons revealed that compared to HC, the BN group showed relative deactivation in the bilateral superior temporal gyrus/insula, and visual cortex, and compared to AN had relative deactivation in the parietal lobe and dorsal posterior cingulate cortex, but greater activation in the caudate, superior temporal gyrus, right insula and supplementary motor area. Conclusions Women with AN and BN activate top-down cognitive control in response to food images, yet women with BN have increased activation in reward and somatosensory regions, which might impinge on cognitive control over food consumption and binge eating. PMID:21799807
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Badre, David; Wagner, Anthony D
2004-02-05
Prefrontal cortex (PFC) supports flexible behavior by mediating cognitive control, though the elemental forms of control supported by PFC remain a central debate. Dorsolateral PFC (DLPFC) is thought to guide response selection under conditions of response conflict or, alternatively, may refresh recently active representations within working memory. Lateral frontopolar cortex (FPC) may also adjudicate response conflict, though others propose that FPC supports higher order control processes such as subgoaling and integration. Anterior cingulate cortex (ACC) is hypothesized to upregulate response selection by detecting response conflict; it remains unclear whether ACC functions generalize beyond monitoring response conflict. The present fMRI experiment directly tested these competing theories regarding the functional roles of DLPFC, FPC, and ACC. Results reveal dissociable control processes in PFC, with mid-DLPFC selectively mediating resolution of response conflict and FPC further mediating subgoaling/integration. ACC demonstrated a broad sensitivity to control demands, suggesting a generalized role in modulating cognitive control.
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Specialized prefrontal auditory fields: organization of primate prefrontal-temporal pathways
Directory of Open Access Journals (Sweden)
Maria eMedalla
2014-04-01
Full Text Available No other modality is more frequently represented in the prefrontal cortex than the auditory, but the role of auditory information in prefrontal functions is not well understood. Pathways from auditory association cortices reach distinct sites in the lateral, orbital, and medial surfaces of the prefrontal cortex in rhesus monkeys. Among prefrontal areas, frontopolar area 10 has the densest interconnections with auditory association areas, spanning a large antero-posterior extent of the superior temporal gyrus from the temporal pole to auditory parabelt and belt regions. Moreover, auditory pathways make up the largest component of the extrinsic connections of area 10, suggesting a special relationship with the auditory modality. Here we review anatomic evidence showing that frontopolar area 10 is indeed the main frontal auditory field as the major recipient of auditory input in the frontal lobe and chief source of output to auditory cortices. Area 10 is thought to be the functional node for the most complex cognitive tasks of multitasking and keeping track of information for future decisions. These patterns suggest that the auditory association links of area 10 are critical for complex cognition. The first part of this review focuses on the organization of prefrontal-auditory pathways at the level of the system and the synapse, with a particular emphasis on area 10. Then we explore ideas on how the elusive role of area 10 in complex cognition may be related to the specialized relationship with auditory association cortices.
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Meehan, Sean K.; Randhawa, Bubblepreet; Wessel, Brenda; Boyd, Lara A.
2010-01-01
Implicit motor learning is preserved after stroke, but how the brain compensates for damage to facilitate learning is unclear. We used a random effects analysis to determine how stroke alters patterns of brain activity during implicit sequence-specific motor learning as compared to general improvements in motor control. Nine healthy participants and 9 individuals with chronic, right focal sub-cortical stroke performed a continuous joystick-based tracking task during an initial fMRI session, over 5 days of practice, and a retention test during a separate fMRI session. Sequence-specific implicit motor learning was differentiated from general improvements in motor control by comparing tracking performance on a novel, repeated tracking sequences during early practice and again at the retention test. Both groups demonstrated implicit sequence-specific motor learning at the retention test, yet substantial differences were apparent. At retention, healthy control participants demonstrated increased BOLD response in left dorsal premotor cortex (BA 6) but decreased BOLD response left dorsolateral prefrontal cortex (DLPFC; BA 9) during repeated sequence tracking. In contrast, at retention individuals with stroke did not show this reduction in DLPFC during repeated tracking. Instead implicit sequence-specific motor learning and general improvements in motor control were associated with increased BOLD response in the left middle frontal gyrus BA 8, regardless of sequence type after stroke. These data emphasize the potential importance of a prefrontal-based attentional network for implicit motor learning after stroke. The present study is the first to highlight the importance of the prefrontal cortex for implicit sequence-specific motor learning after stroke. PMID:20725908
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Hassel, Stefanie; Almeida, Jorge R; Frank, Ellen; Versace, Amelia; Nau, Sharon A; Klein, Crystal R; Kupfer, David J; Phillips, Mary L
2009-11-01
The spectrum approach was used to examine contributions of comorbid symptom dimensions of substance abuse and eating disorder to abnormal prefrontal-cortical and subcortical-striatal activity to happy and fear faces previously demonstrated in bipolar disorder (BD). Fourteen remitted BD-type I and sixteen healthy individuals viewed neutral, mild and intense happy and fear faces in two event-related fMRI experiments. All individuals completed Substance-Use and Eating-Disorder Spectrum measures. Region-of-Interest analyses for bilateral prefrontal and subcortical-striatal regions were performed. BD individuals scored significantly higher on these spectrum measures than healthy individuals (pright PFC activity to intense happy faces (pright caudate nucleus activity to neutral faces (pright ventral putamen activity to intense happy (pabuse and eating disorder and prefrontal-cortical and subcortical-striatal activity to facial expressions in BD. Our findings suggest that these comorbid features may contribute to observed patterns of functional abnormalities in neural systems underlying mood regulation in BD.
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Egner, Tobias
2013-01-01
Conflict adaptation – a conflict-triggered improvement in the resolution of conflicting stimulus or response representations – has become a widely used probe of cognitive control processes in both healthy and clinical populations. Previous functional magnetic resonance imaging (fMRI) studies have localized activation foci associated with conflict resolution to dorsolateral prefrontal cortex (dlPFC). The traditional group-analysis approach employed in these studies highlights regions that are, on average, activated during conflict resolution, but does not necessarily reveal areas mediating individual differences in conflict resolution, because between-subject variance is treated as noise. Here, we employed a complementary approach in order to elucidate the neural bases of variability in the proficiency of conflict-driven cognitive control. We analyzed two independent fMRI data sets of face-word Stroop tasks by using individual variability in the behavioral expression of conflict adaptation as the metric against which brain activation was regressed, while controlling for individual differences in mean reaction time and Stroop interference. Across the two experiments, a replicable neural substrate of individual variation in conflict adaptation was found in ventrolateral prefrontal cortex (vlPFC), specifically, in the right inferior frontal gyrus, pars orbitalis (BA 47). Unbiased regression estimates showed that variability in activity in this region accounted for ~40% of the variance in behavioral expression of conflict adaptation across subjects, thus documenting a heretofore unsuspected key role for vlPFC in mediating conflict-driven adjustments in cognitive control. We speculate that vlPFC plays a primary role in conflict control that is supplemented by dlPFC recruitment under conditions of suboptimal performance. PMID:21568631
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Ferreri, Laura; Bigand, Emmanuel; Bard, Patrick; Bugaiska, Aurélia
2015-01-01
Music can be thought of as a complex stimulus able to enrich the encoding of an event thus boosting its subsequent retrieval. However, several findings suggest that music can also interfere with memory performance. A better understanding of the behavioral and neural processes involved can substantially improve knowledge and shed new light on the most efficient music-based interventions. Based on fNIRS studies on music, episodic encoding, and the dorsolateral prefrontal cortex (PFC), this work aims to extend previous findings by monitoring the entire lateral PFC during both encoding and retrieval of verbal material. Nineteen participants were asked to encode lists of words presented with either background music or silence and subsequently tested during a free recall task. Meanwhile, their PFC was monitored using a 48-channel fNIRS system. Behavioral results showed greater chunking of words under the music condition, suggesting the employment of associative strategies for items encoded with music. fNIRS results showed that music provided a less demanding way of modulating both episodic encoding and retrieval, with a general prefrontal decreased activity under the music versus silence condition. This suggests that music-related memory processes rely on specific neural mechanisms and that music can positively influence both episodic encoding and retrieval of verbal information. PMID:26508813
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Directory of Open Access Journals (Sweden)
Laura Ferreri
2015-01-01
Full Text Available Music can be thought of as a complex stimulus able to enrich the encoding of an event thus boosting its subsequent retrieval. However, several findings suggest that music can also interfere with memory performance. A better understanding of the behavioral and neural processes involved can substantially improve knowledge and shed new light on the most efficient music-based interventions. Based on fNIRS studies on music, episodic encoding, and the dorsolateral prefrontal cortex (PFC, this work aims to extend previous findings by monitoring the entire lateral PFC during both encoding and retrieval of verbal material. Nineteen participants were asked to encode lists of words presented with either background music or silence and subsequently tested during a free recall task. Meanwhile, their PFC was monitored using a 48-channel fNIRS system. Behavioral results showed greater chunking of words under the music condition, suggesting the employment of associative strategies for items encoded with music. fNIRS results showed that music provided a less demanding way of modulating both episodic encoding and retrieval, with a general prefrontal decreased activity under the music versus silence condition. This suggests that music-related memory processes rely on specific neural mechanisms and that music can positively influence both episodic encoding and retrieval of verbal information.
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Ferreri, Laura; Bigand, Emmanuel; Bard, Patrick; Bugaiska, Aurélia
2015-01-01
Music can be thought of as a complex stimulus able to enrich the encoding of an event thus boosting its subsequent retrieval. However, several findings suggest that music can also interfere with memory performance. A better understanding of the behavioral and neural processes involved can substantially improve knowledge and shed new light on the most efficient music-based interventions. Based on fNIRS studies on music, episodic encoding, and the dorsolateral prefrontal cortex (PFC), this work aims to extend previous findings by monitoring the entire lateral PFC during both encoding and retrieval of verbal material. Nineteen participants were asked to encode lists of words presented with either background music or silence and subsequently tested during a free recall task. Meanwhile, their PFC was monitored using a 48-channel fNIRS system. Behavioral results showed greater chunking of words under the music condition, suggesting the employment of associative strategies for items encoded with music. fNIRS results showed that music provided a less demanding way of modulating both episodic encoding and retrieval, with a general prefrontal decreased activity under the music versus silence condition. This suggests that music-related memory processes rely on specific neural mechanisms and that music can positively influence both episodic encoding and retrieval of verbal information.
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prefrontal como mecanismo putativo del cambio en psicoterapia
Directory of Open Access Journals (Sweden)
Jaime Silva C.
2005-01-01
Full Text Available La corteza prefrontal (CPF es definida como la región cerebral cortical que se conecta recíprocamente con el núcleo dorsolateral del tálamo. La visión tradicional en las ciencias del comportamiento atribuye a la CPF un papel en la organización temporal de la conducta. Adicionalmente, estudios convergentes en el campo de la neurociencia afectiva han revelado el papel fundamental que juega la CPF en la determinación del estilo afectivo y en especial de la regulación emocional. El estilo afectivo involucra las diferencias individuales en diferentes parámetros de la reactividad afectiva y el estado de ánimo disposicional (por ejemplo, amplitud de la respuesta emocional, tiempo de recuperación, etc.. Dado que prácticamente todas las alteraciones psicopatológicas incluyen un trastorno en alguno de esos parámetros, proponemos que la modulación de la actividad de la CPF es una variable fundamental del cambio en psicoterapia. Presentamos nuestro modelo putativo, el cual se fundamenta en el control cognitivo en cascada de la CPF. Específicamente, proponemos que la regulación emocional ocurre asociada a la activación de la CPF lateral en un sentido rostralcaudal, donde zonas rostrales involucran formas complejas de control afectivo.
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Directory of Open Access Journals (Sweden)
Mathieu Verdurand
Full Text Available GABA(A receptors (GABA(AR are composed of several subunits that determine sensitivity to drugs, synaptic localisation and function. Recent studies suggest that agonists targeting selective GABA(AR subunits may have therapeutic value against the cognitive impairments observed in schizophrenia. In this study, we determined whether GABA(AR binding deficits exist in the dorsolateral prefrontal cortex (DLPFC of people with schizophrenia and tested if changes in GABA(AR binding are related to the changes in subunit mRNAs. The GABA orthosteric and the benzodiazepine allosteric binding sites were assessed autoradiographically using [(3H]Muscimol and [(3H]Flumazenil, respectively, in a large cohort of individuals with schizophrenia (n = 37 and their matched controls (n = 37. We measured, using qPCR, mRNA of β (β1, β2, β3, γ (γ1, γ2, γ2S for short and γ2L for long isoform, γ3 and δ subunits and used our previous measurements of GABA(AR α subunit mRNAs in order to relate mRNAs and binding through correlation and regression analysis.Significant increases in both [(3H]Muscimol (p = 0.016 and [(3H]Flumazenil (p = 0.012 binding were found in the DLPFC of schizophrenia patients. Expression levels of mRNA subunits measured did not show any significant difference in schizophrenia compared to controls. Regression analysis revealed that in schizophrenia, the [(3H]Muscimol binding variance was most related to α4 mRNA levels and the [(3H]Flumazenil binding variance was most related to γ2S subunit mRNA levels. [(3H]Muscimol and [(3H]Flumazenil binding were not affected by the lifetime anti-psychotics dose (chlorpromazine equivalent.We report parallel increases in orthosteric and allosteric GABA(AR binding sites in the DLPFC in schizophrenia that may be related to a "shift" in subunit composition towards α4 and γ2S respectively, which may compromise normal GABAergic modulation and function. Our results may have implications for the
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Bradley, Kailyn A L; King, Kelly E; Hernandez, Arturo E
2013-02-15
The purpose of this study was to examine the cognitive control mechanisms in adult English speaking monolinguals compared to early sequential Spanish-English bilinguals during the initial stages of novel word learning. Functional magnetic resonance imaging during a lexico-semantic task after only 2h of exposure to novel German vocabulary flashcards showed that monolinguals activated a broader set of cortical control regions associated with higher-level cognitive processes, including the supplementary motor area (SMA), anterior cingulate (ACC), and dorsolateral prefrontal cortex (DLPFC), as well as the caudate, implicated in cognitive control of language. However, bilinguals recruited a more localized subcortical network that included the putamen, associated more with motor control of language. These results suggest that experience managing multiple languages may differentiate the learning strategy and subsequent neural mechanisms of cognitive control used by bilinguals compared to monolinguals in the early stages of novel word learning. Copyright © 2012 Elsevier Inc. All rights reserved.
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Blumenfeld, Robert S; Nomura, Emi M; Gratton, Caterina; D'Esposito, Mark
2013-10-01
Anatomical connectivity differences between the dorsal and ventral lateral prefrontal cortex (PFC) of the non-human primate strongly suggests that these regions support different functions. However, after years of study, it remains unclear whether these regions are functionally distinct. In contrast, there has been a groundswell of recent studies providing evidence for a rostro-caudal functional organization, along the lateral as well as dorsomedial frontal cortex. Thus, it is not known whether dorsal and ventral regions of lateral PFC form distinct functional networks and how to reconcile any dorso-ventral organization with the medio-lateral and rostro-caudal axes. Here, we used resting-state connectivity data to identify parallel dorsolateral and ventrolateral streams of intrinsic connectivity with the dorsomedial frontal cortex. Moreover, we show that this connectivity follows a rostro-caudal gradient. Our results provide evidence for a novel framework for the intrinsic organization of the frontal cortex that incorporates connections between medio-lateral, dorso-ventral, and rostro-caudal axes.
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tDCS over the left prefrontal cortex enhances cognitive control for positive affective stimuli.
Directory of Open Access Journals (Sweden)
Marie-Anne Vanderhasselt
Full Text Available Transcranial Direct Current Stimulation (tDCS is a neuromodulation technique with promising results for enhancing cognitive information processes. So far, however, research has mainly focused on the effects of tDCS on cognitive control operations for non-emotional material. Therefore, our aim was to investigate the effects on cognitive control considering negative versus positive material. For this sham-controlled, within-subjects study, we selected a homogeneous sample of twenty-five healthy participants. By using behavioral measures and event related potentials (ERP as indexes, we aimed to investigate whether a single session of anodal tDCS of the left dorsolateral prefrontal cortex (DLPFC would have specific effects in enhancing cognitive control for positive and negative valenced stimuli. After tDCS over the left DLPFC (and not sham control stimulation, we observed more negative N450 amplitudes along with faster reaction times when inhibiting a habitual response to happy compared to sad facial expressions. Gender did not influence the effects of tDCS on cognitive control for emotional information. In line with the Valence Theory of side-lateralized activity, this stimulation protocol might have led to a left dominant (relative to right prefrontal cortical activity, resulting in augmented cognitive control specifically for positive relative to negative stimuli. To verify that tDCS induces effects that are in line with all aspects of the well known Valence Theory, future research should investigate the effects of tDCS over the left vs. right DLPFC on cognitive control for emotional information.
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Directory of Open Access Journals (Sweden)
Cui Guang-bin
2012-02-01
Full Text Available Abstract Background Interleukin-8 (IL-8 is known for its roles in inflammation and plays critical roles in the development of pain. Its expression increases in the brain after peripheral inflammation. Prefrontal cortex, including the anterior cingulate cortex (ACC, is a forebrain structure known for its roles in pain transmission and modulation. Painful stimuli potentiate the prefrontal synaptic transmission, however, little is known about the expression of IL-8 and its role in the enhanced ACC synaptic transmission in animals with persistent inflammatory pain. Findings In the present study, we examined IL-8 expression in the ACC, somatosensory cortex (SSC, and the dorsal horn of lumbar spinal cord following hind-paw administration of complete Freund's adjuvant (CFA in mice and its effects on the ACC synaptic transmission. Quantification of IL-8 at protein level (by ELISA revealed enhanced expression in the ACC and spinal cord during the chronic phases of CFA-induced peripheral inflammation. In vitro whole-cell patch-clamp recordings revealed that IL-8 significantly enhanced synaptic transmission through increased probability of neurotransmitter release in the ACC slice. ACC local infusion of repertaxin, a non-competitive allosteric blocker of IL-8 receptors, notably prolonged the paw withdrawal latency to thermal radian heat stimuli bilaterally in mice. Conclusions Our findings suggest that up-regulation of IL-8 in the ACC partly attributable to the enhanced prefrontal synaptic transmission in the mice with persistent inflammatory pain.
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Preparatory neural activity predicts performance on a conflict task.
Stern, Emily R; Wager, Tor D; Egner, Tobias; Hirsch, Joy; Mangels, Jennifer A
2007-10-24
Advance preparation has been shown to improve the efficiency of conflict resolution. Yet, with little empirical work directly linking preparatory neural activity to the performance benefits of advance cueing, it is not clear whether this relationship results from preparatory activation of task-specific networks, or from activity associated with general alerting processes. Here, fMRI data were acquired during a spatial Stroop task in which advance cues either informed subjects of the upcoming relevant feature of conflict stimuli (spatial or semantic) or were neutral. Informative cues decreased reaction time (RT) relative to neutral cues, and cues indicating that spatial information would be task-relevant elicited greater activity than neutral cues in multiple areas, including right anterior prefrontal and bilateral parietal cortex. Additionally, preparatory activation in bilateral parietal cortex and right dorsolateral prefrontal cortex predicted faster RT when subjects responded to spatial location. No regions were found to be specific to semantic cues at conventional thresholds, and lowering the threshold further revealed little overlap between activity associated with spatial and semantic cueing effects, thereby demonstrating a single dissociation between activations related to preparing a spatial versus semantic task-set. This relationship between preparatory activation of spatial processing networks and efficient conflict resolution suggests that advance information can benefit performance by leading to domain-specific biasing of task-relevant information.
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George, M S; Anton, R F; Bloomer, C; Teneback, C; Drobes, D J; Lorberbaum, J P; Nahas, Z; Vincent, D J
2001-04-01
Functional imaging studies have recently demonstrated that specific brain regions become active in cocaine addicts when they are exposed to cocaine stimuli. To test whether there are regional brain activity differences during alcohol cue exposure between alcoholic subjects and social drinkers, we designed a functional magnetic resonance imaging (fMRI) protocol involving alcohol-specific cues. Ten non-treatment-seeking adult alcoholic subjects (2 women) (mean [SD] age, 29.9 [9.9] years) as well as 10 healthy social drinking controls of similar age (2 women) (mean [SD] age, 29.4 [8.9] years) were recruited, screened, and scanned. In the 1.5-T magnetic resonance imaging scanner, subjects were serially rated for alcohol craving before and after a sip of alcohol, and after a 9-minute randomized presentation of pictures of alcoholic beverages, control nonalcoholic beverages, and 2 different visual control tasks. During picture presentation, changes in regional brain activity were measured with the blood oxygen level-dependent technique. Alcoholic subjects, compared with the social drinking subjects, reported higher overall craving ratings for alcohol. After a sip of alcohol, while viewing alcohol cues compared with viewing other beverage cues, only the alcoholic subjects had increased activity in the left dorsolateral prefrontal cortex and the anterior thalamus. The social drinkers exhibited specific activation only while viewing the control beverage pictures. When exposed to alcohol cues, alcoholic subjects have increased brain activity in the prefrontal cortex and anterior thalamus-brain regions associated with emotion regulation, attention, and appetitive behavior.
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Weber, Matthew J; Messing, Samuel B; Rao, Hengyi; Detre, John A; Thompson-Schill, Sharon L
2014-08-01
Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique used both experimentally and therapeutically to modulate regional brain function. However, few studies have directly measured the aftereffects of tDCS on brain activity or examined changes in task-related brain activity consequent to prefrontal tDCS. To investigate the neural effects of tDCS, we collected fMRI data from 22 human subjects, both at rest and while performing the Balloon Analog Risk Task (BART), before and after true or sham transcranial direct current stimulation. TDCS decreased resting blood perfusion in orbitofrontal cortex and the right caudate and increased task-related activity in the right dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) in response to losses but not wins or increasing risk. Network analysis showed that whole-brain connectivity of the right ACC correlated positively with the number of pumps subjects were willing to make on the BART, and that tDCS reduced connectivity between the right ACC and the rest of the brain. Whole-brain connectivity of the right DLPFC also correlated negatively with pumps on the BART, as prior literature would suggest. Our results suggest that tDCS can alter activation and connectivity in regions distal to the electrodes. Copyright © 2014 Wiley Periodicals, Inc.
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Directory of Open Access Journals (Sweden)
Aditya Mungee
2016-11-01
Full Text Available Background: Studies have demonstrated that fear memories can be modified using non-invasive methods. Recently, we demonstrated that anodal transcranial direct current stimulation (tDCS of the right dorsolateral prefrontal cortex is capable of enhancing fear memories. Here, we examined the effects of cathodal tDCS of the right dorsolateral prefrontal cortex during fear reconsolidation in humans. Methods: Seventeen young, healthy subjects were randomly assigned to two groups, which underwent fear conditioning with mild electric stimuli paired with a visual stimulus. Twenty-four hours later, both groups were shown a reminder of the conditioned fearful stimulus. Shortly thereafter, they received either tDCS (right prefrontal—cathodal, left supraorbital—anodal for 20 min at 1 mA, or sham stimulation. A day later, fear responses of both groups were compared. Results: On Day 3, during fear response assessment, there were no significant differences between the tDCS and sham group (p > 0.05. Conclusion: We conclude that cathodal tDCS of the right dorsolateral prefrontal cortex (right prefrontal—cathodal, left supraorbital—anodal did not influence fear memories.
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Erhard, K; Kessler, F; Neumann, N; Ortheil, H-J; Lotze, M
2014-10-15
The aim of the present study was to explore brain activities associated with creativity and expertise in literary writing. Using functional magnetic resonance imaging (fMRI), we applied a real-life neuroscientific setting that consisted of different writing phases (brainstorming and creative writing; reading and copying as control conditions) to well-selected expert writers and to an inexperienced control group. During creative writing, experts showed cerebral activation in a predominantly left-hemispheric fronto-parieto-temporal network. When compared to inexperienced writers, experts showed increased left caudate nucleus and left dorsolateral and superior medial prefrontal cortex activation. In contrast, less experienced participants recruited increasingly bilateral visual areas. During creative writing activation in the right cuneus showed positive association with the creativity index in expert writers. High experience in creative writing seems to be associated with a network of prefrontal (mPFC and DLPFC) and basal ganglia (caudate) activation. In addition, our findings suggest that high verbal creativity specific to literary writing increases activation in the right cuneus associated with increased resources obtained for reading processes. Copyright © 2014 Elsevier Inc. All rights reserved.
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A study of 1H-MR spectroscopy in the prefrontal cortex and amygdala of heroine abusers
International Nuclear Information System (INIS)
Yang Lanying; Wang Yarong; Li Qiang; Xiong Xiaoshuang; Wang Wei; Zhao Wei; Bai Yunliang
2009-01-01
Objective: To explore the characteristic findings of 1 H-MR spectroscopy ( 1 H-MRS) in the prefrontal cortex and amygdala of patients with heroine dependence (HD), and the relationship to total cumulative dose of inhaled heroine. Methods: Fourteen male HD patients and 12 healthy controls (HC) underwent 1 H-MRS at the prefrontal cortex and amygdala regions. The total cumulative in haled heroin dose was (852±341) g in HD. Ratios of N-acetylaspartate/creatine(NAA/Cr) and choline/creatine (Cho/Cr) were respectively measured in the prefrontal cortex and bilateral amygdale regions. The student's t test and the linear correlation were employed for statistical analysis. Results: Compared to HC group, HD patients had a significant lower ratio of NAA/Cr in the prefrontal cortex (1.44±0.46 vs 1.50±0.75, t=1.77, P< 0.05), left amygdala region (1.32±0.08 vs 1.42±0.08, t=3.41, P<0.05), and right amygdala region (1.34±0.09 vs 1.44±0.10, t=2.63, P<0.05), the HD patients had a significant increased ratio of Cho/Cr in the prefrontal cortex (0.92±0.06 vs 0.86±0.08, t=2.31, P<0.05), left amygdala region (1.20±0.12 vs 1.07±0.04, t=3.60, P<0.05) and right amygdala region(1.26±0.15 vs 1.12±0.11, t=2.60, P<0.05). There was a negative linear correlation between the total cumulative inhaled heroine dose and the ratio of NAA/Cr in the prefrontal cortex (r=-0.9159, P<0.01), left amygdala region( r= -0.8756, P<0.01), and right amygdala region (r=-0.9399, P<0.01) respectively. Conclusions: The study indicates that neuronal damage and glial proliferation may occur in the prefrontal cortex and amygdala region, which suggests the abnormalities of executive function and emotion in patients with HD. A relationship exists between the heroin-induced metabolic abnormality and the total cumulative dose of inhaled heroine. (authors)
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Prefrontal cortex activity is associated with biobehavioral components of the stress response
Directory of Open Access Journals (Sweden)
Muriah D Wheelock
2016-11-01
Full Text Available Contemporary theory suggests that prefrontal cortex (PFC function is associated with individual variability in the psychobiology of the stress response. Advancing our understanding of this complex biobehavioral pathway has potential to provide insight into processes that determine individual differences in stress susceptibility. The present study used functional magnetic resonance imaging (fMRI to examine brain activity during a variation of the Montreal Imaging Stress Task (MIST in fifty-three young adults. Salivary cortisol was assessed as an index of the stress response, trait anxiety was assessed as an index of an individual’s disposition towards negative affectivity, and self-reported stress was assessed as an index of an individual’s subjective psychological experience. Heart rate and skin conductance responses were also assessed as additional measures of physiological reactivity. Dorsomedial PFC, dorsolateral PFC, and inferior parietal lobule demonstrated differential activity during the MIST. Further, differences in salivary cortisol reactivity to the MIST were associated with ventromedial PFC and posterior cingulate activity, while trait anxiety and self-reported stress were associated with dorsomedial and ventromedial PFC activity respectively. These findings underscore that PFC activity regulates behavioral and psychobiological components of the stress response.
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Directory of Open Access Journals (Sweden)
Pamphyle Abedi Mukutenga
2012-08-01
Full Text Available Introduction: The dorsal striatum plays an important role in the control of motor activity and learning processes within the basal ganglia circuitry. Furthermore, recent works have suggested functional differentiation between subregions of the dorsal striatum Methods: The present study examined the effects of bilateral electrolytic lesions of the dorsomedial striatum on motor behavior and learning ability in rats using a series of behavioral tests. 20 male wistar rats were used in the experiment and behavioral assessment were conducted using open field test, rotarod test and 8-arm radial maze. Results: In the open field test, rats with bilateral electrolytic lesions of the dorsomedial striatum showed a normal motor function in the horizontal locomotor activity, while in rearing activity they displayed a statistically significant motor impairment when compared to sham operated group. In the rotarod test, a deficit in motor coordination and acquisition of skilled behavior was observed in rats with bilateral electrolytic lesions of the dorsomedial striatum compared to sham. However, radial maze performance revealed similar capacity in the acquisition of learning task between experimental groups. Discussion: Our results support the premise of the existence of functional dissociation between the dorsomedial and the dorsolateral regions of the dorsal striatum. In addition, our data suggest that the associative dorsomedial striatum may be as critical in striatum-based motor control.
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Li, Jay-Shake; Hsiao, Kun-Yuan; Chen, Wei-Min
2011-03-17
Previous animal studies have defined the ability to remember the details of what, where, and when of an event as an episodic-like memory to be used to model episodic memory in humans. Numerous findings indicate that the hippocampal-frontal cortical circuitry plays a major part in its neural mechanism. Researchers have intensively studied roles of diverse hippocampus sub-regions using animal models. By contrast, the impact of prefrontal cortex lesions on episodic-like memory in animals is still unknown. Here we show that Wistar rats with bilateral medial prefrontal cortex lesions failed to use the temporal-contextual information to retrieve memory of a fear-conditioning event, indicating impairments in their episodic-like memory. Subsequent experiments excluded alternative interpretations that the manipulation impaired the fear-conditioning per se, or interfered with the sensory preconditioning process. We concluded that damages in this area might impair temporal information processing, or interfere with integrating temporal and contextual elements of fear-conditioning events to form a conjunctive entity. These findings can help understand how the medial prefrontal cortex contributes to episodic-like memory. Copyright © 2010 Elsevier B.V. All rights reserved.
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Singh, Bhupendra P; Pathak, Hemant R; Andankar, Mukund G
2009-04-01
For management of long segment anterior urethral stricture, dorsal onlay urethroplasty is currently the most favored single-stage procedure. Conventional dorsal onlay urethroplasty requires circumferential mobilization of the urethra, which might cause ischemia of the urethra in addition to chordee. To determine the feasibility and short-term outcomes of applying a dorsolateral free graft to treat anterior urethral stricture by unilateral urethral mobilization through a perineal approach. A prospective study from September 2005 to March 2008 in a tertiary care teaching hospital. Seventeen patients with long or multiple strictures of the anterior urethra were treated by a dorsolateral free buccal mucosa graft. The pendulous urethra was accessed by penile eversion through the perineal wound. The urethra was not separated from the corporal bodies on one side and was only mobilized from the midline on the ventral aspect to beyond the midline on the dorsal aspect. The urethra was opened in the dorsal midline over the stricture. The buccal mucosa graft was secured on the ventral tunica of the corporal bodies. Mean and median. After a follow-up of 12-30 months, one recurrence developed and 1 patient needed an internal urethrotomy. A unilateral urethral mobilization approach for dorsolateral free graft urethroplasty is feasible for panurethral strictures of any length with good short-term success.
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Lateralized frontal activity for Japanese phonological processing during child development
Directory of Open Access Journals (Sweden)
Takaaki eGoto
2015-07-01
Full Text Available Phonological awareness is essential for reading, and is common to all language systems, including alphabetic languages and Japanese. This cognitive factor develops during childhood, and is thought to be associated with shifts in brain activity. However, the nature of this neurobiological developmental shift is unclear for speakers of Japanese, which is not an alphabetical language. The present study aimed to reveal a shift in brain functions for processing phonological information in native-born Japanese children. We conducted a phonological awareness task and examined hemodynamic activity in 103 children aged 7 to 12 years. While younger children made mistakes and needed more time to sort phonological information in reverse order, older children completed the task quickly and accurately. Additionally, younger children exhibited increased activity in the bilateral dorsolateral prefrontal cortex, which may be evidence of immature phonological processing skills. Older children exhibited dominant activity in the left compared with the right dorsolateral prefrontal cortex, suggesting that they had already acquired phonological processing skills. We also found significant effects of age and lateralized activity on behavioral performance. During earlier stages of development, the degree of left lateralization appears to have a smaller effect on behavioral performance. Conversely, in later stages of development, the degree of left lateralization appears to have a stronger influence on behavioral performance. These initial findings regarding a neurobiological developmental shift in Japanese speakers suggest that common brain regions play a critical role in the development of phonological processing skills among different languages systems, such as Japanese and alphabetical languages.
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The cerebral correlates of set-shifting: an fMRI study of the trail making test
Directory of Open Access Journals (Sweden)
Moll Jorge
2002-01-01
Full Text Available The trail making test (TMT pertains to a family of tests that tap the ability to alternate between cognitive categories. However, the value of the TMT as a localizing instrument remains elusive. Here we report the results of a functional magnetic resonance imaging (fMRI study of a verbal adaptation of the TMT (vTMT. The vTMT takes advantage of the set-shifting properties of the TMT and, at the same time, minimizes the visuospatial and visuomotor components of the written TMT. Whole brain BOLD fMRI was performed during the alternating execution of vTMTA and vTMTB in seven normal adults with more than 12 years of formal education. Brain activation related to the set-shifting component of vTMTB was investigated by comparing performance on vTMTB with vTMTA, a simple counting task. There was a marked asymmetry of activation in favor of the left hemisphere, most notably in dorsolateral prefrontal cortex (BA 6 lateral, 44 and 46 and supplementary motor area/cingulate sulcus (BA 6 medial and 32. The intraparietal sulcus (BA 7 and 39 was bilaterally activated. These findings are in line with clinico-anatomic and functional neuroimaging data that point to a critical role of the dorsolateral and medial prefrontal cortices as well as the intraparietal sulci in the regulation of cognitive flexibility, intention, and the covert execution of saccades/anti-saccades. Many commonly used neuropsychological paradigms, such as the Stroop, Wisconsin Card Sorting, and go - no go tasks, share some patterns of cerebral activation with the TMT.
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Hicks, Robert A; Hall, Peter A; Staines, William R; McIlroy, William E
2018-02-01
The left and right prefrontal cortices are linked to networks that control approach and withdrawal motivation, respectively. The relationship between activity in the left and right prefrontal activity is used to assess brain states and specifically their link to motivational behaviours and tendencies. The most common measure used in this context is called the frontal alpha asymmetry (FAA), which compares alpha (8-13Hz) power at each region. Interestingly, research shows that FAA is influenced by aerobic exercise by increasing relative left prefrontal cortex activity. In turn this effect may be beneficial for individuals with mood disorders that are associated with abnormal motivational tendencies. However, it is unknown whether changes in FAA after exercise are due to cardiovascular demands of activity or simply the movement required for the exercise. Therefore, this study aimed to investigate the influence of aerobic exercise and 'no intensity' bilateral movement cycling on FAA in young healthy adults. Results showed aerobic exercise caused a significant increase in FAA scores 22-38min after exercise. However, movement did not lead to a significant change in FAA. This suggests there is an intensity required for physical activity to evoke a change in FAA. Copyright © 2017 Elsevier B.V. All rights reserved.
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Chiang, Huey-Ling; Chen, Yu-Jen; Lo, Yu-Chun; Tseng, Wen-Yih I; Gau, Susan S
2015-09-01
The neural substrate for clinical symptoms and neuropsychological performance in individuals with attention-deficit/hyperactivity disorder (ADHD) has rarely been studied and has yielded inconsistent results. We sought to compare the microstructural property of fibre tracts associated with the prefrontal cortex and its association with ADHD symptoms and a wide range of attention performance in youth with ADHD and healthy controls. We assessed youths with ADHD and age-, sex-, handedness-, coil- and intelligence-matched controls using the Conners' Continuous Performance Test (CCPT) for attention performance and MRI. The 10 target tracts, including the bilateral frontostriatal tracts (caudate to dorsolateral prefrontal cortex, ventrolateral prefrontal cortex and orbitofrontal cortex), superior longitudinal fasciculus (SLF) and cingulum bundle were reconstructed using diffusion spectrum imaging tractography. We computed generalized fractional anisotropy (GFA) values to indicate tract-specific microstructural property. We included 50 youths with ADHD and 50 healthy controls in our study. Youths with ADHD had lower GFA in the left frontostriatal tracts, bilateral SLF and right cingulum bundle and performed worse in the CCPT than controls. Furthermore, alteration of the right SLF GFA was most significantly associated with the clinical symptom of inattention in youths with ADHD. Finally, youths with ADHD had differential association patterns of the 10 fibre tract GFA values with attention performance compared with controls. Ten of the youths with ADHD were treated with methylphenidate, which may have long-term effects on microstructural property. Our study highlights the importance of the SLF, cingulum bundle and frontostriatal tracts for clinical symptoms and attention performance in youths with ADHD and demonstrates the involvement of different fibre tracts in attention performance in these individuals.
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Chen, Yu-Chen; Bo, Fan; Xia, Wenqing; Liu, Shenghua; Wang, Peng; Su, Wen; Xu, Jin-Jing; Xiong, Zhenyu; Yin, Xindao
2017-10-03
Chronic tinnitus is often accompanied with depressive symptom, which may arise from aberrant functional coupling between the amygdala and cerebral cortex. To explore this hypothesis, resting-state functional magnetic resonance imaging (fMRI) was used to investigate the disrupted amygdala-cortical functional connectivity (FC) in chronic tinnitus patients with depressive mood. Chronic tinnitus patients with depressive mood (n=20), without depressive mood (n=20), and well-matched healthy controls (n=23) underwent resting-state fMRI scanning. Amygdala-cortical FC was characterized using a seed-based whole-brain correlation method. The bilateral amygdala FC was compared among the three groups. Compared to non-depressed patients, depressive tinnitus patients showed decreased amygdala FC with the prefrontal cortex and anterior cingulate cortex as well as increased amygdala FC with the postcentral gyrus and lingual gyrus. Relative to healthy controls, depressive tinnitus patients revealed decreased amygdala FC with the superior and middle temporal gyrus, anterior and posterior cingulate cortex, and prefrontal cortex, as well as increased amygdala FC with the postcentral gyrus and lingual gyrus. The current study identified for the first time abnormal resting-state amygdala-cortical FC with the prefrontal-cingulate-temporal circuit in chronic tinnitus patients with depressive mood, which will provide novel insight into the underlying neuropathological mechanisms of tinnitus-induced depressive disorder. Copyright © 2017 Elsevier Inc. All rights reserved.
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Johnson, Marcia K; Raye, Carol L; Mitchell, Karen J; Greene, Erich J; Cunningham, William A; Sanislow, Charles A
2005-09-01
Using fMRI, we investigated the functional organization of prefrontal cortex (PFC) as participants briefly thought of a single just-experienced item (i.e., refreshed an active representation). The results of six studies, and a meta-analysis including previous studies, identified regions in left dorsolateral, anterior, and ventrolateral PFC associated in varying degrees with refreshing different types of information (visual and auditory words, drawings, patterns, people, places, or locations). In addition, activity increased in anterior cingulate with selection demands and in orbitofrontal cortex when a nonselected item was emotionally salient, consistent with a role for these areas in cognitive control (e.g., overcoming "mental rubbernecking"). We also found evidence that presenting emotional information disrupted an anterior component of the refresh circuit. We suggest that refreshing accounts for some neural activity observed in more complex tasks, such as working memory, long-term memory, and problem solving, and that its disruption (e.g., from aging or emotion) could have a broad impact.
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Stødkilde-Jørgensen, Hans; Geertz, Armin W.; Lund, Torben E.; Roepstorff, Andreas
2011-01-01
This study used functional magnetic resonance imaging to investigate how assumptions about speakers’ abilities changed the evoked BOLD response in secular and Christian participants who received intercessory prayer. We find that recipients’ assumptions about senders’ charismatic abilities have important effects on their executive network. Most notably, the Christian participants deactivated the frontal network consisting of the medial and the dorsolateral prefrontal cortex bilaterally in response to speakers who they believed had healing abilities. An independent analysis across subjects revealed that this deactivation predicted the Christian participants’ subsequent ratings of the speakers’ charisma and experience of God’s presence during prayer. These observations point to an important mechanism of authority that may facilitate charismatic influence, a mechanism which is likely to be present in other interpersonal interactions as well. PMID:20228138
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Cortical and white matter alterations in patients with neuropathic pain after spinal cord injury.
Yoon, Eun Jin; Kim, Yu Kyeong; Shin, Hyung Ik; Lee, Youngjo; Kim, Sang Eun
2013-12-02
Neuropathic pain is one of the major problems of patients with spinal cord injury (SCI), which remains refractory to treatment despite a variety of therapeutic approach. Multimodal neuroimaging could provide complementary information for brain mechanisms underlying neuropathic pain, which could be based on development of more effective treatment strategies. Ten patients suffering from chronic neuropathic pain after SCI and 10 healthy controls underwent FDG-PET, T1-anatomical MRI and diffusion tensor imaging. We found decreases of both metabolism and the gray matter volume in the left dorsolateral prefrontal cortex in patients compared to healthy controls, as well as hypometabolism in the medial prefrontal cortex and gray matter volume loss in bilateral anterior insulae and subgenual anterior cingulate cortices. These brain regions are generally known to participate in pain modulation by affective and cognitive processes. Decreases of mean diffusivity (MD) in the right internal capsule including, cerebral peduncle, pre-and post-central white matter, and prefrontal white matter as components of the corticospinal and thalamocortical tracts were demonstrated in patients. Further, lower MD value of prefrontal white matter was correlated with decreased metabolism of medial prefrontal cortex in patients. These results indicated that white matter changes imply abnormal pain modulation in patients as well as motor impairment. Our study showed the functional and structural multimodal imaging modality commonly identified the possible abnormalities in the brain regions participating pain modulation in neuropathic pain. Multifaceted imaging studies in neuropathic pain could be useful elucidating precise mechanisms of persistent pain, and providing future directions for treatment. © 2013 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Diana Martinez
2018-03-01
Full Text Available BackgroundPrevious studies have shown that repetitive transcranial magnetic stimulation (rTMS to the dorsolateral prefrontal cortex may serve as a potential treatment for cocaine use disorder (CUD, which remains a public health problem that is refractory to treatment. The goal of this pilot study was to investigate the effect of rTMS on cocaine self-administration in the laboratory. In the self-administration sessions, CUD participants chose between cocaine and an alternative reinforcer (money in order to directly measure cocaine-seeking behavior. The rTMS was delivered with the H7 coil, which provides stimulation to the medial prefrontal cortex (mPFC and anterior cingulate cortex (ACC. These brain regions were targeted based on previous imaging studies demonstrating alterations in their activation and connectivity in CUD.MethodsVolunteers with CUD were admitted to an inpatient unit for the entire study and assigned to one of three rTMS groups: high frequency (10 Hz, low frequency (1 Hz, and sham. Six participants were included in each group and the rTMS was delivered on weekdays for 3 weeks. The cocaine self-administration sessions were performed at three time points: at baseline (pre-TMS, session 1, after 4 days of rTMS (session 2, and after 13 days of rTMS (session 3. During each self-administration session, the outcome measure was the number of choices for cocaine.ResultsThe results showed a significant group by time effect (p = 0.02, where the choices for cocaine decreased between sessions 2 and 3 in the high frequency group. There was no effect of rTMS on cocaine self-administration in the low frequency or sham groups.ConclusionTaken in the context of the existing literature, these results contribute to the data showing that high frequency rTMS to the prefrontal cortex may serve as a potential treatment for CUD.
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Wood, Samantha M W; Schembre, Susan M; He, Qinghua; Engelmann, Jeffrey M; Ames, Susan L; Bechara, Antoine
2016-10-15
Researchers have proposed a variety of behavioral traits that may lead to weight gain and obesity; however, little is known about the neurocognitive mechanisms underlying these weight-related eating behaviors. In this study, we measured activation of reward circuitry during a task requiring response and inhibition to food stimuli. We assessed participants' emotional eating, external eating, and two subscales of dietary restraint-routine restraint and compensatory restraint-using the Weight-Related Eating Questionnaire. For routine restraint, we found positive associations with activation in the insula, dorsolateral prefrontal cortex, anterior cingulate cortex, orbitofrontal cortex and ventromedial prefrontal cortex in response to high-calorie versus low-calorie foods. For emotional eating, we found positive associations with insula and dorsolateral prefrontal cortex activation in response to high-calorie versus low-calorie foods. We also found positive associations between emotional eating and dorsolateral prefrontal cortex activation in response to approach versus inhibition towards high-calorie foods. Thus, our results demonstrate an increase in activation across brain regions related to self-control and urges in response to high-calorie food associated with both emotional eating and routine restraint. Overall, these results support the construct validity of both emotional eating and routine restraint and provide preliminary evidence that these subscales have similar neural correlates. Copyright © 2016 Elsevier Inc. All rights reserved.
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The Neural Correlates of Self-Regulatory Fatigability During Inhibitory Control of Eye Blinking.
Abi-Jaoude, Elia; Segura, Barbara; Cho, Sang Soo; Crawley, Adrian; Sandor, Paul
2018-05-30
The capacity to regulate urges is an important human characteristic associated with a range of social and health outcomes. Self-regulatory capacity has been postulated to have a limited reserve, which when depleted leads to failure. The authors aimed to investigate the neural correlates of self-regulatory fatigability. Functional MRI was used to detect brain activations in 19 right-handed healthy subjects during inhibition of eye blinking, in a block design. The increase in number of blinks during blink inhibition from the first to the last block was used as covariate of interest. There was an increase in the number of eye blinks escaping inhibitory control across blink inhibition blocks, whereas there was no change in the number of eye blinks occurring during rest blocks. Inhibition of blinking activated a wide network bilaterally, including the inferior frontal gyrus, dorsolateral prefrontal cortex, dorsal anterior cingulate cortex, supplementary motor area, and caudate. Deteriorating performance was associated with activity in orbitofrontal cortex, ventromedial prefrontal cortex, rostroventral anterior cingulate cortex, precuneus, somatosensory, and parietal areas. As anticipated, effortful eye-blink control resulted in activation of prefrontal control areas and regions involved in urge and interoceptive processing. Worsening performance was associated with activations in brain areas involved in urge, as well as regions involved in motivational evaluation. These findings suggest that self-regulatory fatigability is associated with relatively less recruitment of prefrontal cortical regions involved in executive control.
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Bilateral cochlear implantation in a patient with bilateral temporal bone fractures.
Chung, Jae Ho; Shin, Myung Chul; Min, Hyun Jung; Park, Chul Won; Lee, Seung Hwan
2011-01-01
With the emphasis on bilateral hearing nowadays, bilateral cochlear implantation has been tried out for bilateral aural rehabilitation. Bilateral sensorineural hearing loss caused by head trauma can get help from cochlear implantation. We present the case of a 44-year-old man with bilateral otic capsule violating temporal bone fractures due to head trauma. The patient demonstrated much improved audiometric and psychoacoustic performance after bilateral cochlear implantation. We believe bilateral cochlear implantation in such patient can be a very effective tool for rehabilitation. Copyright © 2011 Elsevier Inc. All rights reserved.
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Carp, Joshua; Fitzgerald, Kate Dimond; Taylor, Stephan F; Weissman, Daniel H
2012-01-02
In functional magnetic resonance imaging (fMRI) studies, researchers often attempt to ensure that group differences in brain activity are not confounded with group differences in mean reaction time (RT). However, even when groups are matched for performance, they may differ in terms of the RT-BOLD relationship: the degree to which brain activity varies with RT on a trial-by-trial basis. Group activation differences might therefore be influenced by group differences in the relationship between brain activity and time on task. Here, we investigated whether correcting for this potential confound alters group differences in brain activity. Specifically, we reanalyzed data from a functional MRI study of response conflict in children and adults, in which conventional analyses indicated that conflict-related activity did not differ between groups. We found that the RT-BOLD relationship was weaker in children than in adults. Consequently, after removing the effect of RT on brain activity, children exhibited greater conflict-related activity than adults in both the posterior medial prefrontal cortex and the right dorsolateral prefrontal cortex. These results identify the RT-BOLD relationship as an important potential confound in fMRI studies of group differences. They also suggest that the magnitude of the RT-BOLD relationship may be a useful biomarker of brain maturity. Copyright © 2011 Elsevier Inc. All rights reserved.
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Ferrari, Chiara; Nadal, Marcos; Schiavi, Susanna; Vecchi, Tomaso; Cela-Conde, Camilo J; Cattaneo, Zaira
2017-05-01
Attractive individuals are perceived as possessing more positive personal traits than unattractive individuals. This reliance on aesthetic features to infer moral character suggests a close link between aesthetic and moral valuation. Here we aimed to investigate the neural underpinnings of the interaction between aesthetic and moral valuation by combining transcranial magnetic stimulation (TMS) with a priming paradigm designed to assess the Beauty-is-Good stereotype. Participants evaluated the trustworthiness of a series of faces (targets), each of which was preceded by an adjective describing desirable, undesirable, or neutral aesthetic qualities (primes). TMS was applied between prime and target to interfere with activity in two regions known to be involved in aesthetic and moral valuation: the dorsomedial prefrontal cortex (dmPFC, a core region in social cognition) and the dorsolateral prefrontal cortex (dlPFC, critical in decision making). Our results showed that when TMS was applied over vertex (control) and over the dlPFC, participants judged faces as more trustworthy when preceded by positive than by negative aesthetic primes (as also shown in two behavioral experiments). However, when TMS was applied over the dmPFC, primes had no effect on trustworthiness judgments. A second Experiment corroborated this finding. Our results suggest that mPFC plays a causal role linking moral and aesthetic valuation. © The Author (2017). Published by Oxford University Press.
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Crone, Eveline A; van der Molen, Maurits W
2004-01-01
Patients with bilateral lesions of the ventromedial prefrontal cortex, when performing gambling tasks modeling real-life decision-making, opt for choices that yield high immediate gains in spite of higher future losses. Under the hypothesis that the prefrontal cortex is the last brain region to mature, it was examined whether young children would show a similar preference for immediate prospects. In Experiment 1, 4 age groups (6-9, 10-12, 13-15 and 18-25 years olds) performed 2 versions of a computerized variant of the original Iowa gambling task under 3 different feedback conditions (no feedback, global feedback, and option-specific feedback) and completed the Raven Standard Progressive Matrices as an index of inductive reasoning ability. In Experiment 2, 3 age groups (7-8, 11-12, and 15-16 year olds) performed both task versions in addition to a working memory task ("Digit Span Backwards"). Results showed a developmental increase in the sensitivity to future consequences, positive or negative, that could not be explained by developmental changes in working memory capacity or inductive reasoning. It was concluded that young children share with ventromedial prefrontal patients the failure to anticipate on future outcomes.
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Pierce, Jordan E; McDowell, Jennifer E
2016-02-01
Cognitive control supports flexible behavior adapted to meet current goals and can be modeled through investigation of saccade tasks with varying cognitive demands. Basic prosaccades (rapid glances toward a newly appearing stimulus) are supported by neural circuitry, including occipital and posterior parietal cortex, frontal and supplementary eye fields, and basal ganglia. These trials can be contrasted with complex antisaccades (glances toward the mirror image location of a stimulus), which are characterized by greater functional magnetic resonance imaging (MRI) blood oxygenation level-dependent (BOLD) signal in the aforementioned regions and recruitment of additional regions such as dorsolateral prefrontal cortex. The current study manipulated the cognitive demands of these saccade tasks by presenting three rapid event-related runs of mixed saccades with a varying probability of antisaccade vs. prosaccade trials (25, 50, or 75%). Behavioral results showed an effect of trial-type probability on reaction time, with slower responses in runs with a high antisaccade probability. Imaging results exhibited an effect of probability in bilateral pre- and postcentral gyrus, bilateral superior temporal gyrus, and medial frontal gyrus. Additionally, the interaction between saccade trial type and probability revealed a strong probability effect for prosaccade trials, showing a linear increase in activation parallel to antisaccade probability in bilateral temporal/occipital, posterior parietal, medial frontal, and lateral prefrontal cortex. In contrast, antisaccade trials showed elevated activation across all runs. Overall, this study demonstrated that improbable performance of a typically simple prosaccade task led to augmented BOLD signal to support changing cognitive control demands, resulting in activation levels similar to the more complex antisaccade task. Copyright © 2016 the American Physiological Society.
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The topology of connections between rat prefrontal and temporal cortices
Directory of Open Access Journals (Sweden)
Stacey eBedwell
2015-05-01
Full Text Available Understanding the structural organisation of the prefrontal cortex (PFC is an important step towards determining its functional organisation. Here we investigated the organisation of PFC using different neuronal tracers. We injected retrograde (Fluoro-Gold, 100nl and anterograde (Biotinylated dextran amine (BDA or Fluoro-Ruby, 100nl tracers into sites within PFC subdivisions (prelimbic, ventral orbital, ventrolateral orbital, dorsolateral orbital along a coronal axis within PFC. At each injection site one injection was made of the anterograde tracer and one injection was made of the retrograde tracer. The projection locations of retrogradely labelled neurons and anterogradely labelled axon terminals were then analysed in the temporal cortex: area Te, entorhinal and perirhinal cortex. We found evidence for an ordering of both the anterograde (anterior-posterior, dorsal-ventral and medial-lateral axes: p<0.001 and retrograde (anterior-posterior, dorsal-ventral and medial-lateral axes: p<0.001 connections of PFC. We observed that anterograde and retrograde labelling in ipsilateral temporal cortex (i.e. PFC inputs and outputs often occurred reciprocally (i.e. the same brain region, such as area 35d in perirhinal cortex, contained anterograde and retrograde labelling. However, often the same specific columnar temporal cortex regions contained only either labelling of retrograde or anterograde tracer, indicating that PFC inputs and outputs are frequently non-matched.
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Directory of Open Access Journals (Sweden)
Marika eCarrieri
2016-02-01
Full Text Available Functional near-infrared spectroscopy (fNIRS is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC in subjects while performing a demanding VR hand-controlled task (HCT. Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3D hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB over a virtual route (VROU reproducing a 42-m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2±37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found
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Carrieri, Marika; Petracca, Andrea; Lancia, Stefania; Basso Moro, Sara; Brigadoi, Sabrina; Spezialetti, Matteo; Ferrari, Marco; Placidi, Giuseppe; Quaresima, Valentina
2016-01-01
Functional near-infrared spectroscopy (fNIRS) is a non-invasive vascular-based functional neuroimaging technology that can assess, simultaneously from multiple cortical areas, concentration changes in oxygenated-deoxygenated hemoglobin at the level of the cortical microcirculation blood vessels. fNIRS, with its high degree of ecological validity and its very limited requirement of physical constraints to subjects, could represent a valid tool for monitoring cortical responses in the research field of neuroergonomics. In virtual reality (VR) real situations can be replicated with greater control than those obtainable in the real world. Therefore, VR is the ideal setting where studies about neuroergonomics applications can be performed. The aim of the present study was to investigate, by a 20-channel fNIRS system, the dorsolateral/ventrolateral prefrontal cortex (DLPFC/VLPFC) in subjects while performing a demanding VR hand-controlled task (HCT). Considering the complexity of the HCT, its execution should require the attentional resources allocation and the integration of different executive functions. The HCT simulates the interaction with a real, remotely-driven, system operating in a critical environment. The hand movements were captured by a high spatial and temporal resolution 3-dimensional (3D) hand-sensing device, the LEAP motion controller, a gesture-based control interface that could be used in VR for tele-operated applications. Fifteen University students were asked to guide, with their right hand/forearm, a virtual ball (VB) over a virtual route (VROU) reproducing a 42 m narrow road including some critical points. The subjects tried to travel as long as possible without making VB fall. The distance traveled by the guided VB was 70.2 ± 37.2 m. The less skilled subjects failed several times in guiding the VB over the VROU. Nevertheless, a bilateral VLPFC activation, in response to the HCT execution, was observed in all the subjects. No correlation was found
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Del Arco, Alberto; Ronzoni, Giacomo; Mora, Francisco
2015-07-01
A dysfunction of prefrontal cortex has been associated with the exacerbated response to stress observed in schizophrenic patients and high-risk individuals to develop psychosis. The hypofunction of NMDA glutamatergic receptors induced by NMDA antagonists produces cortico-limbic hyperactivity, and this is used as an experimental model to resemble behavioural abnormalities observed in schizophrenia. The aim of the present study was to investigate whether injections of NMDA antagonists into the medial prefrontal cortex of the rat change (1) the increases of dopamine, noradrenaline and corticosterone concentrations produced by acute stress in amygdala, and (2) the acquisition of aversive memory related to a stressful event. Male Wistar rats were implanted with guide cannulae to perform microdialysis and bilateral microinjections (0.5 μl/side) of the NMDA antagonist 3-[(R)-2-carboxypiperazin-4-yl]-propyl-1-phophonic acid (CPP) (25 and 100 ng). Prefrontal injections were performed 60 min before restraint stress in microdialysis experiments, or training (footshock; 0.6 mA, 2 s) in inhibitory avoidance test. Retention latency was evaluated 24 h after training as an index of aversive memory. Acute stress increased amygdala dialysate concentrations of dopamine (160% of baseline), noradrenaline (145% of baseline) and corticosterone (170% of baseline). Prefrontal injections of CPP did not change the increases of dopamine, noradrenaline or corticosterone produced by stress. In contrast, CPP significantly reduced the retention latency in the inhibitory avoidance test. These results suggest that the hypofunction of prefrontal NMDA receptors does not change the sensitivity to acute stress of dopamine and noradrenaline projections to amygdala but impairs the acquisition of aversive memory.
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Bogert, Brigitte; Numminen-Kontti, Taru; Gold, Benjamin; Sams, Mikko; Numminen, Jussi; Burunat, Iballa; Lampinen, Jouko; Brattico, Elvira
2016-08-01
Music is often used to regulate emotions and mood. Typically, music conveys and induces emotions even when one does not attend to them. Studies on the neural substrates of musical emotions have, however, only examined brain activity when subjects have focused on the emotional content of the music. Here we address with functional magnetic resonance imaging (fMRI) the neural processing of happy, sad, and fearful music with a paradigm in which 56 subjects were instructed to either classify the emotions (explicit condition) or pay attention to the number of instruments playing (implicit condition) in 4-s music clips. In the implicit vs. explicit condition, stimuli activated bilaterally the inferior parietal lobule, premotor cortex, caudate, and ventromedial frontal areas. The cortical dorsomedial prefrontal and occipital areas activated during explicit processing were those previously shown to be associated with the cognitive processing of music and emotion recognition and regulation. Moreover, happiness in music was associated with activity in the bilateral auditory cortex, left parahippocampal gyrus, and supplementary motor area, whereas the negative emotions of sadness and fear corresponded with activation of the left anterior cingulate and middle frontal gyrus and down-regulation of the orbitofrontal cortex. Our study demonstrates for the first time in healthy subjects the neural underpinnings of the implicit processing of brief musical emotions, particularly in frontoparietal, dorsolateral prefrontal, and striatal areas of the brain. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Burton, Harold; Sinclair, Robert J; Dixit, Sachin
2010-11-01
In blind, occipital cortex showed robust activation to nonvisual stimuli in many prior functional neuroimaging studies. The cognitive processes represented by these activations are not fully determined, although a verbal recognition memory role has been demonstrated. In congenitally blind and sighted (10 per group), we contrasted responses to a vibrotactile one-back frequency retention task with 5-s delays and a vibrotactile amplitude-change task; both tasks involved the same vibration parameters. The one-back paradigm required continuous updating for working memory (WM). Findings in both groups confirmed roles in WM for right hemisphere dorsolateral prefrontal (DLPFC) and dorsal/ventral attention components of posterior parietal cortex. Negative findings in bilateral ventrolateral prefrontal cortex suggested task performance without subvocalization. In bilateral occipital cortex, blind showed comparable positive responses to both tasks, whereas WM evoked large negative responses in sighted. Greater utilization of attention resources in blind were suggested as causing larger responses in dorsal and ventral attention systems, right DLPFC, and persistent responses across delays between trials in somatosensory and premotor cortex. In sighted, responses in somatosensory and premotor areas showed iterated peaks matched to stimulation trial intervals. The findings in occipital cortex of blind suggest that tactile activations do not represent cognitive operations for nonverbal WM task. However, these data suggest a role in sensory processing for tactile information in blind that parallels a similar contribution for visual stimuli in occipital cortex of sighted. © 2010 Wiley-Liss, Inc.
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FMRI Study of Neural Responses to Implicit Infant Emotion in Anorexia Nervosa
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Jenni Leppanen
2017-05-01
Full Text Available Difficulties in social–emotional processing have been proposed to play an important role in the development and maintenance of anorexia nervosa (AN. Few studies, thus far, have investigated neural processes that underlie these difficulties, including processing emotional facial expressions. However, the majority of these studies have investigated neural responses to adult emotional display, which may be confounded by elevated sensitivity to social rank and threat in AN. Therefore, the aim of this study was to investigate the neural processes underlying implicit processing of positively and negatively valenced infant emotional display in AN. Twenty-one adult women with AN and twenty-six healthy comparison (HC women were presented with images of positively valenced, negatively valenced, and neutral infant faces during a fMRI scan. Significant differences between the groups in positive > neutral and negative > neutral contrasts were investigated in a priori regions of interest, including the bilateral amygdala, insula, and lateral prefrontal cortex (PFC. The findings revealed that the AN participants showed relatively increased recruitment while the HC participants showed relatively reduced recruitment of the bilateral amygdala and the right dorsolateral PFC in the positive > neutral contrast. In the negative > neutral contrast, the AN group showed relatively increased recruitment of the left posterior insula while the HC groups showed relatively reduced recruitment of this region. These findings suggest that people with AN may engage in implicit prefrontal down-regulation of elevated limbic reactivity to positively social–emotional stimuli.
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Impaired behavior on real-world tasks following damage to the ventromedial prefrontal cortex.
Tranel, Daniel; Hathaway-Nepple, Julie; Anderson, Steven W
2007-04-01
Patients with damage to the ventromedial prefrontal cortices (VMPC) commonly manifest blatant behavioral navigation defects in the real world, but it has been difficult to measure these impairments in the clinic or laboratory. Using a set of "strategy application" tasks, which were designed by Shallice and Burgess (1991) to be ecologically valid for detecting executive dysfunction, we investigated the hypothesis that VMPC damage would be associated with defective performance on such tasks, whereas damage outside the VMPC region would not. A group of 9 patients with bilateral VMPC damage was contrasted with comparison groups of participants with (a) prefrontal brain damage outside the VMPC region (n = 8); (b) nonprefrontal brain damage (n = 17); and (c) no brain damage (n = 20). We found support for the hypothesis: VMPC patients had more impaired performances on the strategy application tasks, especially on a Multiple Errands Test that required patients to execute a series of unstructured tasks in a real-world setting (shopping mall). The results are consistent with the notion that efficacious behavioral navigation is dependent on the VMPC region. However, the strategy application tasks were relatively time consuming and effortful, and their diagnostic yield over and above conventional executive functioning tests may not be sufficient to warrant their inclusion in standard clinical assessment.
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Bunge, Silvia A; Wendelken, Carter; Badre, David; Wagner, Anthony D
2005-03-01
The present study examined the contributions of prefrontal cortex (PFC) subregions to two component processes underlying verbal analogical reasoning: semantic retrieval and integration. Event-related functional magnetic resonance imaging data were acquired while subjects performed propositional analogy and semantic decision tasks. On each trial, subjects viewed a pair of words (pair 1), followed by an instructional cue and a second word pair (pair 2). On analogy trials, subjects evaluated whether pair 2 was semantically analogous to pair 1. On semantic trials, subjects indicated whether the pair 2 words were semantically related to each other. Thus, analogy--but not semantic--trials required integration across multiple retrieved relations. To identify regions involved in semantic retrieval, we manipulated the associative strength of pair 1 words in both tasks. Anterior left inferior PFC (aLIPC) was modulated by associative strength, consistent with a role in controlled semantic retrieval. Left frontopolar cortex was insensitive to associative strength, but was more sensitive to integration demands than was aLIPC, consistent with a role in integrating the products of semantic retrieval to evaluate whether distinct representations are analogous. Right dorsolateral PFC exhibited a profile consistent with a role in response selection rather than retrieval or integration. These findings indicate that verbal analogical reasoning depends on multiple, PFC-mediated computations.
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Face processing pattern under top-down perception: a functional MRI study
Li, Jun; Liang, Jimin; Tian, Jie; Liu, Jiangang; Zhao, Jizheng; Zhang, Hui; Shi, Guangming
2009-02-01
Although top-down perceptual process plays an important role in face processing, its neural substrate is still puzzling because the top-down stream is extracted difficultly from the activation pattern associated with contamination caused by bottom-up face perception input. In the present study, a novel paradigm of instructing participants to detect faces from pure noise images is employed, which could efficiently eliminate the interference of bottom-up face perception in topdown face processing. Analyzing the map of functional connectivity with right FFA analyzed by conventional Pearson's correlation, a possible face processing pattern induced by top-down perception can be obtained. Apart from the brain areas of bilateral fusiform gyrus (FG), left inferior occipital gyrus (IOG) and left superior temporal sulcus (STS), which are consistent with a core system in the distributed cortical network for face perception, activation induced by top-down face processing is also found in these regions that include the anterior cingulate gyrus (ACC), right oribitofrontal cortex (OFC), left precuneus, right parahippocampal cortex, left dorsolateral prefrontal cortex (DLPFC), right frontal pole, bilateral premotor cortex, left inferior parietal cortex and bilateral thalamus. The results indicate that making-decision, attention, episodic memory retrieving and contextual associative processing network cooperate with general face processing regions to process face information under top-down perception.
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De Raedt, Rudi; Remue, Jonathan; Loeys, Tom; Hooley, Jill M; Baeken, Chris
2017-12-01
It has been proposed that a crucial link between cognitive (i.e., self-schemas) and biological vulnerability is prefrontal control. This is because decreased control leads to impaired ability to inhibit ruminative thinking after the activation of negative self-schemas. However, current evidence is mainly correlational. In the current experimental study we tested whether the effect of neurostimulation of the dorsolateral prefrontal cortex (DLPFC) on self-esteem is mediated by momentary ruminative self-referential thinking (MRST) after the induction of negative self-schemas by criticism. We used a single, sham-controlled crossover session of anodal transcranial Direct Current Stimulation (tDCS) applied to the left DLPFC (cathode over the right supraorbital region) in healthy female individuals. After receiving tDCS/sham stimulation, we measured MRST and exposed the participants to critical audio scripts, followed by another MRST measurement. Subsequently, all participants completed two Implicit Relational Assessment Procedures to implicitly measure actual and ideal self-esteem. Our behavioral data indicated a significant decrease in MRST after real but not sham tDCS. Moreover, although there was no immediate effect of tDCS on implicit self-esteem, an indirect effect was found through double mediation, with the difference in MRST from baseline to after stimulation and from baseline to after criticism as our two mediators. The larger the decrease of criticism induced MRST after real tDCS, the higher the level of actual self-esteem. Our results show that tDCS can influence cognitive processes such as rumination, and subsequently self-esteem, but only after the activation of negative self-schemas. Rumination and negative self-esteem characterize different forms of psychopathology, and these data expand our knowledge of the role of the prefrontal cortex in controlling these self-referential processes, and the mechanisms of action of tDCS. Copyright © 2017 Elsevier Ltd
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Facilitating Access to Emotions: Neural Signature of EMDR Stimulation
Herkt, Deborah; Tumani, Visal; Grön, Georg; Kammer, Thomas; Hofmann, Arne; Abler, Birgit
2014-01-01
Background Eye Movement Desensitisation and Reprocessing (EMDR) is a method in psychotherapy effective in treating symptoms of posttraumatic stress disorder. The client attends to alternating bilateral visual, auditory or sensory stimulation while confronted with emotionally disturbing material. It is thought that the bilateral stimulation as a specific element of EMDR facilitates accessing and processing of negative material while presumably creating new associative links. We hypothesized that the putatively facilitated access should be reflected in increased activation of the amygdala upon bilateral EMDR stimulation even in healthy subjects. Methods We investigated 22 healthy female university students (mean 23.5 years) with fMRI. Subjects were scanned while confronted with blocks of disgusting and neutral picture stimuli. One third of the blocks was presented without any additional stimulation, one third with bilateral simultaneous auditory stimulation, and one third with bilateral alternating auditory stimulation as used in EMDR. Results Contrasting disgusting vs. neutral picture stimuli confirmed the expected robust effect of amygdala activation for all auditory stimulation conditions. The interaction analysis with the type of auditory stimulation revealed a specific increase in activation of the right amygdala for the bilateral alternating auditory stimulation. Activation of the left dorsolateral prefrontal cortex showed the opposite effect with decreased activation. Conclusions We demonstrate first time evidence for a putative neurobiological basis of the bilateral alternating stimulation as used in the EMDR method. The increase in limbic processing along with decreased frontal activation is in line with theoretical models of how bilateral alternating stimulation could help with therapeutic reintegration of information, and present findings may pave the way for future research on EMDR in the context of posttraumatic stress disorder. PMID:25165974
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Emotion regulation ability varies in relation to intrinsic functional brain architecture.
Uchida, Mai; Biederman, Joseph; Gabrieli, John D E; Micco, Jamie; de Los Angeles, Carlo; Brown, Ariel; Kenworthy, Tara; Kagan, Elana; Whitfield-Gabrieli, Susan
2015-12-01
This study investigated the neural basis of individual variation in emotion regulation, specifically the ability to reappraise negative stimuli so as to down-regulate negative affect. Brain functions in young adults were measured with functional Magnetic Resonance Imaging during three conditions: (i) attending to neutral pictures; (ii) attending to negative pictures and (iii) reappraising negative pictures. Resting-state functional connectivity was measured with amygdala and dorsolateral prefrontal cortical (DLPFC) seed regions frequently associated with emotion regulation. Participants reported more negative affect after attending to negative than neutral pictures, and less negative affect following reappraisal. Both attending to negative vs neutral pictures and reappraising vs attending to negative pictures yielded widespread activations that were significantly right-lateralized for attending to negative pictures and left-lateralized for reappraising negative pictures. Across participants, more successful reappraisal correlated with less trait anxiety and more positive daily emotion, greater activation in medial and lateral prefrontal regions, and lesser resting-state functional connectivity between (a) right amygdala and both medial prefrontal and posterior cingulate cortices, and (b) bilateral DLPFC and posterior visual cortices. The ability to regulate emotion, a source of resilience or of risk for distress, appears to vary in relation to differences in intrinsic functional brain architecture. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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Exploring the neural correlates of visual creativity
Liew, Sook-Lei; Dandekar, Francesco
2013-01-01
Although creativity has been called the most important of all human resources, its neural basis is still unclear. In the current study, we used fMRI to measure neural activity in participants solving a visuospatial creativity problem that involves divergent thinking and has been considered a canonical right hemisphere task. As hypothesized, both the visual creativity task and the control task as compared to rest activated a variety of areas including the posterior parietal cortex bilaterally and motor regions, which are known to be involved in visuospatial rotation of objects. However, directly comparing the two tasks indicated that the creative task more strongly activated left hemisphere regions including the posterior parietal cortex, the premotor cortex, dorsolateral prefrontal cortex (DLPFC) and the medial PFC. These results demonstrate that even in a task that is specialized to the right hemisphere, robust parallel activity in the left hemisphere supports creative processing. Furthermore, the results support the notion that higher motor planning may be a general component of creative improvisation and that such goal-directed planning of novel solutions may be organized top-down by the left DLPFC and by working memory processing in the medial prefrontal cortex. PMID:22349801
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Kühn, S; Gleich, T; Lorenz, R C; Lindenberger, U; Gallinat, J
2014-02-01
Video gaming is a highly pervasive activity, providing a multitude of complex cognitive and motor demands. Gaming can be seen as an intense training of several skills. Associated cerebral structural plasticity induced has not been investigated so far. Comparing a control with a video gaming training group that was trained for 2 months for at least 30 min per day with a platformer game, we found significant gray matter (GM) increase in right hippocampal formation (HC), right dorsolateral prefrontal cortex (DLPFC) and bilateral cerebellum in the training group. The HC increase correlated with changes from egocentric to allocentric navigation strategy. GM increases in HC and DLPFC correlated with participants' desire for video gaming, evidence suggesting a predictive role of desire in volume change. Video game training augments GM in brain areas crucial for spatial navigation, strategic planning, working memory and motor performance going along with evidence for behavioral changes of navigation strategy. The presented video game training could therefore be used to counteract known risk factors for mental disease such as smaller hippocampus and prefrontal cortex volume in, for example, post-traumatic stress disorder, schizophrenia and neurodegenerative disease.
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Altered Gray-Matter Volumes Associated With Betel Quid Dependence
Directory of Open Access Journals (Sweden)
Fulai Yuan
2017-08-01
Full Text Available Betel quid (BQ is one of the most commonly consumed psychoactive substances. It has been suggested to be associated with various health issues, especially oral cancer. Evidence also points to possible decreased cognitive functions after long-term BQ chewing, such as attention and inhibition control. The present study aims to investigate the brain structure basis of BQ chewing in Hunan province of China. Twenty-five BQ chewers and 25 controls were recruited to participate in this study. Voxel-based morphormetry analysis revealed that there were three key regions showing structural differences between BQ chewers and controls, including bilateral dorsolateral prefrontal cortex (DLPFC/insula, ventral medial prefrontal cortex, and left orbitofrontal cortex. Moreover, the GMV in the DLPFC could potentially predict BQ dependence scores, level of daily BQ chewing, and history of BQ chewing. These results suggested that participants who showed BQ chewing dependence may have deficit in inhibition control and affective decision-making, and the level of deficit was dependent on the level of daily BQ chewing, and history of BQ chewing. Understanding the neurobiology features of BQ chewing would help us develop novel ways to diagnose and prevent BQ dependence.
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Altered Gray-Matter Volumes Associated With Betel Quid Dependence.
Yuan, Fulai; Kong, Lingyu; Zhu, Xueling; Jiang, Canhua; Fang, Changyun; Liao, Weihua
2017-01-01
Betel quid (BQ) is one of the most commonly consumed psychoactive substances. It has been suggested to be associated with various health issues, especially oral cancer. Evidence also points to possible decreased cognitive functions after long-term BQ chewing, such as attention and inhibition control. The present study aims to investigate the brain structure basis of BQ chewing in Hunan province of China. Twenty-five BQ chewers and 25 controls were recruited to participate in this study. Voxel-based morphormetry analysis revealed that there were three key regions showing structural differences between BQ chewers and controls, including bilateral dorsolateral prefrontal cortex (DLPFC)/insula, ventral medial prefrontal cortex, and left orbitofrontal cortex. Moreover, the GMV in the DLPFC could potentially predict BQ dependence scores, level of daily BQ chewing, and history of BQ chewing. These results suggested that participants who showed BQ chewing dependence may have deficit in inhibition control and affective decision-making, and the level of deficit was dependent on the level of daily BQ chewing, and history of BQ chewing. Understanding the neurobiology features of BQ chewing would help us develop novel ways to diagnose and prevent BQ dependence.
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Hsu, Wan-Yu; Zanto, Theodore P; Anguera, Joaquin A; Lin, Yung-Yang; Gazzaley, Adam
2015-08-01
The dorsolateral prefrontal cortex (DLPFC) has been proposed to play an important role in neural processes that underlie multitasking performance. However, this claim is underexplored in terms of direct causal evidence. The current study aimed to delineate the causal involvement of the DLPFC during multitasking by modulating neural activity with transcranial direct current stimulation (tDCS) prior to engagement in a demanding multitasking paradigm. The study is a single-blind, crossover, sham-controlled experiment. Anodal tDCS or sham tDCS was applied over left DLPFC in forty-one healthy young adults (aged 18-35 years) immediately before they engaged in a 3-D video game designed to assess multitasking performance. Participants were separated into three subgroups: real-sham (i.e., real tDCS in the first session, followed by sham tDCS in the second session 1 h later), sham-real (sham tDCS first session, real tDCS second session), and sham-sham (sham tDCS in both sessions). The real-sham group showed enhanced multitasking performance and decreased multitasking cost during the second session, compared to first session, suggesting delayed cognitive benefits of tDCS. Interestingly, performance benefits were observed only for multitasking and not on a single-task version of the game. No significant changes were found between the first and second sessions for either the sham-real or the sham-sham groups. These results suggest a causal role of left prefrontal cortex in facilitating the simultaneous performance of more than one task, or multitasking. Moreover, these findings reveal that anodal tDCS may have delayed benefits that reflect an enhanced rate of learning. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Joshi, Sangeeta; Nair, Neena; Bedwal, R S
2014-10-01
Zinc deficiency has become a global problem affecting the developed and developing countries due to inhibitors in the diet which prevents its absorption or due to a very low concentration of bioavailable zinc in the diet. Being present in high concentration in the prostate and having diverse biological function, we investigated the effects of dietary zinc deficiency for 2 and 4 weeks on dorso-lateral and ventral prostate. Sixty prepubertal rats were divided into three groups: zinc control (ZC), pair fed (PF) and zinc deficient (ZD) and fed on 100 μg/g (zinc control and pair fed groups) and 1 μg/g (zinc deficient) diet. Zinc deficiency was associated with degenerative changes in dorso-lateral and ventral prostate as made evident by karyolysis, karyorhexis, cytoplasmolysis, loss of cellularisation, decreased intraluminar secretion and degeneration of fibromuscular stroma. In response, protein carbonyl, nitric oxide, acid phosphatase, 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase increased, exhibiting variable level of significance. Total protein and total zinc concentration in dorso-lateral and ventral prostate as well as in serum decreased (P dorso-lateral and ventral prostate after dietary zinc deficiency as well as impairment of metabolic and secretory activity, reduced gonadotropin levels by hypothalamus -hypophysial system which is indicative of a critical role of zinc in maintaining the prostate integrity.
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Directory of Open Access Journals (Sweden)
Monroe P. Turner
2016-01-01
Full Text Available Cognitive slowing is a prevalent symptom observed in Gulf War Illness (GWI. The present study assessed the extent to which functional connectivity between dorsolateral prefrontal cortex (DLPFC and other task-relevant brain regions was predictive of GWI-related cognitive slowing. GWI patients (n = 54 and healthy veteran controls (n = 29 were assessed on performance of a processing speed task (the Digit Symbol Substitution Task; DSST while undergoing functional magnetic resonance imaging (fMRI. GWI patients were slower on the DSST relative to controls. Bilateral DLPFC connectivity with task-relevant nodes was altered in GWI patients compared to healthy controls during DSST performance. Moreover, hyperconnectivity in these networks predicted GWI-related increases in reaction time on the DSST, whereas hypoconnectivity did not. These results suggest that GWI-related cognitive slowing reflects reduced efficiency in cortical networks.
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Co-occurring anxiety influences patterns of brain activity in depression.
Engels, Anna S; Heller, Wendy; Spielberg, Jeffrey M; Warren, Stacie L; Sutton, Bradley P; Banich, Marie T; Miller, Gregory A
2010-03-01
Brain activation associated with anhedonic depression and co-occurring anxious arousal and anxious apprehension was measured by fMRI during performance of an emotion word Stroop task. Consistent with EEG findings, depression was associated with rightward frontal lateralization in the dorsolateral prefrontal cortex (DLPFC), but only when anxious arousal was elevated and anxious apprehension was low. Activity in the right inferior frontal gyrus (IFG) was also reduced for depression under the same conditions. In contrast, depression was associated with more activity in the anterior cingulate cortex (dorsal ACC and rostral ACC) and the bilateral amygdala. Results imply that depression, particularly when accompanied by anxious arousal, may result in a failure to implement top-down processing by appropriate brain regions (left DLPFC, right IFG) due to increased activation in regions associated with responding to emotionally salient information (right DLPFC, amygdala).
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Energy Technology Data Exchange (ETDEWEB)
Jung, J. A.; Son, H. S.; Kim, S. H.; Jung, S. G [The Catholic University of Korea, Seoul (Korea, Republic of)
2004-07-01
Authors report the effectiveness of MCS in extraordinarily extended pain due to intractable CRPS type II and rCBF study result for mechanism of pain control by MCS. A 43-year-old male presented severe spontaneous burning pain in his left hand and forearm and allodynia over the left arm and left hemibody. Authors planned MCS as a neuromodulation therapy for this intractable peripheral neuropathic pain patient because further neurodestructive procedure did not work anymore and have a potential risk of further aggrevation of neuopathic pain. We performed baseline and stimulation brain perfusion SPECT using 20 mCi of Tc-99m ECD. The baseline CBD studies were done with stimulator 'off' state and stimulation studies were done after stimulator 'on' with satisfactory pain relief. For the stimulation study, the radioisotope was injected immediately after pain-relief and the images were taken about 50 minutes after injection of radioisotope. In resting rCBF in the patient was compared with normal control datas, we found significant increase in rCBF in the bilateral prefrontal cortex, right dorsolateral prefrontal cortex, right superior temporal gyrus, left temporooccipital area. When rCBF datas obtained after alleviation of pain with stimulator 'on' . there were significant increase in rCBF in bilateral prefrontal cortex and left temporoocipital area. After subtraction of ECD SPECT, we found significant increase in rCBF in the right premotor and supplementary motor cortex left sensorimotor cortex, right cingulated cortex, right posterior insular cortex, right anterior limb of internal capsule. left orbitofrontal cortex and right pyramidal tract in cerebral peduncle. Authors report exellent pain control by MCS in a case of severe CRPS type II with hemibody involvement and regional cerebral blood flow changes according to successful pain control.
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International Nuclear Information System (INIS)
Jung, J. A.; Son, H. S.; Kim, S. H.; Jung, S. G
2004-01-01
Authors report the effectiveness of MCS in extraordinarily extended pain due to intractable CRPS type II and rCBF study result for mechanism of pain control by MCS. A 43-year-old male presented severe spontaneous burning pain in his left hand and forearm and allodynia over the left arm and left hemibody. Authors planned MCS as a neuromodulation therapy for this intractable peripheral neuropathic pain patient because further neurodestructive procedure did not work anymore and have a potential risk of further aggrevation of neuopathic pain. We performed baseline and stimulation brain perfusion SPECT using 20 mCi of Tc-99m ECD. The baseline CBD studies were done with stimulator 'off' state and stimulation studies were done after stimulator 'on' with satisfactory pain relief. For the stimulation study, the radioisotope was injected immediately after pain-relief and the images were taken about 50 minutes after injection of radioisotope. In resting rCBF in the patient was compared with normal control datas, we found significant increase in rCBF in the bilateral prefrontal cortex, right dorsolateral prefrontal cortex, right superior temporal gyrus, left temporooccipital area. When rCBF datas obtained after alleviation of pain with stimulator 'on' . there were significant increase in rCBF in bilateral prefrontal cortex and left temporoocipital area. After subtraction of ECD SPECT, we found significant increase in rCBF in the right premotor and supplementary motor cortex left sensorimotor cortex, right cingulated cortex, right posterior insular cortex, right anterior limb of internal capsule. left orbitofrontal cortex and right pyramidal tract in cerebral peduncle. Authors report exellent pain control by MCS in a case of severe CRPS type II with hemibody involvement and regional cerebral blood flow changes according to successful pain control
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MRI volumetry of prefrontal cortex
Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.
1995-05-01
Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was volumetry by stereology can yield accurate and repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method.
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Directory of Open Access Journals (Sweden)
Vikram Prabha
2016-06-01
Full Text Available ABSTRACT Objective To assess the outcome of single stage dorsolateral onlay buccal mucosal urethroplasty for long anterior urethral strictures (>4cm long using a perineal incision. Materials and Methods From August 2010 to August 2013, 20 patients underwent BMG urethroplasty. The cause of stricture was Lichen sclerosis in 12 cases (60%, Instrumentation in 5 cases (25%, and unknown in 3 cases (15%. Strictures were approached through a perineal skin incision and penis was invaginated into it to access the entire urethra. All the grafts were placed dorsolaterally, preserving the bulbospongiosus muscle, central tendon of perineum and one-sided attachement of corpus spongiosum. Procedure was considered to be failure if the patient required instrumentation postoperatively. Results Mean stricture length was 8.5cm (range 4 to 12cm. Mean follow-up was 22.7 months (range 12 to 36 months. Overall success rate was 85%. There were 3 failures (meatal stenosis in 1, proximal stricture in 1 and whole length recurrent stricture in 1. Other complications included wound infection, urethrocutaneous fistula, brownish discharge per urethra and scrotal oedema. Conclusion Dorsolateral buccal mucosal urethroplasty for long anterior urethral strictures using a single perineal incision is simple, safe and easily reproducible by urologists with a good outcome.
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Directory of Open Access Journals (Sweden)
Adelaide H Austin
2016-03-01
Full Text Available Negative emotional responses to the daily life stresses have cumulative effects which, in turn, impose wide-ranging negative constraints on emotional well being and neurocognitive performance (Kalueff et al, 2007, Charles et al, 2013, Nadler et al, 2010. Crucial cognitive functions such as memory and problem solving, as well more short term emotional responses (e.g., anticipation of- and response to- monetary rewards or losses are influenced by mood. The negative impact of these behavioural responses is felt at the individual level, but it also imposes major economic burden on modern healthcare systems. Although much research have been undertaken to understand the underlying mechanisms of depressed mood and design efficient treatment pathways, comparatively little was done to characterize mood modulations that remain within the boundaries of a healthy mental functioning. In one placebo-controlled experiments, we applied daily prefrontal transcranial Direct Current Stimulation (tDCS at five points in time, and found reliable improvements on self-reported mood evaluation. We replicated this finding in an independent double-blinded placebo-controlled experiment and showed that stimulation over a shorter period of time (3 days is sufficient to create detectable mood improvements. Taken together, our data show that repeated bilateral prefrontal tDCS can reduce psychological distress in nondepressed individuals.
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Institute of Scientific and Technical Information of China (English)
Feng-Mei Fan; Shu-Ping Tan; Fu-De Yang; Yun-Long Tan; Yan-Li Zhao; Nan Chen; Bin-Bin Li
2013-01-01
People with schizophrenia exhibit impaired social cognitive functions,particularly emotion regulation.Abnormal activations of the ventral medial prefrontal cortex (vMPFC) during emotional tasks have been demonstrated in schizophrenia,suggesting its important role in emotion processing in patients.We used the resting-state functional connectivity approach,setting a functionally relevant region,the vMPFC,as a seed region to examine the intrinsic functional interactions and communication between the vMPFC and other brain regions in schizophrenic patients.We found hypo-connectivity between the vMPFC and the medial frontal cortex,right middle temporal lobe (MTL),right hippocampus,parahippocampal cortex (PHC) and amygdala.Further,there was a decreased strength of the negative connectivity (or anticorrelation) between the vMPFC and the bilateral dorsal lateral prefrontal cortex (DLPFC) and pre-supplementary motor areas.Among these connectivity alterations,reduced vMPFCDLPFC connectivity was positively correlated with positive symptoms on the Positive and Negative Syndrome Scale,while vMPFC-right MTL/PHC/amygdala functional connectivity was positively correlated with the performance of emotional regulation in patients.These findings imply that communication and coordination throughout the brain networks are disrupted in schizophrenia.The emotional correlates of vMPFC connectivity suggest a role of the hypo-connectivity between these regions in the neuropathology of abnormal social cognition in chronic schizophrenia.
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Working Memory in the Prefrontal Cortex
Funahashi, Shintaro
2017-01-01
The prefrontal cortex participates in a variety of higher cognitive functions. The concept of working memory is now widely used to understand prefrontal functions. Neurophysiological studies have revealed that stimulus-selective delay-period activity is a neural correlate of the mechanism for temporarily maintaining information in working memory processes. The central executive, which is the master component of Baddeley’s working memory model and is thought to be a function of the prefrontal cortex, controls the performance of other components by allocating a limited capacity of memory resource to each component based on its demand. Recent neurophysiological studies have attempted to reveal how prefrontal neurons achieve the functions of the central executive. For example, the neural mechanisms of memory control have been examined using the interference effect in a dual-task paradigm. It has been shown that this interference effect is caused by the competitive and overloaded recruitment of overlapping neural populations in the prefrontal cortex by two concurrent tasks and that the information-processing capacity of a single neuron is limited to a fixed level, can be flexibly allocated or reallocated between two concurrent tasks based on their needs, and enhances behavioral performance when its allocation to one task is increased. Further, a metamemory task requiring spatial information has been used to understand the neural mechanism for monitoring its own operations, and it has been shown that monitoring the quality of spatial information represented by prefrontal activity is an important factor in the subject's choice and that the strength of spatially selective delay-period activity reflects confidence in decision-making. Although further studies are needed to elucidate how the prefrontal cortex controls memory resource and supervises other systems, some important mechanisms related to the central executive have been identified. PMID:28448453
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Two oculomotor-related areas of the brainstem project to the dorsolateral periaqueductal gray.
Klop, E.M.; Mouton, Leonora J.; Holstege, Gert
2005-01-01
The dorsolateral column of the periaqueductal gray (PAGdl) is usually associated with defensive behavior, but how this is brought about is not yet fully understood. In order to elucidate the function of PAGdl, its afferents from the brainstem were investigated in cats. Retrograde tracing results
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Kang, Byeong Keun; Kim, June Sic; Ryun, Seokyun; Chung, Chun Kee
2018-01-01
Most brain-machine interface (BMI) studies have focused only on the active state of which a BMI user performs specific movement tasks. Therefore, models developed for predicting movements were optimized only for the active state. The models may not be suitable in the idle state during resting. This potential maladaptation could lead to a sudden accident or unintended movement resulting from prediction error. Prediction of movement intention is important to develop a more efficient and reasonable BMI system which could be selectively operated depending on the user's intention. Physical movement is performed through the serial change of brain states: idle, planning, execution, and recovery. The motor networks in the primary motor cortex and the dorsolateral prefrontal cortex are involved in these movement states. Neuronal communication differs between the states. Therefore, connectivity may change depending on the states. In this study, we investigated the temporal dynamics of connectivity in dorsolateral prefrontal cortex and primary motor cortex to predict movement intention. Movement intention was successfully predicted by connectivity dynamics which may reflect changes in movement states. Furthermore, dorsolateral prefrontal cortex is crucial in predicting movement intention to which primary motor cortex contributes. These results suggest that brain connectivity is an excellent approach in predicting movement intention.
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Directory of Open Access Journals (Sweden)
Bhupendra P Singh
2009-01-01
Settings and Design: A prospective study from September 2005 to March 2008 in a tertiary care teaching hospital. Materials and Methods: Seventeen patients with long or multiple strictures of the anterior urethra were treated by a dorsolateral free buccal mucosa graft. The pendulous urethra was accessed by penile eversion through the perineal wound. The urethra was not separated from the corporal bodies on one side and was only mobilized from the midline on the ventral aspect to beyond the midline on the dorsal aspect. The urethra was opened in the dorsal midline over the stricture. The buccal mucosa graft was secured on the ventral tunica of the corporal bodies. Statistical Analysis Used: Mean and median. Results: After a follow-up of 12-30 months, one recurrence developed and 1 patient needed an internal urethrotomy. Conclusions: A unilateral urethral mobilization approach for dorsolateral free graft urethroplasty is feasible for panurethral strictures of any length with good short-term success.
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Ageing diminishes the modulation of human brain responses to visual food cues by meal ingestion.
Cheah, Y S; Lee, S; Ashoor, G; Nathan, Y; Reed, L J; Zelaya, F O; Brammer, M J; Amiel, S A
2014-09-01
Rates of obesity are greatest in middle age. Obesity is associated with altered activity of brain networks sensing food-related stimuli and internal signals of energy balance, which modulate eating behaviour. The impact of healthy mid-life ageing on these processes has not been characterised. We therefore aimed to investigate changes in brain responses to food cues, and the modulatory effect of meal ingestion on such evoked neural activity, from young adulthood to middle age. Twenty-four healthy, right-handed subjects, aged 19.5-52.6 years, were studied on separate days after an overnight fast, randomly receiving 50 ml water or 554 kcal mixed meal before functional brain magnetic resonance imaging while viewing visual food cues. Across the group, meal ingestion reduced food cue-evoked activity of amygdala, putamen, insula and thalamus, and increased activity in precuneus and bilateral parietal cortex. Corrected for body mass index, ageing was associated with decreasing food cue-evoked activation of right dorsolateral prefrontal cortex (DLPFC) and precuneus, and increasing activation of left ventrolateral prefrontal cortex (VLPFC), bilateral temporal lobe and posterior cingulate in the fasted state. Ageing was also positively associated with the difference in food cue-evoked activation between fed and fasted states in the right DLPFC, bilateral amygdala and striatum, and negatively associated with that of the left orbitofrontal cortex and VLPFC, superior frontal gyrus, left middle and temporal gyri, posterior cingulate and precuneus. There was an overall tendency towards decreasing modulatory effects of prior meal ingestion on food cue-evoked regional brain activity with increasing age. Healthy ageing to middle age is associated with diminishing sensitivity to meal ingestion of visual food cue-evoked activity in brain regions that represent the salience of food and direct food-associated behaviour. Reduced satiety sensing may have a role in the greater risk of
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Directory of Open Access Journals (Sweden)
Vani A Mathur
2016-09-01
Full Text Available Migraine is a pain disorder associated with abnormal brain structure and function, yet the effect of migraine on acute pain processing remains unclear. It also remains unclear whether altered pain-related brain responses and related structural changes are associated with clinical migraine characteristics. Using fMRI and three levels of thermal stimuli (non-painful, mildly painful, and moderately painful, we compared whole-brain activity between 14 migraine patients and 14 matched controls. Although, there were no significant differences in pain thresholds and pre-scan pain ratings to mildly painful thermal stimuli, patients had aberrant suprathreshold nociceptive processing. Compared to controls, patients had reduced activity in pain modulatory regions including left dorsolateral prefrontal, posterior parietal, and middle temporal cortices and, at a lower-threshold, greater activation in the right mid-insula to moderate pain versus mild pain. We also found that pain-related activity in the insula was associated with clinical variables in patients, including associations between: bilateral anterior insula and pain catastrophizing (PCS; bilateral anterior insula and contralateral posterior insula and migraine pain intensity; and bilateral posterior insula and migraine frequency at a lower-threshold. PCS and migraine pain intensity were also negatively associated with activity in midline regions including posterior cingulate and medial prefrontal cortices. Diffusion tensor imaging revealed a negative correlation between fractional anisotropy (a measure of white matter integrity; FA and migraine duration in the right mid-insula and a positive correlation between left mid-insula FA and PCS. In sum, while patients showed lower sensitivity to acute noxious stimuli, the neuroimaging findings suggest enhanced nociceptive processing and significantly disrupted modulatory networks, particularly involving the insula cortex, associated with indices of
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Directory of Open Access Journals (Sweden)
Julian Caspers
2017-05-01
Full Text Available Patients suffering from Parkinson's disease (PD often show impairments in executive function (EF like decision-making and action control. The right dorsolateral prefrontal cortex (dlPFC has been strongly implicated in EF in healthy subjects and has repeatedly been reported to show alterations related to EF impairment in PD. Recently, two key regions for cognitive action control have been identified within the right dlPFC by co-activation based parcellation. While the posterior region is engaged in rather basal EF like stimulus integration and working memory, the anterior region has a more abstract, supervisory function. To investigate whether these functionally distinct subdivisions of right dlPFC are differentially affected in PD, we analyzed resting-state functional connectivity (FC in 39 PD patients and 44 age- and gender-matched healthy controls. Patients were examined both after at least 12 h withdrawal of dopaminergic drugs (OFF and under their regular dopaminergic medication (ON. We found that only the posterior right dlPFC subdivision shows FC alterations in PD, while the anterior part remains unaffected. PD-related decreased FC with posterior right dlPFC was found in the bilateral medial posterior parietal cortex (mPPC and left dorsal premotor region (PMd in the OFF state. In the medical ON, FC with left PMd normalized, while decoupling with bilateral mPPC remained. Furthermore, we observed increased FC between posterior right dlPFC and the bilateral dorsomedial prefrontal cortex (dmPFC in PD in the ON state. Our findings point to differential disturbances of right dlPFC connectivity in PD, which relate to its hierarchical organization of EF processing by stronger affecting the functionally basal posterior aspect than the hierarchically higher anterior part.
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Monge, Zachary A.; Greenwood, Pamela M.; Parasuraman, Raja; Strenziok, Maren
2016-01-01
Objective Although reasoning and attention are two cognitive processes necessary for ensuring the efficiency of many everyday activities in older adults, the role of white matter integrity in these processes has been little studied. This is an important question due to the role of white matter integrity as a neural substrate of cognitive aging. Here, we sought to examine the white matter tracts subserving reasoning and visuospatial attention in healthy older adults. Method Sixty-one adults aged 60 and older completed a battery of cognitive tests to assess reasoning and visuospatial attention. In addition, diffusion tensor images were collected to assess Fractional Anisotropy (FA) – a measure of white matter integrity. A principle component analysis of the test scores yielded two components: reasoning and visuospatial attention. Whole-brain correlations between FA and the cognitive components were submitted to probabilistic tractography analyses for visualization of cortical targets of tracts. Results For reasoning, bilateral thalamo-anterior prefrontal, anterior corpus callosum, and corpus callosum body tracts interconnecting the superior frontal cortices and right cingulum bundle were found. For visuospatial attention, a right inferior fronto-parietal tract, and bilateral parietal and temporal connections were found. Conclusions We conclude that in older adults, prefrontal cortex white matter tracts and interhemispheric communication are important in higher order cognitive functioning. On the other hand, right-sided fronto-parietal tracts appear to be critical for supporting control of cognitive processes, such as redirecting attention. Researchers may use our results to develop neuroscience-based interventions for older adults targeting brain mechanisms involved in cognitive plasticity. PMID:26986750
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A Rare Entity: Bilateral First Rib Fractures Accompanying Bilateral Scapular Fractures
Gulbahar, Gultekin; Kaplan, Tevfik; Turker, Hasan Bozkurt; Gundogdu, Ahmet Gokhan; Han, Serdar
2015-01-01
First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare en...
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A Rare Entity: Bilateral First Rib Fractures Accompanying Bilateral Scapular Fractures.
Gulbahar, Gultekin; Kaplan, Tevfik; Turker, Hasan Bozkurt; Gundogdu, Ahmet Gokhan; Han, Serdar
2015-01-01
First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare entity.
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[Bilateral cochlear implants].
Müller, J
2017-07-01
Cochlear implants (CI) are standard for the hearing rehabilitation of severe to profound deafness. Nowadays, if bilaterally indicated, bilateral implantation is usually recommended (in accordance with German guidelines). Bilateral implantation enables better speech discrimination in quiet and in noise, and restores directional and spatial hearing. Children with bilateral CI are able to undergo hearing-based hearing and speech development. Within the scope of their individual possibilities, bilaterally implanted children develop faster than children with unilateral CI and attain, e.g., a larger vocabulary within a certain time interval. Only bilateral implantation allows "binaural hearing," with all the benefits that people with normal hearing profit from, namely: better speech discrimination in quiet and in noise, as well as directional and spatial hearing. Naturally, the developments take time. Binaural CI users benefit from the same effects as normal hearing persons: head shadow effect, squelch effect, and summation and redundancy effects. Sequential CI fitting is not necessarily disadvantageous-both simultaneously and sequentially fitted patients benefit in a similar way. For children, earliest possible fitting and shortest possible interval between the two surgeries seems to positively influence the outcome if bilateral CI are indicated.
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A Rare Entity: Bilateral First Rib Fractures Accompanying Bilateral Scapular Fractures
Directory of Open Access Journals (Sweden)
Gultekin Gulbahar
2015-01-01
Full Text Available First rib fractures are scarce due to their well-protected anatomic locations. Bilateral first rib fractures accompanying bilateral scapular fractures are very rare, although they may be together with scapular and clavicular fractures. According to our knowledge, no case of bilateral first rib fractures accompanying bilateral scapular fractures has been reported, so we herein discussed the diagnosis, treatment, and complications of bone fractures due to thoracic trauma in bias of this rare entity.
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Pettit, Lewis D; Bastin, Mark E; Smith, Colin; Bak, Thomas H; Gillingwater, Thomas H; Abrahams, Sharon
2013-11-01
, uncinate fasciculus and hippocampal portion of the cingulum bundles. Significant differences also emerged in the anterior corona radiata as well as in white matter underlying the superior, medial and inferior frontal gyri and the temporal gyri. Dual-task performance significantly correlated with fractional anisotropy measures in the middle frontal gyrus white matter and anterior corona radiata. Letter fluency indices significantly correlated with fractional anisotropy measures of the inferior frontal gyrus white matter and corpus callosum in addition to the corticospinal tracts and mean diffusivity measures in the white matter of the superior frontal gyrus. The current study demonstrates that cognitive impairment in amyotrophic lateral sclerosis is not due to generic slowing of processing speed. Moreover, different executive deficits are related to distinct prefrontal tract involvement in amyotrophic lateral sclerosis with dual-task impairment associating with dorsolateral prefrontal dysfunction and letter fluency showing greater dependence on inferolateral prefrontal dysfunction.
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Ito, Takehito; Kimura, Yasuyuki; Seki, Chie; Ichise, Masanori; Yokokawa, Keita; Kawamura, Kazunori; Takahashi, Hidehiko; Higuchi, Makoto; Zhang, Ming-Rong; Suhara, Tetsuya; Yamada, Makiko
2018-06-14
The histamine H 3 receptor is regarded as a drug target for cognitive impairments in psychiatric disorders. H 3 receptors are expressed in neocortical areas, including the prefrontal cortex, the key region of cognitive functions such as working memory. However, the role of prefrontal H 3 receptors in working memory has not yet been clarified. Therefore, using functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) techniques, we aimed to investigate the association between the neural activity of working memory and the density of H 3 receptors in the prefrontal cortex. Ten healthy volunteers underwent both fMRI and PET scans. The N-back task was used to assess the neural activities related to working memory. H 3 receptor density was measured with the selective PET radioligand [ 11 C] TASP457. The neural activity of the right dorsolateral prefrontal cortex during the performance of the N-back task was negatively correlated with the density of H 3 receptors in this region. Higher neural activity of working memory was associated with lower H 3 receptor density in the right dorsolateral prefrontal cortex. This finding elucidates the role of H 3 receptors in working memory and indicates the potential of H 3 receptors as a therapeutic target for the cognitive impairments associated with neuropsychiatric disorders.
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Bon, C; Galvan, M
1996-06-01
1. The actions of GABAB-receptor agonists and antagonists on rat dorso-lateral septal neurones in vitro were recorded with intracellular microelectrodes. 2. In the presence of 1 microM tetrodotoxin to prevent indirect neuronal effects caused by action potential-dependent neurotransmitter release, bath application of baclofen (0.1-30 microM) or SK&F 97541 (0.01-3 microM) evoked concentration-dependent hyperpolarizations which reversed close to the potassium equilibrium potential; the EC50S were 0.55 and 0.05 microM, respectively. No significant desensitization was observed during prolonged agonist exposure (dorso-lateral septal nucleus express conventional GABAB receptors, which are involved in the generation of slow inhibitory postsynaptic potentials. CGP 55845A is the most potent GABAB receptor antagonist described in this brain area.
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Cannabis use in early adolescence: Evidence of amygdala hypersensitivity to signals of threat
Directory of Open Access Journals (Sweden)
Philip A. Spechler
2015-12-01
Full Text Available Cannabis use in adolescence may be characterized by differences in the neural basis of affective processing. In this study, we used an fMRI affective face processing task to compare a large group (n = 70 of 14-year olds with a history of cannabis use to a group (n = 70 of never-using controls matched on numerous characteristics including IQ, SES, alcohol and cigarette use. The task contained short movies displaying angry and neutral faces. Results indicated that cannabis users had greater reactivity in the bilateral amygdalae to angry faces than neutral faces, an effect that was not observed in their abstinent peers. In contrast, activity levels in the cannabis users in cortical areas including the right temporal-parietal junction and bilateral dorsolateral prefrontal cortex did not discriminate between the two face conditions, but did differ in controls. Results did not change after excluding subjects with any psychiatric symptomology. Given the high density of cannabinoid receptors in the amygdala, our findings suggest cannabis use in early adolescence is associated with hypersensitivity to signals of threat. Hypersensitivity to negative affect in adolescence may place the subject at-risk for mood disorders in adulthood.
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Cannabis use in early adolescence: Evidence of amygdala hypersensitivity to signals of threat.
Spechler, Philip A; Orr, Catherine A; Chaarani, Bader; Kan, Kees-Jan; Mackey, Scott; Morton, Aaron; Snowe, Mitchell P; Hudson, Kelsey E; Althoff, Robert R; Higgins, Stephen T; Cattrell, Anna; Flor, Herta; Nees, Frauke; Banaschewski, Tobias; Bokde, Arun L W; Whelan, Robert; Büchel, Christian; Bromberg, Uli; Conrod, Patricia; Frouin, Vincent; Papadopoulos, Dimitri; Gallinat, Jurgen; Heinz, Andreas; Walter, Henrik; Ittermann, Bernd; Gowland, Penny; Paus, Tomáš; Poustka, Luise; Martinot, Jean-Luc; Artiges, Eric; Smolka, Michael N; Schumann, Gunter; Garavan, Hugh
2015-12-01
Cannabis use in adolescence may be characterized by differences in the neural basis of affective processing. In this study, we used an fMRI affective face processing task to compare a large group (n=70) of 14-year olds with a history of cannabis use to a group (n=70) of never-using controls matched on numerous characteristics including IQ, SES, alcohol and cigarette use. The task contained short movies displaying angry and neutral faces. Results indicated that cannabis users had greater reactivity in the bilateral amygdalae to angry faces than neutral faces, an effect that was not observed in their abstinent peers. In contrast, activity levels in the cannabis users in cortical areas including the right temporal-parietal junction and bilateral dorsolateral prefrontal cortex did not discriminate between the two face conditions, but did differ in controls. Results did not change after excluding subjects with any psychiatric symptomology. Given the high density of cannabinoid receptors in the amygdala, our findings suggest cannabis use in early adolescence is associated with hypersensitivity to signals of threat. Hypersensitivity to negative affect in adolescence may place the subject at-risk for mood disorders in adulthood. Copyright © 2015. Published by Elsevier Ltd.
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Wu, Chen-Hao; Hwang, Tzung-Jeng; Chen, Yu-Jen; Hsu, Yun-Chin; Lo, Yu-Chun; Liu, Chih-Min; Hwu, Hai-Gwo; Liu, Chen-Chung; Hsieh, Ming H; Chien, Yi Ling; Chen, Chung-Ming; Tseng, Wen-Yih Isaac
2015-03-01
Trait markers of schizophrenia aid the dissection of the heterogeneous phenotypes into distinct subtypes and facilitate the genetic underpinning of the disease. The microstructural integrity of the white matter tracts could serve as a trait marker of schizophrenia, and tractography-based analysis (TBA) is the current method of choice. Manual tractography is time-consuming and limits the analysis to preselected fiber tracts. Here, we sought to identify a trait marker of schizophrenia from among 74 fiber tracts across the whole brain using a novel automatic TBA method. Thirty-one patients with schizophrenia, 31 unaffected siblings and 31 healthy controls were recruited to undergo diffusion spectrum magnetic resonance imaging at 3T. Generalized fractional anisotropy (GFA), an index reflecting tract integrity, was computed for each tract and compared among the three groups. Ten tracts were found to exhibit significant differences between the groups with a linear, stepwise order from controls to siblings to patients; they included the right arcuate fasciculus, bilateral fornices, bilateral auditory tracts, left optic radiation, the genu of the corpus callosum, and the corpus callosum to the bilateral dorsolateral prefrontal cortices, bilateral temporal poles, and bilateral hippocampi. Posthoc between-group analyses revealed that the GFA of the right arcuate fasciculus was significantly decreased in both the patients and unaffected siblings compared to the controls. Furthermore, the GFA of the right arcuate fasciculus exhibited a trend toward positive symptom scores. In conclusion, the right arcuate fasciculus may be a candidate trait marker and deserves further study to verify any genetic association. © 2014 Wiley Periodicals, Inc.
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Kong, Jian; Wolcott, Emily; Wang, Zengjian; Jorgenson, Kristen; Harvey, William F; Tao, Jing; Rones, Ramel; Wang, Chenchen
2018-05-02
This study examines altered resting state functional connectivity (rsFC) of the cognitive control network (CCN) in fibromyalgia patients as compared to healthy controls, as well as how an effective mind-body intervention, Tai Chi, can modulate the altered rsFC of the CCN. Patients with fibromyalgia and matched healthy subjects were recruited in this study. Fibromyalgia patients were scanned 12 weeks before and after intervention. The bilateral dorsolateral prefrontal cortex (DLPFC) was used as a seed to explore the rsFC of the CCN. Data analysis was conducted with 21 patients and 20 healthy subjects. Compared to healthy subjects, fibromyalgia patients exhibited increased rsFC between the DLPFC and the bilateral rostral anterior cingulate cortex (rACC) and medial prefrontal cortex (MPFC) at baseline. The rsFC between the CCN and rACC/MPFC further increased after Tai Chi intervention, and this increase was accompanied by clinical improvements. This rsFC change was also significantly associated with corresponding changes in the Overall Impact domain of the Revised Fibromyalgia Impact Questionnaire (FIQR). Further analysis showed that the rACC/MPFC rsFC with both the PAG and hippocampus significantly decreased following Tai Chi intervention. Our study suggests that fibromyalgia is associated with altered CCN rsFC and that effective mind-body treatment may elicit clinical improvements by further increasing this altered rsFC. Elucidating this mechanism of enhancing the allostasis process will deepen our understanding of the mechanisms underlying mind-body interventions in fibromyalgia patients and facilitate the development of new pain management methods.
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Voon, Valerie; Brezing, Christina; Gallea, Cecile; Hallett, Mark
2011-11-01
Conversion disorder (CD) is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that CD with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amygdala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Subjects performed either an internally or externally generated 2-button action selection task in a functional MRI study. Eleven CD patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula, and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system, which is both hypoactive and functionally disconnected from prefrontal top-down regulation. Copyright © 2011 Movement Disorder Society.
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Voon, V; Brezing, C; Gallea, C; Hallett, M
2014-01-01
Background Conversion disorder is characterized by unexplained neurological symptoms presumed related to psychological issues. The main hypotheses to explain conversion paralysis, characterized by a lack of movement, include impairments in either motor intention or disruption of motor execution, and further, that hyperactive self-monitoring, limbic processing or top-down regulation from higher order frontal regions may interfere with motor execution. We have recently shown that conversion disorder with positive abnormal or excessive motor symptoms was associated with greater amygdala activity to arousing stimuli along with greater functional connectivity between the amgydala and supplementary motor area. Here we studied patients with such symptoms focusing on motor initiation. Methods Subjects performed either an internally or externally generated two-button action selection task in a functional MRI study. Results Eleven conversion disorder patients without major depression and 11 age- and gender-matched normal volunteers were assessed. During both internally and externally generated movement, conversion disorder patients relative to normal volunteers had lower left supplementary motor area (SMA) (implicated in motor initiation) and higher right amygdala, left anterior insula and bilateral posterior cingulate activity (implicated in assigning emotional salience). These findings were confirmed in a subgroup analysis of patients with tremor symptoms. During internally versus externally generated action in CD patients, the left SMA had lower functional connectivity with bilateral dorsolateral prefrontal cortices. Conclusion We propose a theory in which previously mapped conversion motor representations may in an arousing context hijack the voluntary action selection system which is both hypoactive and functionally disconnected from prefrontal top-down regulation. PMID:21935985
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Prata, Diana P; Mechelli, Andrea; Picchioni, Marco M; Fu, Cynthia H Y; Toulopoulou, Timothea; Bramon, Elvira; Walshe, Muriel; Murray, Robin M; Collier, David A; McGuire, Philip
2009-11-01
The dopamine transporter plays a key role in the regulation of central dopaminergic transmission, which modulates cognitive processing. Disrupted dopamine function and impaired executive processing are robust features of schizophrenia. To examine the effect of a polymorphism in the dopamine transporter gene (the variable number of tandem repeats in the 3' untranslated region) on brain function during executive processing in healthy volunteers and patients with schizophrenia. We hypothesized that this variation would have a different effect on prefrontal and striatal activation in schizophrenia, reflecting altered dopamine function. Case-control study. Psychiatric research center. Eighty-five subjects, comprising 44 healthy volunteers (18 who were 9-repeat carriers and 26 who were 10-repeat homozygotes) and 41 patients with DSM-IV schizophrenia (18 who were 9-repeat carriers and 23 who were 10-repeat homozygotes). Regional brain activation during word generation relative to repetition in an overt verbal fluency task measured by functional magnetic resonance imaging. Main effects of genotype and diagnosis on activation and their interaction were estimated with analysis of variance in SPM5. Irrespective of diagnosis, the 10-repeat allele was associated with greater activation than the 9-repeat allele in the left anterior insula and right caudate nucleus. Trends for the same effect in the right insula and for greater deactivation in the rostral anterior cingulate cortex were also detected. There were diagnosis x genotype interactions in the left middle frontal gyrus and left nucleus accumbens, where the 9-repeat allele was associated with greater activation than the 10-repeat allele in patients but not controls. Insular, cingulate, and striatal function during an executive task is normally modulated by variation in the dopamine transporter gene. Its effect on activation in the dorsolateral prefrontal cortex and ventral striatum is altered in patients with schizophrenia
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Ye, Hang; Chen, Shu; Huang, Daqiang; Wang, Siqi; Luo, Jun
2015-06-01
When making choices under uncertainty, people usually consider both the risks and benefits of each option. Previous studies have found that weighing of risks and benefits during decision-making involves a complex neural network that includes the dorsolateral prefrontal cortex (DLPFC), but the causal effect of this network on risk decision-making has remained unclear. This experiment was based on a risk-measurement table designed to provide a direct measure of risk preference, with a weighted value of the choices (denoted as weighted risk aversion, WRA) as an index of the participant's degree of risk aversion. We studied whether bifrontal transcranial direct current stimulation (tDCS) applied over the right and left prefrontal cortex can change the balance of risky vs. safe responses under both gain frame and loss frame. A total of 60 volunteers performed risk tasks while receiving either anodal over the right with cathodal over the left DLPFC, anodal over the left with cathodal over the right DLPFC, or sham stimulation. The participants tended to choose more risky options in the gain frame and more safe options in the loss frame after the right anodal/left cathodal tDCS. We also found that right anodal/left cathodal tDCS significantly decreased the WRA values compared with those associated with sham stimulation. These findings extend the notion that DLPFC activity is critical for risk decision-making, indicating an asymmetric role of the right DLPFC in the gain frame vs. the loss frame of risk decision-making. Copyright © 2015 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Charmaine Demanuele
Full Text Available Discriminating spatiotemporal stages of information processing involved in complex cognitive processes remains a challenge for neuroscience. This is especially so in prefrontal cortex whose subregions, such as the dorsolateral prefrontal (DLPFC, anterior cingulate (ACC and orbitofrontal (OFC cortices are known to have differentiable roles in cognition. Yet it is much less clear how these subregions contribute to different cognitive processes required by a given task. To investigate this, we use functional MRI data recorded from a group of healthy adults during a "Jumping to Conclusions" probabilistic reasoning task.We used a novel approach combining multivariate test statistics with bootstrap-based procedures to discriminate between different task stages reflected in the fMRI blood oxygenation level dependent signal pattern and to unravel differences in task-related information encoded by these regions. Furthermore, we implemented a new feature extraction algorithm that selects voxels from any set of brain regions that are jointly maximally predictive about specific task stages.Using both the multivariate statistics approach and the algorithm that searches for maximally informative voxels we show that during the Jumping to Conclusions task, the DLPFC and ACC contribute more to the decision making phase comprising the accumulation of evidence and probabilistic reasoning, while the OFC is more involved in choice evaluation and uncertainty feedback. Moreover, we show that in presumably non-task-related regions (temporal cortices all information there was about task processing could be extracted from just one voxel (indicating the unspecific nature of that information, while for prefrontal areas a wider multivariate pattern of activity was maximally informative.We present a new approach to reveal the different roles of brain regions during the processing of one task from multivariate activity patterns measured by fMRI. This method can be a valuable
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A longitudinal study of the bilateral benefit in children with bilateral cochlear implants.
Asp, Filip; Mäki-Torkko, Elina; Karltorp, Eva; Harder, Henrik; Hergils, Leif; Eskilsson, Gunnar; Stenfelt, Stefan
2015-02-01
To study the development of the bilateral benefit in children using bilateral cochlear implants by measurements of speech recognition and sound localization. Bilateral and unilateral speech recognition in quiet, in multi-source noise, and horizontal sound localization was measured at three occasions during a two-year period, without controlling for age or implant experience. Longitudinal and cross-sectional analyses were performed. Results were compared to cross-sectional data from children with normal hearing. Seventy-eight children aged 5.1-11.9 years, with a mean bilateral cochlear implant experience of 3.3 years and a mean age of 7.8 years, at inclusion in the study. Thirty children with normal hearing aged 4.8-9.0 years provided normative data. For children with cochlear implants, bilateral and unilateral speech recognition in quiet was comparable whereas a bilateral benefit for speech recognition in noise and sound localization was found at all three test occasions. Absolute performance was lower than in children with normal hearing. Early bilateral implantation facilitated sound localization. A bilateral benefit for speech recognition in noise and sound localization continues to exist over time for children with bilateral cochlear implants, but no relative improvement is found after three years of bilateral cochlear implant experience.
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Murphy, Clodagh M; Christakou, Anastasia; Giampietro, Vincent; Brammer, Michael; Daly, Eileen M; Ecker, Christine; Johnston, Patrick; Spain, Debbie; Robertson, Dene M; Murphy, Declan G; Rubia, Katya
2017-11-01
People with autism spectrum disorder (ASD) have poor decision-making and temporal foresight. This may adversely impact on their everyday life, mental health, and productivity. However, the neural substrates underlying poor choice behavior in people with ASD, or its' neurofunctional development from childhood to adulthood, are unknown. Despite evidence of atypical structural brain development in ASD, investigation of functional brain maturation in people with ASD is lacking. This cross-sectional developmental fMRI study investigated the neural substrates underlying performance on a temporal discounting (TD) task in 38 healthy (11-35 years old) male adolescents and adults with ASD and 40 age, sex, and IQ-matched typically developing healthy controls. Most importantly, we assessed group differences in the neurofunctional maturation of TD across childhood and adulthood. Males with ASD had significantly poorer task performance and significantly lower brain activation in typical regions that mediate TD for delayed choices, in predominantly right hemispheric regions of ventrolateral/dorsolateral prefrontal cortices, ventromedial prefrontal cortex, striatolimbic regions, and cerebellum. Importantly, differential activation in ventromedial frontal cortex and cerebellum was associated with abnormal functional brain maturation; controls, in contrast to people with ASD, showed progressively increasing activation with increasing age in these regions; which furthermore was associated with performance measures and clinical ASD measures (stereotyped/restricted interests). Findings provide first cross-sectional evidence that reduced activation of TD mediating brain regions in people with ASD during TD is associated with abnormal functional brain development in these regions between childhood and adulthood, and this is related to poor task performance and clinical measures of ASD. Hum Brain Mapp 38:5343-5355, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
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Auditory Connections and Functions of Prefrontal Cortex
Directory of Open Access Journals (Sweden)
Bethany ePlakke
2014-07-01
Full Text Available The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC. In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition.
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Auditory connections and functions of prefrontal cortex
Plakke, Bethany; Romanski, Lizabeth M.
2014-01-01
The functional auditory system extends from the ears to the frontal lobes with successively more complex functions occurring as one ascends the hierarchy of the nervous system. Several areas of the frontal lobe receive afferents from both early and late auditory processing regions within the temporal lobe. Afferents from the early part of the cortical auditory system, the auditory belt cortex, which are presumed to carry information regarding auditory features of sounds, project to only a few prefrontal regions and are most dense in the ventrolateral prefrontal cortex (VLPFC). In contrast, projections from the parabelt and the rostral superior temporal gyrus (STG) most likely convey more complex information and target a larger, widespread region of the prefrontal cortex. Neuronal responses reflect these anatomical projections as some prefrontal neurons exhibit responses to features in acoustic stimuli, while other neurons display task-related responses. For example, recording studies in non-human primates indicate that VLPFC is responsive to complex sounds including vocalizations and that VLPFC neurons in area 12/47 respond to sounds with similar acoustic morphology. In contrast, neuronal responses during auditory working memory involve a wider region of the prefrontal cortex. In humans, the frontal lobe is involved in auditory detection, discrimination, and working memory. Past research suggests that dorsal and ventral subregions of the prefrontal cortex process different types of information with dorsal cortex processing spatial/visual information and ventral cortex processing non-spatial/auditory information. While this is apparent in the non-human primate and in some neuroimaging studies, most research in humans indicates that specific task conditions, stimuli or previous experience may bias the recruitment of specific prefrontal regions, suggesting a more flexible role for the frontal lobe during auditory cognition. PMID:25100931
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Prefrontal and striatal activity related to values of objects and locations
Directory of Open Access Journals (Sweden)
Soyoun eKim
2012-07-01
Full Text Available The value of an object acquired by a particular action often determines the motivation to produce that action. Previous studies found neural signals related to the values of different objects or goods in the orbitofrontal cortex, while the values of outcomes expected from different actions are broadly represented in multiple brain areas implicated in movement planning. However, how the brain combines the values associated with various objects and the information about their locations is not known. In this study, we tested whether the neurons in the dorsolateral prefrontal cortex (DLPFC and striatum in rhesus monkeys might contribute to translating the value signals between multiple frames of reference. Monkeys were trained to perform an oculomotor intertemporal choice in which the color of a saccade target and the number of its surrounding dots signaled the magnitude of reward and its delay, respectively. In both DLPFC and striatum, temporally discounted values associated with specific target colors and locations were encoded by partially overlapping populations of neurons. In the DLPFC, the information about reward delays and temporally discounted values of rewards available from specific target locations emerged earlier than the corresponding signals for target colors. Similar results were reproduced by a simple network model built to compute temporally discounted values of rewards in different locations. Therefore, DLPFC might play an important role in estimating the values of different actions by combining the previously learned values of objects and their present locations.
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Benevolent sexism alters executive brain responses.
Dardenne, Benoit; Dumont, Muriel; Sarlet, Marie; Phillips, Christophe; Balteau, Evelyne; Degueldre, Christian; Luxen, André; Salmon, Eric; Maquet, Pierre; Collette, Fabienne
2013-07-10
Benevolence is widespread in our societies. It is defined as considering a subordinate group nicely but condescendingly, that is, with charity. Deleterious consequences for the target have been reported in the literature. In this experiment, we used functional MRI (fMRI) to identify whether being the target of (sexist) benevolence induces changes in brain activity associated with a working memory task. Participants were confronted by benevolent, hostile, or neutral comments before and while performing a reading span test in an fMRI environment. fMRI data showed that brain regions associated previously with intrusive thought suppression (bilateral, dorsolateral, prefrontal, and anterior cingulate cortex) reacted specifically to benevolent sexism compared with hostile sexism and neutral conditions during the performance of the task. These findings indicate that, despite being subjectively positive, benevolence modifies task-related brain networks by recruiting supplementary areas likely to impede optimal cognitive performance.
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Different Perception of Musical Stimuli in Patients with Monolateral and Bilateral Cochlear Implants
Maglione, Anton Giulio; Leone, Carlo Antonio; Grassia, Rosa; Mosca, Franco; Colosimo, Alfredo; Malerba, Paolo
2014-01-01
The aim of the present study is to measure the perceived pleasantness during the observation of a musical video clip in a group of cochlear implanted adult patients when compared to a group of normal hearing subjects. This comparison was performed by using the imbalance of the EEG power spectra in alpha band over frontal areas as a metric for the perceived pleasantness. Subjects were asked to watch a musical video clip in three different experimental conditions: with the original audio included (Norm), with a distorted version of the audio (Dist), and without the audio (Mute). The frontal EEG imbalance between the estimated power spectra for the left and right prefrontal areas has been calculated to investigate the differences among the two populations. Results suggested that the perceived pleasantness of the musical video clip in the normal hearing population and in the bilateral cochlear implanted populations has similar range of variation across the different stimulations (Norm, Dist, and Mute), when compared to the range of variation of video clip's pleasantness for the monolateral cochlear implanted population. A similarity exists in the trends of the perceived pleasantness across the different experimental conditions in the mono- and bilaterally cochlear implanted patients. PMID:25180046
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Plasticity in the Prefrontal Cortex of Adult Rats
Directory of Open Access Journals (Sweden)
Bryan eKolb
2015-02-01
Full Text Available We review the plastic changes of the prefrontal cortex of the rat in response to a wide range of experiences including sensory and motor experience, gonadal hormones, psychoactive drugs, learning tasks, stress, social experience, metaplastic experiences, and brain injury. Our focus is on synaptic changes (dendritic morphology and spine density in pyramidal neurons and the relationship to behavioral changes. The most general conclusion we can reach is that the prefrontal cortex is extremely plastic and that the medial and orbital prefrontal regions frequently respond very differently to the same experience in the same brain and the rules that govern prefrontal plasticity appear to differ for those of other cortical regions.
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Ferreri, Laura; Bigand, Emmanuel; Perrey, Stephane; Muthalib, Makii; Bard, Patrick; Bugaiska, Aurélia
2014-01-01
Several neuroimaging studies of cognitive aging revealed deficits in episodic memory abilities as a result of prefrontal cortex (PFC) limitations. Improving episodic memory performance despite PFC deficits is thus a critical issue in aging research. Listening to music stimulates cognitive performance in several non-purely musical activities (e.g., language and memory). Thus, music could represent a rich and helpful source during verbal encoding and therefore help subsequent retrieval. Furthermore, such benefit could be reflected in less demand of PFC, which is known to be crucial for encoding processes. This study aimed to investigate whether music may improve episodic memory in older adults while decreasing the PFC activity. Sixteen healthy older adults (μ = 64.5 years) encoded lists of words presented with or without a musical background while their dorsolateral prefrontal cortex (DLPFC) activity was monitored using a eight-channel continuous-wave near-infrared spectroscopy (NIRS) system (Oxymon Mk III, Artinis, The Netherlands). Behavioral results indicated a better source-memory performance for words encoded with music compared to words encoded with silence (p music encoding condition compared to the silence condition (p music modulates the activity of the DLPFC during encoding in a less-demanding direction. Taken together, our results indicate that music can help older adults in memory performances by decreasing their PFC activity. These findings open new perspectives about music as tool for episodic memory rehabilitation on special populations with memory deficits due to frontal lobe damage such as Alzheimer’s patients. PMID:24860481
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Prefrontal cortex stimulation does not affect emotional bias, but may slow emotion identification.
Nord, Camilla L; Forster, Sophie; Halahakoon, D Chamith; Penton-Voak, Ian S; Munafò, Marcus R; Roiser, Jonathan P
2017-05-01
Transcranial direct current stimulation (tDCS) has recently garnered attention as a putative depression treatment. However, the cognitive mechanisms by which it exerts an antidepressant effect are unclear: tDCS may directly alter 'hot' emotional processing biases, or alleviate depression through changes in 'cold' (non-emotional) cognitive function. Here, 75 healthy participants performed a facial emotion identification task during 20 minutes of anodal or sham tDCS over the left dorsolateral prefrontal cortex (DLPFC) in a double-blind, within-subject crossover design. A subset of 31 participants additionally completed a task measuring attentional distraction during stimulation. Compared to sham stimulation, anodal tDCS of the left DLPFC resulted in an increase in response latency across all emotional conditions. Bayesian analysis showed definitively that tDCS exerted no emotion-dependent effect on behaviour. Thus, we demonstrate that anodal tDCS produces a general, rather than an emotion-specific, effect. We also report a preliminary finding in the subset of participants who completed the distractibility task: increased distractibility during active stimulation correlated significantly with the degree to which tDCS slowed emotion identification. Our results provide insight into the possible mechanisms by which DLPFC tDCS may treat symptoms of depression, suggesting that it may not alter emotional biases, but instead may affect 'cold' cognitive processes. © The Author (2017). Published by Oxford University Press.
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Thomson, Amy E; Soukup, Jason W
2018-01-01
Tumors of the rostral maxilla that involve both the oral mucosa and the dermis or subdermis of the dorsolateral muzzle provide unique challenges for the oromaxillofacial surgeon. Traditionally described approaches to such lesions may involve an intraoral incision that extends and involves the upper lip to envelope the involved dermis of the dorsolateral muzzle. However, such an approach unnecessarily resects upper lip tissue resulting in a large defect that likely requires advanced skin flaps or grafts for reconstruction. Such flaps are technically challenging and introduce potential for significance postoperative complications. In this article, we provide a detailed description a combined intra- and extraoral approach that allows for composite resection of tumors of the rostral maxilla that also involve the dorsolateral muzzle. The described technique allows for excellent intraoperative visualization and provides a superior cosmetic outcome that minimizes postoperative complications. In addition, we describe our experience utilizing the technique in three clinical cases.
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Directory of Open Access Journals (Sweden)
Amy E. Thomson
2018-03-01
Full Text Available Tumors of the rostral maxilla that involve both the oral mucosa and the dermis or subdermis of the dorsolateral muzzle provide unique challenges for the oromaxillofacial surgeon. Traditionally described approaches to such lesions may involve an intraoral incision that extends and involves the upper lip to envelope the involved dermis of the dorsolateral muzzle. However, such an approach unnecessarily resects upper lip tissue resulting in a large defect that likely requires advanced skin flaps or grafts for reconstruction. Such flaps are technically challenging and introduce potential for significance postoperative complications. In this article, we provide a detailed description a combined intra- and extraoral approach that allows for composite resection of tumors of the rostral maxilla that also involve the dorsolateral muzzle. The described technique allows for excellent intraoperative visualization and provides a superior cosmetic outcome that minimizes postoperative complications. In addition, we describe our experience utilizing the technique in three clinical cases.
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Gender differences in the functional neuroanatomy of emotional episodic autobiographical memory.
Piefke, Martina; Weiss, Peter H; Markowitsch, Hans J; Fink, Gereon R
2005-04-01
Autobiographical memory is based on interactions between episodic memory contents, associated emotions, and a sense of self-continuity along the time axis of one's life. The functional neuroanatomy subserving autobiographical memory is known to include prefrontal, medial and lateral temporal, as well as retrosplenial brain areas; however, whether gender differences exist in neural correlates of autobiographical memory remains to be clarified. We reanalyzed data from a previous functional magnetic resonance imaging (fMRI) experiment to investigate gender-related differences in the neural bases of autobiographical memories with differential remoteness and emotional valence. On the behavioral level, there were no significant gender differences in memory performance or emotional intensity of memories. Activations common to males and females during autobiographical memory retrieval were observed in a bilateral network of brain areas comprising medial and lateral temporal regions, including hippocampal and parahippocampal structures, posterior cingulate, as well as prefrontal cortex. In males (relative to females), all types of autobiographical memories investigated were associated with differential activation of the left parahippocampal gyrus. By contrast, right dorsolateral prefrontal cortex was activated differentially by females. In addition, the right insula was activated differentially in females during remote and negative memory retrieval. The data show gender-related differential neural activations within the network subserving autobiographical memory in both genders. We suggest that the differential activations may reflect gender-specific cognitive strategies during access to autobiographical memories that do not necessarily affect the behavioral level of memory performance and emotionality. (c) 2005 Wiley-Liss, Inc.
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Assessing the dysexecutive syndrome in dementia.
Gansler, David A; Huey, Edward D; Pan, Jessica J; Wasserman, Eric; Grafman, Jordan H
2017-03-01
We compared performance on tests of dysexecutive behaviour (DB) and executive function (EF) in patients with behavioural variant frontotemporal dementia (bvFTD), primary progressive aphasia (PPA) and corticobasal syndrome (CBS). Patients diagnosed with bvFTD (n=124), PPA (n=34) and CBS (n=85) were recruited. EF was measured with the Delis-Kaplan Executive Function System (DKEFS: performance based), and DB was measured with the Frontal Systems Behavior Scale (FrSBe: caregiver-report based). Confirmatory factor analysis characterised the relationship between EF and DB, binary logistic regression evaluated the incremental diagnostic utility of the measures and neuroimaging data from 110 patients identified neural correlates. EF was lowest and DB was highest in bvFTD participants. EF and DB were distinct but related (r=-0.48). Measures correctly classified 89% of bvFTD from CBS patients and 93% of bvFTD from PPA patients-30% and 13% above base rates (59%, 80%), respectively. All modalities were useful in identifying CBS and PPA, whereas DB alone was useful for identifying bvFTD. EF was uniquely associated with caudal left dorsolateral prefrontal and lateral temporo-parietal cortices. DB was uniquely associated with the cingulate (R>L), right subcallosal and right anterior frontal cortex. EF and DB were associated with the rostral dorsolateral prefrontal cortex bilaterally. EF and DB measures displayed criterion and construct validity, had incremental utility at low DB levels (CBS and PPA) and were associated with overlapping and distinct neural correlates. EF and DB procedures can conjointly provide useful diagnostic and descriptive information in identifying and ruling out the dysexecutive syndrome. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
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van Zutphen, Linda; Siep, Nicolette; Jacob, Gitta A.; Domes, Gregor; Sprenger, Andreas; Willenborg, Bastian; Goebel, Rainer; Arntz, Arnoud
2018-01-01
Background Borderline personality disorder (BPD) is characterized by emotion dysregulation; however, it is unclear whether this is restricted to negative emotional stimuli or to what degree this is specific to BPD. We investigated neural correlates of hypothesized increased emotional sensitivity and impaired emotion regulation in patients with BPD. Methods During functional MRI (fMRI) scanning, patients with BPD, non-patient controls and patients with cluster-C personality disorder completed an emotion regulation task, including negative, positive and erotic social pictures. Results We included 55 patients with BPD, 42 nonpatient controls and 24 patients with cluster-C personality disorder in our analyses. Passive viewing of negative stimuli resulted in greater activity in the anterior insula, temporoparietal junction and dorsolateral prefrontal cortex in patients with BPD than in nonpatient controls. The increased activity in the anterior insula and temporoparietal junction was also present when patients with BPD viewed positive stimuli. During regulation of negative stimuli compared with passive viewing, nonpatient controls showed greater activity in the dorsal anterior cingulate cortex, dorsolateral prefrontal cortex, middle temporal gyrus and bilateral inferior parietal lobule. Patients with BPD did not show this increase in activity. Limitations Findings cannot be generalized to men, and patients represented a heterogeneous group regarding comorbid diagnoses and medication. Conclusion When looking at emotional stimuli, patients with BPD showed a unique pattern of activity, suggesting an increase in brain activity involved in emotion generation. In the case of negative stimuli this is accompanied by increased activity in regulation areas. In contrast, increase of regulation processes seems absent when patients with BPD are explicitly instructed to regulate. Results of diagnosis specificity support a dimensional rather than a dichotomous differentiation between
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Directory of Open Access Journals (Sweden)
Rei eAkaishi
2013-07-01
Full Text Available The dorsal and ventral parts of the lateral prefrontal cortex have been thought to play distinct roles in decision making. Although its dorsal part such as the frontal eye field (FEF is shown to play roles in accumulation of sensory information during perceptual decision making, the role of the ventral prefrontal cortex (PFv is not well-documented. Previous studies have suggested that the PFv is involved in selective attention to the task-relevant information and is associated with accuracy of the behavioral performance. It is unknown, however, whether the accumulation and selection processes are anatomically dissociated between the FEF and PFv. Here we show that, by using concurrent TMS and EEG recording, the short-latency (20 – 40 ms TMS-evoked potentials after stimulation of the FEF change as a function of the time to behavioral response, whereas those after stimulation of the PFv change depending on whether the response is correct or not. The potentials after stimulation of either region did not show significant interaction between time to response and performance accuracy, suggesting dissociation between the processes subserved by the FEF and PFv networks. The results are consistent with the idea that the network involving the FEF plays a role in information accumulation, whereas the network involving the PFv plays a role in selecting task relevant information. In addition, stimulation of the FEF and PFv induced activation in common regions in the dorsolateral and medial frontal cortices, suggesting convergence of information processed in the two regions. Taken together, the results suggest dissociation between the FEF and PFv networks for their computational roles in perceptual decision making. The study also highlights the advantage of TMS-EEG technique in investigating the computational processes subserved by the neural network in the human brain with a high temporal resolution.
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Akaishi, Rei; Ueda, Naoko; Sakai, Katsuyuki
2013-01-01
The dorsal and ventral parts of the lateral prefrontal cortex have been thought to play distinct roles in decision making. Although its dorsal part such as the frontal eye field (FEF) is shown to play roles in accumulation of sensory information during perceptual decision making, the role of the ventral prefrontal cortex (PFv) is not well-documented. Previous studies have suggested that the PFv is involved in selective attention to the task-relevant information and is associated with accuracy of the behavioral performance. It is unknown, however, whether the accumulation and selection processes are anatomically dissociated between the FEF and PFv. Here we show that, by using concurrent TMS and EEG recording, the short-latency (20-40 ms) TMS-evoked potentials after stimulation of the FEF change as a function of the time to behavioral response, whereas those after stimulation of the PFv change depending on whether the response is correct or not. The potentials after stimulation of either region did not show significant interaction between time to response and performance accuracy, suggesting dissociation between the processes subserved by the FEF and PFv networks. The results are consistent with the idea that the network involving the FEF plays a role in information accumulation, whereas the network involving the PFv plays a role in selecting task relevant information. In addition, stimulation of the FEF and PFv induced activation in common regions in the dorsolateral and medial frontal cortices, suggesting convergence of information processed in the two regions. Taken together, the results suggest dissociation between the FEF and PFv networks for their computational roles in perceptual decision making. The study also highlights the advantage of TMS-EEG technique in investigating the computational processes subserved by the neural network in the human brain with a high temporal resolution.
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The Cortical Connectivity of the Prefrontal Cortex in the Monkey Brain
Yeterian, Edward H.; Pandya, Deepak N.; Tomaiuolo, Francesco; Petrides, Michael
2011-01-01
One dimension of understanding the functions of the prefrontal cortex is knowledge of cortical connectivity. We have surveyed three aspects of prefrontal cortical connections: local projections (within the frontal lobe), the termination patterns of long association (post-Rolandic) projections, and the trajectories of major fiber pathways. The local connections appear to be organized in relation to dorsal (hippocampal origin) and ventral (paleocortical origin) architectonic trends. According to the proposal of a dual origin of the cerebral cortex, cortical areas can be traced as originating from archicortex (hippocampus) on the one hand, and paleocortex, on the other hand, in a stepwise manner (e.g., Sanides, 1969; Pandya and Yeterian, 1985). Prefrontal areas within each trend are connected with less architectonically differentiated areas, and, on the other hand, with more differentiated areas. Such organization may allow for the systematic exchange of information within each architectonic trend. The long connections of the prefrontal cortex with post-Rolandic regions seem to be organized preferentially in relation to dorsal and ventral prefrontal architectonic trends. Prefrontal areas are connected with post-Rolandic auditory, visual and somatosensory association areas, and with multimodal and paralimbic regions. This long connectivity likely works in conjunction with local connections to serve prefrontal cortical functions. The afferent and efferent connections of the prefrontal cortex with post-Rolandic regions are conveyed by specific long association pathways. These pathways as well appear to be organized in relation to dorsal and ventral prefrontal architectonic trends. Finally, although prefrontal areas have preferential connections in relation to dual architectonic trends, it is clear that there are interconnections between and among areas in each trend, which may provide a substrate for the overall integrative function of the prefrontal cortex. Prefrontal
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Neves, Ricardo M; van Keulen, Silvia; Yang, Mingyu; Logothetis, Nikos K; Eschenko, Oxana
2018-03-01
The locus coeruleus (LC) noradrenergic (NE) neuromodulatory system is critically involved in regulation of neural excitability via its diffuse ascending projections. Tonic NE release in the forebrain is essential for maintenance of vigilant states and increases the signal-to-noise ratio of cortical sensory responses. The impact of phasic NE release on cortical activity and sensory processing is less explored. We previously reported that LC microstimulation caused a transient desynchronization of population activity in the medial prefrontal cortex (mPFC), similar to noxious somatosensory stimuli. The LC receives nociceptive information from the medulla and therefore may mediate sensory signaling to its forebrain targets. Here we performed extracellular recordings in LC and mPFC while presenting noxious stimuli in urethane-anesthetized rats. A brief train of foot shocks produced a robust phasic response in the LC and a transient change in the mPFC power spectrum, with the strongest modulation in the gamma (30-90 Hz) range. The LC phasic response preceded prefrontal gamma power increase, and cortical modulation was proportional to the LC excitation. We also quantitatively characterized distinct cortical states and showed that sensory responses in both LC and mPFC depend on the ongoing cortical state. Finally, cessation of the LC firing by bilateral local iontophoretic injection of clonidine, an α 2 -adrenoreceptor agonist, completely eliminated sensory responses in the mPFC without shifting cortex to a less excitable state. Together, our results suggest that the LC phasic response induces gamma power increase in the PFC and is essential for mediating sensory information along an ascending noxious pathway. NEW & NOTEWORTHY Our study shows linear relationships between locus coeruleus phasic excitation and the amplitude of gamma oscillations in the prefrontal cortex. Results suggest that the locus coeruleus phasic response is essential for mediating sensory information
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Blasi, Giuseppe; Napolitano, Francesco; Ursini, Gianluca; Di Giorgio, Annabella; Caforio, Grazia; Taurisano, Paolo; Fazio, Leonardo; Gelao, Barbara; Attrotto, Maria Teresa; Colagiorgio, Lucia; Todarello, Giovanna; Piva, Francesco; Papazacharias, Apostolos; Masellis, Rita; Mancini, Marina; Porcelli, Annamaria; Romano, Raffaella; Rampino, Antonio; Quarto, Tiziana; Giulietti, Matteo; Lipska, Barbara K; Kleinman, Joel E; Popolizio, Teresa; Weinberger, Daniel R; Usiello, Alessandro; Bertolino, Alessandro
2013-08-01
OBJECTIVE Glycogen synthase kinase 3β (GSK-3β) is an enzyme implicated in neurodevelopmental processes with a broad range of substrates mediating several canonical signaling pathways in the brain. The authors investigated the association of variation in the GSK-3β gene with a series of progressively more complex phenotypes of relevance to schizophrenia, a neurodevelopmental disorder with strong genetic risk. METHOD Based on computer predictions, the authors investigated in humans the association of GSK-3β functional variation with 1) GSK-3β mRNA expression from postmortem prefrontal cortex, 2) GSK-3β and β-catenin protein expression from peripheral blood mononuclear cells (PBMCs), 3) prefrontal imaging phenotypes, and 4) diagnosis of schizophrenia. RESULTS Consistent with predictions, the TT genotype of a single-nucleotide polymorphism in GSK-3β (rs12630592) was associated with reduced GSK-3β mRNA from postmortem prefrontal cortex. Furthermore, this genotype was associated with GSK-3β protein expression and kinase activity, as well as with downstream effects on β-catenin expression in PBMCs. Finally, the TT genotype was associated with attenuated functional MRI prefrontal activity, reduced prefrontal cortical thickness, and diagnosis of schizophrenia. CONCLUSIONS These results suggest that GSK-3β variation is implicated in multiple phenotypes relevant to schizophrenia.
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Directory of Open Access Journals (Sweden)
Laura eFerreri
2014-05-01
Full Text Available Several neuroimaging studies of cognitive ageing revealed deficits in episodic memory abilities as a result of prefrontal cortex (PFC limitations. Improving episodic memory performance despite PFC deficits is thus a critical issue in ageing research. Listening to music stimulates cognitive performance in several non-purely musical activities (e.g. language and memory. Thus, music could represent a rich and helpful source during verbal encoding and therefore help subsequent retrieval. Furthermore, such benefit could be reflected in less demand of PFC, which is known to be crucial for encoding processes. This study aimed to investigate whether music may improve episodic memory in older adults while decreasing the PFC activity.Sixteen healthy older adults (µ=64.5y encoded lists of words presented with or without a musical background while their dorsolateral PFC (DLPFC activity was monitored using a 8-channel continuous-wave near-infrared spectroscopy (NIRS system (Oxymon Mk III, Artinis, The Netherlands. Behavioral results indicated a better source memory performance for words encoded with music compared to words encoded with silence (p
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The Association between Resting Functional Connectivity and Visual Creativity
Li, Wenfu; Yang, Junyi; Zhang, Qinglin; Li, Gongying; Qiu, Jiang
2016-01-01
Resting-state functional connectivity (RSFC), the temporal correlation of intrinsic activation between different brain regions, has become one of the most fascinating field in the functional imaging studies. To better understand the association between RSFC and individual creativity, we used RSFC and the figure Torrance Tests of Creative Thinking (TTCT-F) to investigate the relationship between creativity measured by TTCT and RSFC within two different brain networks, default mode network and the cognitive control network, in a large healthy sample (304). We took the medial prefrontal cortex (MPFC) and the bilateral dorsolateral prefrontal cortices (DLPFC) to be the seed regions and investigated the association across subjects between the score of TTCT-F and the strength of RSFC between these seed regions and other voxels in the whole brain. Results revealed that the strength of RSFC with the MPFC was significantly and negatively correlated with the score of TTCT-F in the precuneus. Meanwhile, we also found that the strength of RSFC with the left DLPFC was significantly and positively correlated with the score of TTCT-F in the right DLPFC. It suggests that the decreased RSFC within DMN and the increased RSFC within CCN presents a potential interaction mechanism between different region for higher creativity. PMID:27138732
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Dun, Catharina A J; Agterberg, Martijn J H; Cremers, Cor W R J; Hol, Myrthe K S; Snik, Ad F M
2013-01-01
The aim of the study was to investigate whether children with bilateral conductive hearing loss benefit from their second device (i.e., the bilateral bone conduction device [BCD]). Speech recognition in noise was assessed in 10 children fitted with bilateral BCDs during childhood. Speech recognition was measured in 2 conditions with both BCDs active. Spatial resolution was tested with the Minimum Audible Angle test in the bilateral and monaural listening conditions. Children demonstrated an improvement in speech recognition when speech was presented from the front and noise was presented from the right-hand side as compared with both speech and noise being presented from the front. The minimum audible angle decreased from 57° in the best monaural condition to 13° in the bilateral condition. The audiological outcomes demonstrate the advantage of bilateral BCD fitting in children with bilateral conductive hearing loss.
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Ouerchefani, Riadh; Ouerchefani, Naoufel; Allain, Philippe; Ben Rejeb, Mohamed Riadh; Le Gall, Didier
2018-04-17
The results of previous studies are inconsistent in regard to the relationship between the Iowa Gambling Task (IGT), working-memory (WM), and executive tasks, and whether these cognitive processes could be considered as mechanisms underlying a decision-making deficit. Moreover, the relationship between the IGT and executive measures is examined based on a limited number of executive tasks, within different populations showing diffuse damage. In addition, there are fewer studies carried out within control participants, with those studies also being inconclusive. It is also suggested that the association of the IGT performance with executive tasks depends on whether the IGT was running under ambiguity or under risk. In this work, all of these issues are studied. Results showed that both patients with ventromedial (VMPFC, N = 10) and dorsolateral (DLPFC, N = 10) prefrontal cortex lesions are significantly impaired on almost all executive tasks, WM tasks, and the IGT. Furthermore, when the IGT is run under risk, there are significant correlations between executive measures and the IGT for the DLPFC patients and the control participants (N = 34) but not the VMPFC patients. No correlation was found between WM tasks and the IGT for both frontal subgroups and control participants. These findings suggested that the mechanisms underlying the IGT deficit differ according to the lesion locations. © 2018 The British Psychological Society.
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Arion, D; Corradi, J P; Tang, S; Datta, D; Boothe, F; He, A; Cacace, A M; Zaczek, R; Albright, C F; Tseng, G; Lewis, D A
2015-11-01
Schizophrenia is associated with alterations in working memory that reflect dysfunction of dorsolateral prefrontal cortex (DLPFC) circuitry. Working memory depends on the activity of excitatory pyramidal cells in DLPFC layer 3 and, to a lesser extent, in layer 5. Although many studies have profiled gene expression in DLPFC gray matter in schizophrenia, little is known about cell-type-specific transcript expression in these two populations of pyramidal cells. We hypothesized that interrogating gene expression, specifically in DLPFC layer 3 or 5 pyramidal cells, would reveal new and/or more robust schizophrenia-associated differences that would provide new insights into the nature of pyramidal cell dysfunction in the illness. We also sought to determine the impact of other variables, such as a diagnosis of schizoaffective disorder or medication use at the time of death, on the patterns of gene expression in pyramidal neurons. Individual pyramidal cells in DLPFC layers 3 or 5 were captured by laser microdissection from 36 subjects with schizophrenia or schizoaffective disorder and matched normal comparison subjects. The mRNA from cell collections was subjected to transcriptome profiling by microarray followed by quantitative PCR validation. Expression of genes involved in mitochondrial (MT) or ubiquitin-proteasome system (UPS) functions were markedly downregulated in the patient group (P-values for MT-related and UPS-related pathways were schizoaffective disorder subjects (diagnosis of schizoaffective disorder was the most significant covariate, Pschizoaffective disorder, providing a potential molecular-cellular basis of differences in clinical phenotypes.
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Primiani, Christopher T; Ryan, Veronica H; Rao, Jagadeesh S; Cam, Margaret C; Ahn, Kwangmi; Modi, Hiren R; Rapoport, Stanley I
2014-01-01
Age changes in expression of inflammatory, synaptic, and neurotrophic genes are not well characterized during human brain development and senescence. Knowing these changes may elucidate structural, metabolic, and functional brain processes over the lifespan, as well vulnerability to neurodevelopmental or neurodegenerative diseases. Expression levels of inflammatory, synaptic, and neurotrophic genes in the human brain are coordinated over the lifespan and underlie changes in phenotypic networks or cascades. We used a large-scale microarray dataset from human prefrontal cortex, BrainCloud, to quantify age changes over the lifespan, divided into Development (0 to 21 years, 87 brains) and Aging (22 to 78 years, 144 brains) intervals, in transcription levels of 39 genes. Gene expression levels followed different trajectories over the lifespan. Many changes were intercorrelated within three similar groups or clusters of genes during both Development and Aging, despite different roles of the gene products in the two intervals. During Development, changes were related to reported neuronal loss, dendritic growth and pruning, and microglial events; TLR4, IL1R1, NFKB1, MOBP, PLA2G4A, and PTGS2 expression increased in the first years of life, while expression of synaptic genes GAP43 and DBN1 decreased, before reaching plateaus. During Aging, expression was upregulated for potentially pro-inflammatory genes such as NFKB1, TRAF6, TLR4, IL1R1, TSPO, and GFAP, but downregulated for neurotrophic and synaptic integrity genes such as BDNF, NGF, PDGFA, SYN, and DBN1. Coordinated changes in gene transcription cascades underlie changes in synaptic, neurotrophic, and inflammatory phenotypic networks during brain Development and Aging. Early postnatal expression changes relate to neuronal, glial, and myelin growth and synaptic pruning events, while late Aging is associated with pro-inflammatory and synaptic loss changes. Thus, comparable transcriptional regulatory networks that operate
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Directory of Open Access Journals (Sweden)
De Bruyn, Deborah
2017-03-01
Full Text Available Objective: To describe a patient with a right-sided supranuclear facial palsy and concomitant sicca keratopathy of the right eye following right-sided dorsolateral medullary infarction. Methods: Our patient underwent a complete ophthalmologic and neurologic examination including biomicroscopy, fundus examination, cranial nerve examination, Shirmer I test, and magnetic resonance imaging of the brain.Results: A 61-year-old woman presented in emergency with a central facial nerve palsy on the right side and truncal ataxia. Neurologic assessment revealed a concurrent dysphagia, dysarthria, hypoesthesia of the right face, and weakness of the right upper limb. Magnetic resonance imaging of the brain showed an old left-sided cerebellar infarction, but a recent ischemic infarction at the level of the right dorsolateral medulla oblongata was the cause of our patient’s current problems. One month after diagnosis of the right-sided dorsolateral medullary syndrome, there were complaints of ocular irritation and a diminished visual acuity in the right eye. Biomicroscopy showed a sicca keratopathy with nearly complete absence of tear secretion on the Shirmer I test, but with normal eye closure and preserved corneal reflexes and sensitivity.Conclusion: A dorsolateral medullary syndrome can have a variable expression in symptomatology. Our case is special because of the combination of an ipsilateral supranuclear facial palsy with normal upper facial muscle function together with an ipsilateral sicca keratopathy as a result of a nearly absent tear secretion. We hypothesized that the mechanism underlying the patient’s sicca keratopathy ipsilateral to the supranuclear facial palsy involved the superior salivatory nucleus, which is situated in the caudal pons inferiorly of the motor facial nucleus and is most probably affected by a superior extension of the infarcted area in the right medulla oblongata.
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Taurisano, Paolo; Antonucci, Linda A; Fazio, Leonardo; Rampino, Antonio; Romano, Raffaella; Porcelli, Annamaria; Masellis, Rita; Colizzi, Marco; Quarto, Tiziana; Torretta, Silvia; Di Giorgio, Annabella; Pergola, Giulio; Bertolino, Alessandro; Blasi, Giuseppe
2016-08-01
The CB1 cannabinoid receptor is targeted in the brain by endocannabinoids under physiological conditions as well as by delta9-tetrahydrocannabinol under cannabis use. Furthermore, its signaling appears to affect brain cognitive processing. Recent findings highlight a crucial role of cyclooxygenase-2 (COX-2) in the mechanism of intraneuronal CB1 signaling transduction, while others indicate that two single nucleotide polymorphisms (SNPs) (rs1406977 and rs20417) modulate expression of CB1 (CNR1) and COX-2 (PTGS2) coding genes, respectively. Here, our aim was to use fMRI to investigate in healthy humans whether these SNPs interact in modulating prefrontal activity during working memory processing and if this modulation is linked with cannabis use. We recruited 242 healthy subjects genotyped for CNR1 rs1406977 and PTGS2 rs20417 that performed the N-back working memory task during fMRI and were interviewed using the Cannabis Experience Questionnaire (CEQ). We found that the interaction between CNR1 rs1406977 and PTGS2 rs20417 is associated with dorsolateral prefrontal cortex (DLPFC) activity such that specific genotype configurations (CNR1 C carriers/PTGS2 C carriers and CNR1 TT/PTGS2 GG) predict lower cortical response versus others in spite of similar behavioral accuracy. Furthermore, DLPFC activity in the cluster associated with the CNR1 by PTGS2 interaction was negatively correlated with behavioral efficiency and positively correlated with frequency of cannabis use in cannabis users. These results suggest that a genetically modulated balancing of signaling within the CB1-COX-2 pathway may reflect on more or less efficient patterns of prefrontal activity during working memory. Frequency of cannabis use may be a factor for further modulation of CNR1/PTGS2-mediated cortical processing associated with this cognitive process. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Selective updating of working memory content modulates meso-cortico-striatal activity.
Murty, Vishnu P; Sambataro, Fabio; Radulescu, Eugenia; Altamura, Mario; Iudicello, Jennifer; Zoltick, Bradley; Weinberger, Daniel R; Goldberg, Terry E; Mattay, Venkata S
2011-08-01
Accumulating evidence from non-human primates and computational modeling suggests that dopaminergic signals arising from the midbrain (substantia nigra/ventral tegmental area) mediate striatal gating of the prefrontal cortex during the selective updating of working memory. Using event-related functional magnetic resonance imaging, we explored the neural mechanisms underlying the selective updating of information stored in working memory. Participants were scanned during a novel working memory task that parses the neurophysiology underlying working memory maintenance, overwriting, and selective updating. Analyses revealed a functionally coupled network consisting of a midbrain region encompassing the substantia nigra/ventral tegmental area, caudate, and dorsolateral prefrontal cortex that was selectively engaged during working memory updating compared to the overwriting and maintenance of working memory content. Further analysis revealed differential midbrain-dorsolateral prefrontal interactions during selective updating between low-performing and high-performing individuals. These findings highlight the role of this meso-cortico-striatal circuitry during the selective updating of working memory in humans, which complements previous research in behavioral neuroscience and computational modeling. Published by Elsevier Inc.
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Neural signatures of third-party punishment: evidence from penetrating traumatic brain injury.
Glass, Leila; Moody, Lara; Grafman, Jordan; Krueger, Frank
2016-02-01
The ability to survive within a cooperative society depends on impartial third-party punishment (TPP) of social norm violations. Two cognitive mechanisms have been postulated as necessary for the successful completion of TPP: evaluation of legal responsibility and selection of a suitable punishment given the magnitude of the crime. Converging neuroimaging research suggests two supporting domain-general networks; a mentalizing network for evaluation of legal responsibility and a central-executive network for determination of punishment. A whole-brain voxel-based lesion-symptom mapping approach was used in conjunction with a rank-order TPP task to identify brain regions necessary for TPP in a large sample of patients with penetrating traumatic brain injury. Patients who demonstrated atypical TPP had specific lesions in core regions of the mentalizing (dorsomedial prefrontal cortex [PFC], ventromedial PFC) and central-executive (bilateral dorsolateral PFC, right intraparietal sulcus) networks. Altruism and executive functioning (concept formation skills) were significant predictors of TPP: altruism was uniquely associated with TPP in patients with lesions in right dorsolateral PFC and executive functioning was uniquely associated with TPP in individuals with lesions in left PFC. Our findings contribute to the extant literature to support underlying neural networks associated with TPP, with specific brain-behavior causal relationships confirming recent functional neuroimaging research. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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Compulsive Sexual Behavior: Prefrontal and Limbic Volume and Interactions
DEFF Research Database (Denmark)
Schmidt, Casper; Morris, Laurel S.; Kvamme, Timo L.
2017-01-01
prefrontal cortex (whole brain, cluster corrected FWE P motivational salience and emotion processing, and impaired functional connectivity between prefrontal control regulatory and limbic regions...
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Groenewold, Nynke A.; Opmeer, Esther M.; de Jonge, Peter; Aleman, Andre; Costafreda, Sergi G.
Models describing the neural correlates of biased emotion processing in depression have focused on increased activation of anterior cingulate and amygdala and decreased activation of striatum and dorsolateral prefrontal cortex. However, neuroimaging studies investigating emotion processing in
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Directory of Open Access Journals (Sweden)
Daniel M. Blumberger
2017-05-01
Full Text Available Combining transcranial magnetic stimulation (TMS with electroencephalography (EEG allows for the assessment of various neurophysiological processes in the human cortex. One of these paradigms, short-latency afferent inhibition (SAI, is thought to be a sensitive measure of cholinergic activity. In a previous study, we demonstrated the temporal pattern of this paradigm from both the motor (M1 and dorsolateral prefrontal cortex (DLPFC using simultaneous TMS–EEG recording. The SAI paradigm led to marked modulations at N100. In this study, we aimed to investigate the age-related effects on TMS-evoked potentials (TEPs with the SAI from M1 and the DLPFC in younger (18–59 years old and older (≥60 years old participants. Older participants showed significantly lower N100 modulation in M1–SAI as well as DLPFC–SAI compared to the younger participants. Furthermore, the modulation of N100 by DLPFC–SAI in the older participants correlated with executive function as measured with the Trail making test. This paradigm has the potential to non-invasively identify cholinergic changes in cortical regions related to cognition in older participants.
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International Nuclear Information System (INIS)
Kim, David H.; Haffty, Bruce G.
1996-01-01
Purpose: To assess outcome of patients with bilateral breast carcinoma treated with bilateral breast conserving surgery with radiation therapy (CS+RT) and to compare their outcome to (1) patients with unilateral disease treated with CS+RT and (2) patients of comparable stage treated with bilateral mastectomy. Methods and Materials: The charts of all patients with the diagnosis of breast cancer treated with CS+RT at our facilities prior to 1993 were reviewed to identify patients with bilateral disease. A total of 50 patients identified as having bilateral breast cancer conservatively treated(BCT) served as the index population. Out of the 50 patients, 23 presented with synchronous bilateral breast cancer and 27 presented with metachronous bilateral breast cancer. A group of 984 patients with unilateral breast cancer (UCT) treated with CS+RT during the same time interval served as the first control group. A second control group was comprised of 42 patients with early stage bilateral breast cancer presenting during the same time interval treated with bilateral mastectomy (BMAST). Patients who had locally advanced disease in either breast or those patients treated exclusively for lobular carcinoma in situ in either breast were excluded from the analysis. Of the 42 BMAST patients, 33 presented with synchronous disease and nine presented with metachronous disease. Local-regional relapse rates were calculated from the date of treatment of each breast. Overall survival and distant relapse rates were calculated from the date of treatment of the second breast cancer diagnosed. Survival curves were calculated via the life table method and statistical comparisons between curves were performed using the log rank statistic. Chi square analysis was used to detect differences between categorical variables. Results: As of December 1995, the median follow-up of the bilateral conservatively treated patient population was 9.4 years. No statistically significant differences were noted
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Brooks, Samantha J; O'Daly, Owen; Uher, Rudolf; Friederich, Hans-Christoph; Giampietro, Vincent; Brammer, Michael; Williams, Steven C R; Schiöth, Helgi B; Treasure, Janet; Campbell, Iain C
2012-01-01
Women with anorexia nervosa (AN) have aberrant cognitions about food and altered activity in prefrontal cortical and somatosensory regions to food images. However, differential effects on the brain when thinking about eating food between healthy women and those with AN is unknown. Functional magnetic resonance imaging (fMRI) examined neural activation when 42 women thought about eating the food shown in images: 18 with AN (11 RAN, 7 BPAN) and 24 age-matched controls (HC). Group contrasts between HC and AN revealed reduced activation in AN in the bilateral cerebellar vermis, and increased activation in the right visual cortex. Preliminary comparisons between AN subtypes and healthy controls suggest differences in cortical and limbic regions. These preliminary data suggest that thinking about eating food shown in images increases visual and prefrontal cortical neural responses in females with AN, which may underlie cognitive biases towards food stimuli and ruminations about controlling food intake. Future studies are needed to explicitly test how thinking about eating activates restraint cognitions, specifically in those with restricting vs. binge-purging AN subtypes.
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Sensitivity of fNIRS to cognitive state and load
Directory of Open Access Journals (Sweden)
Frank Anthony Fishburn
2014-02-01
Full Text Available Functional near-infrared spectroscopy (fNIRS is an emerging low-cost noninvasive neuroimaging technique that measures cortical bloodflow. While fNIRS has gained interest as a potential alternative to fMRI for use with clinical and pediatric populations, it remains unclear whether fNIRS has the necessary sensitivity to serve as a replacement for fMRI. The present study set out to examine whether fNIRS has the sensitivity to detect linear changes in activation and functional connectivity in response to cognitive load, and functional connectivity changes when transitioning from a task-free resting state to a task. Sixteen young adult subjects were scanned with a continuous-wave fNIRS system during a 10-minute resting-state scan followed by a letter n-back task with three load conditions. Five optical probes were placed over frontal and parietal cortices, covering bilateral dorsolateral PFC (dlPFC, bilateral ventrolateral PFC (vlPFC, frontopolar cortex (FP, and bilateral parietal cortex. Activation was found to scale linearly with working memory load in bilateral prefrontal cortex. Functional connectivity increased with increasing n-back loads for fronto-parietal, interhemispheric dlPFC, and local connections. Functional connectivity differed between the resting state scan and the n-back scan, with fronto-parietal connectivity greater during the n-back, and interhemispheric vlPFC connectivity greater during rest. These results demonstrate that fNIRS is sensitive to both cognitive load and state, suggesting that fNIRS is well-suited to explore the full complement of neuroimaging research questions and will serve as a viable alternative to fMRI.
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The role of the DLPFC in inductive reasoning of MCI patients and normal agings: an fMRI study.
Yang, YanHui; Liang, PeiPeng; Lu, ShengFu; Li, KunCheng; Zhong, Ning
2009-08-01
Previous studies of young people have revealed that the left dorsolateral prefrontal cortex (DLPFC) plays an important role in inductive reasoning. An fMRI experiment was performed in this study to examine whether the left DLPFC was involved in inductive reasoning of MCI patients and normal aging, and whether the activation pattern of this region was different between MCI patients and normal aging. The fMRI results indicated that MCI patients had no difference from normal aging in behavior performance (reaction time and accuracy) and the activation pattern of DLPFC. However, the BOLD response of the DLPFC region for MCI patients was weaker than that for normal aging, and the functional connectivity between the bilateral DLPFC regions for MCI patients was significantly higher than for normal aging. Taken together, these results indicated that DLPFC plays an important role in inductive reasoning of aging, and the functional abnormity of DLPFC may be an earlier marker of MCI before structural alterations.
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Role of Prefrontal Persistent Activity in Working Memory
Riley, Mitchell R.; Constantinidis, Christos
2016-01-01
The prefrontal cortex is activated during working memory, as evidenced by fMRI results in human studies and neurophysiological recordings in animal models. Persistent activity during the delay period of working memory tasks, after the offset of stimuli that subjects are required to remember, has traditionally been thought of as the neural correlate of working memory. In the last few years several findings have cast doubt on the role of this activity. By some accounts, activity in other brain areas, such as the primary visual and posterior parietal cortex, is a better predictor of information maintained in visual working memory and working memory performance; dynamic patterns of activity may convey information without requiring persistent activity at all; and prefrontal neurons may be ill-suited to represent non-spatial information about the features and identity of remembered stimuli. Alternative interpretations about the role of the prefrontal cortex have thus been suggested, such as that it provides a top-down control of information represented in other brain areas, rather than maintaining a working memory trace itself. Here we review evidence for and against the role of prefrontal persistent activity, with a focus on visual neurophysiology. We show that persistent activity predicts behavioral parameters precisely in working memory tasks. We illustrate that prefrontal cortex represents features of stimuli other than their spatial location, and that this information is largely absent from early cortical areas during working memory. We examine memory models not dependent on persistent activity, and conclude that each of those models could mediate only a limited range of memory-dependent behaviors. We review activity decoded from brain areas other than the prefrontal cortex during working memory and demonstrate that these areas alone cannot mediate working memory maintenance, particularly in the presence of distractors. We finally discuss the discrepancy between
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Multitarget transcranial direct current stimulation for freezing of gait in Parkinson's disease.
Dagan, Moria; Herman, Talia; Harrison, Rachel; Zhou, Junhong; Giladi, Nir; Ruffini, Giulio; Manor, Brad; Hausdorff, Jeffrey M
2018-04-01
Recent findings suggest that transcranial direct current stimulation of the primary motor cortex may ameliorate freezing of gait. However, the effects of multitarget simultaneous stimulation of motor and cognitive networks are mostly unknown. The objective of this study was to evaluate the effects of multitarget transcranial direct current stimulation of the primary motor cortex and left dorsolateral prefrontal cortex on freezing of gait and related outcomes. Twenty patients with Parkinson's disease and freezing of gait received 20 minutes of transcranial direct current stimulation on 3 separate visits. Transcranial direct current stimulation targeted the primary motor cortex and left dorsolateral prefrontal cortex simultaneously, primary motor cortex only, or sham stimulation (order randomized and double-blinded assessments). Participants completed a freezing of gait-provoking test, the Timed Up and Go, and the Stroop test before and after each transcranial direct current stimulation session. Performance on the freezing of gait-provoking test (P = 0.010), Timed Up and Go (P = 0.006), and the Stroop test (P = 0.016) improved after simultaneous stimulation of the primary motor cortex and left dorsolateral prefrontal cortex, but not after primary motor cortex only or sham stimulation. Transcranial direct current stimulation designed to simultaneously target motor and cognitive regions apparently induces immediate aftereffects in the brain that translate into reduced freezing of gait and improvements in executive function and mobility. © 2018 International Parkinson and Movement Disorder Society. © 2018 International Parkinson and Movement Disorder Society.
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Cognitive deficits caused by prefrontal cortical and hippocampal neural disinhibition.
Bast, Tobias; Pezze, Marie; McGarrity, Stephanie
2017-10-01
We review recent evidence concerning the significance of inhibitory GABA transmission and of neural disinhibition, that is, deficient GABA transmission, within the prefrontal cortex and the hippocampus, for clinically relevant cognitive functions. Both regions support important cognitive functions, including attention and memory, and their dysfunction has been implicated in cognitive deficits characterizing neuropsychiatric disorders. GABAergic inhibition shapes cortico-hippocampal neural activity, and, recently, prefrontal and hippocampal neural disinhibition has emerged as a pathophysiological feature of major neuropsychiatric disorders, especially schizophrenia and age-related cognitive decline. Regional neural disinhibition, disrupting spatio-temporal control of neural activity and causing aberrant drive of projections, may disrupt processing within the disinhibited region and efferent regions. Recent studies in rats showed that prefrontal and hippocampal neural disinhibition (by local GABA antagonist microinfusion) dysregulates burst firing, which has been associated with important aspects of neural information processing. Using translational tests of clinically relevant cognitive functions, these studies showed that prefrontal and hippocampal neural disinhibition disrupts regional cognitive functions (including prefrontal attention and hippocampal memory function). Moreover, hippocampal neural disinhibition disrupted attentional performance, which does not require the hippocampus but requires prefrontal-striatal circuits modulated by the hippocampus. However, some prefrontal and hippocampal functions (including inhibitory response control) are spared by regional disinhibition. We consider conceptual implications of these findings, regarding the distinct relationships of distinct cognitive functions to prefrontal and hippocampal GABA tone and neural activity. Moreover, the findings support the proposition that prefrontal and hippocampal neural disinhibition
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Singh K; Bajaj A; Dwivedi N; Merchery A
1993-01-01
A case of bilateral herpes zoster of lumbosacral region is reported in association with diabetes mellitus in a 55 years old female. The case is of interest due to bilateral distribution which is rare and sacral region involvement which is quite uncommon.
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Bilateral Testicular Tumors Resulting in Recurrent Cushing Disease After Bilateral Adrenalectomy
Puar, T.; Engels, M.; Herwaarden, A.E. van; Sweep, F.C.; Hulsbergen-van de Kaa, C.A.; Kamphuis-van Ulzen, K.; Chortis, V.; Arlt, W.; Stikkelbroeck, N.; Claahsen-van der Grinten, H.L.; Hermus, A.R.M.M.
2017-01-01
Context: Recurrence of hypercortisolism in patients after bilateral adrenalectomy for Cushing disease is extremely rare. Patient: We present a 27-year-old man who previously underwent bilateral adrenalectomy for Cushing disease with complete clinical resolution. Cushingoid features recurred 12 years
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Directory of Open Access Journals (Sweden)
Singh K
1993-01-01
Full Text Available A case of bilateral herpes zoster of lumbosacral region is reported in association with diabetes mellitus in a 55 years old female. The case is of interest due to bilateral distribution which is rare and sacral region involvement which is quite uncommon.
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Prefrontal glucose deficits in murderers lacking psychosocial deprivation.
Raine, A; Phil, D; Stoddard, J; Bihrle, S; Buchsbaum, M
1998-01-01
Previous research has suggested that links between autonomic nervous system functioning and violence are strongest in those who come from benign home backgrounds, but there appears to be no similar research using brain-imaging measures of central nervous system functioning. It was hypothesized that murderers who had no early psychosocial deprivation (e.g., no childhood abuse, family neglect) would demonstrate lower prefrontal glucose metabolism than murderers with early psychosocial deprivation and a group of normal controls. Murderers from a previous study, which showed prefrontal deficits in murderers, were assessed for psychosocial deprivation and divided into those with and without deprivation. Murderers without any clear psychosocial deficits were significantly lower on prefrontal glucose metabolism than murderers with psychosocial deficits and controls. These results suggest that murderers lacking psychosocial deficits are characterized by prefrontal deficits. It is argued that among violent offenders without deprived home backgrounds, the "social push" to violence is minimized, and consequently, brain abnormalities provide a relatively stronger predisposition to violence in this group.
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Selective reductions in prefrontal glucose metabolism in murderers.
Raine, A; Buchsbaum, M S; Stanley, J; Lottenberg, S; Abel, L; Stoddard, J
1994-09-15
This study tests the hypothesis that seriously violent offenders pleading not guilty by reason of insanity or incompetent to stand trial are characterized by prefrontal dysfunction. This hypothesis was tested in a group of 22 subjects accused of murder and 22 age-matched and gender-matched controls by measuring local cerebral uptake of glucose using positron emission tomography during the continuous performance task. Murderers had significantly lower glucose metabolism in both lateral and medial prefrontal cortex relative to controls. No group differences were observed for posterior frontal, temporal, and parietal glucose metabolism, indicating regional specificity for the prefrontal deficit. Group differences were not found to be a function of raised levels of left-handedness, schizophrenia, ethnic minority status, head injury, or motivation deficits in the murder group. These preliminary results suggest that deficits localized to the prefrontal cortex may be related to violence in a selected group of offenders, although further studies are needed to establish the generalizability of these findings to violent offenders in the community.
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Weissman, David G; Schriber, Roberta A; Fassbender, Catherine; Atherton, Olivia; Krafft, Cynthia; Robins, Richard W; Hastings, Paul D; Guyer, Amanda E
2015-12-01
Early adolescent onset of substance use is a robust predictor of future substance use disorders. We examined the relation between age of substance use initiation and resting state functional connectivity (RSFC) of the core reward processing (nucleus accumbens; NAcc) to cognitive control (prefrontal cortex; PFC) brain networks. Adolescents in a longitudinal study of Mexican-origin youth reported their substance use annually from ages 10 to 16 years. At age 16, 69 adolescents participated in a resting state functional magnetic resonance imaging scan. Seed-based correlational analyses were conducted using regions of interest in bilateral NAcc. The earlier that adolescents initiated substance use, the stronger the connectivity between bilateral NAcc and right dorsolateral PFC, right dorsomedial PFC, right pre-supplementary motor area, right inferior parietal lobule, and left medial temporal gyrus. The regions that demonstrated significant positive linear relationships between the number of adolescent years using substances and connectivity with NAcc are nodes in the right frontoparietal network, which is central to cognitive control. The coupling of reward and cognitive control networks may be a mechanism through which earlier onset of substance use is related to brain function over time, a trajectory that may be implicated in subsequent substance use disorders. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Ashkenazi, Sarit; Rosenberg-Lee, Miriam; Tenison, Caitlin; Menon, Vinod
2012-02-15
Developmental dyscalculia (DD) is a disability that impacts math learning and skill acquisition in school-age children. Here we investigate arithmetic problem solving deficits in young children with DD using univariate and multivariate analysis of fMRI data. During fMRI scanning, 17 children with DD (ages 7-9, grades 2 and 3) and 17 IQ- and reading ability-matched typically developing (TD) children performed complex and simple addition problems which differed only in arithmetic complexity. While the TD group showed strong modulation of brain responses with increasing arithmetic complexity, children with DD failed to show such modulation. Children with DD showed significantly reduced activation compared to TD children in the intraparietal sulcus, superior parietal lobule, supramarginal gyrus and bilateral dorsolateral prefrontal cortex in relation to arithmetic complexity. Critically, multivariate representational similarity revealed that brain response patterns to complex and simple problems were less differentiated in the DD group in bilateral anterior IPS, independent of overall differences in signal level. Taken together, these results show that children with DD not only under-activate key brain regions implicated in mathematical cognition, but they also fail to generate distinct neural responses and representations for different arithmetic problems. Our findings provide novel insights into the neural basis of DD. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Savic, Branislav; Müri, René; Meier, Beat
Transcranial direct current stimulation (tDCS) is assumed to affect cortical excitability and dependent on the specific stimulation conditions either to increase or decrease learning. The purpose of this study was to modulate implicit task sequence learning with tDCS. As cortico-striatal loops are critically involved in implicit task sequence learning, tDCS was applied above the dorsolateral prefrontal cortex (DLPFC). In Experiment 1, anodal, cathodal, or sham tDCS was applied before the start of the sequence learning task. In Experiment 2, stimulation was applied during the sequence learning task. Consolidation of learning was assessed after 24 h. The results of both experiments showed that implicit task sequence learning occurred consistently but it was not modulated by different tDCS conditions. Similarly, consolidation measured after a 24 h-interval including sleep was also not affected by stimulation. These results indicate that a single session of DLPFC tDCS is not sufficient to modulate implicit task sequence learning. This study adds to the accumulating evidence that tDCS may not be as effective as originally thought. Copyright © 2017 Elsevier Inc. All rights reserved.
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Wei, Shengnan; Geng, Haiyang; Jiang, Xiaowei; Zhou, Qian; Chang, Miao; Zhou, Yifang; Xu, Ke; Tang, Yanqing; Wang, Fei
2017-02-22
Bipolar disorder (BD) is one of the most complex mental illnesses, characterized by interactive depressive and manic states that are 2 contrary symptoms of disease states. The bilateral amygdala and prefrontal cortex (PFC) appear to play critical roles in BD; however, abnormalities seem to manifest differently in the 2 states and may provide further insight into underlying mechanisms. Sixteen participants with first-episode depressive and 13 participants with first-episode manic states of bipolar disorder as well as 30 healthy control (HC) participants underwent resting-state functional magnetic resonance imaging (fMRI). Resting-state functional connectivity (rsFC) between the bilateral amygdala and PFC was compared among the 3 groups. Compared with depressive state participants of the BD group, manic state participants of the BD group showed a significant decrease in rsFC between the amygdala and right orbital frontal cortex (pamygdala and left middle frontal cortex was significantly decreased in depressive and manic state participants of the BD group when compared with the HC group (pamygdala- left PFC functional connectivity might present the trait feature for BD, while deficits in amygdala- right PFC functional connectivity might be specific to manic episode, compared to depressive episode. Copyright © 2017 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Christopher T Primiani
Full Text Available Age changes in expression of inflammatory, synaptic, and neurotrophic genes are not well characterized during human brain development and senescence. Knowing these changes may elucidate structural, metabolic, and functional brain processes over the lifespan, as well vulnerability to neurodevelopmental or neurodegenerative diseases.Expression levels of inflammatory, synaptic, and neurotrophic genes in the human brain are coordinated over the lifespan and underlie changes in phenotypic networks or cascades.We used a large-scale microarray dataset from human prefrontal cortex, BrainCloud, to quantify age changes over the lifespan, divided into Development (0 to 21 years, 87 brains and Aging (22 to 78 years, 144 brains intervals, in transcription levels of 39 genes.Gene expression levels followed different trajectories over the lifespan. Many changes were intercorrelated within three similar groups or clusters of genes during both Development and Aging, despite different roles of the gene products in the two intervals. During Development, changes were related to reported neuronal loss, dendritic growth and pruning, and microglial events; TLR4, IL1R1, NFKB1, MOBP, PLA2G4A, and PTGS2 expression increased in the first years of life, while expression of synaptic genes GAP43 and DBN1 decreased, before reaching plateaus. During Aging, expression was upregulated for potentially pro-inflammatory genes such as NFKB1, TRAF6, TLR4, IL1R1, TSPO, and GFAP, but downregulated for neurotrophic and synaptic integrity genes such as BDNF, NGF, PDGFA, SYN, and DBN1.Coordinated changes in gene transcription cascades underlie changes in synaptic, neurotrophic, and inflammatory phenotypic networks during brain Development and Aging. Early postnatal expression changes relate to neuronal, glial, and myelin growth and synaptic pruning events, while late Aging is associated with pro-inflammatory and synaptic loss changes. Thus, comparable transcriptional regulatory networks
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Primiani, Christopher T.; Ryan, Veronica H.; Rao, Jagadeesh S.; Cam, Margaret C.; Ahn, Kwangmi; Modi, Hiren R.; Rapoport, Stanley I.
2014-01-01
Background Age changes in expression of inflammatory, synaptic, and neurotrophic genes are not well characterized during human brain development and senescence. Knowing these changes may elucidate structural, metabolic, and functional brain processes over the lifespan, as well vulnerability to neurodevelopmental or neurodegenerative diseases. Hypothesis Expression levels of inflammatory, synaptic, and neurotrophic genes in the human brain are coordinated over the lifespan and underlie changes in phenotypic networks or cascades. Methods We used a large-scale microarray dataset from human prefrontal cortex, BrainCloud, to quantify age changes over the lifespan, divided into Development (0 to 21 years, 87 brains) and Aging (22 to 78 years, 144 brains) intervals, in transcription levels of 39 genes. Results Gene expression levels followed different trajectories over the lifespan. Many changes were intercorrelated within three similar groups or clusters of genes during both Development and Aging, despite different roles of the gene products in the two intervals. During Development, changes were related to reported neuronal loss, dendritic growth and pruning, and microglial events; TLR4, IL1R1, NFKB1, MOBP, PLA2G4A, and PTGS2 expression increased in the first years of life, while expression of synaptic genes GAP43 and DBN1 decreased, before reaching plateaus. During Aging, expression was upregulated for potentially pro-inflammatory genes such as NFKB1, TRAF6, TLR4, IL1R1, TSPO, and GFAP, but downregulated for neurotrophic and synaptic integrity genes such as BDNF, NGF, PDGFA, SYN, and DBN1. Conclusions Coordinated changes in gene transcription cascades underlie changes in synaptic, neurotrophic, and inflammatory phenotypic networks during brain Development and Aging. Early postnatal expression changes relate to neuronal, glial, and myelin growth and synaptic pruning events, while late Aging is associated with pro-inflammatory and synaptic loss changes. Thus, comparable
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International Nuclear Information System (INIS)
Kim, Eung Jo; Oh, Ki Keun
1990-01-01
We evaluate 311 breast cancer patients admitted to Yong Dong Severance Hospital Between October 1st 1985 and July 31th 1989, and were able to obtain the following conclusions. 1) There were 14(4.5%) bilateral breast cancers among the 311 confirmed breast cancers. 2) Among the bilateral breast cancers, 5(31%) were synchronous and 9(69%) metachronous. 3) Average interval between the first and the second breast cancer in metachronous cancers was 3.8 year(1-15 years). 4) Bilateral breast cancer was most prevalent in the fifth decade (6/14) with the mean age of 47 years. 5) Film mammogram and sonomammogram showed findings of typical breast malignancies. There was no additional specific findings for each cancer in bilateral breast cancers which was different from unilateral cancers. Therefor, in the patients with unilateral breast cancer, possibility of the second lesion in the contralateral side must be considered and a close follow up observation should be done for at least 3 years
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Rubin, Uriel; De Jager, Cornelis; Zakour, Moayed; Gonder, J Thomas
2017-01-01
To present a case of a patient with simultaneous bilateral retinal detachments treated successfully with bilateral pneumatic retinopexy. Case report. This is a case of an otherwise healthy 49-year-old woman with no remarkable ocular history that presented with simultaneous phakic superior bilateral rhegmatogenous retinal detachments. Treatment on the day of presentation included laser retinopexy of the inferior lattice degeneration in the left eye and bilateral intravitreal injection of 0.4 cc of 100% C3F8 gas preceded by topical anesthesia. After 48 hours, both retinas were completely reattached, and bilateral laser retinopexy was performed to the superior tears. After a review of the literature, the authors could find only two reported cases of simultaneous bilateral retinal detachments treated successfully with pneumatic retinopexy. This is not only a cost-effective procedure but also allows treatment when there is no immediate operating room availability or a when a quick referral for surgery is not possible.
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Effects of non-invasive neurostimulation on craving: a meta-analysis
Jansen, Jochem M.; Daams, Joost G.; Koeter, Maarten W. J.; Veltman, Dick J.; van den Brink, Wim; Goudriaan, Anna E.
2013-01-01
This meta-analysis was conducted to evaluate the available evidence regarding the effects of non-invasive neurostimulation of the dorsolateral prefrontal cortex (DLPFC), on craving in substance dependence and craving for high palatable food. Non-invasive neurostimulation techniques were restricted
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Effects of non-invasive neurostimulation on craving: A meta-analysis
Jansen, J.M.; Daams, J.G.; Koeter, M.W.; Veltman, D.J.; van den Brink, W.; Goudriaan, A.E.
2013-01-01
This meta-analysis was conducted to evaluate the available evidence regarding the effects of non-invasive neurostimulation of the dorsolateral prefrontal cortex (DLPFC), on craving in substance dependence and craving for high palatable food. Non-invasive neurostimulation techniques were restricted
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The Development of the Ventral Prefrontal Cortex and Social Flexibility
Nelson, Eric E.; Guyer, Amanda E.
2011-01-01
Over the last several years a number of studies in both humans and animals have suggested that the orbitofrontal and ventrolateral prefrontal cortices play an important role in generating flexible behavior. We suggest that input from these brain regions contribute to three functions involved in generating flexible behavior within social contexts: valuation, inhibition, and rule use. Recent studies have also demonstrated that the prefrontal cortex undergoes a prolonged course of maturation that extends well after puberty. Here, we review evidence that the prolonged development of these prefrontal regions parallels a slowly emerging ability for flexible social behavior. We also speculate on the possibility that sensitive periods for organizing social behavior may be embedded within this developmental time-fame. Finally, we discuss the role of prefrontal cortex in adolescent mood and anxiety disorders, particularly as orbitofrontal and ventrolateral prefrontal cortices are engaged in a social context. PMID:21804907
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McDonald, R J; Hong, N S
2004-01-01
This experiment tested the idea that the amygdala-based learning and memory system covertly acquires a stimulus-reward (stimulus-outcome) association during acquisition of a stimulus-response (S-R) habit task developed for the eight-arm radial maze. Groups of rats were given dorso-lateral striatal or amygdala lesions and then trained on the S-R habit task on the eight-arm radial maze. Rats with neurotoxic damage to the dorso-lateral striatum were severely impaired on the acquisition of the S-R habit task but showed a conditioned-cue preference for the stimulus reinforced during S-R habit training. Rats with neurotoxic damage to the amygdala were able to acquire the S-R habit task but did not show a conditioned-cue preference for the stimulus reinforced during S-R habit training. This pattern of results represents a dissociation of learning and memory functions of the dorsal striatum and amygdala on the same task.
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Philip, Noah S; Barredo, Jennifer; van 't Wout-Frank, Mascha; Tyrka, Audrey R; Price, Lawrence H; Carpenter, Linda L
2018-02-01
Repetitive transcranial magnetic stimulation (TMS) therapy can modulate pathological neural network functional connectivity in major depressive disorder (MDD). Posttraumatic stress disorder is often comorbid with MDD, and symptoms of both disorders can be alleviated with TMS therapy. This is the first study to evaluate TMS-associated changes in connectivity in patients with comorbid posttraumatic stress disorder and MDD. Resting-state functional connectivity magnetic resonance imaging was acquired before and after TMS therapy in 33 adult outpatients in a prospective open trial. TMS at 5 Hz was delivered, in up to 40 daily sessions, to the left dorsolateral prefrontal cortex. Analyses used a priori seeds relevant to TMS, posttraumatic stress disorder, or MDD (subgenual anterior cingulate cortex [sgACC], left dorsolateral prefrontal cortex, hippocampus, and basolateral amygdala) to identify imaging predictors of response and to evaluate clinically relevant changes in connectivity after TMS, followed by leave-one-out cross-validation. Imaging results were explored using data-driven multivoxel pattern activation. More negative pretreatment connectivity between the sgACC and the default mode network predicted clinical improvement, as did more positive amygdala-to-ventromedial prefrontal cortex connectivity. After TMS, symptom reduction was associated with reduced connectivity between the sgACC and the default mode network, left dorsolateral prefrontal cortex, and insula, and reduced connectivity between the hippocampus and the salience network. Multivoxel pattern activation confirmed seed-based predictors and correlates of treatment outcomes. These results highlight the central role of the sgACC, default mode network, and salience network as predictors of TMS response and suggest their involvement in mechanisms of action. Furthermore, this work indicates that there may be network-based biomarkers of clinical response relevant to these commonly comorbid disorders
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Curley, Allison A; Arion, Dominique; Volk, David W; Asafu-Adjei, Josephine K; Sampson, Allan R; Fish, Kenneth N; Lewis, David A
2011-09-01
Cognitive deficits in schizophrenia are associated with altered activity of the dorsolateral prefrontal cortex, which has been attributed to lower expression of the 67 kDa isoform of glutamic acid decarboxylase (GAD67), the major γ-aminobutyric acid (GABA)-synthesizing enzyme. However, little is known about the relationship of prefrontal GAD67 mRNA levels and illness severity, translation of the transcript into protein, and protein levels in axon terminals, the key site of GABA production and function. Quantitative polymerase chain reaction was used to measure GAD67 mRNA levels in postmortem specimens of dorsolateral prefrontal cortex from subjects with schizophrenia and matched comparison subjects with no known history of psychiatric or neurological disorders (N=42 pairs). In a subset of this cohort in which potential confounds of protein measures were controlled (N=19 pairs), Western blotting was used to quantify tissue levels of GAD67 protein in tissue. In five of these pairs, multilabel confocal immunofluorescence was used to quantify GAD67 protein levels in the axon terminals of parvalbumin-containing GABA neurons, which are known to have low levels of GAD67 mRNA in schizophrenia. GAD67 mRNA levels were significantly lower in schizophrenia subjects (by 15%), but transcript levels were not associated with predictors or measures of illness severity or chronicity. In schizophrenia subjects, GAD67 protein levels were significantly lower in total gray matter (by 10%) and in parvalbumin axon terminals (by 49%). The findings that lower GAD67 mRNA expression is common in schizophrenia, that it is not a consequence of having the illness, and that it leads to less translation of the protein, especially in the axon terminals of parvalbumin-containing neurons, support the hypothesis that lower GABA synthesis in parvalbumin neurons contributes to dorsolateral prefrontal cortex dysfunction and impaired cognition in schizophrenia.
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Kim, Sun Mi; Han, Doug Hyun; Lee, Young Sik; Kim, Jieun E; Renshaw, Perry F
2012-06-01
Several studies have suggested that addictive disorders including substance abuse and pathologic gambling might be associated with dysfunction on working memory and prefrontal activity. We hypothesized that excessive online game playing is associated with deficits in prefrontal cortex function and that recovery from excessive online game playing might improve prefrontal cortical activation in response to working memory stimulation. Thirteen adolescents with excessive online game playing (AEOP) and ten healthy adolescents (HC) agreed to participate in this study. The severity of online game play and playing time were evaluated for a baseline measurement and again following four weeks of treatment. Brain activation in response to working memory tasks (simple and complex calculations) at baseline and subsequent measurements was assessed using BOLD functional magnetic resonance imaging (fMRI). Compared to the HC subjects, the AEOP participants exhibited significantly greater activity in the right middle occipital gyrus, left cerebellum posterior lobe, left premotor cortex and left middle temporal gyrus in response to working memory tasks during baseline measurements. After four weeks of treatment, the AEOP subjects showed increased activity within the right dorsolateral prefrontal cortex and left occipital fusiform gyrus. After four weeks of treatment, changes in the severity of online game playing were negatively correlated with changes in the mean β value of the right dorsolateral prefrontal cortex in response to complex stimulation. We suggest that the effects of online game addiction on working memory may be similar to those observed in patients with substance dependence.
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White, Daniela; Tavakoli, Sason
2015-08-01
Repetitive transcranial magnetic stimulation (rTMS) has shown promising results in treating individuals with behavioral disorders such as major depressive disorder (MDD), posttraumatic stress disorder, obsessive-compulsive disorder, and social anxiety disorder. A number of applications of rTMS to different regions of the left and right prefrontal cortex have been used to treat these disorders, but no study of treatment for MDD with generalized anxiety disorder (GAD) has been conducted with application of rTMS to both the left and right prefrontal cortex. We hypothesized that applying low-frequency rTMS to the right dorsolateral prefrontal cortex (DLPFC) before applying it to the left DLPFC for the treatment of depression would be anxiolytic in patients with MDD with GAD. Thirteen adult patients with comorbid MDD and GAD received treatment with rTMS in an outpatient setting. The number of treatments ranged from 24 to 36 over 5 to 6 weeks. Response was defined as a ≥ 50% reduction in symptoms from baseline, and remission was defined as a score of anxiety symptoms on the 7-item Generalized Anxiety Disorder (GAD-7) scale and depressive symptoms on the 21-item Hamilton Rating Scale for Depression (HAM-D-21). At the end of the treatment period, for the GAD-7 scale, 11 out of 13 (84.6%) patients' anxiety symptoms were in remission, achieving a score of depressive symptoms. In this small pilot study of 13 patients with comorbid MDD and GAD, significant improvement in anxiety symptoms along with depressive symptoms was achieved in a majority of patients after bilateral rTMS application.
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Medvedev, Andrei V.; Kainerstorfer, Jana M.; Borisov, Sergey V.; Vanmeter, John
2011-01-01
Near-infrared spectroscopy (NIRS) is a developing technology for low-cost noninvasive functional brain imaging. With multichannel optical instruments, it becomes possible to measure not only local changes in hemoglobin concentrations but also temporal correlations of those changes in different brain regions which gives an optical analog of functional connectivity traditionally measured by fMRI. We recorded hemodynamic activity during the Go-NoGo task from 11 right-handed subjects with probes placed bilaterally over prefrontal areas. Subjects were detecting animals as targets in natural scenes pressing a mouse button. Data were low-pass filtered right versus left hemisphere. Intra- and interhemispheric functional connectivity was also significantly stronger during the task compared to baseline. Functional connectivity between the inferior and the middle frontal regions was significantly stronger in the right hemisphere. Our results demonstrate that optical methods can be used to detect transient changes in functional connectivity during rapid cognitive processes.
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Turner, Gary R; Spreng, R Nathan
2015-12-01
Reduced executive control is a hallmark of neurocognitive aging. Poor modulation of lateral pFC activity in the context of increasing task challenge in old adults and a "failure to deactivate" the default network during cognitive control tasks have been observed. Whether these two patterns represent discrete mechanisms of neurocognitive aging or interact into older adulthood remains unknown. We examined whether altered pFC and default network dynamics co-occur during goal-directed planning over increasing levels of difficulty during performance on the Tower of London task. We used fMRI to investigate task- and age-related changes in brain activation and functional connectivity across four levels of task challenge. Frontoparietal executive control regions were activated and default network regions were suppressed during planning relative to counting performance in both groups. Older adults, unlike young, failed to modulate brain activity in executive control and default regions as planning demands increased. Critically, functional connectivity analyses revealed bilateral dorsolateral pFC coupling in young adults and dorsolateral pFC to default coupling in older adults with increased planning complexity. We propose a default-executive coupling hypothesis of aging. First, this hypothesis suggests that failure to modulate control and default network activity in response to increasing task challenge are linked in older adulthood. Second, functional brain changes involve greater coupling of lateral pFC and the default network as cognitive control demands increase in older adults. We speculate that these changes reflect an adaptive shift in cognitive approach as older adults come to rely more upon stored representations to support goal-directed task performance.
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Directory of Open Access Journals (Sweden)
Andre J Szameitat
2016-03-01
Full Text Available Human information processing suffers from severe limitations in parallel processing. In particular, when required to respond to two stimuli in rapid succession, processing bottlenecks may appear at central and peripheral stages of task processing. Importantly, it has been suggested that executive functions are needed to resolve the interference arising at such bottlenecks. The aims of the present study were to test whether central attentional limitations (i.e., bottleneck at the decisional response selection stage as well as peripheral limitations (i.e., bottleneck at response initiation both demand executive functions located in the lateral prefrontal cortex. For this, we re-analysed two previous studies, in which a total of 33 participants performed a dual-task according to the paradigm of the psychological refractory period (PRP during fMRI. In one study (N=17, the PRP task consisted of two two-choice response tasks known to suffer from a central bottleneck (CB group. In the other study (N=16, the PRP task consisted of two simple-response tasks known to suffer from a peripheral bottleneck (PB group. Both groups showed considerable dual-task costs in form of slowing of the second response in the dual-task (PRP effect. Imaging results are based on the subtraction of both single-tasks from the dual-task within each group. In the CB group, the bilateral middle frontal gyri and inferior frontal gyri were activated. Higher activation in these areas was associated with lower dual-task costs. In the PB group, the right middle frontal and inferior frontal gyrus were activated. Here, higher activation was associated with higher dual-task costs. In conclusion we suggest that central and peripheral bottlenecks both demand executive functions located in lateral prefrontal cortices. Differences between the CB and PB groups with respect to the exact prefrontal areas activated and the correlational patterns suggest that the executive functions resolving
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Repetitive transcranial magnetic stimulation modulates the impact of a negative mood induction
Möbius, M.; Lacomblé, L.M.T.; Meyer, T.; Schutter, D.J.L.G.; Gielkens, T.; Becker, E.S.; Tendolkar, I.; Eijndhoven, P.F.P. van
2017-01-01
High frequency repetitive Transcranial Magnetic Stimulation (rTMS) over the left dorsolateral prefrontal cortex (DLPFC) has been found to alleviate depressive symptoms. However, the mechanisms driving these effects are still poorly understood. In the current study, we tested the idea that this
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Transcranial direct current stimulation, implicit alcohol associations and craving
den Uijl, T.E.; Gladwin, T.E.; Wiers, R.W.
2015-01-01
Previous research has shown that stimulation of the left dorsolateral prefrontal cortex (DLPFC) enhances working memory (e.g. in the n-back task), and reduces craving for cigarettes and alcohol. Stimulation of the right inferior frontal gyrus (IFG) improves response inhibition. The underlying
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The role of the inferior frontal junction area in cognitive control
Brass, M.; Derrfuss, J.; Forstmann, B.U.; Cramon, D.Y. von
2005-01-01
Cognitive control processes refer to our ability to coordinate thoughts and actions in accordance with internal goals. In the fronto-lateral cortex such processes have been primarily related to mid-dorsolateral prefrontal cortex (mid-DLPFC). However, recent brain-imaging and meta-analytic studies
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Directory of Open Access Journals (Sweden)
S Bala Murugan
2018-01-01
Full Text Available Bilateral uveal effusion syndrome associated with bilateral acute retinal necrosis is a diagnostic and therapeutic challenge. A 52 year old man presented with bilateral angle closure with choroidal detachment. With restricted fundus view, parenteral steroid was started. During close follow up bilateral discrete areas of peripheral retinitis were noted. Parenteral steroids were promptly stopped and parenteral antivirals with oral steroids were continued. It showed healing response with nil recurrences till last follow up. Aggressive treatment of bilateral uveal effusion with parenteral steroids can cause progression of bilateral acute retinal necrosis leading to phthisis bulbi. However early diagnosis, prompt intervention and close follow up are the key elements to therapeutic success even during diagnostic surprises and avoid costly mistakes.
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The neural basis of social risky decision making in females with major depressive disorder.
Shao, Robin; Zhang, Hui-jun; Lee, Tatia M C
2015-01-01
Recent evidence indicates that Major Depressive Disorder (MDD) may be associated with reduced tendency of committing noncompliant actions during social decision-making even when the risk of being punished is low. The neural underpinnings of this behavioral pattern are unknown, although it likely relates to compromised functioning of the lateral prefrontal-striatal/limbic networks implicated in executive control, emotion regulation and risk/value-based instrumental behaviors. We employed a modified trust game (TG) that provided explicit information on the risk levels of cheating behaviors being detected and punished. Behavioral and neuro-image data were acquired and analyzed from 14 first-episode female MDD patients and 15 age- and gender-matched controls performing the role of trustee in the TG. Relative to controls, MDD patients exhibited less behavioral switching to making cheating choices under low risk, and reduced activity in the dorsal putamen, anterior insula and dorsolateral prefrontal cortex (DLPFC) during making low-risk cheating versus benevolent choices, with limited evidence indicating abnormal bilateral inferior frontal gyrus activities of patients when making high-risk cheating versus benevolent choices. Patients' left dorsal putamen/anterior insular signals correlated positively with their frequency of low-risk cheating. MDD patients' symptom severity correlated positively with their signals in the lateral prefrontal networks during decision-making. A psycho-physiological interaction analysis provided tentative evidence for the recruitment of IFG-striatal/limbic circuitry among the control participants, but greater frontopolar-striatal/limbic connectivity among the MDD patients, during low-risk decision-making. We propose that making risky social decisions based on the balancing of self-gain and other's welfare relies on the functioning of the integrated lateral prefrontal-striatal/limbic networks, which are less efficient and dysregulated among MDD
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38 CFR 4.26 - Bilateral factor.
2010-07-01
... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Bilateral factor. 4.26... DISABILITIES General Policy in Rating § 4.26 Bilateral factor. When a partial disability results from disease... disability. The bilateral factor will be applied to such bilateral disabilities before other combinations are...
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Marin, Bianca M; VanHaerents, Stephen A; Voss, Joel L; Bridge, Donna J
2018-01-01
Dorsolateral prefrontal cortex (DLPFC) is thought to organize items in working memory and this organizational role may also influence long-term memory. To causally test this hypothesized role of DLPFC in long-term memory formation, we used θ-burst noninvasive stimulation (TBS) to modulate DLPFC involvement in a memory task that assessed the influence of active short-term retrieval on later memory. Human subjects viewed three objects on a grid and then either actively retrieved or passively restudied one object's location after a brief delay. Long-term memory for the other objects was assessed after a delay to evaluate the beneficial role of active short-term retrieval on subsequent memory for the entire set of object locations. We found that DLPFC TBS had no significant effects on short-term memory. In contrast, DLPFC TBS impaired long-term memory selectively in the active-retrieval condition but not in the passive-restudy condition. These findings are consistent with the hypothesized contribution of DLPFC to the organizational processes operative during active short-term retrieval that influence long-term memory, although other regions that were not stimulated could provide similar contributions. Notably, active-retrieval and passive-restudy conditions were intermixed, and therefore nonspecific influences of stimulation were well controlled. These results suggest that DLPFC is causally involved in organizing event information during active retrieval to support coherent long-term memory formation.
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Richieri, Raphaëlle; Boyer, Laurent; Padovani, Romain; Adida, Marc; Colavolpe, Cécile; Mundler, Olivier; Lançon, Christophe; Guedj, Eric
2012-12-03
Functional neuroimaging studies have suggested similar mechanisms underlying antidepressant effects of distinct therapeutics. This study aimed to determine and compare functional brain patterns underlying the antidepressant response of 2 distinct protocols of repetitive transcranial magnetic stimulation (rTMS). 99mTc-ECD SPECT was performed before and after rTMS of dorsolateral prefrontal cortex in 61 drug-resistant right-handed patients with major depression, using high frequency (10Hz) left-side stimulation in 33 patients, and low frequency (1Hz) right-side stimulation in 28 patients. Efficiency of rTMS response was defined as at least 50% reduction of the baseline Beck Depression Inventory score. We compared the whole-brain voxel-based brain SPECT changes in perfusion after rTMS, between responders and non-responders in the whole sample (pleft- and right-stimulation. Before rTMS, the left- and right-prefrontal stimulation groups did not differ from clinical data and brain SPECT perfusion. rTMS efficiency (evaluated on % of responders) was statistically equivalent in the two groups of patients. In the whole-group of responder patients, a perfusion decrease was found after rTMS, in comparison to non-responders, within the left perirhinal cortex (BA35, BA36). This result was secondarily confirmed separately in the two subgroups, i.e. after either left stimulation (p=0.017) or right stimulation (pbrain functional changes associated to antidepressive efficiency, consisting to a remote brain limbic activity decrease within the left perirhinal cortex. However, these results will have to be confirmed in a double-blind randomized trial using a sham control group. Copyright © 2012 Elsevier Inc. All rights reserved.
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Effects of transcranial direct current stimulation for treating depression: A modeling study
DEFF Research Database (Denmark)
Csifcsák, Gábor; Boayue, Nya Mehnwolo; Puonti, Oula
2018-01-01
Background: Transcranial direct current stimulation (tDCS) above the left dorsolateral prefrontal cortex (lDLPFC) has been widely used to improve symptoms of major depressive disorder (MDD). However, the effects of different stimulation protocols in the entire frontal lobe have not been investiga......Background: Transcranial direct current stimulation (tDCS) above the left dorsolateral prefrontal cortex (lDLPFC) has been widely used to improve symptoms of major depressive disorder (MDD). However, the effects of different stimulation protocols in the entire frontal lobe have not been...... regions. We evaluated effects of seven bipolar and two multi-electrode 4 × 1 tDCS protocols. Results: For bipolar montages, EFs were of comparable strength in the lDLPFC and in the medial prefrontal cortex (MPFC). Depending on stimulation parameters, EF cortical maps varied to a considerable degree......, but were found to be similar in controls and patients. 4 × 1 montages produced more localized, albeit weaker effects. Limitations: White matter anisotropy was not modeled. The relationship between EF strength and clinical response to tDCS could not be evaluated. Conclusions: In addition to l...
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Directory of Open Access Journals (Sweden)
Nadine Gögler
2017-11-01
Full Text Available BackgroundAttentional dysfunctions constitute core cognitive symptoms in schizophrenia, but the precise underlying neurocognitive mechanisms remain to be elucidated.MethodsIn this randomized, double-blind, sham-controlled study, we applied, for the first time, a theoretically grounded modeling approach based on Bundesen’s Theory of Visual Attention (TVA to (i identify specific visual attentional parameters affected in schizophrenia and (ii assess, as a proof of concept, the potential of single-dose anodal transcranial direct current stimulation (tDCS; 20 min, 2 mA to the left dorsolateral prefrontal cortex to modulate these attentional parameters. To that end, attentional parameters were measured before (baseline, immediately after, and 24 h after the tDCS intervention in 20 schizophrenia patients and 20 healthy controls.ResultsAt baseline, analyses revealed significantly reduced visual processing speed and visual short-term memory storage capacity in schizophrenia. A significant stimulation condition × time point interaction in the schizophrenia patient group indicated improved processing speed at the follow-up session only in the sham condition (a practice effect, whereas performance remained stable across the three time points in patients receiving verum stimulation. In healthy controls, anodal tDCS did not result in a significant change in attentional performance.ConclusionWith regard to question (i above, these findings are indicative of a processing speed and short-term memory deficit as primary sources of attentional deficits in schizophrenia. With regard to question (ii, the efficacy of single-dose anodal tDCS for improving (speed aspects of visual cognition, it appears that prefrontal tDCS (at the settings used in the present study, rather than ameliorating the processing speed deficit in schizophrenia, actually may interfere with practice-dependent improvements in the rate of visual information uptake. Such potentially
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Halari, Rozmin; Simic, Mima; Pariante, Carmine M; Papadopoulos, Andrew; Cleare, Anthony; Brammer, Michael; Fombonne, Eric; Rubia, Katya
2009-03-01
There is increasing recognition of major depressive disorder (MDD) in adolescence. In adult MDD, abnormalities of fronto-striatal and fronto-cingulate circuitries mediating cognitive control functions have been implicated in the pathogenesis and been related to problems with controlling negative thoughts. No neuroimaging studies of cognitive control functions, however, exist in paediatric depression. This study investigated whether medication-naïve adolescents with MDD show abnormal brain activation of fronto-striatal and fronto-cingulate networks when performing tasks of attentional and cognitive control. Event-related functional magnetic resonance imaging was used to compare brain activation between 21 medication-naïve adolescents with a first-episode of MDD aged 14-17 years and 21 healthy adolescents, matched for handedness, age, sex, demographics and IQ. Activation paradigms were tasks of selective attention (Simon task), attentional switching (Switch task), and motor response inhibition and error detection (Stop task). In all three tasks, adolescents with depression compared to healthy controls demonstrated reduced activation in task-relevant right dorsolateral (DLPFC), inferior prefrontal cortex (IFC) and anterior cingulate gyrus (ACG). Additional areas of relatively reduced activation were in the parietal lobes during the Stop and Switch tasks, putamen, insula and temporal lobes during the Switch task and precuneus during the Simon task. This study shows first evidence that medication-naïve adolescents with MDD are characterised by abnormal function in ACG and right lateral prefrontal cortex during tasks of attention and performance monitoring, suggesting an early pathogenesis of these functional abnormalities attributed to MDD.
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Functional organization and visual representations in human ventral lateral prefrontal cortex
Directory of Open Access Journals (Sweden)
Annie Wai Yiu Chan
2013-07-01
Full Text Available Recent neuroimaging studies in both human and non-human primates have identified face selective activation in the ventral lateral prefrontal cortex even in the absence of working memory demands. Further, research has suggested that this face-selective response is largely driven by the presence of the eyes. However, the nature and origin of visual category responses in the ventral lateral prefrontal cortex remain unclear. Further, in a broader sense, how do these findings relate to our current understandings of lateral prefrontal cortex? What do these findings tell us about the underlying function and organization principles of the ventral lateral prefrontal cortex? What is the future direction for investigating visual representations in this cortex? This review focuses on the function, topography, and circuitry of the ventral lateral prefrontal cortex to enhance our understanding of the evolution and development of this cortex.
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Prefrontal cortex activation during obstacle negotiation: What's the effect size and timing?
Maidan, Inbal; Shustak, Shiran; Sharon, Topaz; Bernad-Elazari, Hagar; Geffen, Nimrod; Giladi, Nir; Hausdorff, Jeffrey M; Mirelman, Anat
2018-04-01
Obstacle negotiation is a daily activity that requires the integration of sensorimotor and cognitive information. Recent studies provide evidence for the important role of prefrontal cortex during obstacle negotiation. We aimed to explore the effects of obstacle height and available response time on prefrontal activation. Twenty healthy young adults (age: 30.1 ± 1.0 years; 50% women) walked in an obstacle course while negotiating anticipated and unanticipated obstacles at heights of 50 mm and 100 mm. Prefrontal activation was measured using a functional near-infrared spectroscopy system. Kinect cameras measured the obstacle negotiation strategy. Prefrontal activation was defined based on mean level of HbO 2 before, during and after obstacle negotiation and the HbO 2 slope from gait initiation and throughout the task. Changes between types of obstacles were assessed using linear-mix models and partial correlation analyses evaluated the relationship between prefrontal activation and the distance between the feet as the subjects traversed the obstacles. Different obstacle heights showed similar changes in prefrontal activation measures (p > 0.210). However, during unanticipated obstacles, the slope of the HbO 2 response was steeper (p = 0.048), as compared to anticipated obstacles. These changes in prefrontal activation during negotiation of unanticipated obstacles were correlated with greater distance of the leading foot after the obstacles (r = 0.831, p = 0.041). These findings are the first to show that the pattern of prefrontal activation depends on the nature of the obstacle. More specifically, during unanticipated obstacles the recruitment of the prefrontal cortex is faster and greater than during negotiating anticipated obstacles. These results provide evidence of the important role of the prefrontal cortex and the ability of healthy young adults to tailor the activation pattern to different types of obstacles. Copyright © 2018
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Pregnancy following bilateral salpingectomy
DEFF Research Database (Denmark)
Oturai, Annette Bang
2008-01-01
This report presents a rare case of spontaneous pregnancy following bilateral salpingectomy. A woman with a history of bilateral salpingectomy was admitted to hospital because of abdominal pain and positive urine HCG. Surprisingly, ultrasound confirmed a live intrauterine fetus. The pregnancy...... was unwanted, and the woman decided to terminate the pregnancy. She was offered diagnostic examination to localise a potential fistula, but she declined. In a MEDLINE search of English literature this is only the second case of spontaneous pregnancy following bilateral salpingectomy Udgivelsesdato: 2008/4/21...
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State of expectancy modulates the neural response to visual food stimuli in humans.
Malik, Saima; McGlone, Francis; Dagher, Alain
2011-04-01
Human brain imaging studies demonstrate distributed activation of limbic, paralimbic and sensory systems to food and food-associated cues. Activity in this circuit may be modulated by internal factors, such as hunger, and cognitive factors. Anticipation to eat is one such factor, which likely impacts consummatory behavior. Here, the neural substrates of food expectancy were identified in 10 healthy male participants who underwent two whole-brain functional Magnetic Resonance Imaging scans on separate days. Fasted subjects viewed images of food and scenery, in two counterbalanced states. During one condition, subjects were 'expecting' to eat right after the scan and during the other they were 'not expecting' to eat for 1 h after the scan. Food pictures compared with scenery yielded bilateral activation in visual areas as well as in the left insula and amygdala in both conditions. The left dorsolateral prefrontal cortex, hippocampus and putamen were additionally activated in the 'not expecting' condition while right orbitofrontal cortex activity was enhanced in the 'expecting' condition. These data suggest that cognitive manipulations affect the response to food cues in the prefrontal cortex, in areas involved in the planning and control of motivated behaviors, while the amygdala and insula responded equally in both conditions, consistent with a more basic role in homeostatically driven appetitive behavior. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Bode, Stefan; Bennett, Daniel; Sewell, David K; Paton, Bryan; Egan, Gary F; Smith, Philip L; Murawski, Carsten
2018-03-01
According to sequential sampling models, perceptual decision-making is based on accumulation of noisy evidence towards a decision threshold. The speed with which a decision is reached is determined by both the quality of incoming sensory information and random trial-by-trial variability in the encoded stimulus representations. To investigate those decision dynamics at the neural level, participants made perceptual decisions while functional magnetic resonance imaging (fMRI) was conducted. On each trial, participants judged whether an image presented under conditions of high, medium, or low visual noise showed a piano or a chair. Higher stimulus quality (lower visual noise) was associated with increased activation in bilateral medial occipito-temporal cortex and ventral striatum. Lower stimulus quality was related to stronger activation in posterior parietal cortex (PPC) and dorsolateral prefrontal cortex (DLPFC). When stimulus quality was fixed, faster response times were associated with a positive parametric modulation of activation in medial prefrontal and orbitofrontal cortex, while slower response times were again related to more activation in PPC, DLPFC and insula. Our results suggest that distinct neural networks were sensitive to the quality of stimulus information, and to trial-to-trial variability in the encoded stimulus representations, but that reaching a decision was a consequence of their joint activity. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Prefrontal activity during response inhibition decreases over time in the postpartum period.
Bannbers, Elin; Gingnell, Malin; Engman, Jonas; Morell, Arvid; Sylvén, Sara; Skalkidou, Alkistis; Kask, Kristiina; Bäckström, Torbjörn; Wikström, Johan; Poromaa, Inger Sundström
2013-03-15
The postpartum period is characterized by complex hormonal changes, but human imaging studies in the postpartum period have thus far predominantly focused on the neural correlates of maternal behavior or postpartum depression, whereas longitudinal studies on neural correlates of cognitive function across the postpartum period in healthy women are lacking. The aim of this study was to longitudinally examine response inhibition, as a measure of executive function, during the postpartum period and its neural correlates in healthy postpartum women and non-postpartum controls. Thirteen healthy postpartum women underwent event-related functional magnetic resonance imaging while performing a Go/NoGo task. The first assessment was made within 48 h of delivery, and the second at 4-7 weeks postpartum. In addition, 13 healthy women examined twice during the menstrual cycle were included as non-postpartum controls. In postpartum women region of interest analyses revealed task-related decreased activations in the right inferior frontal gyrus, right anterior cingulate, and bilateral precentral gyri at the late postpartum assessment. Generally, postpartum women displayed lower activity during response inhibition in the bilateral inferior frontal gyri and precentral gyri compared to non-postpartum controls. No differences in performance on the Go/NoGo task were found between time-points or between groups. In conclusion, this study has discovered that brain activity in prefrontal areas during a response inhibition task decreases throughout the course of the first postpartum weeks and is lower than in non-postpartum controls. Further studies on the normal adaptive brain activity changes that occur during the postpartum period are warranted. Copyright © 2012 Elsevier B.V. All rights reserved.
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White matter integrity deficits in prefrontal-amygdala pathways in Williams syndrome.
Avery, Suzanne N; Thornton-Wells, Tricia A; Anderson, Adam W; Blackford, Jennifer Urbano
2012-01-16
Williams syndrome is a neurodevelopmental disorder associated with significant non-social fears. Consistent with this elevated non-social fear, individuals with Williams syndrome have an abnormally elevated amygdala response when viewing threatening non-social stimuli. In typically-developing individuals, amygdala activity is inhibited through dense, reciprocal white matter connections with the prefrontal cortex. Neuroimaging studies suggest a functional uncoupling of normal prefrontal-amygdala inhibition in individuals with Williams syndrome, which might underlie both the extreme amygdala activity and non-social fears. This functional uncoupling might be caused by structural deficits in underlying white matter pathways; however, prefrontal-amygdala white matter deficits have yet to be explored in Williams syndrome. We used diffusion tensor imaging to investigate prefrontal-amygdala white matter integrity differences in individuals with Williams syndrome and typically-developing controls with high levels of non-social fear. White matter pathways between the amygdala and several prefrontal regions were isolated using probabilistic tractography. Within each pathway, we tested for between-group differences in three measures of white matter integrity: fractional anisotropy (FA), radial diffusivity (RD), and parallel diffusivity (λ(1)). Individuals with Williams syndrome had lower FA, compared to controls, in several of the prefrontal-amygdala pathways investigated, indicating a reduction in white matter integrity. Lower FA in Williams syndrome was explained by significantly higher RD, with no differences in λ(1), suggestive of lower fiber density or axon myelination in prefrontal-amygdala pathways. These results suggest that deficits in the structural integrity of prefrontal-amygdala white matter pathways might underlie the increased amygdala activity and extreme non-social fears observed in Williams syndrome. Copyright © 2011 Elsevier Inc. All rights reserved.
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Chen, Tianyi; Wang, Yingchan; Zhang, Jianye; Wang, Zuowei; Xu, Jiale; Li, Yao; Yang, Zhilei; Liu, Dengtang
2017-10-25
The etiology and pathomechanism of schizophrenia are unknown. The traditional dopamine (DA) hypothesis is unable to fully explain its pathology and therapeutics. The glutamate (Glu) and γ-aminobutyric acid (GABA) hypotheses suggest Glu or GABA concentrations are abnormal in the brains of patients with schizophrenia. Magnetic resonance spectroscopy (MRS) show glutamate level increases in the ventromedial prefrontal cortex (vmPFC) including the anterior cingulated cortex (ACC) in those with schizophrenia. To investigate the function of the glutamate system (glutamate and γ-aminobutyric acid) in the etiology and pathomechanism of schizophrenia. 24 drug naïve patients with schizophrenia and 24 healthy volunteers were matched by gender, age, and educational level. The Siemens 3T MRI system was used to collect the magnetic resonance spectroscopy (MRS) data of the subjects. The regions of interest included the left dorsolateral prefrontal cortex (IDLPFC), ventromedial prefrontal cortex (vmPFC), and anterior cingulate cortex (ACC). LCModel software was used to analyze the concentrations of γ-aminobutyric acid (GABA), glutamate (Glu), glutamine (Gln), N-acetylaspartate (NAA), and N-acetylaspartylglutamate (NAAG) in the region of interest. Meanwhile, the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression Scale (CGI) were used to assess the mental symptoms and severity of the disease. The median GABA concentrations in the anterior cingulate cortex of the schizophrenia group and the healthy control group were 1.90 (Q1=1.55, Q3=2.09) and 2.16 (Q1=1.87, Q3=2.59) respectively; the mean (sd) Glu concentrations were 6.07 (2.48) and 6.54 (1.99); the median Gln concentrations were 0.36 (Q1=0.00, Q3=0.74) and 0.29 (Q1=0.00, Q3=0.59); the between-group difference of the GABA concentrations was statistically significant ( Z =-2.95, p =0.003); the between-group difference of the GABA/(NAA+NAAG) was statistically significant ( Z =-2.72, p =0.012); the
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Lewis, David A; Hashimoto, Takanori; Morris, Harvey M
2008-10-01
Impairments in cognitive control, such as those involved in working memory, are associated with dysfunction of the dorsolateral prefrontal cortex (DLPFC) in individuals with schizophrenia. This dysfunction appears to result, at least in part, from abnormalities in GABA-mediated neurotransmission. In this paper, we review recent findings indicating that the altered DLPFC circuitry in subjects with schizophrenia reflects changes in the expression of genes that encode selective presynaptic and postsynaptic components of GABA neurotransmission. Specifically, using a combination of methods, we found that subjects with schizophrenia exhibited expression deficits in GABA-related transcripts encoding presynaptic regulators of GABA neurotransmission, neuropeptide markers of specific subpopulations of GABA neurons, and certain subunits of the GABA(A) receptor. In particular, alterations in the expression of the neuropeptide somatostatin suggested that GABA neurotransmission is impaired in the Martinotti subset of GABA neurons that target the dendrites of pyramidal cells. In contrast, none of the GABA-related transcripts assessed to date were altered in the DLPFC of monkeys chronically exposed to antipsychotic medications, suggesting that the effects observed in the human studies reflect the disease process and not its treatment. In concert with previous findings, these data suggest that working memory dysfunction in schizophrenia may be attributable to altered GABA neurotransmission in specific DLPFC microcircuits.
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Predicting risk-taking behavior from prefrontal resting-state activity and personality.
Directory of Open Access Journals (Sweden)
Bettina Studer
Full Text Available Risk-taking is subject to considerable individual differences. In the current study, we tested whether resting-state activity in the prefrontal cortex and trait sensitivity to reward and punishment can help predict risk-taking behavior. Prefrontal activity at rest was assessed in seventy healthy volunteers using electroencephalography, and compared to their choice behavior on an economic risk-taking task. The Behavioral Inhibition System/Behavioral Activation System scale was used to measure participants' trait sensitivity to reward and punishment. Our results confirmed both prefrontal resting-state activity and personality traits as sources of individual differences in risk-taking behavior. Right-left asymmetry in prefrontal activity and scores on the Behavioral Inhibition System scale, reflecting trait sensitivity to punishment, were correlated with the level of risk-taking on the task. We further discovered that scores on the Behavioral Inhibition System scale modulated the relationship between asymmetry in prefrontal resting-state activity and risk-taking. The results of this study demonstrate that heterogeneity in risk-taking behavior can be traced back to differences in the basic physiology of decision-makers' brains, and suggest that baseline prefrontal activity and personality traits might interplay in guiding risk-taking behavior.
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Predicting Risk-Taking Behavior from Prefrontal Resting-State Activity and Personality
Studer, Bettina; Pedroni, Andreas; Rieskamp, Jörg
2013-01-01
Risk-taking is subject to considerable individual differences. In the current study, we tested whether resting-state activity in the prefrontal cortex and trait sensitivity to reward and punishment can help predict risk-taking behavior. Prefrontal activity at rest was assessed in seventy healthy volunteers using electroencephalography, and compared to their choice behavior on an economic risk-taking task. The Behavioral Inhibition System/Behavioral Activation System scale was used to measure participants’ trait sensitivity to reward and punishment. Our results confirmed both prefrontal resting-state activity and personality traits as sources of individual differences in risk-taking behavior. Right-left asymmetry in prefrontal activity and scores on the Behavioral Inhibition System scale, reflecting trait sensitivity to punishment, were correlated with the level of risk-taking on the task. We further discovered that scores on the Behavioral Inhibition System scale modulated the relationship between asymmetry in prefrontal resting-state activity and risk-taking. The results of this study demonstrate that heterogeneity in risk-taking behavior can be traced back to differences in the basic physiology of decision-makers’ brains, and suggest that baseline prefrontal activity and personality traits might interplay in guiding risk-taking behavior. PMID:24116176
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Bilateral persistent hyperplastic primary vitreous
Directory of Open Access Journals (Sweden)
Jain Tarun
2009-01-01
Full Text Available A case of bilateral persistent hyperplastic primary vitreous (PHPV in a 3-month-old male infant, who had bilateral leukokoria, is presented. The child was referred for imaging with a clinical suspicion of retinoblastoma. Gray-scale ultrasound evaluation revealed an echogenic band in the posterior segment of both globes, extending from the posterior surface of the lens capsule to the optic disc. Doppler examination revealed the presence of arterial flow in the band in both globes. Associated echogenic hemorrhage was also seen, which was confirmed by computed tomography. Most cases of PHPV are sporadic and unilateral, and bilateral PHPV is rare. The imaging features in this case suggest the diagnosis of bilateral PHPV and differentiate it from retinoblastoma. This entity, although infrequent, should be considered in the differential diagnosis while evaluating bilateral leukokoria.
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Role of prefrontal cortex and the midbrain dopamine system in working memory updating
D’Ardenne, Kimberlee; Eshel, Neir; Luka, Joseph; Lenartowicz, Agatha; Nystrom, Leigh E.; Cohen, Jonathan D.
2012-01-01
Humans are adept at switching between goal-directed behaviors quickly and effectively. The prefrontal cortex (PFC) is thought to play a critical role by encoding, updating, and maintaining internal representations of task context in working memory. It has also been hypothesized that the encoding of context representations in PFC is regulated by phasic dopamine gating signals. Here we use multimodal methods to test these hypotheses. First we used functional MRI (fMRI) to identify regions of PFC associated with the representation of context in a working memory task. Next we used single-pulse transcranial magnetic stimulation (TMS), guided spatially by our fMRI findings and temporally by previous event-related EEG recordings, to disrupt context encoding while participants performed the same working memory task. We found that TMS pulses to the right dorsolateral PFC (DLPFC) immediately after context presentation, and well in advance of the response, adversely impacted context-dependent relative to context-independent responses. This finding causally implicates right DLPFC function in context encoding. Finally, using the same paradigm, we conducted high-resolution fMRI measurements in brainstem dopaminergic nuclei (ventral tegmental area and substantia nigra) and found phasic responses after presentation of context stimuli relative to other stimuli, consistent with the timing of a gating signal that regulates the encoding of representations in PFC. Furthermore, these responses were positively correlated with behavior, as well as with responses in the same region of right DLPFC targeted in the TMS experiment, lending support to the hypothesis that dopamine phasic signals regulate encoding, and thereby the updating, of context representations in PFC. PMID:23086162
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Effects of selective REM sleep deprivation on prefrontal gamma activity and executive functions.
Corsi-Cabrera, M; Rosales-Lagarde, A; del Río-Portilla, Y; Sifuentes-Ortega, R; Alcántara-Quintero, B
2015-05-01
Given that the dorsolateral prefrontal cortex is involved in executive functions and is deactivated and decoupled from posterior associative regions during REM sleep, that Gamma temporal coupling involved in information processing is enhanced during REM sleep, and that adult humans spend about 90 min of every 24h in REM sleep, it might be expected that REM sleep deprivation would modify Gamma temporal coupling and have a deteriorating effect on executive functions. We analyzed EEG Gamma activity and temporal coupling during implementation of a rule-guided task before and after REM sleep deprivation and its effect on verbal fluency, flexible thinking and selective attention. After two nights in the laboratory for adaptation, on the third night subjects (n=18) were randomly assigned to either selective REM sleep deprivation effectuated by awakening them at each REM sleep onset or, the same number of NREM sleep awakenings as a control for unspecific effects of sleep interruptions. Implementation of abstract rules to guide behavior required greater activation and synchronization of Gamma activity in the frontopolar regions after REM sleep reduction from 20.6% at baseline to just 3.93% of total sleep time. However, contrary to our hypothesis, both groups showed an overall improvement in executive task performance and no effect on their capacity to sustain selective attention. These results suggest that after one night of selective REM sleep deprivation executive functions can be compensated by increasing frontal activation and they still require the participation of supervisory control by frontopolar regions. Copyright © 2015 Elsevier B.V. All rights reserved.
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Idiopathic bilateral male breast abscess.
Sinha, Rajan Kumar; Sinha, Mithilesh Kumar; Gaurav, Kumar; Kumar, Amar
2014-03-10
A 38-year-old man presented with bilateral breast swelling, along with pain and redness for 7 days. Bilateral axillary nodes were also palpable; which were multiple and discrete. A provisional diagnosis of bilateral breast abscess was made with suspicion of underlying malignancy. Incision and drainage through subareolar incision was performed and the adjoining tissue was excised and sent for histopathological examination.
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Reduced prefrontal dopaminergic activity in valproic acid-treated mouse autism model.
Hara, Yuta; Takuma, Kazuhiro; Takano, Erika; Katashiba, Keisuke; Taruta, Atsuki; Higashino, Kosuke; Hashimoto, Hitoshi; Ago, Yukio; Matsuda, Toshio
2015-08-01
Previous studies suggest that dysfunction of neurotransmitter systems is associated with the pathology of autism in humans and the disease model rodents, but the precise mechanism is not known. Rodent offspring exposed prenatally to VPA shows autism-related behavioral abnormalities. The present study examined the effect of prenatal VPA exposure on brain monoamine neurotransmitter systems in male and female mice. The prenatal VPA exposure did not affect the levels of dopamine (DA), noradrenaline (NA), serotonin (5-HT) and their metabolites in the prefrontal cortex and striatum, while it significantly reduced methamphetamine (METH) (1.0 mg/kg)-induced hyperlocomotion in male offspring. In vivo microdialysis study demonstrated that prenatal VPA exposure attenuated METH-induced increases in extracellular DA levels in the prefrontal cortex, while it did not affect those in extracellular NA and 5-HT levels. Prenatal VPA exposure also decreased METH-induced c-Fos expression in the prefrontal cortex and the mRNA levels of DA D1 and D2 receptors in the prefrontal cortex. These effects of VPA were not observed in the striatum. In contrast to male offspring, prenatal VPA exposure did not affect METH-induced increases in locomotor activity and prefrontal DA levels and the D1 and D2 receptor mRNA levels in the prefrontal cortex in female offspring. These findings suggest that prenatal VPA exposure causes hypofunction of prefrontal DA system in a sex-dependent way. Copyright © 2015 Elsevier B.V. All rights reserved.
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Role of Prefrontal Cortex in Learning and Generalizing Hierarchical Rules in 8-Month-Old Infants.
Werchan, Denise M; Collins, Anne G E; Frank, Michael J; Amso, Dima
2016-10-05
Recent research indicates that adults and infants spontaneously create and generalize hierarchical rule sets during incidental learning. Computational models and empirical data suggest that, in adults, this process is supported by circuits linking prefrontal cortex (PFC) with striatum and their modulation by dopamine, but the neural circuits supporting this form of learning in infants are largely unknown. We used near-infrared spectroscopy to record PFC activity in 8-month-old human infants during a simple audiovisual hierarchical-rule-learning task. Behavioral results confirmed that infants adopted hierarchical rule sets to learn and generalize spoken object-label mappings across different speaker contexts. Infants had increased activity over right dorsal lateral PFC when rule sets switched from one trial to the next, a neural marker related to updating rule sets into working memory in the adult literature. Infants' eye blink rate, a possible physiological correlate of striatal dopamine activity, also increased when rule sets switched from one trial to the next. Moreover, the increase in right dorsolateral PFC activity in conjunction with eye blink rate also predicted infants' generalization ability, providing exploratory evidence for frontostriatal involvement during learning. These findings provide evidence that PFC is involved in rudimentary hierarchical rule learning in 8-month-old infants, an ability that was previously thought to emerge later in life in concert with PFC maturation. Hierarchical rule learning is a powerful learning mechanism that allows rules to be selected in a context-appropriate fashion and transferred or reused in novel contexts. Data from computational models and adults suggests that this learning mechanism is supported by dopamine-innervated interactions between prefrontal cortex (PFC) and striatum. Here, we provide evidence that PFC also supports hierarchical rule learning during infancy, challenging the current dogma that PFC is an
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Goodman, Jarid; Ressler, Reed L; Packard, Mark G
2017-06-03
The present experiments investigated the involvement of N-methyl-d-aspartate (NMDA) receptors of the dorsolateral striatum (DLS) in consolidation of extinction in a habit memory task. Adult male Long-Evans rats were initially trained in a food-reinforced response learning version of a plus-maze task and were subsequently given extinction training in which the food was removed from the maze. In experiment 1, immediately after the first day of extinction training, rats received bilateral intra-DLS injections of the NMDA receptor antagonist 2-amino-5-phosphonopentanoic acid (AP5; 2µg/side) or physiological saline. In experiment 2, immediately following the first day of extinction training, animals were given intra-DLS injections of NMDA receptor partial agonist d-cycloserine (DCS; 10 or 20µg/side) or saline. In both experiments, the number of perseverative trials (a trial in which a rat made the same previously reinforced body-turn response) and latency to reach the previously correct food well were used as measures of extinction behavior. Results indicated that post-training intra-DLS injections of AP5 impaired extinction. In contrast, post-training intra-DLS infusions of DCS (20µg) enhanced extinction. Intra-DLS administration of AP5 or DCS given two hours after extinction training did not influence extinction of response learning, indicating that immediate post-training administration of AP5 and DCS specifically influenced consolidation of the extinction memory. The present results indicate a critical role for DLS NMDA receptors in modulating extinction of habit memory and may be relevant to developing therapeutic approaches to combat the maladaptive habits observed in human psychopathologies in which DLS-dependent memory has been implicated (e.g. drug addiction and relapse and obsessive compulsive disorder). Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.