Xue, Gui; Aron, Adam R; Poldrack, Russell A
The inhibition of speech acts is a critical aspect of human executive control over thought and action, but its neural underpinnings are poorly understood. Using functional magnetic resonance imaging and the stop-signal paradigm, we examined the neural correlates of speech control in comparison to manual motor control. Initiation of a verbal response activated left inferior frontal cortex (IFC: Broca's area). Successful inhibition of speech (naming of letters or pseudowords) engaged a region of right IFC (including pars opercularis and anterior insular cortex) as well as presupplementary motor area (pre-SMA); these regions were also activated by successful inhibition of a hand response (i.e., a button press). Moreover, the speed with which subjects inhibited their responses, stop-signal reaction time, was significantly correlated between speech and manual inhibition tasks. These findings suggest a functional dissociation of left and right IFC in initiating versus inhibiting vocal responses, and that manual responses and speech acts share a common inhibitory mechanism localized in the right IFC and pre-SMA.
Lueken, Ulrike; Straube, Benjamin; Konrad, Carsten; Wittchen, Hans-Ulrich; Ströhle, Andreas; Wittmann, André; Pfleiderer, Bettina; Uhlmann, Christina; Arolt, Volker; Jansen, Andreas; Kircher, Tilo
Although exposure-based cognitive-behavioral therapy (CBT) is an effective treatment option for panic disorder with agoraphobia, the neural substrates of treatment response remain unknown. Evidence suggests that panic disorder with agoraphobia is characterized by dysfunctional safety signal processing. Using fear conditioning as a neurofunctional probe, the authors investigated neural baseline characteristics and neuroplastic changes after CBT that were associated with treatment outcome in patients with panic disorder with agoraphobia. Neural correlates of fear conditioning and extinction were measured using functional MRI before and after a manualized CBT program focusing on behavioral exposure in 49 medication-free patients with a primary diagnosis of panic disorder with agoraphobia. Treatment response was defined as a reduction exceeding 50% in Hamilton Anxiety Rating Scale scores. At baseline, nonresponders exhibited enhanced activation in the right pregenual anterior cingulate cortex, the hippocampus, and the amygdala in response to a safety signal. While this activation pattern partly resolved in nonresponders after CBT, successful treatment was characterized by increased right hippocampal activation when processing stimulus contingencies. Treatment response was associated with an inhibitory functional coupling between the anterior cingulate cortex and the amygdala that did not change over time. This study identified brain activation patterns associated with treatment response in patients with panic disorder with agoraphobia. Altered safety signal processing and anterior cingulate cortex-amygdala coupling may indicate individual differences among these patients that determine the effectiveness of exposure-based CBT and associated neuroplastic changes. Findings point to brain networks by which successful CBT in this patient population is mediated.
DeMarco, Andrew T; Wilson, Stephen M; Rising, Kindle; Rapcsak, Steven Z; Beeson, Pélagie M
We used fMRI to examine the neural substrates of sublexical phoneme-grapheme conversion during spelling in a group of healthy young adults. Participants performed a writing-to-dictation task involving irregular words (e.g., choir), plausible nonwords (e.g., kroid), and a control task of drawing familiar geometric shapes (e.g., squares). Written production of both irregular words and nonwords engaged a left-hemisphere perisylvian network associated with reading/spelling and phonological processing skills. Effects of lexicality, manifested by increased activation during nonword relative to irregular word spelling, were noted in anterior perisylvian regions (posterior inferior frontal gyrus/operculum/precentral gyrus/insula), and in left ventral occipito-temporal cortex. In addition to enhanced neural responses within domain-specific components of the language network, the increased cognitive demands associated with spelling nonwords engaged domain-general frontoparietal cortical networks involved in selective attention and executive control. These results elucidate the neural substrates of sublexical processing during written language production and complement lesion-deficit correlation studies of phonological agraphia. Copyright © 2016 Elsevier Inc. All rights reserved.
de Manzano, Örjan; Ullén, Fredrik
To what extent free response generation in different tasks uses common and task-specific neurocognitive processes has remained unclear. Here, we investigated overlap and differences in neural activity during musical improvisation and pseudo-random response generation. Brain activity was measured using fMRI in a group of professional classical pianists, who performed musical improvisation of melodies, pseudo-random key-presses and a baseline condition (sight-reading), on either two, six or twelve keys on a piano keyboard. The results revealed an extensive overlap in neural activity between the two generative conditions. Active regions included the dorsolateral and dorsomedial prefrontal cortices, inferior frontal gyrus, anterior cingulate cortex and pre-SMA. No regions showed higher activity in improvisation than in pseudo-random generation. These findings suggest that the activated regions fulfill generic functions that are utilized in different types of free generation tasks, independent of overall goal. In contrast, pseudo-random generation was accompanied by higher activity than improvisation in several regions. This presumably reflects the participants' musical expertise as well as the pseudo-random generation task's high load on attention, working memory, and executive control. The results highlight the significance of using naturalistic tasks to study human behavior and cognition. No brain activity was related to the size of the response set. We discuss that this may reflect that the musicians were able to use specific strategies for improvisation, by which there was no simple relationship between response set size and neural activity. Copyright © 2011 Elsevier Inc. All rights reserved.
Full Text Available Background: It has been established that the inability to inhibit a response to negative stimuli is the genesis of anxiety. However, the neural substrates of response inhibition to sad faces across explicit and implicit tasks in general anxiety disorder (GAD patients remain unclear.Methods: Electrophysiological data were recorded when subjects performed two modified emotional go/no-go tasks in which neutral and sad faces were presented: one task was explicit (emotion categorization, and the other task was implicit (gender categorization.Results: In the explicit task, electrophysiological evidence showed decreased amplitudes of no-go/go difference waves at the N2 interval in the GAD group compared to the control group. However, in the implicit task, the amplitudes of no-go/go difference waves at the N2 interval showed a reversed trend. Source localization analysis on no-go/N2 components revealed a decreased current source density (CSD in the right dorsal lateral prefrontal cortex in GAD individuals relative to controls. In the implicit task, the left superior temporal gyrus and the left inferior parietal lobe showed enhanced activation in GAD individuals and may compensate for the dysfunction of the right dorsal lateral prefrontal cortex.Conclusions: These findings indicated that the processing of response inhibition to socially sad faces in GAD individuals was interrupted in the explicit task. However, this processing was preserved in the implicit task. The neural substrates of response inhibition to sad faces were dissociated between implicit and explicit tasks.
Yu, Fengqiong; Ye, Rong; Sun, Shiyue; Carretié, Luis; Zhang, Lei; Dong, Yi; Zhu, Chunyan; Luo, Yuejia; Wang, Kai
Although ample evidence suggests that emotion and response inhibition are interrelated at the behavioral and neural levels, neural substrates of response inhibition to negative facial information remain unclear. Thus we used event-related potential (ERP) methods to explore the effects of explicit and implicit facial expression processing in response inhibition. We used implicit (gender categorization) and explicit emotional Go/Nogo tasks (emotion categorization) in which neutral and sad faces were presented. Electrophysiological markers at the scalp and the voxel level were analyzed during the two tasks. We detected a task, emotion and trial type interaction effect in the Nogo-P3 stage. Larger Nogo-P3 amplitudes during sad conditions versus neutral conditions were detected with explicit tasks. However, the amplitude differences between the two conditions were not significant for implicit tasks. Source analyses on P3 component revealed that right inferior frontal junction (rIFJ) was involved during this stage. The current source density (CSD) of rIFJ was higher with sad conditions compared to neutral conditions for explicit tasks, rather than for implicit tasks. The findings indicated that response inhibition was modulated by sad facial information at the action inhibition stage when facial expressions were processed explicitly rather than implicitly. The rIFJ may be a key brain region in emotion regulation.
Full Text Available BACKGROUND: Although ample evidence suggests that emotion and response inhibition are interrelated at the behavioral and neural levels, neural substrates of response inhibition to negative facial information remain unclear. Thus we used event-related potential (ERP methods to explore the effects of explicit and implicit facial expression processing in response inhibition. METHODS: We used implicit (gender categorization and explicit emotional Go/Nogo tasks (emotion categorization in which neutral and sad faces were presented. Electrophysiological markers at the scalp and the voxel level were analyzed during the two tasks. RESULTS: We detected a task, emotion and trial type interaction effect in the Nogo-P3 stage. Larger Nogo-P3 amplitudes during sad conditions versus neutral conditions were detected with explicit tasks. However, the amplitude differences between the two conditions were not significant for implicit tasks. Source analyses on P3 component revealed that right inferior frontal junction (rIFJ was involved during this stage. The current source density (CSD of rIFJ was higher with sad conditions compared to neutral conditions for explicit tasks, rather than for implicit tasks. CONCLUSIONS: The findings indicated that response inhibition was modulated by sad facial information at the action inhibition stage when facial expressions were processed explicitly rather than implicitly. The rIFJ may be a key brain region in emotion regulation.
Warraich, Zuha; Kleim, Jeffrey A
Decades of basic science have clearly demonstrated the capacity of the central nervous system (CNS) to structurally and functionally adapt in response to experience. The field of neurorehabilitation has begun to use this body of work to develop neurobiologically informed therapies that harness the key behavioral and neural signals that drive neural plasticity. The present review describes how neural plasticity supports both learning in the intact CNS and functional improvement in the damaged or diseased CNS. A pragmatic, interdisciplinary definition of neural plasticity is presented that may be used by both clinical and basic scientists studying neurorehabilitation. Furthermore, a description of how neural plasticity may act to drive different neural strategies underlying functional improvement after CNS injury or disease is provided. The understanding of the relationship between these different neural strategies, mechanisms of neural plasticity, and changes in behavior may facilitate the development of novel, more effective rehabilitation interventions. Copyright © 2010 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.
Stukel, Jessica M.
Neurons and neural stem cells are sensitive to their mechanical and topographical environment, and cell–substrate binding contributes to this sensitivity to activate signaling pathways for basic cell functions. Many transmembrane proteins transmit signals into and out of the cell, including integrins, growth factor receptors, G-protein-coupled receptors, cadherins, cell adhesion molecules, and ion channels. Specifically, integrins are one of the main transmembrane proteins that transmit force across the cell membrane between a cell and its extracellular matrix, making them critical in the study of cell–material interactions. This review focuses on mechanotransduction, defined as the conversion of force a cell generates through cell–substrate bonds to a chemical signal, of neural cells. The chemical signals relay information via pathways through the cellular cytoplasm to the nucleus, where signaling events can affect gene expression. Pathways and the cellular response initiated by substrate binding are explored to better understand their effect on neural cells mechanotransduction. As the results of mechanotransduction affect cell adhesion, cell shape, and differentiation, knowledge regarding neural mechanotransduction is critical for most regenerative strategies in tissue engineering, where novel environments are developed to improve conduit design for central and peripheral nervous system repair in vivo. PMID:26669274
Stukel, Jessica M; Willits, Rebecca Kuntz
Neurons and neural stem cells are sensitive to their mechanical and topographical environment, and cell-substrate binding contributes to this sensitivity to activate signaling pathways for basic cell functions. Many transmembrane proteins transmit signals into and out of the cell, including integrins, growth factor receptors, G-protein-coupled receptors, cadherins, cell adhesion molecules, and ion channels. Specifically, integrins are one of the main transmembrane proteins that transmit force across the cell membrane between a cell and its extracellular matrix, making them critical in the study of cell-material interactions. This review focuses on mechanotransduction, defined as the conversion of force a cell generates through cell-substrate bonds to a chemical signal, of neural cells. The chemical signals relay information via pathways through the cellular cytoplasm to the nucleus, where signaling events can affect gene expression. Pathways and the cellular response initiated by substrate binding are explored to better understand their effect on neural cells mechanotransduction. As the results of mechanotransduction affect cell adhesion, cell shape, and differentiation, knowledge regarding neural mechanotransduction is critical for most regenerative strategies in tissue engineering, where novel environments are developed to improve conduit design for central and peripheral nervous system repair in vivo.
Wang, Lili; Lu, Xiaping; Gu, Ruolei; Zhu, Ruida; Xu, Rui; Broster, Lucas S; Feng, Chunliang
Human altruistic behaviors are heterogeneous across both contexts and people, whereas the neural signatures underlying the heterogeneity remain to be elucidated. To address this issue, we examined the neural signatures underlying the context- and person-dependent altruistic punishment, conjoining event-related fMRI with both task-based and resting-state functional connectivity (RSFC). Acting as an impartial third party, participants decided how to punish norm violators either alone or in the presence of putative others. We found that the presence of others decreased altruistic punishment due to diffusion of responsibility. Those behavioral effects paralleled altered neural responses in the dorsal anterior cingulate cortex (dACC) and putamen. Further, we identified modulation of responsibility diffusion on task-based functional connectivity of dACC with the brain regions implicated in reward processing (i.e., posterior cingulate cortex and amygdala/orbital frontal cortex). Finally, the RSFC results revealed that (i) increased intrinsic connectivity strengths of the putamen with temporoparietal junction and dorsolateral PFC were associated with attenuated responsibility diffusion in altruistic punishment and (ii) increased putamen-dorsomedial PFC connectivity strengths were associated with reduced responsibility diffusion in self-reported responsibility. Taken together, our findings elucidate the context- and person-dependent altruistic behaviors as well as associated neural substrates and thus provide a potential neurocognitive mechanism of heterogeneous human altruistic behaviors. Hum Brain Mapp 38:5535-5550, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Kubota, Yasutaka; Sawada, Reiko; Yoshimura, Sayaka; Toichi, Motomi
Happiness is a subjective experience that is an ultimate goal for humans. Psychological studies have shown that subjective happiness can be measured reliably and consists of emotional and cognitive components. However, the neural substrates of subjective happiness remain unclear. To investigate this issue, we used structural magnetic resonance imaging and questionnaires that assessed subjective happiness, the intensity of positive and negative emotional experiences, and purpose in life. We found a positive relationship between the subjective happiness score and gray matter volume in the right precuneus. Moreover, the same region showed an association with the combined positive and negative emotional intensity and purpose in life scores. Our findings suggest that the precuneus mediates subjective happiness by integrating the emotional and cognitive components of happiness.
Sato, Wataru; Kochiyama, Takanori; Uono, Shota; Kubota, Yasutaka; Sawada, Reiko; Yoshimura, Sayaka; Toichi, Motomi
Happiness is a subjective experience that is an ultimate goal for humans. Psychological studies have shown that subjective happiness can be measured reliably and consists of emotional and cognitive components. However, the neural substrates of subjective happiness remain unclear. To investigate this issue, we used structural magnetic resonance imaging and questionnaires that assessed subjective happiness, the intensity of positive and negative emotional experiences, and purpose in life. We found a positive relationship between the subjective happiness score and gray matter volume in the right precuneus. Moreover, the same region showed an association with the combined positive and negative emotional intensity and purpose in life scores. Our findings suggest that the precuneus mediates subjective happiness by integrating the emotional and cognitive components of happiness. PMID:26586449
Goldenberg, Georg; Randerath, Jennifer
Apraxia is regularly associated with aphasia, but there is controversy whether their co-occurrence is the expression of a common basic deficit or results from anatomical proximity of their neural substrates. However, neither aphasia nor apraxia is an indivisible entity. Both diagnoses embrace diverse manifestations that may occur more or less independently from each other. Thus, the question whether apraxia is always accompanied by aphasia may lead to conflicting answers depending on which of their manifestations are considered. We used voxel based lesion symptom mapping (VLSM) for exploring communalities between lesion sites associated with aphasia and with apraxia. Linguistic impairment was assessed by the Aachen Aphasia Test (AAT) subtests naming, comprehension, repetition, written language, and Token Test. Apraxia was examined for imitation of meaningless hand and finger postures and for pantomime of tool use. There were two areas of overlap between aphasia and apraxia. Lesions in the anterior temporal lobe interfered with pantomime of tool use and with all linguistic tests. In the left inferior parietal lobe there was a large area where lesions were associated with defective imitation of hand postures and with poor scores on written language and the Token Test. Within this large area there were also two spots in supramarginal and angular gyrus where lesions were also associated with defective pantomime. We speculate that the coincidence of language impairment and defective pantomime after anterior temporal lesions is due to impaired access to semantic memory. The combination of defective imitation of hand postures with poor scores on Token Test and written language is not easily compatible with a crucial role of parietal regions for the conversion of concepts of intended actions into motor commands. It accords better with a role of left inferior parietal lobe regions for the categorical perception of spatial relationships. Copyright © 2015 Elsevier Ltd. All
Broche-Pérez, Y; Herrera Jiménez, L F; Omar-Martínez, E
Decision-making is the process of selecting a course of action from among 2 or more alternatives by considering the potential outcomes of selecting each option and estimating its consequences in the short, medium and long term. The prefrontal cortex (PFC) has traditionally been considered the key neural structure in decision-making process. However, new studies support the hypothesis that describes a complex neural network including both cortical and subcortical structures. The aim of this review is to summarise evidence on the anatomical structures underlying the decision-making process, considering new findings that support the existence of a complex neural network that gives rise to this complex neuropsychological process. Current evidence shows that the cortical structures involved in decision-making include the orbitofrontal cortex (OFC), anterior cingulate cortex (ACC), and dorsolateral prefrontal cortex (DLPFC). This process is assisted by subcortical structures including the amygdala, thalamus, and cerebellum. Findings to date show that both cortical and subcortical brain regions contribute to the decision-making process. The neural basis of decision-making is a complex neural network of cortico-cortical and cortico-subcortical connections which includes subareas of the PFC, limbic structures, and the cerebellum. Copyright © 2014 Sociedad Española de Neurología. Published by Elsevier España, S.L.U. All rights reserved.
Homae, Fumitaka; Watanabe, Hama; Taga, Gentaro
Infants often pay special attention to speech sounds, and they appear to detect key features of these sounds. To investigate the neural foundation of speech perception in infants, we measured cortical activation using near-infrared spectroscopy. We presented the following three types of auditory stimuli while 3-month-old infants watched a silent…
Neural substrates of normal and impaired preattentive sensory discrimination in large cohorts of nonpsychiatric subjects and schizophrenia patients as indexed by MMN and P3a change detection responses.
Takahashi, Hidetoshi; Rissling, Anthony J; Pascual-Marqui, Roberto; Kirihara, Kenji; Pela, Marlena; Sprock, Joyce; Braff, David L; Light, Gregory A
Schizophrenia (SZ) patients have information processing deficits, spanning from low level sensory processing to higher-order cognitive functions. Mismatch negativity (MMN) and P3a are event-related potential (ERP) components that are automatically elicited in response to unattended changes in ongoing, repetitive stimuli that provide a window into abnormal information processing in SZ. MMN and P3a are among the most robust and consistently identified deficits in SZ, yet the neural substrates of these responses and their associated deficits in SZ are not fully understood. This study examined the neural sources of MMN and P3a components in a large cohort of SZ and nonpsychiatric control subjects (NCS) using Exact Low Resolution Electromagnetic Tomography Analyses (eLORETA) in order to identify the neural sources of MMN and P3a as well as the brain regions associated with deficits commonly observed among SZ patients. 410 SZ and 247 NCS underwent EEG testing using a duration-deviant auditory oddball paradigm (1-kHz tones, 500ms SOA; standard p=0.90, 50-ms duration; deviant tones P=0.10, 100-ms duration) while passively watching a silent video. Voxel-by-voxel within- (MMN vs. P3a) and between-group (SZ vs. NCS) comparisons were performed using eLORETA. SZ had robust deficits in MMN and P3a responses measured at scalp electrodes consistent with other studies. These components mapped onto neural sources broadly distributed across temporal, frontal, and parietal regions. MMN deficits in SZ were associated with reduced activations in discrete medial frontal brain regions, including the anterior-posterior cingulate and medial frontal gyri. These early sensory discriminatory MMN impairments were followed by P3a deficits associated with widespread reductions in the activation of attentional networks (frontal, temporal, parietal regions), reflecting impaired orienting or shifts of attention to the infrequent stimuli. MMN and P3a are dissociable responses associated with broadly
Yu, Hongbo; Cai, Qiang; Shen, Bo; Gao, Xiaoxue; Zhou, Xiaolin
Voluntary help during a time of need fosters interpersonal gratitude, which has positive social and personal consequences such as improved social relationships, increased reciprocity, and decreased distress. In a behavioral and a functional magnetic resonance imaging (fMRI) experiment, participants played a multiround interactive game where they received pain stimulation. An anonymous partner interacted with the participants and either intentionally or unintentionally (i.e., determined by a computer program) bore part of the participants' pain. In each round, participants either evaluated their perceived pain intensity (behavioral experiment) or transferred an amount of money to the partner (fMRI experiment). Intentional (relative to unintentional) help led to lower experience of pain, higher reciprocity (money allocation), and increased interpersonal closeness toward the partner. fMRI revealed that for the most grateful condition (i.e., intentional help), value-related structures such as the ventromedial prefrontal cortex (vmPFC) showed the highest activation in response to the partner's decision, whereas the primary sensory area and the anterior insula exhibited the lowest activation at the pain delivery stage. Moreover, the vmPFC activation was predictive of the individual differences in reciprocal behavior, and the posterior cingulate cortex (PCC) activation was predictive of self-reported gratitude. Furthermore, using multivariate pattern analysis (MVPA), we showed that the neural activation pattern in the septum/hypothalamus, an area associated with affiliative affect and social bonding, and value-related structures specifically and sensitively dissociated intentional help from unintentional help conditions. These findings contribute to our understanding of the psychological and neural substrates of the experience of interpersonal gratitude and the social consequences of this emotion. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Han-Chiao Isaac Chen
Full Text Available Restoring neurological and cognitive function in individuals who have suffered brain damage is one of the principal objectives of modern translational neuroscience. Electrical stimulation approaches, such as deep-brain stimulation, have achieved the most clinical success, but they ultimately may be limited by the computational capacity of the residual cerebral circuitry. An alternative strategy is brain substrate expansion, in which the computational capacity of the brain is augmented through the addition of new processing units and the reconstitution of network connectivity. This latter approach has been explored to some degree using both biological and electronic means but thus far has not demonstrated the ability to reestablish the function of large-scale neuronal networks. In this review, we contend that fulfilling the potential of brain substrate expansion will require a significant shift from current methods that emphasize direct manipulations of the brain (e.g., injections of cellular suspensions and the implantation of multi-electrode arrays to the generation of more sophisticated neural tissues and neural-electric hybrids in vitro that are subsequently transplanted into the brain. Drawing from neural tissue engineering, stem cell biology, and neural interface technologies, this strategy makes greater use of the manifold techniques available in the laboratory to create biocompatible constructs that recapitulate brain architecture and thus are more easily recognized and utilized by brain networks.
Full Text Available Stem cell function is regulated by intrinsic as well as microenvironmental factors, including chemical and mechanical signals. Conducting polymer-based cell culture substrates provide a powerful tool to control both chemical and physical stimuli sensed by stem cells. Here we show that polypyrrole (PPy, a commonly used conducting polymer, can be tailored to modulate survival and maintenance of rat fetal neural stem cells (NSCs. NSCs cultured on PPy substrates containing different counter ions, dodecylbenzenesulfonate (DBS, tosylate (TsO, perchlorate (ClO(4 and chloride (Cl, showed a distinct correlation between PPy counter ion and cell viability. Specifically, NSC viability was high on PPy(DBS but low on PPy containing TsO, ClO(4 and Cl. On PPy(DBS, NSC proliferation and differentiation was comparable to standard NSC culture on tissue culture polystyrene. Electrical reduction of PPy(DBS created a switch for neural stem cell viability, with widespread cell death upon polymer reduction. Coating the PPy(DBS films with a gel layer composed of a basement membrane matrix efficiently prevented loss of cell viability upon polymer reduction. Here we have defined conditions for the biocompatibility of PPy substrates with NSC culture, critical for the development of devices based on conducting polymers interfacing with NSCs.
Greene, Ciara M.; Vidaki, Kleio; Soto, David
Familiar stimuli are typically accompanied by decreases in neural response relative to the presentation of novel items, but these studies often include explicit instructions to discriminate old and new items; this creates difficulties in partialling out the contribution of top-down intentional orientation to the items based on recognition goals.…
Karl A E Karlsson
Full Text Available Sleep is a poorly understood behavior that predominates during infancy but is studied almost exclusively in adults. One perceived impediment to investigations of sleep early in ontogeny is the absence of state-dependent neocortical activity. Nonetheless, in infant rats, sleep is reliably characterized by the presence of tonic (i.e., muscle atonia and phasic (i.e., myoclonic twitching components; the neural circuitry underlying these components, however, is unknown. Recently, we described a medullary inhibitory area (MIA in week-old rats that is necessary but not sufficient for the normal expression of atonia. Here we report that the infant MIA receives projections from areas containing neurons that exhibit state-dependent activity. Specifically, neurons within these areas, including the subcoeruleus (SubLC, pontis oralis (PO, and dorsolateral pontine tegmentum (DLPT, exhibit discharge profiles that suggest causal roles in the modulation of muscle tone and the production of myoclonic twitches. Indeed, lesions in the SubLC and PO decreased the expression of muscle atonia without affecting twitching (resulting in "REM sleep without atonia", whereas lesions of the DLPT increased the expression of atonia while decreasing the amount of twitching. Thus, the neural substrates of infant sleep are strikingly similar to those of adults, a surprising finding in light of theories that discount the contribution of supraspinal neural elements to sleep before the onset of state-dependent neocortical activity.
Aupperle, Robin L; Melrose, Andrew J; Francisco, Alex; Paulus, Martin P; Stein, Murray B
Animal approach-avoidance conflict paradigms have been used extensively to operationalize anxiety, quantify the effects of anxiolytic agents, and probe the neural basis of fear and anxiety. Results from human neuroimaging studies support that a frontal-striatal-amygdala neural circuitry is important for approach-avoidance learning. However, the neural basis of decision-making is much less clear in this context. Thus, we combined a recently developed human approach-avoidance paradigm with functional magnetic resonance imaging (fMRI) to identify neural substrates underlying approach-avoidance conflict decision-making. Fifteen healthy adults completed the approach-avoidance conflict (AAC) paradigm during fMRI. Analyses of variance were used to compare conflict to nonconflict (avoid-threat and approach-reward) conditions and to compare level of reward points offered during the decision phase. Trial-by-trial amplitude modulation analyses were used to delineate brain areas underlying decision-making in the context of approach/avoidance behavior. Conflict trials as compared to the nonconflict trials elicited greater activation within bilateral anterior cingulate cortex, anterior insula, and caudate, as well as right dorsolateral prefrontal cortex (PFC). Right caudate and lateral PFC activation was modulated by level of reward offered. Individuals who showed greater caudate activation exhibited less approach behavior. On a trial-by-trial basis, greater right lateral PFC activation related to less approach behavior. Taken together, results suggest that the degree of activation within prefrontal-striatal-insula circuitry determines the degree of approach versus avoidance decision-making. Moreover, the degree of caudate and lateral PFC activation related to individual differences in approach-avoidance decision-making. Therefore, the approach-avoidance conflict paradigm is ideally suited to probe anxiety-related processing differences during approach-avoidance decision
Full Text Available The ability to read the minds of others in their eyes plays an important role in human adaptation to social environments. Behavioral studies have resulted in the development of a test to measure this ability (Reading the Mind in the Eyes Test, revised version; Eyes Test, and have demonstrated that this ability is consistent over time. Although functional neuroimaging studies revealed brain activation while performing the Eyes Test, the structural neural substrates supporting consistent performance on the Eyes Test remain unclear. In this study we assessed the Eyes Test and analyzed structural magnetic resonance images using voxel-based morphometry in healthy participants. Test performance was positively associated with the gray matter volumes of the dorsomedial prefrontal cortex, inferior parietal lobule (temporoparietal junction, and precuneus in the left hemisphere. These results suggest that the fronto-temporoparietal network structures support the consistent ability to read the mind in the eyes.
Lazar, Steven M; Evans, David W; Myers, Scott M; Moreno-De Luca, Andres; Moore, Gregory J
Social cognition is an important aspect of social behavior in humans. Social cognitive deficits are associated with neurodevelopmental and neuropsychiatric disorders. In this study we examine the neural substrates of social cognition and face processing in a group of healthy young adults to examine the neural substrates of social cognition. Fifty-seven undergraduates completed a battery of social cognition tasks and were assessed with electroencephalography (EEG) during a face-perception task. A subset (N=22) were administered a face-perception task during functional magnetic resonance imaging. Variance in the N170 EEG was predicted by social attribution performance and by a quantitative measure of empathy. Neurally, face processing was more bilateral in females than in males. Variance in fMRI voxel count in the face-sensitive fusiform gyrus was predicted by quantitative measures of social behavior, including the Social Responsiveness Scale (SRS) and the Empathizing Quotient. When measured as a quantitative trait, social behaviors in typical and pathological populations share common neural pathways. The results highlight the importance of viewing neurodevelopmental and neuropsychiatric disorders as spectrum phenomena that may be informed by studies of the normal distribution of relevant traits in the general population. Copyright © 2014 Elsevier B.V. All rights reserved.
Pelagie M Beeson
All participants improved written language abilities in response to treatment, but one subgroup was limited in their ability to regain phonological skills. Both anterior and posterior components of the perisylvian phonological network were damaged in that group. These findings are consistent with fMRI activation when healthy adults write nonwords, and provide insight regarding neural support necessary for phonological rehabilitation.
Wilson, V J; Schor, R H
The purpose of this review is to assess the role of short-latency pathways in the vestibulocollic reflex (VCR). First the current knowledge about the disynaptic and trisynaptic pathways linking semicircular canal and otolith afferents with cat neck motoneurons is summarized. We then discuss whether these pathways are sufficient or necessary to produce the responses observed in neck muscles by natural vestibular stimulation and conclude that they are neither. Finally, alternate pathways are considered, most likely involving reticulospinal fibers, which are an important part of the neural substrate of the VCR.
Full Text Available It is widely recognized that animals respond to odors by generating or modulating specific motor behaviors. These reactions are important for daily activities, reproduction, and survival. In the sea lamprey, mating occurs after ovulated females are attracted to spawning sites by male sex pheromones. The ubiquity and reliability of olfactory-motor behavioral responses in vertebrates suggest tight coupling between the olfactory system and brain areas controlling movements. However, the circuitry and the underlying cellular neural mechanisms remain largely unknown. Using lamprey brain preparations, and electrophysiology, calcium imaging, and tract tracing experiments, we describe the neural substrate responsible for transforming an olfactory input into a locomotor output. We found that olfactory stimulation with naturally occurring odors and pheromones induced large excitatory responses in reticulospinal cells, the command neurons for locomotion. We have also identified the anatomy and physiology of this circuit. The olfactory input was relayed in the medial part of the olfactory bulb, in the posterior tuberculum, in the mesencephalic locomotor region, to finally reach reticulospinal cells in the hindbrain. Activation of this olfactory-motor pathway generated rhythmic ventral root discharges and swimming movements. Our study bridges the gap between behavior and cellular neural mechanisms in vertebrates, identifying a specific subsystem within the CNS, dedicated to producing motor responses to olfactory inputs.
Shibata, Midori; Toyomura, Akira; Itoh, Hiroaki; Abe, Jun-ichi
In daily communication, we sometimes use ironic expressions to convey the opposite meaning. To understand these contradictory statements, we have to infer contextual implications and the speaker's mental state. However, little is known about how our brains carry out these complex processes. In this study, we investigated the neural substrates involved in irony comprehension using echoic utterance (Sperber and Wilson, 1986, 1995). Participants read a short scenario that consisted of five sentences. The first four sentences explained the situation of the protagonists. The fifth connoted either an ironic, literal, or unconnected meaning. The participants had to press a button to indicate whether or not the final sentence expressed irony. In the ironic sentence condition, the bilateral superior frontal gyrus, middle frontal gyrus, inferior frontal gyrus, medial prefrontal cortex, superior temporal gyrus, inferior parietal lobule, caudate, thalamus, the left insula, and amygdala were activated. In the literal sentence condition, the right superior frontal gyrus, the bilateral middle frontal gyrus, inferior frontal gyrus, medial prefrontal cortex, superior temporal gyrus, inferior parietal lobule, caudate, the left insula, the right thalamus, and the left amygdala were activated. However, in the ironic sentence condition minus the literal sentence condition, we observed higher activation in the right medial prefrontal cortex (BA 10), the right precentral (BA 6), and the left superior temporal sulcus (BA 21). Our results suggest that irony comprehension is strongly related to mentalizing processes and that activation in these regions might be affected by higher-order cognitive operations.
Rebecca M. Todd
Full Text Available It is well known that emotionally salient events are remembered more vividly than mundane ones. Our recent research has demonstrated that such memory vividness is due in part to the subjective experience of emotional events as more perceptually vivid, an effect we call emotion-enhanced vividness, or EEV. The present study built on previously reported research in which fMRI data were collected while participants rated relative levels of visual noise overlaid on emotionally salient and neutral images. Ratings of greater EEV were associated with greater activation in the amygdala, visual cortex, and posterior insula. In the present study, we measured BOLD activation that predicted recognition memory vividness for these same images one week later. Results showed that, after controlling for differences between scenes in low-level objective features, hippocampus activation uniquely predicted subsequent memory vividness. In contrast, amygdala and visual cortex regions that were sensitive to EEV were also modulated by subsequent ratings of memory vividness. These findings suggest shared neural substrates for the influence of emotional salience on perceptual and mnemonic vividness, with amygdala and visual cortex activation at encoding contributing to the experience of both perception and subsequent memory.
Full Text Available Categorization is essential to all cognitive processes, but identifying the neural substrates underlying categorization processes is a real challenge. Among animals that have been shown to be able of categorization, songbirds are particularly interesting because they provide researchers with clear examples of categories of acoustic signals allowing different levels of recognition, and they possess a system of specialized brain structures found only in birds that learn to sing: the song system. Moreover, an avian brain nucleus that is analogous to the mammalian secondary auditory cortex (the caudo-medial nidopallium, or NCM has recently emerged as a plausible site for sensory representation of birdsong, and appears as a well positioned brain region for categorization of songs. Hence, we tested responses in this non-primary, associative area to clear and distinct classes of songs with different functions and social values, and for a possible correspondence between these responses and the functional aspects of songs, in a highly social songbird species: the European starling. Our results clearly show differential neuronal responses to the ethologically defined classes of songs, both in the number of neurons responding, and in the response magnitude of these neurons. Most importantly, these differential responses corresponded to the functional classes of songs, with increasing activation from non-specific to species-specific and from species-specific to individual-specific sounds. These data therefore suggest a potential neural substrate for sorting natural communication signals into categories, and for individual vocal recognition of same-species members. Given the many parallels that exist between birdsong and speech, these results may contribute to a better understanding of the neural bases of speech.
Watkins, Tristan J; Di Iorio, Christina R; Olatunji, Bunmi O; Benningfield, Margaret M; Blackford, Jennifer U; Dietrich, Mary S; Bhatia, Monisha; Theiss, Justin D; Salomon, Ronald M; Niswender, Kevin; Cowan, Ronald L
Defects in experiencing disgust may contribute to obesity by allowing for the overconsumption of food. However, the relationship of disgust proneness and its associated neural locus has yet to be explored in the context of obesity. Thirty-three participants (17 obese, 16 lean) completed the Disgust Propensity and Sensitivity Scale-Revised and a functional magnetic resonance imaging paradigm where images from 4 categories (food, contaminates, contaminated food or fixation) were randomly presented. Independent two-sample t-tests revealed significantly lower levels of Disgust Sensitivity for the obese group (mean score = 14.7) compared with the lean group (mean score = 17.6, P = 0.026). The obese group had less activation in the right insula than the lean group when viewing contaminated food images. Multiple regression with interaction analysis revealed one left insula region where the association of Disgust Sensitivity scores with activation differed by group when viewing contaminated food images. These interaction effects were driven by the negative correlation of Disgust Sensitivity scores with beta values extracted from the left insula in the obese group (r = -0.59) compared with a positive correlation in the lean group (r = 0.65). Given these body mass index-dependent differences in Disgust Sensitivity and neural responsiveness to disgusting food images, it is likely that altered Disgust Sensitivity may contribute to obesity. © The Author (2015). Published by Oxford University Press. For Permissions, please email: firstname.lastname@example.org.
Gradin, Victoria B; Waiter, Gordon; Kumar, Poornima; Stickle, Catriona; Milders, Maarten; Matthews, Keith; Reid, Ian; Hall, Jeremy; Steele, J Douglas
Social exclusion is an influential concept in politics, mental health and social psychology. Studies on healthy subjects have implicated the medial prefrontal cortex (mPFC), a region involved in emotional and social information processing, in neural responses to social exclusion. Impairments in social interactions are common in schizophrenia and are associated with reduced quality of life. Core symptoms such as delusions usually have a social content. However little is known about the neural underpinnings of social abnormalities. The aim of this study was to investigate the neural substrates of social exclusion in schizophrenia. Patients with schizophrenia and healthy controls underwent fMRI while participating in a popular social exclusion paradigm. This task involves passing a 'ball' between the participant and two cartoon representations of other subjects. The extent of social exclusion (ball not being passed to the participant) was parametrically varied throughout the task. Replicating previous findings, increasing social exclusion activated the mPFC in controls. In contrast, patients with schizophrenia failed to modulate mPFC responses with increasing exclusion. Furthermore, the blunted response to exclusion correlated with increased severity of positive symptoms. These data support the hypothesis that the neural response to social exclusion differs in schizophrenia, highlighting the mPFC as a potential substrate of impaired social interactions.
Full Text Available The ability to envisage personally relevant events at a future time point represents an incredibly sophisticated cognitive endeavor and one that appears to be intimately linked to episodic memory integrity. Far less is known regarding the neurocognitive mechanisms underpinning the capacity to envisage non-personal future occurrences, known as semantic future thinking. Moreover the degree of overlap between the neural substrates supporting episodic and semantic forms of prospection remains unclear. To this end, we sought to investigate the capacity for episodic and semantic future thinking in Alzheimer’s disease (n = 15 and disease-matched behavioral-variant frontotemporal dementia (n = 15, neurodegenerative disorders characterized by significant medial temporal lobe and frontal pathology. Participants completed an assessment of past and future thinking across personal (episodic and non-personal (semantic domains, as part of a larger neuropsychological battery investigating episodic and semantic processing, and their performance was contrasted with 20 age- and education-matched healthy older Controls. Participants underwent whole-brain T1 weighted structural imaging and voxel-based morphometry analysis was conducted to determine the relationship between grey matter integrity and episodic and semantic future thinking. Relative to Controls, both patient groups displayed marked future thinking impairments, extending across episodic and semantic domains. Analyses of covariance revealed that while episodic future thinking deficits could be explained solely in terms of episodic memory proficiency, semantic prospection deficits reflected the interplay between episodic and semantic processing. Distinct neural correlates emerged for each form of future simulation with differential involvement of prefrontal, lateral temporal and medial temporal regions. Notably, the hippocampus was implicated irrespective of future thinking domain, with the suggestion of
Cascio, Carissa J; Foss-Feig, Jennifer H; Heacock, Jessica; Schauder, Kimberly B; Loring, Whitney A; Rogers, Baxter P; Pryweller, Jennifer R; Newsom, Cassandra R; Cockhren, Jurnell; Cao, Aize; Bolton, Scott
Restricted interests are a class of repetitive behavior in autism spectrum disorders (ASD) whose intensity and narrow focus often contribute to significant interference with daily functioning. While numerous neuroimaging studies have investigated executive circuits as putative neural substrates of repetitive behavior, recent work implicates affective neural circuits in restricted interests. We sought to explore the role of affective neural circuits and determine how restricted interests are distinguished from hobbies or interests in typical development. We compared a group of children with ASD to a typically developing (TD) group of children with strong interests or hobbies, employing parent report, an operant behavioral task, and functional imaging with personalized stimuli based on individual interests. While performance on the operant task was similar between the two groups, parent report of intensity and interference of interests was significantly higher in the ASD group. Both the ASD and TD groups showed increased BOLD response in widespread affective neural regions to the pictures of their own interest. When viewing pictures of other children's interests, the TD group showed a similar pattern, whereas BOLD response in the ASD group was much more limited. Increased BOLD response in the insula and anterior cingulate cortex distinguished the ASD from the TD group, and parent report of the intensity and interference with daily life of the child's restricted interest predicted insula response. While affective neural network response and operant behavior are comparable in typical and restricted interests, the narrowness of focus that clinically distinguishes restricted interests in ASD is reflected in more interference in daily life and aberrantly enhanced insula and anterior cingulate response to individuals' own interests in the ASD group. These results further support the involvement of affective neural networks in repetitive behaviors in ASD. © 2013 The
Ames, Daniel L.; Fiske, Susan T.
How do people maintain consistent impressions of other people when other people are often inconsistent? The present research addresses this question by combining recent neuroscientific insights with ecologically meaningful behavioral methods. Participants formed impressions of real people whom they met in a personally involving situation. fMRI and supporting behavioral data revealed that outcome dependency (i.e., depending on another person for a desired outcome) alters previously identified neural dynamics of impression formation. Consistent with past research, a functional localizer identified a region of dorsomedial PFC previously linked to social impression formation. In the main task, this ROI revealed the predicted patterns of activity across outcome dependency conditions: greater BOLD response when information confirmed (vs. violated) social expectations if participants were outcome-independent and the reverse pattern if participants were outcome-dependent. We suggest that, although social perceivers often discount expectancy-disconfirming information as noise, being dependent on another person for a desired outcome focuses impression-formation processing on the most diagnostic information, rather than on the most tractable information. PMID:23850465
Limbrick-Oldfield, E H; Mick, I; Cocks, R E; McGonigle, J; Sharman, S P; Goldstone, A P; Stokes, P R A; Waldman, A; Erritzoe, D; Bowden-Jones, H; Nutt, D; Lingford-Hughes, A; Clark, L
Cue reactivity is an established procedure in addictions research for examining the subjective experience and neural basis of craving. This experiment sought to quantify cue-related brain responses in gambling disorder using personally tailored cues in conjunction with subjective craving, as well as a comparison with appetitive non-gambling stimuli. Participants with gambling disorder (n=19) attending treatment and 19 controls viewed personally tailored blocks of gambling-related cues, as well as neutral cues and highly appetitive (food) images during a functional magnetic resonance imaging (fMRI) scan performed ~2-3 h after a usual meal. fMRI analysis examined cue-related brain activity, cue-related changes in connectivity and associations with block-by-block craving ratings. Craving ratings in the participants with gambling disorder increased following gambling cues compared with non-gambling cues. fMRI analysis revealed group differences in left insula and anterior cingulate cortex, with the gambling disorder group showing greater reactivity to the gambling cues, but no differences to the food cues. In participants with gambling disorder, craving to gamble correlated positively with gambling cue-related activity in the bilateral insula and ventral striatum, and negatively with functional connectivity between the ventral striatum and the medial prefrontal cortex. Gambling cues, but not food cues, elicit increased brain responses in reward-related circuitry in individuals with gambling disorder (compared with controls), providing support for the incentive sensitization theory of addiction. Activity in the insula co-varied with craving intensity, and may be a target for interventions.
Full Text Available The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population.
Takahashi, Hirokazu; Yokota, Ryo; Kanzaki, Ryohei
The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population.
Lee, Woogul; Reeve, Johnmarshall
Intrinsic motivation is the inherent tendency to seek out novelty and challenge, to explore and investigate, and to stretch and extend one's capacities. When people imagine performing intrinsically motivating tasks, they show heightened anterior insular cortex (AIC) activity. To fully explain the neural system of intrinsic motivation, however, requires assessing neural activity while people actually perform intrinsically motivating tasks (i.e., while answering curiosity-inducing questions or solving competence-enabling anagrams). Using event-related functional magnetic resonance imaging, we found that the neural system of intrinsic motivation involves not only AIC activity, but also striatum activity and, further, AIC-striatum functional interactions. These findings suggest that subjective feelings of intrinsic satisfaction (associated with AIC activations), reward processing (associated with striatum activations), and their interactions underlie the actual experience of intrinsic motivation. These neural findings are consistent with the conceptualization of intrinsic motivation as the pursuit and satisfaction of subjective feelings (interest and enjoyment) as intrinsic rewards.
Lee, Jong Ho; Kang, Seok Hee; Hwang, Eun Young; Hwang, Yu-Shik; Lee, Mi Hee; Park, Jong-Chul
Neural cell adhesion and neurite outgrowth were examined on graphene-based biomimetic substrates. The biocompatibility of carbon nanomaterials such as graphene and carbon nanotubes (CNTs), that is, single-walled and multiwalled CNTs, against pheochromocytoma-derived PC-12 neural cells was also evaluated by quantifying metabolic activity (with WST-8 assay), intracellular oxidative stress (with ROS assay), and membrane integrity (with LDH assay). Graphene films were grown by using chemical vapor deposition and were then coated onto glass coverslips by using the scooping method. Graphene sheets were patterned on SiO2/Si substrates by using photolithography and were then covered with serum for a neural cell culture. Both types of CNTs induced significant dose-dependent decreases in the viability of PC-12 cells, whereas graphene exerted adverse effects on the neural cells just at over 62.5 ppm. This result implies that graphene and CNTs, even though they were the same carbon-based nanomaterials, show differential influences on neural cells. Furthermore, graphene-coated or graphene-patterned substrates were shown to substantially enhance the adhesion and neurite outgrowth of PC-12 cells. These results suggest that graphene-based substrates as biomimetic cues have good biocompatibility as well as a unique surface property that can enhance the neural cells, which would open up enormous opportunities in neural regeneration and nanomedicine. PMID:24592382
Louder, Matthew I M; Voss, Henning U; Manna, Thomas J; Carryl, Sophia S; London, Sarah E; Balakrishnan, Christopher N; Hauber, Mark E
In many social animals, early exposure to conspecific stimuli is critical for the development of accurate species recognition. Obligate brood parasitic songbirds, however, forego parental care and young are raised by heterospecific hosts in the absence of conspecific stimuli. Having evolved from non-parasitic, parental ancestors, how brood parasites recognize their own species remains unclear. In parental songbirds (e.g. zebra finch Taeniopygia guttata), the primary and secondary auditory forebrain areas are known to be critical in the differential processing of conspecific vs. heterospecific songs. Here we demonstrate that the same auditory brain regions underlie song discrimination in adult brood parasitic pin-tailed whydahs (Vidua macroura), a close relative of the zebra finch lineage. Similar to zebra finches, whydahs showed stronger behavioral responses during conspecific vs. heterospecific song and tone pips as well as increased neural responses within the auditory forebrain, as measured by both functional magnetic resonance imaging (fMRI) and immediate early gene (IEG) expression. Given parallel behavioral and neuroanatomical patterns of song discrimination, our results suggest that the evolutionary transition to brood parasitism from parental songbirds likely involved an "evolutionary tinkering" of existing proximate mechanisms, rather than the wholesale reworking of the neural substrates of species recognition. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Cerf-Ducastel, Barbara; Murphy, Claire
Impaired ability to remember what has gone before is one of the most distressing aspects of the aging process. Odor recognition memory is particularly vulnerable to the effects of aging, yet the underlying neural substrate is unknown. This study investigated the neural substrate of cross-modal olfactory recognition memory in young and older adults using fMRI. Participants were presented with 16 familiar odors immediately before entering the scanner, and were then tested for retrieval with words, either names of odors previously presented (targets) or names of new odors (foils), while being scanned at 3 T. Activation was reduced in the old subjects, both in regions involved in episodic memory retrieval and in regions involved in olfactory processing. Greater activation in the cerebellum of older adults was observed, suggesting increased response to attentional demands or compensatory mechanisms. Unlike in a number of studies in other sensory modalities, no increase in activation in frontal areas in older adults was observed during retrieval.
Occelli, F; Suied, C; Pressnitzer, D; Edeline, J-M; Gourévitch, B
The timbre of a sound plays an important role in our ability to discriminate between behaviorally relevant auditory categories, such as different vowels in speech. Here, we investigated, in the primary auditory cortex (A1) of anesthetized guinea pigs, the neural representation of vowels with impoverished timbre cues. Five different vowels were presented with durations ranging from 2 to 128 ms. A psychophysical experiment involving human listeners showed that identification performance was near ceiling for the longer durations and degraded close to chance level for the shortest durations. This was likely due to spectral splatter, which reduced the contrast between the spectral profiles of the vowels at short durations. Effects of vowel duration on cortical responses were well predicted by the linear frequency responses of A1 neurons. Using mutual information, we found that auditory cortical neurons in the guinea pig could be used to reliably identify several vowels for all durations. Information carried by each cortical site was low on average, but the population code was accurate even for durations where human behavioral performance was poor. These results suggest that a place population code is available at the level of A1 to encode spectral profile cues for even very short sounds. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: email@example.com.
Jones, Erin Boote [Iowa State Univ., Ames, IA (United States)
In recent years the study of stem and progenitor cells has moved to the forefront of research. Since the isolation of human hematopoietic stem cells in 1988 and the subsequent discovery of a self renewing population of multipotent cells in many tissues, many researchers have envisioned a better understanding of development and potential clinical usage in intractable diseases. Both these goals, however, depend on a solid understanding of the intracellular and extracellular forces that cause stem cells to differentiate to a specific cell fate. Many diseases of large scale cell loss have been suggested as candidates for stem cell based treatments. It is proposed that replacing the function of the damaged or defective cells by specific differentiation of stem or progenitor cells could treat the disease. Before cells can be directed to specific lineages, the mechanisms of differentiation must be better understood. Differentiation in vivo is an intensively complex system that is difficult to study. The goal of this research is to develop further understanding of the effects of soluble and extracellular matrix (ECM) cues on the differentiation of neural progenitor cells with the use of a simplified in vitro culture system. Specific research objectives are to study the differentiation of neural progenitor cells in response to astrocyte conditioned medium and protein substrate composition and concentration. In an effort to reveal the mechanism of the conditioned medium interaction, a test for the presence of a feedback loop between progenitor cells and astrocytes is presented along with an examination of conditioned medium storage temperature, which can reveal enzymatic dependencies. An examination of protein substrate composition and concentration will help to reveal the role of any ECM interactions on differentiation. This thesis is organized into a literature review covering recent advances in use of external modulators of differentiation such as surface coatings, co
Murch, W Spencer; Clark, Luke
As a popular form of recreational risk taking, gambling games offer a paradigm for decision neuroscience research. As an individual behavior, gambling becomes dysfunctional in a subset of the population, with debilitating consequences. Gambling disorder has been recently reconceptualized as a "behavioral addiction" in the DSM-5, based on emerging parallels with substance use disorders. Why do some individuals undergo this transition from recreational to disordered gambling? The biomedical model of problem gambling is a "brain disorder" account that posits an underlying neurobiological abnormality. This article first delineates the neural circuitry that underpins gambling-related decision making, comprising ventral striatum, ventromedial prefrontal cortex, dopaminergic midbrain, and insula, and presents evidence for pathophysiology in this circuitry in gambling disorder. These biological dispositions become translated into clinical disorder through the effects of gambling games. This influence is better articulated in a public health approach that describes the interplay between the player and the (gambling) product. Certain forms of gambling, including electronic gambling machines, appear to be overrepresented in problem gamblers. These games harness psychological features, including variable ratio schedules, near-misses, "losses disguised as wins," and the illusion of control, which modulate the core decision-making circuitry that is perturbed in gambling disorder. © The Author(s) 2015.
Lombardo, Michael V; Pierce, Karen; Eyler, Lisa T; Carter Barnes, Cindy; Ahrens-Barbeau, Clelia; Solso, Stephanie; Campbell, Kathleen; Courchesne, Eric
Autism (ASD) is vastly heterogeneous, particularly in early language development. While ASD language trajectories in the first years of life are highly unstable, by early childhood these trajectories stabilize and are predictive of longer-term outcome. Early neural substrates that predict/precede such outcomes are largely unknown, but could have considerable translational and clinical impact. Pre-diagnosis fMRI response to speech in ASD toddlers with relatively good language outcome was highly similar to non-ASD comparison groups and robustly recruited language-sensitive superior temporal cortices. In contrast, language-sensitive superior temporal cortices were hypoactive in ASD toddlers with poor language outcome. Brain-behavioral relationships were atypically reversed in ASD, and a multimodal combination of pre-diagnostic clinical behavioral measures and speech-related fMRI response showed the most promise as an ASD prognosis classifier. Thus, before ASD diagnoses and outcome become clinically clear, distinct functional neuroimaging phenotypes are already present that can shed insight on an ASD toddler's later outcome. VIDEO ABSTRACT. Copyright © 2015 Elsevier Inc. All rights reserved.
Shames, H; Raz, N; Levin, Netta
Posterior cortical atrophy (PCA) is a neurodegenerative syndrome in which the most pronounced pathologic involvement is in the occipito-parietal visual regions. Herein, we aimed to better define the cortical reflection of this unique syndrome using a thorough battery of behavioral and functional MRI (fMRI) tests. Eight PCA patients underwent extensive testing to map their visual deficits. Assessments included visual functions associated with lower and higher components of the cortical hierarchy, as well as dorsal- and ventral-related cortical functions. fMRI was performed on five patients to examine the neuronal substrate of their visual functions. The PCA patient cohort exhibited stereopsis, saccadic eye movements and higher dorsal stream-related functional impairments, including simultant perception, image orientation, figure-from-ground segregation, closure and spatial orientation. In accordance with the behavioral findings, fMRI revealed intact activation in the ventral visual regions of face and object perception while more dorsal aspects of perception, including motion and gestalt perception, revealed impaired patterns of activity. In most of the patients, there was a lack of activity in the word form area, which is known to be linked to reading disorders. Finally, there was evidence of reduced cortical representation of the peripheral visual field, corresponding to the behaviorally assessed peripheral visual deficit. The findings are discussed in the context of networks extending from parietal regions, which mediate navigationally related processing, visually guided actions, eye movement control and working memory, suggesting that damage to these networks might explain the wide range of deficits in PCA patients.
Solomon, Marjorie; Yoon, Jong H; Ragland, J Daniel; Niendam, Tara A; Lesh, Tyler A; Fairbrother, Wonja; Carter, Cameron S
Autism spectrum disorders (ASDs) involve impairments in cognitive control. In typical development (TYP), neural systems underlying cognitive control undergo substantial maturation during adolescence. Development is delayed in adolescents with ASD. Little is known about the neural substrates of this delay. We used event-related functional magnetic resonance imaging and a cognitive control task involving overcoming a prepotent response tendency to examine the development of cognitive control in young (ages 12-15; n = 13 with ASD and n = 13 with TYP) and older (ages 16-18; n = 14 with ASD and n = 14 with TYP) adolescents with whole-brain voxelwise univariate and task-related functional connectivity analyses. Older ASD and TYP showed reduced activation in sensory and premotor areas relative to younger ones. The older ASD group showed reduced left parietal activation relative to TYP. Functional connectivity analyses showed a significant age by group interaction with the older ASD group exhibiting increased functional connectivity strength between the ventrolateral prefrontal cortex and the anterior cingulate cortex, bilaterally. This functional connectivity strength was related to task performance in ASD, whereas that between dorsolateral prefrontal cortex and parietal cortex (Brodmann areas 9 and 40) was related to task performance in TYP. Adolescents with ASD rely more on reactive cognitive control, involving last-minute conflict detection and control implementation by the anterior cingulate cortex and ventrolateral prefrontal cortex, versus proactive cognitive control requiring processing by dorsolateral prefrontal cortex and parietal cortex. Findings await replication in larger longitudinal studies that examine their functional consequences and amenability to intervention. © 2013 Society of Biological Psychiatry Published by Society of Biological Psychiatry All rights reserved.
Yu, Hongbo; Li, Jia; Zhou, Xiaolin
When evaluating interpersonal transgressions, people take into account both the consequential damage and the intention of the agent. The intention and consequence, however, do not always match, as is the case with accidents and failed attempts. We combined an interactive game and functional MRI to investigate the neural substrates underlying the processing of intention and consequence, and its bearing on reactive punishment. The participant interacted with anonymous partners, who decided to deliver pain stimulation either to himself/herself or to the participant to earn a monetary reward. In some cases, the decision was reversed by the computer. After pain delivery, the partner's intention was revealed. Unbeknownst to the partner, the participant was then allowed to punish the partner by reducing his/her monetary reward. Behaviorally, the punishment was lower in the accidental condition (unintended harm relative to intended harm) but higher in the failed-attempt condition (unintended no-harm relative to intended no-harm). Neurally, the left amygdala/hippocampus was activated in the conditions with blameworthy intention (i.e., intentional harm and failed attempt). The accidental (relative to intentional) harm activated the right temporoparietal junction (TPJ) and the anterior inferior frontal gyrus (IFG), while the failed attempt (relative to genuine no-harm) activated the anterior insula (AI) and the posterior IFG. Effective connectivity analysis revealed that in the unintentional conditions (i.e., accidental and failed attempt) the IFG received input from the TPJ and AI, and sent regulatory signals to the amygdala. These findings demonstrate that the processing of intention may gate the emotional responses to transgression and regulate subsequent reactive punishment. Copyright © 2015 the authors 0270-6474/15/354917-09$15.00/0.
Marsden, Karen E; Ma, Wei Ji; Deci, Edward L; Ryan, Richard M; Chiu, Pearl H
The duration and quality of human performance depend on both intrinsic motivation and external incentives. However, little is known about the neuroscientific basis of this interplay between internal and external motivators. Here, we used functional magnetic resonance imaging to examine the neural substrates of intrinsic motivation, operationalized as the free-choice time spent on a task when this was not required, and tested the neural and behavioral effects of external reward on intrinsic motivation. We found that increased duration of free-choice time was predicted by generally diminished neural responses in regions associated with cognitive and affective regulation. By comparison, the possibility of additional reward improved task accuracy, and specifically increased neural and behavioral responses following errors. Those individuals with the smallest neural responses associated with intrinsic motivation exhibited the greatest error-related neural enhancement under the external contingency of possible reward. Together, these data suggest that human performance is guided by a "tonic" and "phasic" relationship between the neural substrates of intrinsic motivation (tonic) and the impact of external incentives (phasic).
Zatorre, Robert J.; Salimpoor, Valorie N.
Music has existed in human societies since prehistory, perhaps because it allows expression and regulation of emotion and evokes pleasure. In this review, we present findings from cognitive neuroscience that bear on the question of how we get from perception of sound patterns to pleasurable responses. First, we identify some of the auditory cortical circuits that are responsible for encoding and storing tonal patterns and discuss evidence that cortical loops between auditory and frontal cortices are important for maintaining musical information in working memory and for the recognition of structural regularities in musical patterns, which then lead to expectancies. Second, we review evidence concerning the mesolimbic striatal system and its involvement in reward, motivation, and pleasure in other domains. Recent data indicate that this dopaminergic system mediates pleasure associated with music; specifically, reward value for music can be coded by activity levels in the nucleus accumbens, whose functional connectivity with auditory and frontal areas increases as a function of increasing musical reward. We propose that pleasure in music arises from interactions between cortical loops that enable predictions and expectancies to emerge from sound patterns and subcortical systems responsible for reward and valuation. PMID:23754373
Zatorre, Robert J; Salimpoor, Valorie N
Music has existed in human societies since prehistory, perhaps because it allows expression and regulation of emotion and evokes pleasure. In this review, we present findings from cognitive neuroscience that bear on the question of how we get from perception of sound patterns to pleasurable responses. First, we identify some of the auditory cortical circuits that are responsible for encoding and storing tonal patterns and discuss evidence that cortical loops between auditory and frontal cortices are important for maintaining musical information in working memory and for the recognition of structural regularities in musical patterns, which then lead to expectancies. Second, we review evidence concerning the mesolimbic striatal system and its involvement in reward, motivation, and pleasure in other domains. Recent data indicate that this dopaminergic system mediates pleasure associated with music; specifically, reward value for music can be coded by activity levels in the nucleus accumbens, whose functional connectivity with auditory and frontal areas increases as a function of increasing musical reward. We propose that pleasure in music arises from interactions between cortical loops that enable predictions and expectancies to emerge from sound patterns and subcortical systems responsible for reward and valuation.
Full Text Available The essential part of amperometric biosensor is an enzyme. It should be selective, i.e., react only with certain substrate. The selectivity of enzyme reduces the set of possible to use enzymes. This paper demonstrates that non selective enzymes (reacting with two substrates can be used to determine concentrations of two substrates. For this purpose the steady-state current of two double biosensors was measured. The currents were used as input for an artificial neural network to determine concentrations of the substrates. The proposed approach was approved as the relative error of determined concentrations was relatively small. Paper analyses the influence of biosensor parameters to error values. The recommendations to error values minimisation were obtained.DOI: 10.15181/csat.v3i2.1109
Hogrefe, Katharina; Ziegler, Wolfram; Weidinger, Nicole; Goldenberg, Georg
Communicative gestures can compensate incomprehensibility of oral speech in severe aphasia, but the brain damage that causes aphasia may also have an impact on the production of gestures. We compared the comprehensibility of gestural communication of persons with severe aphasia and non-aphasic persons and used voxel based lesion symptom mapping (VLSM) to determine lesion sites that are responsible for poor gestural expression in aphasia. On group level, persons with aphasia conveyed more information via gestures than controls indicating a compensatory use of gestures in persons with severe aphasia. However, individual analysis showed a broad range of gestural comprehensibility. VLSM suggested that poor gestural expression was associated with lesions in anterior temporal and inferior frontal regions. We hypothesize that likely functional correlates of these localizations are selection of and flexible changes between communication channels as well as between different types of gestures and between features of actions and objects that are expressed by gestures. Copyright © 2017 Elsevier Inc. All rights reserved.
Golarai, Golijeh; Liberman, Alina; Grill-Spector, Kalanit
In adult humans, the ventral temporal cortex (VTC) represents faces in a reproducible topology. However, it is unknown what role visual experience plays in the development of this topology. Using functional magnetic resonance imaging in children and adults, we found a sequential development, in which the topology of face-selective activations across the VTC was matured by age 7, but the spatial extent and degree of face selectivity continued to develop past age 7 into adulthood. Importantly, own- and other-age faces were differentially represented, both in the distributed multivoxel patterns across the VTC, and also in the magnitude of responses of face-selective regions. These results provide strong evidence that experience shapes cortical representations of faces during development from childhood to adulthood. Our findings have important implications for the role of experience and age in shaping the neural substrates of face processing in the human VTC. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: firstname.lastname@example.org.
Humbert, Ianessa A; Joel, Suresh
It has been well established that swallowing kinematics are modified with different forms of exogenous and endogenous input, however the underlying neural substrates associated with these effects are largely unknown. Our objective was to determine whether the swallowing BOLD response is modulated with heightened sensory modalities (taste, cutaneous electrical stimulation, and visual biofeedback) compared to water ingestion (control) in healthy adults across the age span. Habituation and sensitization were also examined for each sensory condition. Our principal findings are that each sensory swallowing condition activated components of the swallowing cortical network, plus regions associated with the particular sensory modality (i.e. primarily frontal motor planning and integration areas with visual condition). Overall, the insula was most commonly active among the sensory modalities. We also discuss gradual increases and decreases in BOLD signal with repeated exposures for each condition. We conclude that both stimulus- and intention-based inputs have unique cortical swallowing networks relative to their modality. This scientific contribution advances our understanding of the mechanisms of normal swallowing cortical control and has the potential to impact clinical uses of these modalities in treatments for neurogenic dysphagia. Copyright © 2011 Elsevier Inc. All rights reserved.
Full Text Available In the search for a neural substrate of cognitive processes, a frequently utilized method is the scrutiny of posttraumatic symptoms exhibited by individuals suffering focal injury to the brain. For instance, the presence or absence of conscious awareness within a particular domain may, combined with knowledge of which regions of the brain have been injured, provide important data in the search for neural correlates of consciousness. Like all studies addressing the consequences of brain injury, however, such research has to face the fact that in most cases, posttraumatic impairments are accompanied by a functional recovery during which symptoms are reduced or eliminated. The apparent contradiction between localization and recovery, respectively, of functions constitutes a problem to almost all aspects of cognitive neuroscience. Several lines of investigation indicate that although the brain remains highly plastic throughout life, the posttraumatic plasticity does not recreate a copy of the neural mechanisms lost to injury. Instead, the uninjured parts of the brain are functionally reorganized in a manner which – in spite of not recreating the basic information processing lost to injury – is able to allow a more or less complete return of the surface phenomena (including manifestations of consciousness originally impaired by the trauma. A novel model (the REF-model of these processes is presented – and some of its implications discussed relative to studies of the neural substrates of cognition and consciousness.
Full Text Available Smooth-pursuit eye movements allow primates to track moving objects. Efficient pursuit requires appropriate target selection and predictive compensation for inherent processing delays. Prediction depends on expectation of future object motion, storage of motion information and use of extra-retinal mechanisms in addition to visual feedback. We present behavioural evidence of how cognitive processes are involved in predictive pursuit in normal humans and then describe neuronal responses in monkeys and behavioural responses in patients using a new technique to test these cognitive controls. The new technique examines the neural substrate of working memory and movement preparation for predictive pursuit by using a memory-based task in macaque monkeys trained to pursue (go or not pursue (no-go according to a go/no-go cue, in a direction based on memory of a previously presented visual motion display. Single-unit task-related neuronal activity was examined in medial superior temporal cortex (MST, supplementary eye fields (SEF, caudal frontal eye fields (FEF, cerebellar dorsal vermis lobules VI-VII, caudal fastigial nuclei (cFN, and floccular region. Neuronal activity reflecting working memory of visual motion direction and go/no-go selection was found predominantly in SEF, cerebellar dorsal vermis and cFN, whereas movement preparation related signals were found predominantly in caudal FEF and the same cerebellar areas. Chemical inactivation produced effects consistent with differences in signals represented in each area. When applied to patients with Parkinson's disease, the task revealed deficits in movement preparation but not working memory. In contrast, patients with frontal cortical or cerebellar dysfunction had high error rates, suggesting impaired working memory. We show how neuronal activity may be explained by models of retinal and extra-retinal interaction in target selection and predictive control and thus aid understanding of underlying
Fukushima, Kikuro; Fukushima, Junko; Warabi, Tateo; Barnes, Graham R
Smooth-pursuit eye movements allow primates to track moving objects. Efficient pursuit requires appropriate target selection and predictive compensation for inherent processing delays. Prediction depends on expectation of future object motion, storage of motion information and use of extra-retinal mechanisms in addition to visual feedback. We present behavioral evidence of how cognitive processes are involved in predictive pursuit in normal humans and then describe neuronal responses in monkeys and behavioral responses in patients using a new technique to test these cognitive controls. The new technique examines the neural substrate of working memory and movement preparation for predictive pursuit by using a memory-based task in macaque monkeys trained to pursue (go) or not pursue (no-go) according to a go/no-go cue, in a direction based on memory of a previously presented visual motion display. Single-unit task-related neuronal activity was examined in medial superior temporal cortex (MST), supplementary eye fields (SEF), caudal frontal eye fields (FEF), cerebellar dorsal vermis lobules VI-VII, caudal fastigial nuclei (cFN), and floccular region. Neuronal activity reflecting working memory of visual motion direction and go/no-go selection was found predominantly in SEF, cerebellar dorsal vermis and cFN, whereas movement preparation related signals were found predominantly in caudal FEF and the same cerebellar areas. Chemical inactivation produced effects consistent with differences in signals represented in each area. When applied to patients with Parkinson's disease (PD), the task revealed deficits in movement preparation but not working memory. In contrast, patients with frontal cortical or cerebellar dysfunction had high error rates, suggesting impaired working memory. We show how neuronal activity may be explained by models of retinal and extra-retinal interaction in target selection and predictive control and thus aid understanding of underlying
Fukushima, Kikuro; Fukushima, Junko; Warabi, Tateo; Barnes, Graham R.
Smooth-pursuit eye movements allow primates to track moving objects. Efficient pursuit requires appropriate target selection and predictive compensation for inherent processing delays. Prediction depends on expectation of future object motion, storage of motion information and use of extra-retinal mechanisms in addition to visual feedback. We present behavioral evidence of how cognitive processes are involved in predictive pursuit in normal humans and then describe neuronal responses in monkeys and behavioral responses in patients using a new technique to test these cognitive controls. The new technique examines the neural substrate of working memory and movement preparation for predictive pursuit by using a memory-based task in macaque monkeys trained to pursue (go) or not pursue (no-go) according to a go/no-go cue, in a direction based on memory of a previously presented visual motion display. Single-unit task-related neuronal activity was examined in medial superior temporal cortex (MST), supplementary eye fields (SEF), caudal frontal eye fields (FEF), cerebellar dorsal vermis lobules VI–VII, caudal fastigial nuclei (cFN), and floccular region. Neuronal activity reflecting working memory of visual motion direction and go/no-go selection was found predominantly in SEF, cerebellar dorsal vermis and cFN, whereas movement preparation related signals were found predominantly in caudal FEF and the same cerebellar areas. Chemical inactivation produced effects consistent with differences in signals represented in each area. When applied to patients with Parkinson's disease (PD), the task revealed deficits in movement preparation but not working memory. In contrast, patients with frontal cortical or cerebellar dysfunction had high error rates, suggesting impaired working memory. We show how neuronal activity may be explained by models of retinal and extra-retinal interaction in target selection and predictive control and thus aid understanding of underlying
Full Text Available In this paper we study neural responses to inequitable distributions of rewards despite equal performance. We specifically focus on differences between advantageous (AI and disadvantageous inequity (DI. AI and DI were realized in a hyperscanning fMRI experiment with pairs of subjects simultaneously performing a task in adjacent scanners and observing both subjects' rewards. Results showed i hypoactivation of the ventral striatum under DI but not under AI; ii inequity induced activation of medial and dorsolateral prefrontal regions, that were stronger under DI than AI; iii correlations between subjective evaluations of DI and amygdala activity, and between AI evaluation and right ventrolateral prefrontal activity. Our study provides neurophysiological evidence for different cognitive processes that occur when exposed to DI and AI, respectively. Our data is compatible with the assumption that any form of inequity represents a norm violation, but that important differences between AI and DI emerge from an asymmetric involvement of status concerns.
Full Text Available Inhibition of irrelevant information (conflict monitoring and/or of prepotent actions is an essential component of adaptive self-organized behavior. Neural dynamics underlying these functions has been studied in humans using event-related brain potentials (ERPs elicited in Go/NoGo tasks that require a speeded motor response to the Go stimuli and withholding a prepotent response when a NoGo stimulus is presented. However, averaged ERP waveforms provide only limited information about the neuronal mechanisms underlying stimulus processing, motor preparation, and response production or inhibition. In this study, we examine the cortical representation of conflict monitoring and response inhibition using time-frequency analysis of electroencephalographic (EEG recordings during continuous performance Go/NoGo task in 50 young adult females. We hypothesized that response inhibition would be associated with a transient boost in both temporal and spatial synchronization of prefrontal cortical activity, consistent with the role of the anterior cingulate and lateral prefrontal cortices in cognitive control. Overall, phase synchronization across trials measured by Phase Locking Index and phase synchronization between electrode sites measured by Phase Coherence were the highest in the Go and NoGo conditions, intermediate in the Warning condition, and the lowest under Neutral condition. The NoGo condition was characterized by significantly higher fronto-central synchronization in the 300-600 ms window, whereas in the Go condition, delta- and theta-band synchronization was higher in centro-parietal regions in the first 300 ms after the stimulus onset. The present findings suggest that response production and inhibition is supported by dynamic functional networks characterized by distinct patterns of temporal and spatial synchronization of brain oscillations.
Hjerrild, M.; Stensballe, A.; Rasmussen, T.E.
Protein phosphorylation plays a key role in cell regulation and identification of phosphorylation sites is important for understanding their functional significance. Here, we present an artificial neural network algorithm: NetPhosK (http://www.cbs.dtu.dk/services/NetPhosK/) that predicts protein...... kinase A (PKA) phosphorylation sites. The neural network was trained with a positive set of 258 experimentally verified PKA phosphorylation sites. The predictions by NetPhosK were! validated using four novel PKA substrates: Necdin, RFX5, En-2, and Wee 1. The four proteins were phosphorylated by PKA...... in vitro and 13 PKA phosphorylation sites were identified by mass spectrometry. NetPhosK was 100% sensitive and 41% specific in predicting PKA sites in the four proteins. These results demonstrate the potential of using integrated computational and experimental methods for detailed investigations...
Schendel, Amelia A.; Nonte, Michael W.; Vokoun, Corinne; Richner, Thomas J.; Brodnick, Sarah K.; Atry, Farid; Frye, Seth; Bostrom, Paige; Pashaie, Ramin; Thongpang, Sanitta; Eliceiri, Kevin W.; Williams, Justin C.
Objective. There is great interest in designing implantable neural electrode arrays that maximize function while minimizing tissue effects and damage. Although it has been shown that substrate geometry plays a key role in the tissue response to intracortically implanted, penetrating neural interfaces, there has been minimal investigation into the effect of substrate footprint on the tissue response to surface electrode arrays. This study investigates the effect of micro-electrocorticography (micro-ECoG) device geometry on the longitudinal tissue response. Approach. The meningeal tissue response to two micro-ECoG devices with differing geometries was evaluated. The first device had each electrode site and trace individually insulated, with open regions in between, while the second device had a solid substrate, in which all 16 electrode sites were embedded in a continuous insulating sheet. These devices were implanted bilaterally in rats, beneath cranial windows, through which the meningeal tissue response was monitored for one month after implantation. Electrode site impedance spectra were also monitored during the implantation period. Main results. It was observed that collagenous scar tissue formed around both types of devices. However, the distribution of the tissue growth was different between the two array designs. The mesh devices experienced thick tissue growth between the device and the cranial window, and minimal tissue growth between the device and the brain, while the solid device showed the opposite effect, with thick tissue forming between the brain and the electrode sites. Significance. These data suggest that an open architecture device would be more ideal for neural recording applications, in which a low impedance path from the brain to the electrode sites is critical for maximum recording quality.
Full Text Available Findings on song perception and song production have increasingly suggested that common but partially distinct neural networks exist for processing lyrics and melody. However, the neural substrates of song recognition remain to be investigated. The purpose of this study was to examine the neural substrates involved in the accessing "song lexicon" as corresponding to a representational system that might provide links between the musical and phonological lexicons using positron emission tomography (PET. We exposed participants to auditory stimuli consisting of familiar and unfamiliar songs presented in three ways: sung lyrics (song, sung lyrics on a single pitch (lyrics, and the sung syllable 'la' on original pitches (melody. The auditory stimuli were designed to have equivalent familiarity to participants, and they were recorded at exactly the same tempo. Eleven right-handed nonmusicians participated in four conditions: three familiarity decision tasks using song, lyrics, and melody and a sound type decision task (control that was designed to engage perceptual and prelexical processing but not lexical processing. The contrasts (familiarity decision tasks versus control showed no common areas of activation between lyrics and melody. This result indicates that essentially separate neural networks exist in semantic memory for the verbal and melodic processing of familiar songs. Verbal lexical processing recruited the left fusiform gyrus and the left inferior occipital gyrus, whereas melodic lexical processing engaged the right middle temporal sulcus and the bilateral temporo-occipital cortices. Moreover, we found that song specifically activated the left posterior inferior temporal cortex, which may serve as an interface between verbal and musical representations in order to facilitate song recognition.
Lefebvre, Stéphanie; Dricot, Laurence; Laloux, Patrice; Gradkowski, Wojciech; Desfontaines, Philippe; Evrard, Frédéric; Peeters, André; Jamart, Jacques; Vandermeeren, Yves
Motor skill learning is critical in post-stroke motor recovery, but little is known about its underlying neural substrates. Recently, using a new visuomotor skill learning paradigm involving a speed/accuracy trade-off in healthy individuals we identified three subpopulations based on their behavioral trajectories: fitters (in whom improvement in speed or accuracy coincided with deterioration in the other parameter), shifters (in whom speed and/or accuracy improved without degradation of the other parameter), and non-learners. We aimed to identify the neural substrates underlying the first stages of motor skill learning in chronic hemiparetic stroke patients and to determine whether specific neural substrates were recruited in shifters versus fitters. During functional magnetic resonance imaging (fMRI), 23 patients learned the visuomotor skill with their paretic upper limb. In the whole-group analysis, correlation between activation and motor skill learning was restricted to the dorsal prefrontal cortex of the damaged hemisphere (DLPFCdamh: r = -0.82) and the dorsal premotor cortex (PMddamh: r = 0.70); the correlations was much lesser (-0.16 0.25) in the other regions of interest. In a subgroup analysis, significant activation was restricted to bilateral posterior parietal cortices of the fitters and did not correlate with motor skill learning. Conversely, in shifters significant activation occurred in the primary sensorimotor cortexdamh and supplementary motor areadamh and in bilateral PMd where activation changes correlated significantly with motor skill learning (r = 0.91). Finally, resting-state activity acquired before learning showed a higher functional connectivity in the salience network of shifters compared with fitters (qFDR skill learning with the paretic upper limb in chronic hemiparetic stroke patients, with a key role of bilateral PMd.
Goldstein, Martin; Brendel, Gary; Tuescher, Oliver; Pan, Hong; Epstein, Jane; Beutel, Manfred; Yang, Yihong; Thomas, Katherine; Levy, Kenneth; Silverman, Michael; Clarkin, Jonathon; Posner, Michael; Kernberg, Otto; Stern, Emily; Silbersweig, David
Neural substrates of behavioral inhibitory control have been probed in a variety of animal model, physiologic, behavioral, and imaging studies, many emphasizing the role of prefrontal circuits. Likewise, the neurocircuitry of emotion has been investigated from a variety of perspectives. Recently, neural mechanisms mediating the interaction of emotion and behavioral regulation have become the focus of intense study. To further define neurocircuitry specifically underlying the interaction between emotional processing and response inhibition, we developed an emotional linguistic go/no-go fMRI paradigm with a factorial block design which joins explicit inhibitory task demand (i.e., go or no-go) with task-unrelated incidental emotional stimulus valence manipulation, to probe the modulation of the former by the latter. In this study of normal subjects focusing on negative emotional processing, we hypothesized activity changes in specific frontal neocortical and limbic regions reflecting modulation of response inhibition by negative stimulus processing. We observed common fronto-limbic activations (including orbitofrontal cortical and amygdalar components) associated with the interaction of emotional stimulus processing and response suppression. Further, we found a distributed cortico-limbic network to be a candidate neural substrate for the interaction of negative valence-specific processing and inhibitory task demand. These findings have implications for elucidating neural mechanisms of emotional modulation of behavioral control, with relevance to a variety of neuropsychiatric disease states marked by behavioral dysregulation within the context of negative emotional processing.
Uchiyama, Hitoshi; Seki, Ayumi; Kageyama, Hiroko; Saito, Daisuke N; Koeda, Tatsuya; Ohno, Kousaku; Sadato, Norihiro
The understanding of sarcasm reflects a complex process, which involves recognizing the beliefs of the speaker. There is a clear association between deficits in mentalizing, which is the ability to understand other people's behavior in terms of their mental state, and the understanding of sarcasm in individuals with autistic spectrum disorders. This suggests that mentalizing is important in pragmatic non-literal language comprehension. To highlight the neural substrates of sarcasm, 20 normal adult volunteers underwent functional magnetic-resonance imaging. We used scenario-reading tasks, in which sentences describing a certain situation were presented, followed by the protagonist's comments regarding that situation. Depending on the situation, the semantic content of the comments was classified as sarcastic, non-sarcastic, or contextually unconnected. As the combination of the first and second sentences represented discourse-level information that was not encoded in the individual sentences, sarcasm detection was represented as the differential activation induced by the second sentences. Sarcasm detection activated the left temporal pole, the superior temporal sulcus, the medial prefrontal cortex, and the inferior frontal gyrus (Brodmann's area [BA] 47). The left BA 47 was activated more prominently by sarcasm detection than by the first sentence. These findings indicate that the detection of sarcasm recruits the medial prefrontal cortex, which is part of the mentalizing system, as well as the neural substrates involved in reading sentences. The left BA 47 might therefore be where mentalizing and language processes interact during sarcasm detection.
Full Text Available Although behavioral and neuropsychological studies have suggested two distinct routes of phonological access, their neural substrates have not been clearly elucidated. Here, we designed an artificial language (based on Korean Hangul that can be read either through addressed (i.e., whole word mapping or assembled (i.e., grapheme-to-phoneme mapping phonology. Two matched groups of native English-speaking participants were trained in one of the two conditions, one hour per day for eight days. Behavioral results showed that both groups correctly named more than 90% of the trained words after training. At the neural level, we found a clear dissociation of the neural pathways for addressed and assembled phonologies: There was greater involvement of the anterior cingulate cortex, posterior cingulate cortex, right orbital frontal cortex, angular gyrus and middle temporal gyrus for addressed phonology, but stronger activation in the left precentral gyrus/inferior frontal gyrus and supramarginal gyrus for assembled phonology. Furthermore, we found evidence supporting the strategy-shift hypothesis, which postulates that, with practice, reading strategy shifts from assembled to addressed phonology. Specifically, compared to untrained words, trained words in the assembled phonology group showed stronger activation in the addressed phonology network and less activation in the assembled phonology network. Our results provide clear brain-imaging evidence for the dual-route models of reading.
Full Text Available It is known that sleep reshapes the neural representations that subtend the memories acquired while navigating in a virtual environment. However, navigation is not process-pure, as manifold learning components contribute to performance, notably the spatial and contextual memory constituents. In this context, it remains unclear whether post-training sleep globally promotes consolidation of all of the memory components embedded in virtual navigation, or rather favors the development of specific representations. Here, we investigated the effect of post-training sleep on the neural substrates of the consolidation of spatial and contextual memories acquired while navigating in a complex 3D, naturalistic virtual town. Using fMRI, we mapped regional cerebral activity during various tasks designed to tap either the spatial or the contextual memory component, or both, 72 h after encoding with or without sleep deprivation during the first post-training night. Behavioral performance was not dependent upon post-training sleep deprivation, neither in a natural setting that engages both spatial and contextual memory processes nor when looking more specifically at each of these memory representations. At the neuronal level however, analyses that focused on contextual memory revealed distinct correlations between performance and neuronal activity in frontal areas associated with recollection processes after post-training sleep, and in the parahippocampal gyrus associated with familiarity processes in sleep-deprived participants. Likewise, efficient spatial memory was associated with posterior cortical activity after sleep whereas it correlated with parahippocampal/medial temporal activity after sleep deprivation. Finally, variations in place-finding efficiency in a natural setting encompassing spatial and contextual elements were associated with caudate activity after post-training sleep, suggesting the automation of navigation. These data indicate that post
Full Text Available The ability to reconcentrate on the present situation by recognizing one’s own recent errors is a cognitive mechanism that is crucial for safe and appropriate behavior in a particular situation. However, an individual may not be able to adequately perform a subsequent task even if he/she recognize his/her own error; thus, it is hypothesized that the neural mechanisms underlying the reconcentration process are different from the neural substrates supporting error recognition. The present study performed a functional magnetic resonance imaging (fMRI analysis to explore the neural substrates associated with reconcentration related to achieving an appropriate cognitive state, and to dissociate these brain regions from the neural substrates involved in recognizing one’s own mistake. This study included 44 healthy volunteers who completed an experimental procedure that was based on the Eriksen flanker task and included feedback regarding the results of the current trial. The hemodynamic response induced by each instance of feedback was modeled using a combination of the successes and failures of the current and subsequent trials in order to identify the neural substrates underlying the ability to reconcentrate for the next situation and to dissociate them from those involved in recognizing current errors. The fMRI findings revealed significant and specific activation in the dorsal aspect of the medial prefrontal cortex (MFC when participants successfully reconcentrated on the task after recognizing their own error based on feedback. Additionally, this specific activation was clearly dissociated from the activation foci that occurred during error recognition. These findings indicate that the dorsal aspect of the MFC may be a distinct functional region that specifically supports the reconcentration process and that is associated with the prevention of successive errors when a human subject recognizes his/her own mistake. Furthermore, it is likely
Miura, Naoki; Nozawa, Takayuki; Takahashi, Makoto; Yokoyama, Ryoichi; Sasaki, Yukako; Sakaki, Kohei; Kawashima, Ryuta
The ability to reconcentrate on the present situation by recognizing one’s own recent errors is a cognitive mechanism that is crucial for safe and appropriate behavior in a particular situation. However, an individual may not be able to adequately perform a subsequent task even if he/she recognize his/her own error; thus, it is hypothesized that the neural mechanisms underlying the reconcentration process are different from the neural substrates supporting error recognition. The present study performed a functional magnetic resonance imaging (fMRI) analysis to explore the neural substrates associated with reconcentration related to achieving an appropriate cognitive state, and to dissociate these brain regions from the neural substrates involved in recognizing one’s own mistake. This study included 44 healthy volunteers who completed an experimental procedure that was based on the Eriksen flanker task and included feedback regarding the results of the current trial. The hemodynamic response induced by each instance of feedback was modeled using a combination of the successes and failures of the current and subsequent trials in order to identify the neural substrates underlying the ability to reconcentrate for the next situation and to dissociate them from those involved in recognizing current errors. The fMRI findings revealed significant and specific activation in the dorsal aspect of the medial prefrontal cortex (MFC) when participants successfully reconcentrated on the task after recognizing their own error based on feedback. Additionally, this specific activation was clearly dissociated from the activation foci that occurred during error recognition. These findings indicate that the dorsal aspect of the MFC may be a distinct functional region that specifically supports the reconcentration process and that is associated with the prevention of successive errors when a human subject recognizes his/her own mistake. Furthermore, it is likely that this
Yeo, S.; Choe, I.H.; Noort, M.W.M.L. van den; Bosch, M.P.C.; Lim, S.
Objective: Functional magnetic resonance imaging (fMRI), in combination with block design paradigms with consecutive acupuncture stimulations, has often been used to investigate the neural responses to acupuncture. In this study, we investigated whether previous acupuncture stimulations can affect
A fundamental question in human brain plasticity is how sensory, motor, and cognitive functions adapt in the process of skill acquisition extended over a period of many years. Recently, there has emerged a growing interest in cognitive neuroscience on studying the functional and structural differences in the brains of elite athletes. Elite performance in sports, music, or the arts, allows us to observe sensorimotor and cognitive performance at the limits of human capability. In this mini-review, we look at driving expertise. The emerging brain imaging literature on the neural substrates of real and simulated driving is reviewed (for the first time), and used as the context for interpreting recent findings on the differences between racing drivers and non-athlete controls. Also the cognitive psychology and cognitive neuroscience of expertise are discussed.
Borra, Elena; Gerbella, Marzio; Rozzi, Stefano; Luppino, Giuseppe
In primates, neural mechanisms for controlling skilled hand actions primarily rely on sensorimotor transformations. These transformations are mediated by circuits linking specific inferior parietal with ventral premotor areas in which sensory coding of objects' features automatically triggers appropriate hand motor programs. Recently, connectional studies in macaques showed that these parietal and premotor areas are nodes of a large-scale cortical network, designated as "lateral grasping network," including specific temporal and prefrontal sectors involved in object recognition and executive functions, respectively. These data extend grasping models so far proposed in providing a possible substrate for interfacing perceptual, cognitive, and hand-related sensorimotor processes for controlling hand actions based on object identity, goals, and memory-based or contextual information and for the contribution of motor signals to cognitive motor functions. Human studies provided evidence for a possible counterpart of the macaque lateral grasping network, suggesting that in primate evolution the neural mechanisms for controlling hand actions described in the macaque have been retained and exploited for the emergence of human-specific motor and cognitive motor capacities. Copyright © 2017 Elsevier Ltd. All rights reserved.
Charles J Limb
Full Text Available To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance as well as deactivation of limbic structures (that regulate motivation and emotional tone. This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity.
Limb, Charles J; Braun, Allen R
To investigate the neural substrates that underlie spontaneous musical performance, we examined improvisation in professional jazz pianists using functional MRI. By employing two paradigms that differed widely in musical complexity, we found that improvisation (compared to production of over-learned musical sequences) was consistently characterized by a dissociated pattern of activity in the prefrontal cortex: extensive deactivation of dorsolateral prefrontal and lateral orbital regions with focal activation of the medial prefrontal (frontal polar) cortex. Such a pattern may reflect a combination of psychological processes required for spontaneous improvisation, in which internally motivated, stimulus-independent behaviors unfold in the absence of central processes that typically mediate self-monitoring and conscious volitional control of ongoing performance. Changes in prefrontal activity during improvisation were accompanied by widespread activation of neocortical sensorimotor areas (that mediate the organization and execution of musical performance) as well as deactivation of limbic structures (that regulate motivation and emotional tone). This distributed neural pattern may provide a cognitive context that enables the emergence of spontaneous creative activity.
Full Text Available Individuals with autism spectrum condition (ASC are known to excel in some perceptual cognitive tasks, but such developed functions have been often regarded as "islets of abilities" that do not significantly contribute to broader intellectual capacities. However, recent behavioral studies have reported that individuals with ASC have advantages for performing Raven's (Standard Progressive Matrices (RPM/RSPM, a standard neuropsychological test for general fluid intelligence, raising the possibility that ASC's cognitive strength can be utilized for more general purposes like novel problem solving. Here, the brain activity of 25 adults with high-functioning ASC and 26 matched normal controls (NC was measured using functional magnetic resonance imaging (fMRI to examine neural substrates of geometric reasoning during the engagement of a modified version of the RSPM test. Among the frontal and parietal brain regions involved in fluid intelligence, ASC showed larger activation in the left lateral occipitotemporal cortex (LOTC during an analytic condition with moderate difficulty than NC. Activation in the left LOTC and ventrolateral prefrontal cortex (VLPFC increased with task difficulty in NC, whereas such modulation of activity was absent in ASC. Furthermore, functional connectivity analysis revealed a significant reduction of activation coupling between the left inferior parietal cortex and the right anterior prefrontal cortex during both figural and analytic conditions in ASC. These results indicate altered pattern of functional specialization and integration in the neural system for geometric reasoning in ASC, which may explain its atypical cognitive pattern, including performance on the Raven's Matrices test.
Siri, Simona; Tettamanti, Marco; Cappa, Stefano F; Della Rosa, Pasquale; Saccuman, Cristina; Scifo, Paola; Vigliocco, Gabriella
Grammatical class is a fundamental property of language, and all natural languages distinguish between nouns and verbs. Brain activation studies have provided conflicting evidence concerning the neural substrates of noun and verb processing. A major limitation of many previous imaging studies is that they did not disentangle the impact of grammatical class from the differences in semantic correlates. In order to tease apart the role of semantic and grammatical factors, we performed a functional magnetic resonance imaging study presenting Italian speakers with pictures of events and asked them to name them as 1) Infinitive Verb (e.g., mangiare [to eat]); 2) Inflected Verb (e.g., mangia [she/he eats]); and 3) Action Noun (e.g., mangiata [the eating]). We did not find any verb-specific activation. However, reliable left inferior frontal gyrus (IFG) activations were found when contrasting the Action Noun with the Infinitive Verb condition. A second-level analysis indicated then that activation in left IFG was greatest for Action Nouns, intermediate for Inflected Verbs, and least for Infinitive Verbs. We conclude that, when all other factors are controlled, nouns and verbs are processed by a common neural system. In the present case, differences in left IFG activation emerge as a consequence of increasing linguistic and/or general processing demands.
Zhang, Wenwen; Wang, Xiangpeng; Feng, Tingyong
Procrastination is a prevalent problematic behavior that brings serious consequences to individuals who suffer from it. Although this phenomenon has received increasing attention from researchers, the underpinning neural substrates of it is poorly studied. To examine the neural bases subserving procrastination, the present study employed resting-state fMRI. The main results were as follows: (1) the behavioral procrastination was positively correlated with the regional activity of the ventromedial prefrontal cortex (vmPFC) and the parahippocampal cortex (PHC), while negatively correlated with that of the anterior prefrontal cortex (aPFC). (2) The aPFC-seed connectivity with the anterior medial prefrontal cortex and the posterior cingulate cortex was positively associated with procrastination. (3) The connectivity between vmPFC and several other regions, such as the dorsomedial prefrontal cortex, the bilateral inferior prefrontal cortex showed a negative association with procrastination. These results suggested that procrastination could be attributed to, on the one hand, hyper-activity of the default mode network (DMN) that overrides the prefrontal control signal; while on the other hand, the failure of top-down control exerted by the aPFC on the DMN. Therefore, the present study unravels the biomarkers of procrastination and provides treatment targets for procrastination prevention.
Farashahi, Shiva; Donahue, Christopher H; Khorsand, Peyman; Seo, Hyojung; Lee, Daeyeol; Soltani, Alireza
Value-based decision making often involves integration of reward outcomes over time, but this becomes considerably more challenging if reward assignments on alternative options are probabilistic and non-stationary. Despite the existence of various models for optimally integrating reward under uncertainty, the underlying neural mechanisms are still unknown. Here we propose that reward-dependent metaplasticity (RDMP) can provide a plausible mechanism for both integration of reward under uncertainty and estimation of uncertainty itself. We show that a model based on RDMP can robustly perform the probabilistic reversal learning task via dynamic adjustment of learning based on reward feedback, while changes in its activity signal unexpected uncertainty. The model predicts time-dependent and choice-specific learning rates that strongly depend on reward history. Key predictions from this model were confirmed with behavioral data from non-human primates. Overall, our results suggest that metaplasticity can provide a neural substrate for adaptive learning and choice under uncertainty. Copyright © 2017 Elsevier Inc. All rights reserved.
Kara J Blacker
Full Text Available Previous work has demonstrated a distinction between maintenance of two types of spatial information in working memory (WM: spatial locations and spatial relations. While a body of work has investigated the neural mechanisms of sensory-based information like spatial locations, little is known about how spatial relations are maintained in WM. In two experiments, we used fMRI to investigate the involvement of early visual cortex in the maintenance of spatial relations in WM. In both experiments, we found less quadrant-specific BOLD activity in visual cortex when a single spatial relation, compared to a single spatial location, was held in WM. Also across both experiments, we found a consistent set of brain regions that were differentially activated during maintenance of locations versus relations. Maintaining a location, compared to a relation, was associated with greater activity in typical spatial WM regions like posterior parietal cortex and prefrontal regions. Whereas maintaining a relation, compared to a location, was associated with greater activity in the parahippocampal gyrus and precuneus/retrosplenial cortex. Further, in Experiment 2 we manipulated WM load and included trials where participants had to maintain three spatial locations or relations. Under this high load condition, the regions sensitive to locations versus relations were somewhat different than under low load. We also identified regions that were sensitive to load specifically for location or relation maintenance, as well as overlapping regions sensitive to load more generally. These results suggest that the neural substrates underlying WM maintenance of spatial locations and relations are distinct from one another and that the neural representations of these distinct types of spatial information change with load.
Full Text Available It is believed that depression impedes and motivation enhances functional recovery after neuronal damage such as spinal-cord injury and stroke. However, the neuronal substrate underlying such psychological effects on functional recovery remains unclear. A longitudinal study of brain activation in the non-human primate model of partial spinal-cord injury using positron emission tomography (PET revealed a contribution of the primary motor cortex (M1 to the recovery of finger dexterity through the rehabilitative training. Here, we show that activity of the ventral striatum, including the nucleus accumbens (NAc, which plays a critical role in processing of motivation, increased and its functional connectivity with M1 emerged and was progressively strengthened during the recovery. In addition, functional connectivities among M1, the ventral striatum and other structures belonging to neural circuits for processing motivation, such as the orbitofrontal cortex, anterior cingulate cortex and pedunculopontine tegmental nucleus were also strengthened during the recovery. These results give clues to the neuronal substrate for motivational regulation of motor learning required for functional recovery after spinal-cord injury.
The trade-off between current strength and duration of a stimulating pulse was studied for the rewarding and priming effects of brain stimulation reward (BSR). With cathodal pulses, strenght-duration functions for BSR had chronaxies of .8-3 msec. No differences were observed between the results for rewarding and priming effects. With anodal pulses. strength-duration curves were parallel to the cathodal curves at pulse durations of .1-5 msec, but at pulse durations greater than 5 msec the anodal curves showed a greater drop in required current intensity than did the cathodal curves. The parallel portion of the anodal curves was interpreted as due to anode-make excitation, and the drop at longer pulse durations was interpreted as due to anode-break excitation. Cathodal strength-duration functions for the motor effect elicited through the BSR electrodes had chronaxies of .15-.48 msec. Measurements of the latency of the muscle twitch confirmed that anode-make and anode-break excitation occurred, the latter becoming evident at pulse durations as brief as .3-.4 msec. The results provide quantitative characterization of cathodal and anodal strength-duration properties of the neural substrate for BSR and are discussed in terms of their value in guiding electrophysiological investigation of that substrate.
Hu, Yue; Liu, Peiwei; Guo, Yiqun; Feng, Tingyong
Procrastination is a pervasive phenomenon across different cultures and brings about lots of serious consequences, including performance, subjective well-being, and even public policy. However, little is known about the neural substrates of procrastination. In order to shed light upon this question, we investigated the neuroanatomical substrates of procrastination across two independent samples using voxel-based morphometry (VBM) method. The whole-brain analysis showed procrastination was positively correlated with the graymatter (GM) volume of clusters in the parahippocampal gyrus (PHG) and the orbital frontal cortex (OFC), while negatively correlated with the GM volume of clusters in the inferior frontal gyrus (IFG) and the middle frontal gyrus (MFG) in sample one (151 participants). We further conducted a verification procedure on another sample (108 participants) using region-of-interest analysis to examine the reliability of these results. Results showed procrastination can be predicted by the GM volume of the OFC and the MFG. The present findings suggest that the MFG and OFC, which are the key regions of self-control and emotion regulation, may play an important role in procrastination. Copyright © 2018 Elsevier Inc. All rights reserved.
Kring, Ann M; Barch, Deanna M
A range of emotional and motivation impairments have long been clinically documented in people with schizophrenia, and there has been a resurgence of interest in understanding the psychological and neural mechanisms of the so-called "negative symptoms" in schizophrenia, given their lack of treatment responsiveness and their role in constraining function and life satisfaction in this illness. Negative symptoms comprise two domains, with the first covering diminished motivation and pleasure across a range of life domains and the second covering diminished verbal and non-verbal expression and communicative output. In this review, we focus on four aspects of the motivation/pleasure domain, providing a brief review of the behavioral and neural underpinnings of this domain. First, we cover liking or in-the-moment pleasure: immediate responses to pleasurable stimuli. Second, we cover anticipatory pleasure or wanting, which involves prediction of a forthcoming enjoyable outcome (reward) and feeling pleasure in anticipation of that outcome. Third, we address motivation, which comprises effort computation, which involves figuring out how much effort is needed to achieve a desired outcome, planning, and behavioral response. Finally, we cover the maintenance emotional states and behavioral responses. Throughout, we consider the behavioral manifestations and brain representations of these four aspects of motivation/pleasure deficits in schizophrenia. We conclude with directions for future research as well as implications for treatment. Copyright © 2013 Elsevier B.V. and ECNP. All rights reserved.
Full Text Available Studies on the characteristics of individuals with hypersexual disorder have been accumulating due to increasing concerns about problematic hypersexual behavior (PHB. Currently, relatively little is known about the underlying behavioral and neural mechanisms of sexual desire. Our study aimed to investigate the neural correlates of sexual desire with event-related functional magnetic resonance imaging (fMRI. Twenty-three individuals with PHB and 22 age-matched healthy controls were scanned while they passively viewed sexual and nonsexual stimuli. The subjects’ levels of sexual desire were assessed in response to each sexual stimulus. Relative to controls, individuals with PHB experienced more frequent and enhanced sexual desire during exposure to sexual stimuli. Greater activation was observed in the caudate nucleus, inferior parietal lobe, dorsal anterior cingulate gyrus, thalamus, and dorsolateral prefrontal cortex in the PHB group than in the control group. In addition, the hemodynamic patterns in the activated areas differed between the groups. Consistent with the findings of brain imaging studies of substance and behavior addiction, individuals with the behavioral characteristics of PHB and enhanced desire exhibited altered activation in the prefrontal cortex and subcortical regions. In conclusion, our results will help to characterize the behaviors and associated neural mechanisms of individuals with PHB.
Adam E. Green
Conclusions: In this sample of young adult smokers, GWLs promoted neural activation in brain regions involved in cognitive and affective decision-making and memory formation and the effects of GWLs did not differ on branded or plain cigarette packaging. These findings complement other recent neuroimaging GWL studies conducted with older adult smokers and with adolescents by demonstrating similar patterns of neural activation in response to GWLs among young adult smokers.
WILLIAMS, P P; ROBBINS, J D; GUTIERREZ, J; DAVIS, R E
Insecticides containing organophosphate, chlorinated hydrocarbon, and carbamate were tested with bovine ruminal ingesta fractions. Rumen bacteria exposed to insecticide levels of 0 to 500 ppm in rumen fluid for 4 hr were inoculated into rumen fluid-starch feed extract medium. No apparent significant bacterial count inhibitions were noted. Also, when insecticides were used as carbon sources at concentrations of 500 ppm in carbohydrate-limited media, no increases in bacterial counts were indicated. Warburg manometric data showed that paraffin oil-Triton X-155 preparations of dimethoate, Diazinon, lindane, Thiodan and Sevin stimulated gas production in holotrich protozoa. Entodinium simplex, an oligotrich, produced less gas with insecticide substrates per unit of dry weight than did an Isotricha sp. Rumen bacteria and plant debris fractions from ruminal ingesta provided with insecticides did not give increased manometric responses over the endogenous control vessels. Washed suspensions of I. intestinalis produced volatile fatty acids in excess of the endogenous suspensions when provided insecticide substrates. Thiodan dissimilation by I. intestinalis was followed colorimetrically with 15% loss in substrate in 1 hr of incubation at 39 C. Diazinon-C(14) substrate uptake was demonstrated with suspensions of E. simplex and I. intestinalis. Rumen ciliates are suggested as a possible means for screening out useful insecticides susceptible to microbial dissimilation for use on forage and other cattle-feed crops.
Nagels, Arne; Kauschke, Christina; Schrauf, Judith; Whitney, Carin; Straube, Benjamin; Kircher, Tilo
Many figurative expressions are fully conventionalized in everyday speech. Regarding the neural basis of figurative language processing, research has predominantly focused on metaphoric expressions in minimal semantic context. It remains unclear in how far metaphoric expressions during continuous text comprehension activate similar neural networks as isolated metaphors. We therefore investigated the processing of similes (figurative language, e.g., "He smokes like a chimney!") occurring in a short story. Sixteen healthy, male, native German speakers listened to similes that came about naturally in a short story, while blood-oxygenation-level-dependent (BOLD) responses were measured with functional magnetic resonance imaging (fMRI). For the event-related analysis, similes were contrasted with non-figurative control sentences (CS). The stimuli differed with respect to figurativeness, while they were matched for frequency of words, number of syllables, plausibility, and comprehensibility. Similes contrasted with CS resulted in enhanced BOLD responses in the left inferior (IFG) and adjacent middle frontal gyrus. Concrete CS as compared to similes activated the bilateral middle temporal gyri as well as the right precuneus and the left middle frontal gyrus (LMFG). Activation of the left IFG for similes in a short story is consistent with results on single sentence metaphor processing. The findings strengthen the importance of the left inferior frontal region in the processing of abstract figurative speech during continuous, ecologically-valid speech comprehension; the processing of concrete semantic contents goes along with a down-regulation of bilateral temporal regions.
Full Text Available Many figurative expressions are fully conventionalized in everyday speech. Regarding the neural basis of figurative language processing, research has predominantly focused on metaphoric expressions in minimal semantic context. It remains unclear in how far metaphoric expressions during continuous text comprehension activate similar neural networks as isolated metaphors. We therefore investigated the processing of similes (figurative language, e.g. He smokes like a chimney! occurring in a short story.Sixteen healthy, male, native German speakers listened to similes that came about naturally in a short story, while blood-oxygenation-level-dependent (BOLD responses were measured with functional magnetic resonance imaging (fMRI. For the event-related analysis, similes were contrasted with non-figurative control sentences. The stimuli differed with respect to figurativeness, while they were matched for frequency of words, number of syllables, plausibility and comprehensibility.Similes contrasted with control sentences resulted in enhanced BOLD responses in the left inferior (IFG and adjacent middle frontal gyrus. Concrete control sentences as compared to similes activated the bilateral middle temporal gyri as well as the right precuneus and the left middle frontal gyrus.Activation of the left IFG for similes in a short story is consistent with results on single sentence metaphor processing. The findings strengthen the importance of the left inferior frontal region in the processing of abstract figurative speech during continuous, ecologically-valid speech comprehension; the processing of concrete semantic contents goes along with a down-regulation of bilateral temporal regions.
Kurikawa, Tomoki; Kaneko, Kunihiko
Recent experimental measurements have demonstrated that spontaneous neural activity in the absence of explicit external stimuli has remarkable spatiotemporal structure. This spontaneous activity has also been shown to play a key role in the response to external stimuli. To better understand this role, we proposed a viewpoint, "memories-as-bifurcations," that differs from the traditional "memories-as-attractors" viewpoint. Memory recall from the memories-as-bifurcations viewpoint occurs when the spontaneous neural activity is changed to an appropriate output activity upon application of an input, known as a bifurcation in dynamical systems theory, wherein the input modifies the flow structure of the neural dynamics. Learning, then, is a process that helps create neural dynamical systems such that a target output pattern is generated as an attractor upon a given input. Based on this novel viewpoint, we introduce in this paper an associative memory model with a sequential learning process. Using a simple hebbian-type learning, the model is able to memorize a large number of input/output mappings. The neural dynamics shaped through the learning exhibit different bifurcations to make the requested targets stable upon an increase in the input, and the neural activity in the absence of input shows chaotic dynamics with occasional approaches to the memorized target patterns. These results suggest that these dynamics facilitate the bifurcations to each target attractor upon application of the corresponding input, which thus increases the capacity for learning. This theoretical finding about the behavior of the spontaneous neural activity is consistent with recent experimental observations in which the neural activity without stimuli wanders among patterns evoked by previously applied signals. In addition, the neural networks shaped by learning properly reflect the correlations of input and target-output patterns in a similar manner to those designed in our previous study.
Full Text Available Recent experimental measurements have demonstrated that spontaneous neural activity in the absence of explicit external stimuli has remarkable spatiotemporal structure. This spontaneous activity has also been shown to play a key role in the response to external stimuli. To better understand this role, we proposed a viewpoint, "memories-as-bifurcations," that differs from the traditional "memories-as-attractors" viewpoint. Memory recall from the memories-as-bifurcations viewpoint occurs when the spontaneous neural activity is changed to an appropriate output activity upon application of an input, known as a bifurcation in dynamical systems theory, wherein the input modifies the flow structure of the neural dynamics. Learning, then, is a process that helps create neural dynamical systems such that a target output pattern is generated as an attractor upon a given input. Based on this novel viewpoint, we introduce in this paper an associative memory model with a sequential learning process. Using a simple hebbian-type learning, the model is able to memorize a large number of input/output mappings. The neural dynamics shaped through the learning exhibit different bifurcations to make the requested targets stable upon an increase in the input, and the neural activity in the absence of input shows chaotic dynamics with occasional approaches to the memorized target patterns. These results suggest that these dynamics facilitate the bifurcations to each target attractor upon application of the corresponding input, which thus increases the capacity for learning. This theoretical finding about the behavior of the spontaneous neural activity is consistent with recent experimental observations in which the neural activity without stimuli wanders among patterns evoked by previously applied signals. In addition, the neural networks shaped by learning properly reflect the correlations of input and target-output patterns in a similar manner to those designed in
Payer, Doris E; Baicy, Kate; Lieberman, Matthew D; London, Edythe D
Emotion regulation can be achieved in various ways, but few studies have evaluated the extent to which the neurocognitive substrates of these distinct operations overlap. In the study reported here, functional magnetic resonance imaging (fMRI) was used to measure activity in the amygdala and prefrontal cortex of 10 participants who completed two independent tasks of emotion regulation-reappraisal, measuring intentional emotion regulation, and affect labeling, measuring incidental emotion regulation-with the objective of identifying potential overlap in the neural substrates underlying each task. Analyses focused on a priori regions of interest in the amygdala and inferior frontal gyrus (IFG). For both tasks, fMRI showed decreased amygdala activation during emotion regulation compared with emotion conditions. During reappraisal, this decrease in amygdala activation was accompanied by a proportional decrease in emotional intensity ratings; during affect labeling, the decrease in amygdala activation correlated with self-reported aggression. Importantly, across participants, the magnitude of decrease in amygdala activation during reappraisal correlated with the magnitude of decrease during affect labeling, even though the tasks were administered on separate days, and values indexing amygdala activation during each task were extracted independently of one another. In addition, IFG-amygdala connectivity, assessed via psychophysiological interaction analysis, overlapped between tasks in two regions within the right IFG. The results suggest that the two tasks recruit overlapping regions of prefrontal cortex, resulting in similar reductions in amygdala activation, regardless of the strategy employed. Intentional and incidental forms of emotion regulation, despite their phenomenological differences, may therefore converge on a common neurocognitive pathway. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
Daly, Ian; Malik, Asad; Hwang, Faustina; Roesch, Etienne; Weaver, James; Kirke, Alexis; Williams, Duncan; Miranda, Eduardo; Nasuto, Slawomir J
This paper presents an EEG study into the neural correlates of music-induced emotions. We presented participants with a large dataset containing musical pieces in different styles, and asked them to report on their induced emotional responses. We found neural correlates of music-induced emotion in a number of frequencies over the pre-frontal cortex. Additionally, we found a set of patterns of functional connectivity, defined by inter-channel coherence measures, to be significantly different between groups of music-induced emotional responses. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Chang, Soo-Eun; Kenney, Mary Kay; Loucks, Torrey M J; Poletto, Christopher J; Ludlow, Christy L
The issue of whether speech is supported by the same neural substrates as non-speech vocal tract gestures has been contentious. In this fMRI study we tested whether producing non-speech vocal tract gestures in humans shares the same functional neuroanatomy as non-sense speech syllables. Production of non-speech vocal tract gestures, devoid of phonological content but similar to speech in that they had familiar acoustic and somatosensory targets, was compared to the production of speech syllables without meaning. Brain activation related to overt production was captured with BOLD fMRI using a sparse sampling design for both conditions. Speech and non-speech were compared using voxel-wise whole brain analyses, and ROI analyses focused on frontal and temporoparietal structures previously reported to support speech production. Results showed substantial activation overlap between speech and non-speech function in regions. Although non-speech gesture production showed greater extent and amplitude of activation in the regions examined, both speech and non-speech showed comparable left laterality in activation for both target perception and production. These findings posit a more general role of the previously proposed "auditory dorsal stream" in the left hemisphere--to support the production of vocal tract gestures that are not limited to speech processing.
Faget-Agius, Catherine; Catherine, Faget-Agius; Boyer, Laurent; Wirsich, Jonathan; Jonathan, Wirsich; Ranjeva, Jean-Philippe; Jean-Philippe, Ranjeva; Richieri, Raphaelle; Raphaelle, Richieri; Soulier, Elisabeth; Elisabeth, Soulier; Confort-Gouny, Sylviane; Sylviane, Confort-Gouny; Auquier, Pascal; Pascal, Auquier; Guye, Maxime; Maxime, Guye; Lançon, Christophe; Christophe, Lançon
The aim of this study was to investigate the neural substrate underlying quality of life (QoL) and to demonstrate the microstructural abnormalities associated with impaired QoL in a large sample of patients with schizophrenia, using magnetisation transfer imaging. A total of 81 right-handed men with a diagnosis of schizophrenia and 25 age- and sex-similar healthy controls were included and underwent a 3T MRI with magnetization transfer ratio (MTR) to detect microstructural abnormalities. Compared with healthy controls, patients with schizophrenia had grey matter (GM) decreased MTR values in the temporal lobe (BA21, BA37 and BA38), the bilateral insula, the occipital lobe (BA17, BA18 and BA19) and the cerebellum. Patients with impaired QoL had lower GM MTR values relative to patients with preserved QoL in the bilateral temporal pole (BA38), the bilateral insula, the secondary visual cortex (BA18), the vermis and the cerebellum. Significant correlations between MTR values and QoL scores (p < 0.005) were observed in the GM of patients in the right temporal pole (BA38), the bilateral insula, the vermis and the right cerebellum. Our study shows that QoL impairment in patients with schizophrenia is related to the microstructural changes in an extensive network, suggesting that QoL is a bio-psychosocial marker.
Takemura, Shin-ya; Nern, Aljoscha; Chklovskii, Dmitri B; Scheffer, Louis K; Rubin, Gerald M; Meinertzhagen, Ian A
Analysing computations in neural circuits often uses simplified models because the actual neuronal implementation is not known. For example, a problem in vision, how the eye detects image motion, has long been analysed using Hassenstein-Reichardt (HR) detector or Barlow-Levick (BL) models. These both simulate motion detection well, but the exact neuronal circuits undertaking these tasks remain elusive. We reconstructed a comprehensive connectome of the circuits of Drosophila‘s motion-sensing T4 cells using a novel EM technique. We uncover complex T4 inputs and reveal that putative excitatory inputs cluster at T4’s dendrite shafts, while inhibitory inputs localize to the bases. Consistent with our previous study, we reveal that Mi1 and Tm3 cells provide most synaptic contacts onto T4. We are, however, unable to reproduce the spatial offset between these cells reported previously. Our comprehensive connectome reveals complex circuits that include candidate anatomical substrates for both HR and BL types of motion detectors. DOI: http://dx.doi.org/10.7554/eLife.24394.001 PMID:28432786
Full Text Available Little is known about disorder-specific biomarkers of bipolar disorder (BD and major depressive disorder (MDD. Our aim was to determine a neural substrate that could be used to distinguish BD from MDD. Our study included a BD group (10 patients with BD, 10 first-degree relatives (FDRs of individuals with BD, MDD group (17 patients with MDD, 17 FDRs of individuals with MDD, and 27 healthy individuals. Structural and functional brain abnormalities were evaluated by voxel-based morphometry and a trail making test (TMT, respectively. The BD group showed a significant main effect of diagnosis in the gray matter (GM volume of the anterior cingulate cortex (ACC; p = 0.01 and left insula (p < 0.01. FDRs of individuals with BD showed significantly smaller left ACC GM volume than healthy subjects (p < 0.01, and patients with BD showed significantly smaller ACC (p < 0.01 and left insular GM volume (p < 0.01 than healthy subjects. The MDD group showed a tendency toward a main effect of diagnosis in the right and left insular GM volume. The BD group showed a significantly inverse correlation between the left insular GM volume and TMT-A scores (p < 0.05. Our results suggest that the ACC volume could be a distinct endophenotype of BD, while the insular volume could be a shared BD and MDD endophenotype. Moreover, the insula could be associated with cognitive decline and poor outcome in BD.
In these studies, we addressed the issues of: (1) whether neural protein kinase C (PKC) substrates might be altered in phosphorylation following induction of long-term potentiation (LTP); (2) whether PKC substrate phosphorylation might be specifically related to a model of neural plasticity other than LTP; and (3) whether the PKC substrates implicated in adult synaptic plasticity might be present in axonal growth cones given reports that high concentrations of PKC are found in these structures. Using quantitative analysis of multiple two-dimensional gels, we found that the two major substrates of exogenous purified PKC in adult hippocampal homogenate are both directly correlated to persistence of LTP. In rhesus monkey cerebral cortex, the proteins corresponding to protein F1 and 80k displayed topographical gradients in /sup 32/P-incorporation along the occipitotemporal visual processing pathway. The phosphorylation of both proteins was 11- and 14-fold higher, respectively, in temporal regions of this pathway implicated in the storage of visual representations, than in occipital regions, which do not appear to directly participate in visual memory functions.
Falk, Emily B; Cascio, Christopher N; O'Donnell, Matthew Brook; Carp, Joshua; Tinney, Francis J; Bingham, C Raymond; Shope, Jean T; Ouimet, Marie Claude; Pradhan, Anuj K; Simons-Morton, Bruce G
Social influence is prominent across the lifespan, but sensitivity to influence is especially high during adolescence and is often associated with increased risk taking. Such risk taking can have dire consequences. For example, in American adolescents, traffic-related crashes are leading causes of nonfatal injury and death. Neural measures may be especially useful in understanding the basic mechanisms of adolescents' vulnerability to peer influence. We examined neural responses to social exclusion as potential predictors of risk taking in the presence of peers in recently licensed adolescent drivers. Risk taking was assessed in a driving simulator session occurring approximately 1 week after the neuroimaging session. Increased activity in neural systems associated with the distress of social exclusion and mentalizing during an exclusion episode predicted increased risk taking in the presence of a peer (controlling for solo risk behavior) during a driving simulator session outside the neuroimaging laboratory 1 week later. These neural measures predicted risky driving behavior above and beyond self-reports of susceptibility to peer pressure and distress during exclusion. These results address the neural bases of social influence and risk taking; contribute to our understanding of social and emotional function in the adolescent brain; and link neural activity in specific, hypothesized, regions to risk-relevant outcomes beyond the neuroimaging laboratory. Results of this investigation are discussed in terms of the mechanisms underlying risk taking in adolescents and the public health implications for adolescent driving. Copyright © 2014 Society for Adolescent Health and Medicine. All rights reserved.
Campbell, Luke J.; Sly, David James; O'Leary, Stephen John
This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s-1. A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s-1. Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.
Full Text Available Although attention deficit hyperactivity disorders (ADHD and autism spectrum disorders (ASD share certain neurocognitive characteristics, it has been hypothesized to differentiate the two disorders based on their brain's reward responsiveness to either social or monetary reward. Thus, the present fMRI study investigated neural activation in response to both reward types in age and IQ-matched boys with ADHD versus ASD relative to typically controls (TDC. A significant group by reward type interaction effect emerged in the ventral striatum with greater activation to monetary versus social reward only in TDC, whereas subjects with ADHD responded equally strong to both reward types, and subjects with ASD showed low striatal reactivity across both reward conditions. Moreover, disorder-specific neural abnormalities were revealed, including medial prefrontal hyperactivation in response to social reward in ADHD versus ventral striatal hypoactivation in response to monetary reward in ASD. Shared dysfunction was characterized by fronto-striato-parietal hypoactivation in both clinical groups when money was at stake. Interestingly, lower neural activation within parietal circuitry was associated with higher autistic traits across the entire study sample. In sum, the present findings concur with the assumption that both ASD and ADHD display distinct and shared neural dysfunction in response to reward.
Michael S Beauchamp
Full Text Available As sensory systems deteriorate in aging or disease, the brain must relearn the appropriate weights to assign each modality during multisensory integration. Using blood-oxygen level dependent functional magnetic resonance imaging (BOLD fMRI of human subjects, we tested a model for the neural mechanisms of sensory weighting, termed “weighted connections”. This model holds that the connection weights between early and late areas vary depending on the reliability of the modality, independent of the level of early sensory cortex activity. When subjects detected viewed and felt touches to the hand, a network of brain areas was active, including visual areas in lateral occipital cortex, somatosensory areas in inferior parietal lobe, and multisensory areas in the intraparietal sulcus (IPS. In agreement with the weighted connection model, the connection weight measured with structural equation modeling between somatosensory cortex and IPS increased for somatosensory-reliable stimuli, and the connection weight between visual cortex and IPS increased for visual-reliable stimuli. This double dissociation of connection strengths was similar to the pattern of behavioral responses during incongruent multisensory stimulation, suggesting that weighted connections may be a neural mechanism for behavioral reliability weighting.for behavioral reliability weighting.
Seok, Ji-Woo; Lee, Kyung Hwa; Sohn, Sunju; Sohn, Jin-Hun
With the wide and rapid expansion of computers and smartphones, Internet use has become an essential part of life and an important tool that serves various purposes. Despite the advantages of Internet use, psychological and behavioral problems, including Internet addiction, have been reported. In response to growing concern, researchers have focused on the characteristics of Internet addicts. However, relatively little is known about the behavioral and neural mechanisms that underlie Internet addiction, especially with respect to risky decision making, which is an important domain frequently reported in other types of addictions. To examine the neural characteristics of decision making in Internet addicts, Internet addicts and healthy controls were scanned while they performed a financial decision-making task. Relative to healthy controls, Internet addicts showed (1) more frequent risky decision making; (2) greater activation in the dorsal anterior cingulate cortex and the left caudate nucleus, which are brain regions involved in conflict monitoring and reward, respectively; and (3) less activation in the ventrolateral prefrontal cortex, an area associated with cognitive control/regulation. These findings suggest that risky decision making may be an important behavioral characteristic of Internet addiction and that altered brain function in regions associated with conflict monitoring, reward and cognitive control/regulation might be critical biological risk factors for Internet addiction. © The Royal Australian and New Zealand College of Psychiatrists 2015.
Artificial Neural Networks (ANNs) are introduced as robust and versatile tools in quantitative structure-activity relationship (QSAR) modeling. Their application to the modeling of enzyme reactivity is discussed, along with methodological issues. Methods of input variable selection, optimization of network internal structure, data set division and model validation are discussed. The application of ANNs in the modeling of enzyme activity over the last 20 years is briefly recounted. The discussed methodology is exemplified by the case of ethylbenzene dehydrogenase (EBDH). Intelligent Problem Solver and genetic algorithms are applied for input vector selection, whereas k-means clustering is used to partition the data into training and test cases. The obtained models exhibit high correlation between the predicted and experimental values (R(2) > 0.9). Sensitivity analyses and study of the response curves are used as tools for the physicochemical interpretation of the models in terms of the EBDH reaction mechanism. Neural networks are shown to be a versatile tool for the construction of robust QSAR models that can be applied to a range of aspects important in drug design and the prediction of biological activity.
Andrillon, Thomas; Poulsen, Andreas Trier; Hansen, Lars Kai
Sleep is characterized by a loss of behavioral responsiveness. However, recent research has shown that the sleeping brain is not completely disconnected from its environment. How neural activity constrains the ability to process sensory information while asleep is yet unclear. Here, we instructed...... by Lempel-Ziv complexity (LZc), a measure shown to track arousal in sleep and anesthesia. Neural activity related to the semantic content of stimuli was conserved in light non-rapid eye movement (NREM) sleep. However, these processes were suppressed in deep NREM sleep and, importantly, also in REM sleep......, despite the recovery of wake-like neural activity in the latter. In NREM sleep, sensory activations were counterbalanced by evoked down states, which, when present, blocked further processing of external information. In addition, responsiveness markers correlated positively with baseline complexity, which...
Liddell, Belinda J; Jobson, Laura
A significant body of literature documents the neural mechanisms involved in the development and maintenance of posttraumatic stress disorder (PTSD). However, there is very little empirical work considering the influence of culture on these underlying mechanisms. Accumulating cultural neuroscience research clearly indicates that cultural differences in self-representation modulate many of the same neural processes proposed to be aberrant in PTSD. The objective of this review paper is to consider how culture may impact on the neural mechanisms underlying PTSD. We first outline five key affective and cognitive functions and their underlying neural correlates that have been identified as being disrupted in PTSD: (1) fear dysregulation; (2) attentional biases to threat; (3) emotion and autobiographical memory; (4) self-referential processing; and (5) attachment and interpersonal processing. Second, we consider prominent cultural theories and review the empirical research that has demonstrated the influence of cultural variations in self-representation on the neural substrates of these same five affective and cognitive functions. Finally, we propose a conceptual model that suggests that these five processes have major relevance to considering how culture may influence the neural processes underpinning PTSD.
Belinda J. Liddell
Full Text Available A significant body of literature documents the neural mechanisms involved in the development and maintenance of posttraumatic stress disorder (PTSD. However, there is very little empirical work considering the influence of culture on these underlying mechanisms. Accumulating cultural neuroscience research clearly indicates that cultural differences in self-representation modulate many of the same neural processes proposed to be aberrant in PTSD. The objective of this review paper is to consider how culture may impact on the neural mechanisms underlying PTSD. We first outline five key affective and cognitive functions and their underlying neural correlates that have been identified as being disrupted in PTSD: (1 fear dysregulation; (2 attentional biases to threat; (3 emotion and autobiographical memory; (4 self-referential processing; and (5 attachment and interpersonal processing. Second, we consider prominent cultural theories and review the empirical research that has demonstrated the influence of cultural variations in self-representation on the neural substrates of these same five affective and cognitive functions. Finally, we propose a conceptual model that suggests that these five processes have major relevance to considering how culture may influence the neural processes underpinning PTSD. Highlights of the article:
Kildemo, Morten; Banon, Jean-Philippe; Baron, Alexandre; Svendsen, Brage B.; Brakstad, Thomas; Simonsen, Ingve
Square arrays of gold (Au) hemispheroids deposited on a UV-transparent glass substrate reveal a rich optical response when investigated by spectroscopic Mueller Matrix Ellipsometry. Two samples were studied; the first consisted of hemispheroids of parallel radius of 58 nm and height 30 nm with lattice constant 210 nm; the corresponding parameters for the second sample were 38 nm, 20 nm and 125 nm, respectively. By a full azimuthal rotation of the samples, we observe all the Rayleigh anomalies corresponding to grazing diffracted waves, with strong resonances for co-polarization scattered light near the high symmetry points and cross-polarization scattered light around the Localized Surface Plasmon Resonance. Polarization-conversion becomes particularly important at grazing incidence, and the cross-polarization follows the Rayleigh lines. The optical response (neglecting polarization conversion) is modelled in the quasi-static approximation using the so-called Bedeaux-Vlieger formalism, and the Finite Element Method using COMSOL. The direct inversion of the effective (substrate dependent) dielectric function is discussed.
Hu, Xiaochen; Ackermann, Hermann; Martin, Jason A; Erb, Michael; Winkler, Susanne; Reiterer, Susanne M
Individual differences in second language (L2) aptitude have been assumed to depend upon a variety of cognitive and personality factors. Especially, the cognitive factor phonological working memory has been conceptualised as language learning device. However, strong associations between phonological working memory and L2 aptitude have been previously found in early-stage learners only, not in advanced learners. The current study aimed at investigating the behavioural and neurobiological predictors of advanced L2 learning. Our behavioural results showed that phonetic coding ability and empathy, but not phonological working memory, predict L2 pronunciation aptitude in advanced learners. Second, functional neuroimaging revealed this behavioural trait to be correlated with hemodynamic responses of the cerebral network of speech motor control and auditory-perceptual areas. We suggest that the acquisition of L2 pronunciation aptitude is a dynamic process, requiring a variety of neural resources at different processing stages over time. Copyright © 2012 Elsevier Inc. All rights reserved.
Castelluccio, Brian C; Myers, Emily B; Schuh, Jillian M; Eigsti, Inge-Marie
Emotions are conveyed primarily through two channels in language: semantics and prosody. While many studies confirm the role of a left hemisphere network in processing semantic emotion, there has been debate over the role of the right hemisphere in processing prosodic emotion. Some evidence suggests a preferential role for the right hemisphere, and other evidence supports a bilateral model. The relative contributions of semantics and prosody to the overall processing of affect in language are largely unexplored. The present work used functional magnetic resonance imaging to elucidate the neural bases of processing anger conveyed by prosody or semantic content. Results showed a robust, distributed, bilateral network for processing angry prosody and a more modest left hemisphere network for processing angry semantics when compared to emotionally neutral stimuli. Findings suggest the nervous system may be more responsive to prosodic cues in speech than to the semantic content of speech.
Three adaptive single-neuron models based on neural analogies of behavior modification episodes are proposed, which attempt to bridge the gap between psychology and neurophysiology. The proposed models capture the predictive nature of Pavlovian conditioning, which is essential to the theory of adaptive/learning systems. The models learn to anticipate the occurrence of a conditioned response before the presence of a reinforcing stimulus when training is complete. Furthermore, each model can find the most nonredundant and earliest predictor of reinforcement. The behavior of the models accounts for several aspects of basic animal learning phenomena in Pavlovian conditioning beyond previous related models. Computer simulations show how well the models fit empirical data from various animal learning paradigms.
Full Text Available Orexins are neuro-modulatory peptides involved in the control of diverse physiological functions through interaction with two receptors, orexin-1 (OX1R and orexin-2 (OX2R. Recent evidence in pre-clinical models points toward a putative dichotomic role of the two receptors, with OX2R predominantly involved in the regulation of the sleep/wake cycle and arousal, and the OX1R being more specifically involved in reward processing and motivated behaviour. However, the specific neural substrates underlying these distinct processes in the rat brain remain to be elucidated. Here we used functional magnetic resonance imaging (fMRI in the rat to map the modulatory effect of selective OXR blockade on the functional response produced by D-amphetamine, a psychostimulant and arousing drug that stimulates orexigenic activity. OXR blockade was produced by GSK1059865 and JNJ1037049, two novel OX1R and OX2R antagonists with unprecedented selectivity at the counter receptor type. Both drugs inhibited the functional response to D-amphetamine albeit with distinct neuroanatomical patterns: GSK1059865 focally modulated functional responses in striatal terminals, whereas JNJ1037049 induced a widespread pattern of attenuation characterised by a prominent cortical involvement. At the same doses tested in the fMRI study, JNJ1037049 exhibited robust hypnotic properties, while GSK1059865 failed to display significant sleep-promoting effects, but significantly reduced drug-seeking behaviour in cocaine-induced conditioned place preference. Collectively, these findings highlight an essential contribution of the OX2R in modulating cortical activity and arousal, an effect that is consistent with the robust hypnotic effect exhibited by JNJ1037049. The subcortical and striatal pattern observed with GSK1059865 represent a possible neurofunctional correlate for the modulatory role of OX1R in controlling reward-processing and goal-oriented behaviours in the rat.
Lefebvre, Stéphanie; Dricot, Laurence; Laloux, Patrice; Gradkowski, Wojciech; Desfontaines, Philippe; Evrard, Frédéric; Peeters, André; Jamart, Jacques; Vandermeeren, Yves
Motor skill learning is one of the key components of motor function recovery after stroke, especially recovery driven by neurorehabilitation. Transcranial direct current stimulation can enhance neurorehabilitation and motor skill learning in stroke patients. However, the neural mechanisms underlying the retention of stimulation-enhanced motor skill learning involving a paretic upper limb have not been resolved. These neural substrates were explored by means of functional magnetic resonance imaging. Nineteen chronic hemiparetic stroke patients participated in a double-blind, cross-over randomized, sham-controlled experiment with two series. Each series consisted of two sessions: (i) an intervention session during which dual transcranial direct current stimulation or sham was applied during motor skill learning with the paretic upper limb; and (ii) an imaging session 1 week later, during which the patients performed the learned motor skill. The motor skill learning task, called the 'circuit game', involves a speed/accuracy trade-off and consists of moving a pointer controlled by a computer mouse along a complex circuit as quickly and accurately as possible. Relative to the sham series, dual transcranial direct current stimulation applied bilaterally over the primary motor cortex during motor skill learning with the paretic upper limb resulted in (i) enhanced online motor skill learning; (ii) enhanced 1-week retention; and (iii) superior transfer of performance improvement to an untrained task. The 1-week retention's enhancement driven by the intervention was associated with a trend towards normalization of the brain activation pattern during performance of the learned motor skill relative to the sham series. A similar trend towards normalization relative to sham was observed during performance of a simple, untrained task without a speed/accuracy constraint, despite a lack of behavioural difference between the dual transcranial direct current stimulation and sham
Gillihan, Seth J.; Detre, John A.; Martha J Farah; Rao, Hengyi
Daily variations in weather are known to be associated with variations in mood. However, little is known about the specific brain regions that instantiate weather-related mood changes. We used a data-driven approach and ASL perfusion fMRI to assess the neural substrates associated with weather-induced mood variability. The data-driven approach was conducted with mood ratings under various weather conditions (N = 464). Forward stepwise regression was conducted to develop a statistical model of...
Guyer, Amanda E; Choate, Victoria R; Pine, Daniel S; Nelson, Eric E
Peer feedback affects adolescents' behaviors, cognitions and emotions. We examined neural circuitry underlying adolescents' emotional response to peer feedback using a functional neuroimaging paradigm whereby, 36 adolescents (aged 9-17 years) believed they would interact with unknown peers postscan. Neural activity was expected to vary based on adolescents' perceptions of peers and feedback type. Ventrolateral prefrontal cortex (vlPFC) activity was found when adolescents indicated how they felt following feedback (acceptance or rejection) from peers of low vs high interest. Greater activation in both cortical (e.g. superior temporal gyrus, insula, anterior cingulate) and subcortical (e.g. striatum, thalamus) regions emerged in response to acceptance vs rejection feedback. Response to acceptance also varied by age and gender in similar regions (e.g. superior temporal gyrus, fusiform, insula), with greater age-related increases in activation to acceptance vs rejection for females than males. Affective response to rejection vs acceptance did not yield significantly greater neural activity in any region. vlPFC response suggests cognitive flexibility in reappraising initial perceptions of peers following feedback. Striatal response suggests that acceptance is a potent social reward for adolescents, an interpretation supported by more positive self-reported affective response to acceptance than rejection from high- but not low-interest peers.
Full Text Available The methods of cognitive neuroscience are beginning to be applied to the study of political behavior. The neural substrates of value-based decision-making have been extensively examined in economic contexts; this might provide a powerful starting point for understanding political decision-making. Here, we asked to what extent the neuropolitics literature to date has used conceptual frameworks and experimental designs that make contact with the reward-related approaches that have dominated decision neuroscience. We then asked whether the studies of political behavior that can be considered in this light implicate the brain regions that have been associated with subjective value related to economic rewards. We performed a systematic literature review to identify papers addressing the neural substrates of political behavior and extracted the fMRI studies reporting behavioral measures of subjective value as defined in decision neuroscience studies of reward. A minority of neuropolitics studies met these criteria and relatively few brain activation foci from these studies overlapped with regions where activity has been related to subjective value. These findings show modest influence of reward-focused decision neuroscience on neuropolitics research to date. Whether the neural substrates of subjective value identified in economic choice paradigms generalize to political choice thus remains an open question. We argue that systematically addressing the commonalities and differences in these two classes of value-based choice will be important in developing a more comprehensive model of the brain basis of human decision-making.
Gilbert, Heather J; Shackleton, Trevor M; Krumbholz, Katrin; Palmer, Alan R
The binaural masking level difference (BMLD) is a phenomenon whereby a signal that is identical at each ear (S0), masked by a noise that is identical at each ear (N0), can be made 12-15 dB more detectable by inverting the waveform of either the tone or noise at one ear (Sπ, Nπ). Single-cell responses to BMLD stimuli were measured in the primary auditory cortex of urethane-anesthetized guinea pigs. Firing rate was measured as a function of signal level of a 500 Hz pure tone masked by low-passed white noise. Responses were similar to those reported in the inferior colliculus. At low signal levels, the response was dominated by the masker. At higher signal levels, firing rate either increased or decreased. Detection thresholds for each neuron were determined using signal detection theory. Few neurons yielded measurable detection thresholds for all stimulus conditions, with a wide range in thresholds. However, across the entire population, the lowest thresholds were consistent with human psychophysical BMLDs. As in the inferior colliculus, the shape of the firing-rate versus signal-level functions depended on the neurons' selectivity for interaural time difference. Our results suggest that, in cortex, BMLD signals are detected from increases or decreases in the firing rate, consistent with predictions of cross-correlation models of binaural processing and that the psychophysical detection threshold is based on the lowest neural thresholds across the population. Copyright © 2015 Gilbert et al.
Hayashi, Atsuko; Nomura, Hiroshi; Mochizuki, Ruriko; Ohnuma, Ayumu; Kimpara, Teiko; Ootomo, Kazumasa; Hosokai, Yoshiyuki; Ishioka, Toshiyuki; Suzuki, Kyoko; Mori, Etsuro
Language is fairly well preserved in most patients with mild Alzheimer's disease, but writing ability seems to be impaired even in the early stages of the disease. To investigate the neural bases of writing impairments in Alzheimer's disease (AD), we examined the correlation between writing ability and regional cerebral blood flow (rCBF) in 52 Japanese patients with mild AD compared to 22 controls, using single photon emission computed tomography (SPECT). We found that, compared with control subjects, Kana writing to dictation and copying Kanji words were preserved in AD patients, but writing to dictating Kanji words was impaired. We classified the errors in the Kanji dictation task into four types to investigate the correlation between rCBF and the error type, as follows: non-response errors, phonologically plausible errors, non-phonologically plausible errors, and peripheral errors. Non-response errors, which indicated difficulty with retrieving Kanji graphic images, were the most frequent. When controlled for confounding factors, the number of non-response errors negatively correlated with rCBF in the left inferior parietal lobule, the posterior middle and inferior temporal gyri, and the posterior middle frontal gyrus. Thus, the impaired recall of Kanji in early Alzheimer's disease is related to dysfunctional cortical activity, which appears to be predominant in the left frontal, parietal, and temporal regions. Copyright © 2011 Elsevier Ltd. All rights reserved.
Rosso, Andrea L; Verghese, Joe; Metti, Andrea L; Boudreau, Robert M; Aizenstein, Howard J; Kritchevsky, Stephen; Harris, Tamara; Yaffe, Kristine; Satterfield, Suzanne; Studenski, Stephanie; Rosano, Caterina
To identify the shared neuroimaging signature of gait slowing and cognitive impairment. We assessed a cohort of older adults (n = 175, mean age 73 years, 57% female, 65% white) with repeated measures of gait speed over 14 years, MRI for gray matter volume (GMV) at year 10 or 11, and adjudicated cognitive status at year 14. Gait slowing was calculated by bayesian slopes corrected for intercepts, with higher values indicating faster decline. GMV was normalized to intracranial volume, with lower values indicating greater atrophy for 10 regions of interest (hippocampus, anterior and posterior cingulate, primary and supplementary motor cortices, posterior parietal lobe, middle frontal lobe, caudate, putamen, pallidum). Nonparametric correlations adjusted for demographics, comorbidities, muscle strength, and knee pain assessed associations of time to walk with GMV. Logistic regression models calculated odds ratios (ORs) of gait slowing with dementia or mild cognitive impairment with and without adjustment for GMV. Gait slowing was associated with cognitive impairment at year 14 (OR per 0.1 s/y slowing 1.47; 95% confidence interval 1.04-2.07). The right hippocampus was the only region that was related to both gait slowing (ρ = -0.16, p = 0.03) and cognitive impairment (OR 0.17, p = 0.009). Adjustment for right hippocampal volume attenuated the association of gait slowing with cognitive impairment by 23%. The association between gait slowing and cognitive impairment is supported by a shared neural substrate that includes a smaller right hippocampus. This finding underscores the value of long-term gait slowing as an early indicator of dementia risk. © 2017 American Academy of Neurology.
Full Text Available Learning to modulate one’s own brain activity is the fundament of neurofeedback (NF applications. Besides the neural networks directly involved in the generation and modulation of the neurophysiological parameter being specifically trained, more general determinants of NF efficacy such as self-referential processes and cognitive control have been frequently disregarded. Nonetheless, deeper insight into these cognitive mechanisms and their neuronal underpinnings sheds light on various open NF related questions concerning individual differences, brain-computer interface (BCI illiteracy as well as a more general model of NF learning. In this context, we investigated the neuronal substrate of these more general regulatory mechanisms that are engaged when participants believe that they are receiving NF. Twenty healthy participants (40-63 years, 10 female performed a sham NF paradigm during fMRI scanning. All participants were novices to NF-experiments and were instructed to voluntarily modulate their own brain activity based on a visual display of moving color bars. However, the bar depicted a recording and not the actual brain activity of participants. Reports collected at the end of the experiment indicate that participants were unaware of the sham feedback. In comparison to a passive watching condition, bilateral insula, anterior cingulate cortex and supplementary motor and dorsomedial and lateral prefrontal area were activated when participants actively tried to control the bar. In contrast, when merely watching moving bars, increased activation in the left angular gyrus was observed. These results show that the intention to control a moving bar is sufficient to engage a broad frontoparietal and cingulo-opercular network involved in cognitive control. The results of the present study indicate that tasks such as those generally employed in NF training recruit the neuronal correlates of cognitive control even when only sham NF is presented.
Park, Mona; Hennig-Fast, Kristina; Bao, Yan; Carl, Petra; Pöppel, Ernst; Welker, Lorenz; Reiser, Maximilian; Meindl, Thomas; Gutyrchik, Evgeny
Music communicates and evokes emotions. The number of studies on the neural correlates of musical emotion processing is increasing but few have investigated the factors that modulate these neural activations. Previous research has shown that personality traits account for individual variability of neural responses. In this study, we used functional magnetic resonance imaging (fMRI) to investigate how the dimensions Extraversion and Neuroticism are related to differences in brain reactivity to musical stimuli expressing the emotions happiness, sadness and fear. 12 participants (7 female, M=20.33 years) completed the NEO-Five Factor Inventory (NEO-FFI) and were scanned while performing a passive listening task. Neurofunctional analyses revealed significant positive correlations between Neuroticism scores and activations in bilateral basal ganglia, insula and orbitofrontal cortex in response to music expressing happiness. Extraversion scores were marginally negatively correlated with activations in the right amygdala in response to music expressing fear. Our findings show that subjects' personality may have a predictive power in the neural correlates of musical emotion processing and should be considered in the context of experimental group homogeneity. Copyright © 2013 Elsevier B.V. All rights reserved.
Markwardt, Neil T.; Stokol, Jodi; Rennaker, Robert L.
Glial scar formation around neural interfaces inhibits their ability to acquire usable signals from the surrounding neurons. To improve neural recording performance, the inflammatory response and glial scarring must be minimized. Previous work has indicated that meningeally derived cells participate in the immune response, and it is possible that the meninges may grow down around the shank of a neural implant, contributing to the formation of the glial scar. This study examines whether the glial scar can be reduced by placing a neural probe completely below the meninges. Rats were implanted with sets of loose microwire implants placed either completely below the meninges or implanted conventionally with the upper end penetrating the meninges, but not attached to the skull. Histological analysis was performed 4 weeks following surgical implantation to evaluate the glial scar. Our results found that sub-meninges implants showed an average reduction in reactive astrocyte activity of 63% compared to trans-meninges implants. Microglial activity was also reduced for sub-meninges implants. These results suggest that techniques that isolate implants from the meninges offer the potential to reduce the encapsulation response which should improve chronic recording quality and stability. PMID:23370311
Chizhova, L. A.; Burgdörfer, J.; Libisch, F.
Magneto-optical transitions between Landau levels can provide precise spectroscopic information on the electronic structure and excitation spectra of graphene, enabling probes of substrate and many-body effects. We calculate the magneto-optical conductivity of large-size graphene flakes using a tight-binding approach. Our method allows us to directly compare the magneto-optical response of an isolated graphene flake with one aligned on hexagonal boron nitride giving rise to a periodic superlattice potential. The substrate interaction induces band gaps away from the Dirac point. In the presence of a perpendicular magnetic field, Landau-level-like structures emerge from these zero-field band gaps. The energy dependence of these satellite structures is, however, not easily accessible by conventional probes of the density of states by varying the back-gate voltage. Here we propose the magneto-optical probing of the superlattice perturbed spectrum. Our simulation includes magneto-excitonic effects in first-order perturbation theory. Our approach yields a quantitative explanation of recently observed Landau-level-dependent renormalizations of the Fermi velocity.
Vega-Torres, Julio David; Haddad, Elizabeth; Lee, Jeong Bin; Kalyan-Masih, Priya; George, Wanda I Maldonado; Pérez, Leonardo López; Vázquez, Darla M Piñero; Torres, Yaría Arroyo; Santana, José M Santiago; Obenaus, Andre; Figueroa, Johnny D
Post-traumatic stress disorder (PTSD) and obesity are highly prevalent in adolescents. Emerging findings from our laboratory and others are consistent with the novel hypothesis that obese individuals may be predisposed to developing PTSD. Given that aberrant fear responses are pivotal in the pathogenesis of PTSD, the objective of this study was to determine the impact of an obesogenic Western-like high-fat diet (WD) on neural substrates associated with fear. Adolescent Lewis rats (n = 72) were fed with either the experimental WD (41.4% kcal from fat) or the control diet. The fear-potentiated startle paradigm was used to determine sustained and phasic fear responses. Diffusion tensor imaging metrics and T2 relaxation times were used to determine the structural integrity of the fear circuitry including the medial prefrontal cortex (mPFC) and the basolateral complex of the amygdala (BLA). The rats that consumed the WD exhibited attenuated fear learning and fear extinction. These behavioral impairments were associated with oversaturation of the fear circuitry and astrogliosis. The BLA T2 relaxation times were significantly decreased in the WD rats relative to the controls. We found elevated fractional anisotropy in the mPFC of the rats that consumed the WD. We show that consumption of a WD may lead to long-lasting damage to components of the fear circuitry. Our findings demonstrate that consumption of an obesogenic diet during adolescence has a profound impact in the maturation of the fear neurocircuitry. The implications of this research are significant as they identify potential biomarkers of risk for psychopathology in the growing obese population. Copyright © 2018 Elsevier Inc. All rights reserved.
Gayet, Surya; Guggenmos, Matthias; Christophel, Thomas B; Haynes, John-Dylan; Paffen, Chris L E; Van der Stigchel, Stefan; Sterzer, Philipp
Visual working memory (VWM) is used to maintain visual information available for subsequent goal-directed behavior. The content of VWM has been shown to affect the behavioral response to concurrent visual input, suggesting that visual representations originating from VWM and from sensory input draw upon a shared neural substrate (i.e., a sensory recruitment stance on VWM storage). Here, we hypothesized that visual information maintained in VWM would enhance the neural response to concurrent visual input that matches the content of VWM. To test this hypothesis, we measured fMRI BOLD responses to task-irrelevant stimuli acquired from 15 human participants (three males) performing a concurrent delayed match-to-sample task. In this task, observers were sequentially presented with two shape stimuli and a retro-cue indicating which of the two shapes should be memorized for subsequent recognition. During the retention interval, a task-irrelevant shape (the probe) was briefly presented in the peripheral visual field, which could either match or mismatch the shape category of the memorized stimulus. We show that this probe stimulus elicited a stronger BOLD response, and allowed for increased shape-classification performance, when it matched rather than mismatched the concurrently memorized content, despite identical visual stimulation. Our results demonstrate that VWM enhances the neural response to concurrent visual input in a content-specific way. This finding is consistent with the view that neural populations involved in sensory processing are recruited for VWM storage, and it provides a common explanation for a plethora of behavioral studies in which VWM-matching visual input elicits a stronger behavioral and perceptual response. SIGNIFICANCE STATEMENT Humans heavily rely on visual information to interact with their environment and frequently must memorize such information for later use. Visual working memory allows for maintaining such visual information in the mind
van Well, S.; Visser, R.M.; Scholte, H.S.; Kindt, M.
To provide insight into individual differences in fear learning, we examined the emotional and cognitive expressions of discriminative fear conditioning in direct relation to its neural substrates. Contrary to previous behavioral-neural (fMRI) research on fear learning—in which the emotional
Full Text Available Agar substrates for in vitro culture are well adapted to plant micropropagation, but not to plant rooting and acclimatization. Conversely, paper-pulp-based substrates appear as potentially well adapted for in vitro culture and functional root production. To reinforce this hypothesis, this study compares in vitro development of nemesia on several substrates. Strong differences between nemesia roots growing in agar or in paper-pulp substrates were evidenced through scanning electron microscopy. Roots developed in agar have shorter hairs, larger rhizodermal cells, and less organized root caps than those growing on paper pulp. In conclusion, it should be noted that in this study, in vitro microporous substrates such as paper pulp lead to the production of similar root hairs to those found in greenhouse peat substrates. Consequently, if agar could be used for micropropagation, rooting, and plant acclimatization, enhancement could be achieved if rooting stage was performed on micro-porous substrates such as paper pulp.
Meltzer-Asscher, Aya; Schuchard, Julia; den Ouden, Dirk-Bart; Thompson, Cynthia K
This study examines the neural correlates of processing verbal entries with multiple argument structures using fMRI. We compared brain activation in response to 'alternating transitivity' verbs, corresponding to two different verbal alternates - one transitive and one intransitive - and simple verbs, with only one, intransitive, thematic grid. Fourteen young healthy participants performed a lexical decision task with the two verb types. Results showed significantly greater activation in the angular and supramarginal gyri (BAs 39 and 40) extending to the posterior superior and middle temporal gyri bilaterally, for alternating compared to simple verbs. Additional activation was detected in bilateral middle and superior frontal gyri (BAs 8 and 9). The opposite contrast, simple compared to alternating verbs, showed no significant differential activation in any regions of the brain. These findings are consistent with previous studies implicating a posterior network including the superior temporal, supramarginal and angular gyri for processing verbs with multiple thematic roles, as well as with those suggesting involvement of the middle and superior frontal gyri in lexical ambiguity processing. However, because 'alternating transitivity' verbs differ from simple intransitives with regard to both the number of thematic grids (two vs. one) and the number of thematic roles (two vs. one), our findings do not distinguish between activations associated with these two differences.
Meltzer-Asscher, Aya; Schuchard, Julia; den Ouden, Dirk-Bart; Thompson, Cynthia K.
This study examines the neural correlates of processing verbal entries with multiple argument structures using fMRI. We compared brain activation in response to ‘alternating transitivity’ verbs, corresponding to two different verbal alternates – one transitive and one intransitive - and simple verbs, with only one, intransitive, thematic grid. Fourteen young healthy participants performed a lexical decision task with the two verb types. Results showed significantly greater activation in the angular and supramarginal gyri (BAs 39 and 40) extending to the posterior superior and middle temporal gyri bilaterally, for alternating compared to simple verbs. Additional activation was detected in bilateral middle and superior frontal gyri (BAs 8 and 9). The opposite contrast, simple compared to alternating verbs, showed no significant differential activation in any regions of the brain. These findings are consistent with previous studies implicating a posterior network including the superior temporal, supramarginal and angular gyri for processing verbs with multiple thematic roles, as well as with those suggesting involvement of the middle and superior frontal gyri in lexical ambiguity processing. However, because ‘alternating transitivity’ verbs differ from simple intransitives with regard to both the number of thematic grids (two vs. one) and the number of thematic roles (two vs. one), our findings do not distinguish between activations associated with these two differences. PMID:26139954
Tseng, Ming-Tsung; Kong, Yazhuo; Eippert, Falk; Tracey, Irene
To convert a painful stimulus into a briefly maintainable construct when the painful stimulus is no longer accessible is essential to guide human behavior and avoid dangerous situations. Because of the aversive nature of pain, this encoding process might be influenced by emotional aspects and could thus vary across individuals, but we have yet to understand both the basic underlying neural mechanisms as well as potential interindividual differences. Using fMRI in combination with a delayed-discrimination task in healthy volunteers of both sexes, we discovered that brain regions involved in this working memory encoding process were dissociable according to whether the to-be-remembered stimulus was painful or not, with the medial thalamus and the rostral anterior cingulate cortex encoding painful and the primary somatosensory cortex encoding nonpainful stimuli. Encoding of painful stimuli furthermore significantly enhanced functional connectivity between the thalamus and medial prefrontal cortex (mPFC). With regards to emotional aspects influencing encoding processes, we observed that more anxious participants showed significant performance advantages when encoding painful stimuli. Importantly, only during the encoding of pain, the interindividual differences in anxiety were associated with the strength of coupling between medial thalamus and mPFC, which was furthermore related to activity in the amygdala. These results indicate not only that there is a distinct signature for the encoding of a painful experience in humans, but also that this encoding process involves a strong affective component. SIGNIFICANCE STATEMENT To convert the sensation of pain into a briefly maintainable construct is essential to guide human behavior and avoid dangerous situations. Although this working memory encoding process is implicitly contained in the majority of studies, the underlying neural mechanisms remain unclear. Using fMRI in a delayed-discrimination task, we found that the
Fortier, Emilie; Noreau, Anne; Lepore, Franco; Boivin, Michel; Pérusse, Daniel; Rouleau, Guy A; Beauregard, Mario
CREB1 has previously been implicated in mood disorders, suicide, and antidepressant response. There is some evidence that the T allele in rs4675690, a single-nucleotide polymorphism near the CREB1 gene, is involved in the modulation of neural responses to negative stimuli. It is not known whether differential brain activity during negative mood state appears early in life in T allele carriers. Functional magnetic resonance imaging (fMRI) was used to measure brain activity, during a transient state of sadness, in children homozygous for the T allele or the C allele. This primary emotion was selected given that it is the prevailing mood in major depressive disorder (MDD). Blood-oxygen-level dependent (BOLD) signal changes were measured while subjects viewed blocks of neutral film excerpts and blocks of sad film excerpts. There was significantly greater BOLD activation in the TT group, compared to the CC group, in the right dorsal anterior cingulate cortex (Brodmann area [BA 24]), right putamen, right caudate nucleus and left anterior temporal pole (BA 21), when the brain activity associated with the viewing of the emotionally neutral film excerpts was subtracted from that associated with the viewing of the sad film excerpts. A replication study using larger samples may be required for more definitive conclusions. The different pattern of regional brain activation found here during transient sadness - in children carrying the T allele, compared to those carrying the C allele - might increase later in life susceptibility to emotional dysregulation and depressive symptoms. Copyright © 2011 Elsevier B.V. All rights reserved.
Han, Shihui; Northoff, Georg
Our brains and minds are shaped by our experiences, which mainly occur in the context of the culture in which we develop and live. Although psychologists have provided abundant evidence for diversity of human cognition and behaviour across cultures, the question of whether the neural correlates of human cognition are also culture-dependent is often not considered by neuroscientists. However, recent transcultural neuroimaging studies have demonstrated that one's cultural background can influence the neural activity that underlies both high- and low-level cognitive functions. The findings provide a novel approach by which to distinguish culture-sensitive from culture-invariant neural mechanisms of human cognition.
Full Text Available Intense development of research equipment leads directly to increasing cognitive abilities. However, along with the raising amount of data generated, the development of the techniques allowing the analysis is also essential. Currently, one of the most dynamically developing branch of computer science and mathematics are the Artificial Neural Networks (ANN. Their main advantage is very high ability to solve the regression and approximation issues. This paper presents the possibility of application of artificial intelligence methods to optimize the selection of co-substrates intended for methane fermentation of chicken manure. 4-layer MLP network has proven to be the optimal structure modeling the obtained empirical data.
Song, Penglong; Wang, Ningyu; Wang, Hui; Xie, Yan; Jia, Jun; Li, Huijun
The precedence effect (PE) is thought to be beneficial for proper localization and perception of sounds. The majority of recent physiological studies focus on the neural discharges correlated with PE in the inferior colliculus (IC). Pentobarbital anesthesia is widely used in physiological studies. However, little is known of the effect of pentobarbital on the discharge of neurons in PE. Neuronal responses in the IC from 23 male SD rats were recorded by standard extracellular recording techniques following presentation of 4 ms white noise bursts, presented from either or both of two loud speakers, at different interstimulus delays (ISDs). The neural responses were recorded for off-line analysis before or after intraperitoneal administration of pentobarbital at a loading or maintenance dose. Data were assessed by one-way repeated measures analysis of variance and pairwise comparisons. When the ipsilateral stimuli were leading, pentobarbital at a loading dose significantly increased normalized response to lagging stimuli during recovery from anesthesia. However, it was not the case when the contralateral stimuli were leading. At a maintenance dose, the normalized response to lagging stimuli were significantly reduced, independent of whether contralateral or ipsilateral stimuli were leading. These data show that pentobarbital have no effect on the normalized response of leading stimuli but can prolong the recovery time of lagging stimuli to paired sources produced PE illusions, which was gradually attenuated during recovery from anesthesia. Thus, extracellular recording immediately after administration of pentobarbital should be avoided in physiological studies of neural correlates of PE. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
is connected to thousands of other neurons. The rst question is: how to model neural networks through stochastic processes? A multivariate Ornstein-Uhlenbeck process, obtained as a diffusion approximation of a jump process, is the proposed answer. Obviously, dependencies between neurons imply dependencies...... between their spike times. Therefore, the second question is: how to detect neural network connectivity from simultaneously recorded spike trains? Answering this question corresponds to investigate the joint distribution of sequences of rst passage times. A non-parametric method based on copulas...... generation of pikes. When a stimulus is applied to the network, the spontaneous rings may prevail and hamper detection of the effects of the stimulus. Therefore, the spontaneous rings cannot be ignored and the response latency has to be detected on top of a background signal. Everything becomes more dicult...
Weng, Helen Y; Fox, Andrew S; Shackman, Alexander J; Stodola, Diane E; Caldwell, Jessica Z K; Olson, Matthew C; Rogers, Gregory M; Davidson, Richard J
Compassion is a key motivator of altruistic behavior, but little is known about individuals' capacity to cultivate compassion through training. We examined whether compassion may be systematically trained by testing whether (a) short-term compassion training increases altruistic behavior and (b) individual differences in altruism are associated with training-induced changes in neural responses to suffering. In healthy adults, we found that compassion training increased altruistic redistribution of funds to a victim encountered outside of the training context. Furthermore, increased altruistic behavior after compassion training was associated with altered activation in brain regions implicated in social cognition and emotion regulation, including the inferior parietal cortex and dorsolateral prefrontal cortex (DLPFC), and in DLPFC connectivity with the nucleus accumbens. These results suggest that compassion can be cultivated with training and that greater altruistic behavior may emerge from increased engagement of neural systems implicated in understanding the suffering of other people, executive and emotional control, and reward processing.
Petrican, Raluca; Rosenbaum, R. Shayna; Grady, Cheryl
responsiveness to nonverbal affective cues, while also suggesting one explanation for the suppressors’ poorer cognitive performance in social situations. Moreover, our results point to a potential neural mechanism supporting the development and perpetuation of expressive suppression as an emotion regulation strategy. PMID:26365712
Hawkes, Teresa D; Manselle, Wayne; Woollacott, Marjorie H
We report the first controlled study of Tai Chi effects on the P300 event-related potential, a neuroelectric index of human executive function. Tai Chi is a form of exercise and moving meditation. Exercise and meditation have been associated with enhanced executive function. This cross-sectional, controlled study utilized the P300 event-related potential (ERP) to compare executive network neural function between self-selected long-term Tai Chi, meditation, aerobic fitness, and sedentary groups. We hypothesized that because Tai Chi requires moderate aerobic and mental exertion, this group would show similar or better executive neural function compared to meditation and aerobic exercise groups. We predicted all health training groups would outperform sedentary controls. Fifty-four volunteers (Tai Chi, n=10; meditation, n=16; aerobic exercise, n=16; sedentary, n=12) were tested with the Rockport 1-mile walk (estimated VO2 Max), a well-validated measure of aerobic capacity, and an ecologically valid visuo-spatial, randomized, alternating runs Task Switch test during dense-array electroencephalographic (EEG) recording. Only Tai Chi and meditation plus exercise groups demonstrated larger P3b ERP switch trial amplitudes compared to sedentary controls. Our results suggest long-term Tai Chi practice, and meditation plus exercise may benefit the neural substrates of executive function.
Loui, Psyche; Zamm, Anna; Schlaug, Gottfried
People with Absolute Pitch can categorize musical pitches without a reference, whereas people with tone-color synesthesia can see colors when hearing music. Both of these special populations perceive music in an above-normal manner. In this study we asked whether AP possessors and tone-color synesthetes might recruit specialized neural mechanisms during music listening. Furthermore, we tested the degree to which neural substrates recruited for music listening may be shared between these special populations. AP possessors, tone-color synesthetes, and matched controls rated the perceived arousal levels of musical excerpts in a sparse-sampled fMRI study. Both APs and synesthetes showed enhanced superior temporal gyrus (STG, secondary auditory cortex) activation relative to controls during music listening, with left-lateralized enhancement in the APs and right-lateralized enhancement in the synesthetes. When listening to highly arousing excerpts, AP possessors showed additional activation in the left STG whereas synesthetes showed enhanced activity in the bilateral lingual gyrus and inferior temporal gyrus (late visual areas). Results support both shared and distinct neural enhancements in AP and synesthesia: common enhancements in early cortical mechanisms of perceptual analysis, followed by relative specialization in later association and categorization processes that support the unique behaviors of these special populations during music listening. PMID:23508195
Chen, Zhencai; De Beuckelaer, Alain; Wang, Xu; Liu, Jia
Recent studies revealed spontaneous neural activity to be associated with fluid intelligence (gF) which is commonly assessed by Raven's Advanced Progressive Matrices, and embeds two types of reasoning: visuospatial and verbal-analytic reasoning. With resting-state fMRI data, using global brain connectivity (GBC) analysis which averages functional connectivity of a voxel in relation to all other voxels in the brain, distinct neural correlates of these two reasoning types were found. For visuospatial reasoning, negative correlations were observed in both the primary visual cortex (PVC) and the precuneus, and positive correlations were observed in the temporal lobe. For verbal-analytic reasoning, negative correlations were observed in the right inferior frontal gyrus (rIFG), dorsal anterior cingulate cortex and temporoparietal junction, and positive correlations were observed in the angular gyrus. Furthermore, an interaction between GBC value and type of reasoning was found in the PVC, rIFG and the temporal lobe. These findings suggest that visuospatial reasoning benefits more from elaborate perception to stimulus features, whereas verbal-analytic reasoning benefits more from feature integration and hypothesis testing. In sum, the present study offers, for different types of reasoning in gF, first empirical evidence of separate neural substrates in the resting brain.
Hawes, Daniel R; DeYoung, Colin G; Gray, Jeremy R; Rustichini, Aldo
The relations between intelligence (IQ) and neural responses to monetary gains and losses were investigated in a simple decision task. In 94 healthy adults, typical responses of striatal blood oxygen level-dependent (BOLD) signal after monetary reward and punishment were weaker for subjects with higher IQ. IQ-moderated differential responses to gains and losses were also found for regions in the medial prefrontal cortex, posterior cingulate cortex, and left inferior frontal cortex. These regions have previously been identified with the subjective utility of monetary outcomes. Analysis of subjects' behavior revealed a correlation between IQ and the extent to which choices were related to experienced decision outcomes in preceding trials. Specifically, higher IQ predicted behavior to be more strongly correlated with an extended period of previously experienced decision outcomes, whereas lower IQ predicted behavior to be correlated exclusively to the most recent decision outcomes. We link these behavioral and imaging findings to a theoretical model capable of describing a role for intelligence during the evaluation of rewards generated by unknown probabilistic processes. Our results demonstrate neural differences in how people of different intelligence respond to experienced monetary rewards and punishments. Our theoretical discussion offers a functional description for how these individual differences may be linked to choice behavior. Together, our results and model support the hypothesis that observed correlations between intelligence and preferences may be rooted in the way decision outcomes are experienced ex post, rather than deriving exclusively from how choices are evaluated ex ante.
Hjerrild, Majbrit; Stensballe, Allan; Rasmussen, Thomas E
Protein phosphorylation plays a key role in cell regulation and identification of phosphorylation sites is important for understanding their functional significance. Here, we present an artificial neural network algorithm: NetPhosK (http://www.cbs.dtu.dk/services/NetPhosK/) that predicts protein...
Zhang, Ruibin; Geng, Xiujuan; Lee, Tatia M C
An influential hypothesis from the last decade proposed that regions within the right inferior frontal cortex of the human brain were dedicated to supporting response inhibition. There is growing evidence, however, to support an alternative model, which proposes that neural areas associated with specific inhibitory control tasks co-exist as common network mechanisms, supporting diverse cognitive processes. This meta-analysis of 225 studies comprising 323 experiments examined the common and distinct neural correlates of cognitive processes for response inhibition, namely interference resolution, action withholding, and action cancellation. Activation coordinates for each subcategory were extracted using multilevel kernel density analysis (MKDA). The extracted activity patterns were then mapped onto the brain functional network atlas to derive the common (i.e., process-general) and distinct (i.e., domain-oriented) neural network correlates of these processes. Independent of the task types, activation of the right hemispheric regions (inferior frontal gyrus, insula, median cingulate, and paracingulate gyri) and superior parietal gyrus was common across the cognitive processes studied. Mapping the activation patterns to a brain functional network atlas revealed that the fronto-parietal and ventral attention networks were the core neural systems that were commonly engaged in different processes of response inhibition. Subtraction analyses elucidated the distinct neural substrates of interference resolution, action withholding, and action cancellation, revealing stronger activation in the ventral attention network for interference resolution than action inhibition. On the other hand, action withholding/cancellation primarily engaged the fronto-striatal circuit. Overall, our results suggest that response inhibition is a multidimensional cognitive process involving multiple neural regions and networks for coordinating optimal performance. This finding has significant
von Trapp, Gardiner; Buran, Bradley N; Sen, Kamal; Semple, Malcolm N; Sanes, Dan H
The detection of a sensory stimulus arises from a significant change in neural activity, but a sensory neuron's response is rarely identical to successive presentations of the same stimulus. Large trial-to-trial variability would limit the central nervous system's ability to reliably detect a stimulus, presumably affecting perceptual performance. However, if response variability were to decrease while firing rate remained constant, then neural sensitivity could improve. Here, we asked whether engagement in an auditory detection task can modulate response variability, thereby increasing neural sensitivity. We recorded telemetrically from the core auditory cortex of gerbils, both while they engaged in an amplitude-modulation detection task and while they sat quietly listening to the identical stimuli. Using a signal detection theory framework, we found that neural sensitivity was improved during task performance, and this improvement was closely associated with a decrease in response variability. Moreover, units with the greatest change in response variability had absolute neural thresholds most closely aligned with simultaneously measured perceptual thresholds. Our findings suggest that the limitations imposed by response variability diminish during task performance, thereby improving the sensitivity of neural encoding and potentially leading to better perceptual sensitivity. The detection of a sensory stimulus arises from a significant change in neural activity. However, trial-to-trial variability of the neural response may limit perceptual performance. If the neural response to a stimulus is quite variable, then the response on a given trial could be confused with the pattern of neural activity generated when the stimulus is absent. Therefore, a neural mechanism that served to reduce response variability would allow for better stimulus detection. By recording from the cortex of freely moving animals engaged in an auditory detection task, we found that variability
Mueller, Stefanie Verena; Mihov, Yoan; Federspiel, Andrea; Wiest, Roland; Hasler, Gregor
Bulimia nervosa has been associated with a dysregulated catecholamine system. Nevertheless, the influence of this dysregulation on bulimic symptoms, on neural activity, and on the course of the illness is not clear yet. An instructive paradigm for directly investigating the relationship between catecholaminergic functioning and bulimia nervosa has involved the behavioral and neural responses to experimental catecholamine depletion. The purpose of this study was to examine the neural substrate of catecholaminergic dysfunction in bulimia nervosa and its relationship to relapse. In a randomized, double-blind and crossover study design, catecholamine depletion was achieved by using the oral administration of alpha-methyl-paratyrosine (AMPT) over 24 h in 18 remitted bulimic (rBN) and 22 healthy (HC) female participants. Cerebral blood flow (CBF) was measured using a pseudo continuous arterial spin labeling (pCASL) sequence. In a follow-up telephone interview, bulimic relapse was assessed. Following AMPT, rBN participants revealed an increased vigor reduction and CBF decreases in the pallidum and posterior midcingulate cortex (pMCC) relative to HC participants showing no CBF changes in these regions. These results indicated that the pallidum and the pMCC are the functional neural correlates of the dysregulated catecholamine system in bulimia nervosa. Bulimic relapse was associated with increased depressive symptoms and CBF reduction in the hippocampus/parahippocampal gyrus following catecholamine depletion. AMPT-induced increased CBF in this region predicted staying in remission. These findings demonstrated the importance of depressive symptoms and the stress system in the course of bulimia nervosa. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.
Flexas, Albert; de Miguel, Pedro; Cela-Conde, Camilo J.; Munar, Enric
This study provides exploratory evidence about how behavioral and neural responses to standard moral dilemmas are influenced by religious belief. Eleven Catholics and 13 Atheists (all female) judged 48 moral dilemmas. Differential neural activity between the two groups was found in precuneus and in prefrontal, frontal and temporal regions. Furthermore, a double dissociation showed that Catholics recruited different areas for deontological (precuneus; temporoparietal junction) and utilitarian moral judgments [dorsolateral prefrontal cortex (DLPFC); temporal poles], whereas Atheists did not (superior parietal gyrus for both types of judgment). Finally, we tested how both groups responded to personal and impersonal moral dilemmas: Catholics showed enhanced activity in DLPFC and posterior cingulate cortex during utilitarian moral judgments to impersonal moral dilemmas and enhanced responses in anterior cingulate cortex and superior temporal sulcus during deontological moral judgments to personal moral dilemmas. Our results indicate that moral judgment can be influenced by an acquired set of norms and conventions transmitted through religious indoctrination and practice. Catholic individuals may hold enhanced awareness of the incommensurability between two unequivocal doctrines of the Catholic belief set, triggered explicitly in a moral dilemma: help and care in all circumstances—but thou shalt not kill. PMID:23160812
Braams, Barbara R; Güroğlu, Berna; de Water, Erik; Meuwese, Rosa; Koolschijn, P Cédric; Peper, Jiska S; Crone, Eveline A
Prior studies have suggested that positive social interactions are experienced as rewarding. Yet, it is not well understood how social relationships influence neural responses to other persons' gains. In this study, we investigated neural responses during a gambling task in which healthy participants (N = 31; 18 females) could win or lose money for themselves, their best friend or a disliked other (antagonist). At the moment of receiving outcome, person-related activity was observed in the dorsal medial prefrontal cortex (dmPFC), precuneus and temporal parietal junction (TPJ), showing higher activity for friends and antagonists than for self, and this activity was independent of outcome. The only region showing an interaction between the person-participants played for and outcome was the ventral striatum. Specifically, the striatum was more active following gains than losses for self and friends, whereas for the antagonist this pattern was reversed. Together, these results show that, in a context with social and reward information, social aspects are processed in brain regions associated with social cognition (mPFC, TPJ), and reward aspects are processed in primary reward areas (striatum). Furthermore, there is an interaction of social and reward information in the striatum, such that reward-related activity was dependent on social relationship. © The Author (2013). Published by Oxford University Press. For Permissions, please email: email@example.com.
Lueken, Ulrike; Hilbert, Kevin; Stolyar, Veronika; Maslowski, Nina I; Beesdo-Baum, Katja; Wittchen, Hans-Ulrich
Depending on threat proximity, different defensive behaviours are mediated by a descending neural network involving forebrain (distal threat) vs midbrain areas (proximal threat). Compared to healthy subjects, it can be assumed that phobics are characterized by shortened defensive distances on a behavioural and neural level. This study aimed at characterizing defensive reactivity in two subtypes of specific phobia [snake (SP) and dental phobics (DP)]. Using functional magnetic resonance imaging (fMRI), n = 39 subjects (13 healthy controls, HC; 13 SP; 13 DP) underwent an event-related fMRI task employing an anticipation (5-10 s) and immediate perception phase (phobic pictures and matched neutral stimuli; 1250 ms) to modulate defensive distance. Although no differential brain activity in any comparisons was observed in DP, areas associated with defensive behaviours (e.g. amygdala, hippocampus, midbrain) were activated in SP. Decreasing defensive distance in SP was characterized by a shift to midbrain activity. Present findings substantiate differences between phobia types in their physiological and neural organization that can be expanded to early stages of defensive behaviours. Findings may contribute to a better understanding of the dynamic organization of defensive reactivity in different types of phobic fear. © The Author (2013). Published by Oxford University Press. For Permissions, please email: firstname.lastname@example.org.
Perkes, Ammon; White, David; Wild, J Martin; Schmidt, Marc
Songbirds hold a prominent role in the fields of neurobiology, evolution, and social behavior. Many of these fields have assumed that females lacked the ability to produce song and have therefore treated song as a male-specific behavior. Consequently, much of our understanding regarding the evolution and neural control of song behavior has been driven by these assumptions. Here we review literature from diverse fields to provide a broader perspective of the role of females in vocal communication and courtship. Recent evidence indicates that song evolved in both males and females and instances of female song are still common. The specialized neural circuit known as the "song system," which is necessary for singing in males, is also present in females, including those that do not sing, implying broader functions that include evaluating male song and controlling courtship behavior. In addition to having flexible, individualized preferences, females actively shape their social network through their interactions with males, females, and juveniles. We suggest that by developing more accurate hypotheses concerning the role of females we may better understand the evolution and neural mechanisms of song production and courtship behavior. Copyright © 2017. Published by Elsevier B.V.
Full Text Available Avoidance learning poses a challenge for reinforcement-based theories of instrumental conditioning, because once an aversive outcome is successfully avoided an individual may no longer experience extrinsic reinforcement for their behavior. One possible account for this is to propose that avoiding an aversive outcome is in itself a reward, and thus avoidance behavior is positively reinforced on each trial when the aversive outcome is successfully avoided. In the present study we aimed to test this possibility by determining whether avoidance of an aversive outcome recruits the same neural circuitry as that elicited by a reward itself. We scanned 16 human participants with functional MRI while they performed an instrumental choice task, in which on each trial they chose from one of two actions in order to either win money or else avoid losing money. Neural activity in a region previously implicated in encoding stimulus reward value, the medial orbitofrontal cortex, was found to increase, not only following receipt of reward, but also following successful avoidance of an aversive outcome. This neural signal may itself act as an intrinsic reward, thereby serving to reinforce actions during instrumental avoidance.
Susan B. Perlman
Full Text Available Irritability is an aspect of the negative affectivity domain of temperament, but in severe and dysregulated forms is a symptom of a range of psychopathologies. Better understanding of the neural underpinnings of irritability, outside the context of specific disorders, can help to understand normative variation but also characterize its clinical salience in psychopathology diagnosis. This study assessed brain activation during reward and frustration, domains of behavioral deficits in childhood irritability. Children (age 6–9 presenting in mental health clinics for extreme and impairing irritability (n = 26 were compared to healthy children (n = 28. Using developmentally sensitive methods, neural activation was measured via a negative mood induction paradigm during fMRI scanning. The clinical group displayed more activation of the anterior cingulate and middle frontal gyrus during reward, but less activation during frustration, than healthy comparison children. The opposite pattern was found in the posterior cingulate. Further, in clinical subjects, parent report of irritability was dimensionally related to decreased activation of the anterior cingulate and striatum during frustration. The results of this study indicate neural dysfunction within brain regions related to reward processing, error monitoring, and emotion regulation underlying clinically impairing irritability. Results are discussed in the context of a growing field of neuroimaging research investigating irritable children.
Beaton, Elliott A; Schmidt, Louis A; Schulkin, Jay; Antony, Martin M; Swinson, Richard P; Hall, Geoffrey B
The shy-bold continuum is a fundamental behavioral trait conserved across human and nonhuman animals. Individual differences along the shy-bold continuum are presumed to arise from, and are maintained by, differences in the excitability of forebrain limbic areas involved in the evaluation of stimulus saliency. To test this hypothesis, the authors conducted an event-related functional MRI (fMRI) study in which brain scans were acquired on shy and bold adults during the presentation of neutral stranger and personally familiar faces. Shy adults exhibited greater bilateral amygdala activation during the presentation of stranger faces and greater left amygdala activation during personally familiar faces than their bold counterparts. Bold adults exhibited greater bilateral nucleus accumbens activation in response to stranger and personally familiar faces than shy adults. Findings suggest that there are distinct neural substrates underlying and maintaining individual differences along a shy-bold continuum in humans. (Copyright) 2008 APA, all rights reserved.
Blagodatskaya, Evgenia; Khomyakov, Nikita; Myachina, Olga; Blagodatsky, Sergey; Kuzyakov, Yakov
Decomposition of organic substrates in soil is enzymes mediated process. Activity of enzymes is substrate dependent and mostly increases with temperature up to an optimum. Quantity of the substrate is the main limiting factor for enzymatic or microbial heterotrophic activity in mountain soils. It remains unclear whether the lack of available substrate can counterbalance the temperature induced acceleration of mineralization of soil organic carbon caused by global warming. Different mechanisms of enzymes response to temperature suggested for low and high substrate availability were never proved for real soil conditions. The ecological importance of temperature acclimation of enzyme activity also remains to be tested. To estimate the possible "temperature acclimation" of enzyme activity we compared the responses of enzymes-catalyzed reactions using the natural climatic differences in soils located at 950, 2010, 2435, 2780 and 3020 m altitudes of Mt. Kilimanjaro. Basing on Michaelis-Menten kinetics we determined the enzymes affinity to substrate (Km) and mineralization potential of heterotrophic microorganisms (Vmax) 1) for three hydrolytic enzymes: β-1,4-glucosidase, N-acetyl- β -D-glucosaminidase and phosphatase by the application of fluorogenically labeled substrates and 2) for mineralization of 14C-labeled glucose by substrate-dependent respiratory response. Here we show that the amount of available substrate is responsible for temperature sensitivity of hydrolysis of polymers in soil, whereas monomers oxidation to CO2 does not depend on substrate amount and is mainly temperature governed. We also found different response of Km to warming for the processes of depolymerisation and monomers oxidation. So, the enzymes responsible for hydrolysis of polymers and for monomers oxidation have different temperature sensitivity. Both substrate affinity and heterotrophic potential showed the weaker response to increasing temperature at high versus low altitudes. This
Full Text Available A fundamental question in human brain plasticity is how sensory, motor, and cognitive functions adapt in the process of skill acquisition extended over a period of many years. Recently, there has emerged a growing interest in cognitive neuroscience on studying the functional and structural differences in the brains of elite athletes. Elite performance in sports, music or the arts, allows us to observe sensorimotor and cognitive performance at the limits of human capability. In this mini-review we look at driving expertise. The emerging brain imaging literature on the neural substrates of real and simulated driving is reviewed (for the first time, and used as the context for interpreting recent findings on the differences between racing drivers and non-athlete controls. Also the cognitive psychology and cognitive neuroscience of expertise are discussed.
Chen, Yvonnes; Fowler, Carina H; Papa, Vlad B; Lepping, Rebecca J; Brucks, Morgan G; Fox, Andrew T; Martin, Laura E
Although adolescents are a group heavily targeted by the e-cigarette industry, research in cue-reactivity has not previously examined adolescents' behavioral and neural responses to e-cigarette advertising. This study addressed this gap through two experiments. In Experiment One, adult traditional cigarette smokers (n = 41) and non-smokers (n = 41) answered questions about e-cigarette and neutral advertising images. The 40 e-cigarette advertising images that most increased desire to use the product were matched to 40 neutral advertising images with similar content. In Experiment Two, the 80 advertising images selected in Experiment One were presented to adolescents (n = 30) during an functional magnetic resonance imaging brain scan. There was a range of traditional cigarette smoking across the sample with some adolescents engaging in daily smoking and others who had never smoked. Adolescents self-reported that viewing the e-cigarette advertising images increased their desire to smoke. Additionally, all participants regardless of smoking statuses showed significantly greater brain activation to e-cigarette advertisements in areas associated with cognitive control (left middle frontal gyrus), reward (right medial frontal gyrus), visual processing/attention (left lingual gyrus/fusiform gyrus, right inferior parietal lobule, left posterior cingulate, left angular gyrus) and memory (right parahippocampus, left insula). Further, an exploratory analysis showed that compared with age-matched non-smokers (n = 7), adolescent smokers (n = 7) displayed significantly greater neural activation to e-cigarette advertising images in the left inferior temporal gyrus/fusiform gyrus, compared with their responses to neutral advertising images. Overall, participants' brain responses to e-cigarette advertisements suggest a need to further investigate the long-run impact of e-cigarette advertising on adolescents. © 2017 Society for the Study of Addiction.
Full Text Available Economic status played an important role in the modulation of economic decision making. The present fMRI study aimed at investigating how economic status modulated behavioral and neural responses to unfairness in a modified Ultimatum Game (UG. During scanning, participants played as responders in the UG, and they were informed of the economic status of proposers before receiving offers. At the behavioral level, higher rejection rates and lower fairness ratings were revealed when proposers were in high economic status than in low economic status. Besides, the most time-consuming decisions tended to occur at lower unfairness level when the proposers were in high (relative to low economic status. At the neural level, stronger activation of left thalamus was revealed when fair offers were proposed by proposers in high rather than in low economic status. Greater activation of right medial prefrontal cortex was revealed during acceptance to unfair offers in high economic status condition rather than in low economic status condition. Taken together, these findings shed light on the significance of proposers’ economic status in responders’ social decision making in UG.
Li, Yanwei; Grabell, Adam S; Wakschlag, Lauren S; Huppert, Theodore J; Perlman, Susan B
Preschool (age 3-5) is a phase of rapid development in both cognition and emotion, making this a period in which the neurodevelopment of each domain is particularly sensitive to that of the other. During this period, children rapidly learn how to flexibly shift their attention between competing demands and, at the same time, acquire critical emotion regulation skills to respond to negative affective challenges. The integration of cognitive flexibility and individual differences in irritability may be an important developmental process of early childhood maturation. However, at present it is unclear if they share common neural substrates in early childhood. Our main goal was to examine the neural correlates of cognitive flexibility in preschool children and test for associations with irritability. Forty-six preschool aged children completed a novel, child-appropriate, Stroop task while dorsolateral prefrontal cortex (DLPFC) activation was recorded using functional Near Infrared Spectroscopy (fNIRS). Parents rated their child's irritability. Results indicated that left DLPFC activation was associated with cognitive flexibility and positively correlated with irritability. Right DLPFC activation was also positively correlated with irritability. Results suggest the entwined nature of cognitive and emotional neurodevelopment during a developmental period of rapid and mutual acceleration. Published by Elsevier Ltd.
Full Text Available Preschool (age 3–5 is a phase of rapid development in both cognition and emotion, making this a period in which the neurodevelopment of each domain is particularly sensitive to that of the other. During this period, children rapidly learn how to flexibly shift their attention between competing demands and, at the same time, acquire critical emotion regulation skills to respond to negative affective challenges. The integration of cognitive flexibility and individual differences in irritability may be an important developmental process of early childhood maturation. However, at present it is unclear if they share common neural substrates in early childhood. Our main goal was to examine the neural correlates of cognitive flexibility in preschool children and test for associations with irritability. Forty-six preschool aged children completed a novel, child-appropriate, Stroop task while dorsolateral prefrontal cortex (DLPFC activation was recorded using functional Near Infrared Spectroscopy (fNIRS. Parents rated their child’s irritability. Results indicated that left DLPFC activation was associated with cognitive flexibility and positively correlated with irritability. Right DLPFC activation was also positively correlated with irritability. Results suggest the entwined nature of cognitive and emotional neurodevelopment during a developmental period of rapid and mutual acceleration.
Full Text Available Introduction Neural response telemetry (NRT is a method of capturing the action potential of the distal portion of the auditory nerve in cochlear implant (CI users, using the CI itself to elicit and record the answers. In addition, it can also measure the recovery function of the auditory nerve (REC, that is, the refractory properties of the nerve. It is not clear in the literature whether the responses from adults are the same as those from children. Objective To compare the results of NRT and REC between adults and children undergoing CI surgery. Methods Cross-sectional, descriptive, and retrospective study of the results of NRT and REC for patients undergoing IC at our service. The NRT is assessed by the level of amplitude (microvolts and REC as a function of three parameters: A (saturation level, in microvolts, t0 (absolute refractory period, in seconds, and tau (curve of the model function, measured in three electrodes (apical, medial, and basal. Results Fifty-two patients were evaluated with intraoperative NRT (26 adults and 26 children, and 24 with REC (12 adults and 12 children. No statistically significant difference was found between intraoperative responses of adults and children for NRT or for REC's three parameters, except for parameter A of the basal electrode. Conclusion The results of intraoperative NRT and REC were not different between adults and children, except for parameter A of the basal electrode.
Carvalho, Bettina; Hamerschmidt, Rogerio; Wiemes, Gislaine
Introduction Neural response telemetry (NRT) is a method of capturing the action potential of the distal portion of the auditory nerve in cochlear implant (CI) users, using the CI itself to elicit and record the answers. In addition, it can also measure the recovery function of the auditory nerve (REC), that is, the refractory properties of the nerve. It is not clear in the literature whether the responses from adults are the same as those from children. Objective To compare the results of NRT and REC between adults and children undergoing CI surgery. Methods Cross-sectional, descriptive, and retrospective study of the results of NRT and REC for patients undergoing IC at our service. The NRT is assessed by the level of amplitude (microvolts) and REC as a function of three parameters: A (saturation level, in microvolts), t0 (absolute refractory period, in seconds), and tau (curve of the model function), measured in three electrodes (apical, medial, and basal). Results Fifty-two patients were evaluated with intraoperative NRT (26 adults and 26 children), and 24 with REC (12 adults and 12 children). No statistically significant difference was found between intraoperative responses of adults and children for NRT or for REC's three parameters, except for parameter A of the basal electrode. Conclusion The results of intraoperative NRT and REC were not different between adults and children, except for parameter A of the basal electrode. PMID:25992145
Full Text Available Contemporary mental health practice primarily centers around the neurobiological and psychological processes at the individual level. However, a more careful consideration of interpersonal and other group-level attributes (e.g., interpersonal relationship, mutual trust/hostility, interdependence, and cooperation and a better grasp of their pathology can add a crucial dimension to our understanding of mental health problems. A few recent studies have delved into the interpersonal behavioral processes in the context of different psychiatric abnormalities. Neuroimaging can supplement these approaches by providing insight into the neurobiology of interpersonal functioning. Keeping this view in mind, we discuss a recently developed approach in functional neuroimaging that calls for a shift from a focus on neural information contained within brain space to a multi-brain framework exploring degree of similarity/dissimilarity of neural signals between multiple interacting brains. We hypothesize novel applications of quantitative neuroimaging markers like inter-subject correlation that might be able to evaluate the role of interpersonal attributes affecting an individual or a group. Empirical evidences of the usage of these markers in understanding the neurobiology of social interactions are provided to argue for their application in future mental health research.
Wang, Tingting; Mo, Lei; Vartanian, Oshin; Cant, Jonathan S.; Cupchik, Gerald
The present study was conducted to investigate whether the calming effect induced by viewing traditional Chinese landscape paintings would make disengagement from that mental state more difficult, as measured by performance on a cognitive control task. In Experiment 1 we examined the subjective experience of viewing traditional Chinese landscape paintings vs. realistic oil landscape paintings in a behavioral study. Our results confirmed that, as predicted, traditional Chinese landscape paintings induce greater levels of relaxation and mind wandering and lower levels of object-oriented absorption and recognition, compared to realistic oil landscape paintings. In Experiment 2 we used functional Magnetic Resonance Imaging to explore the behavioral and neural effects of viewing traditional Chinese landscape paintings on a task requiring cognitive control (i.e., the flanker task)—administered immediately following exposure to paintings. Contrary to our prediction, the behavioral data demonstrated that compared to realistic oil landscape paintings, exposure to traditional Chinese landscape paintings had no effect on performance on the flanker task. However, the neural data demonstrated an interaction effect such that there was greater activation in the inferior parietal cortex and the superior frontal gyrus on incongruent compared with congruent flanker trials when participants switched from viewing traditional Chinese landscape paintings to the flanker task than when they switched from realistic oil landscape paintings. These results suggest that switching from traditional Chinese landscape paintings placed greater demands on the brain’s attention and working memory networks during the flanker task than did switching from realistic oil landscape paintings. PMID:25610386
Zhou, Yuan; Wang, Yun; Rao, Li-Lin; Yang, Liu-Qing; Li, Shu
A unique feature of the human species is compliance with social norms, e.g., fairness, even though this normative decision means curbing self-interest. However, sometimes people prefer to pursue wealth at the expense of moral goodness. Specifically, deviations from a fairness-related normative choice have been observed in the presence of a high monetary incentive. The neural mechanism underlying this deviation from the fairness-related normative choice has yet to be determined. In order to address this issue, using functional magnetic resonance imaging we employed an ultimatum game (UG) paradigm in which fairness and a proposed monetary amount were orthogonally varied. We found evidence for a significant modulation by the proposed amount on fairness in the right lateral prefrontal cortex (PFC) and the bilateral insular cortices. Additionally, the insular subregions showed dissociable modulation patterns. Inter-individual differences in the modulation effects in the left inferior frontal gyrus (IFG) accounted for inter-individual differences in the behavioral modulation effect as measured by the rejection rate, supporting the concept that the PFC plays a critical role in making fairness-related normative decisions in a social interaction condition. Our findings provide neural evidence for the modulation of fairness by monetary incentives as well as accounting for inter-individual differences.
Long, Zhiying; Peng, Danling; Chen, Kewei; Jin, Zhen; Yao, Li
Although several studies provide evidence of differences in the neural mechanisms of art professionals and non-professionals, little is known about the neural mechanism differences between painting professionals/majors and non-professionals/non-majors during color processing. For the first time, we compared functional activation patterns, functional connectivity during both color naming and passive color viewing, and gray-matter density in 12 painting majors and 12 controls through both functional and structural magnetic resonance imaging techniques. Inter-group comparisons revealed that the painting majors showed more activation in the color selective areas and increased correlation between left V4 and the left ventral lateral prefrontal cortex during color naming. In contrast, the controls exhibited stronger activity in the Broca's area during color naming. Moreover, increased gray matter density in the left V4 complex was found when the painting majors were compared to the controls. This study demonstrates that the left V4 complex shows both functional and structural differences between painting majors and non-majors. In addition, the results suggest the reorganization of the brain circuit underlying lexical retrieval during color naming in the anterior regions of the painting major group. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Full Text Available A unique feature of the human species is compliance with social norms, e.g., fairness, even though this normative decision means curbing self-interest. However, sometimes people prefer to pursue wealth at the expense of moral goodness. Specifically, deviations from a fairness-related normative choice have been observed in the presence of a high monetary incentive. The neural mechanism underlying this deviation from the fairness-related normative choice has yet to be determined. In order to address this issue, using functional magnetic resonance imaging we employed an ultimatum game paradigm in which fairness and a proposed monetary amount were orthogonally varied. We found evidence for a significant modulation by the proposed amount on fairness in the right lateral prefrontal cortex and the bilateral insular cortices. Additionally, the insular subregions showed dissociable modulation patterns. Inter-individual differences in the modulation effects in the left inferior frontal gyrus accounted for inter-individual differences in the behavioral modulation effect as measured by the rejection rate, supporting the concept that the prefrontal cortex plays a critical role in making fairness-related normative decisions in a social interaction condition. Our findings provide neural evidence for the modulation of fairness by monetary incentives as well as accounting for inter-individual differences.
Sun, Yan; Yu, Hongbo; Chen, Jie; Liang, Jie; Lu, Lin; Zhou, Xiaolin; Shi, Jie
Jealousy is not only a way of experiencing love but also a stabilizer of romantic relationships, although morbid romantic jealousy is maladaptive. Being engaged in a formal romantic relationship can tune one's romantic jealousy towards a specific target. Little is known about how the human brain processes romantic jealousy by now. Here, by combining scenario-based imagination and functional MRI, we investigated the behavioral and neural correlates of romantic jealousy and their development across stages (before vs. after being in a formal relationship). Romantic jealousy scenarios elicited activations primarily in the basal ganglia (BG) across stages, and were significantly higher after the relationship was established in both the behavioral rating and BG activation. The intensity of romantic jealousy was related to the intensity of romantic happiness, which mainly correlated with ventral medial prefrontal cortex activation. The increase in jealousy across stages was associated with the tendency for interpersonal aggression. These results bridge the gap between the theoretical conceptualization of romantic jealousy and its neural correlates and shed light on the dynamic changes in jealousy.
McPherson, Malinda J; Barrett, Frederick S; Lopez-Gonzalez, Monica; Jiradejvong, Patpong; Limb, Charles J
Emotion is a primary motivator for creative behaviors, yet the interaction between the neural systems involved in creativity and those involved in emotion has not been studied. In the current study, we addressed this gap by using fMRI to examine piano improvisation in response to emotional cues. We showed twelve professional jazz pianists photographs of an actress representing a positive, negative or ambiguous emotion. Using a non-ferromagnetic thirty-five key keyboard, the pianists improvised music that they felt represented the emotion expressed in the photographs. Here we show that activity in prefrontal and other brain networks involved in creativity is highly modulated by emotional context. Furthermore, emotional intent directly modulated functional connectivity of limbic and paralimbic areas such as the amygdala and insula. These findings suggest that emotion and creativity are tightly linked, and that the neural mechanisms underlying creativity may depend on emotional state.
Li, Hong; Wei, Yantao; Li, Luoqing; Chen, C L P
In this paper, a hierarchical feature extraction method is proposed for image recognition. The key idea of the proposed method is to extract an effective feature, called local neural response (LNR), of the input image with nontrivial discrimination and invariance properties by alternating between local coding and maximum pooling operation. The local coding, which is carried out on the locally linear manifold, can extract the salient feature of image patches and leads to a sparse measure matrix on which maximum pooling is carried out. The maximum pooling operation builds the translation invariance into the model. We also show that other invariant properties, such as rotation and scaling, can be induced by the proposed model. In addition, a template selection algorithm is presented to reduce computational complexity and to improve the discrimination ability of the LNR. Experimental results show that our method is robust to local distortion and clutter compared with state-of-the-art algorithms.
Vagnoni, Eleonora; Lourenco, Stella F; Longo, Matthew R
Objects on a collision course with an observer produce a specific pattern of optical expansion on the retina known as looming, which in theory exactly specifies the time-to-collision (TTC) of approaching objects. It was recently demonstrated that the affective content of looming stimuli influences perceived TTC, with threatening objects judged as approaching sooner than non-threatening objects. Here, the neural mechanisms by which perceived threat modulates spatiotemporal perception were investigated. Participants judged the TTC of threatening (snakes, spiders) or non-threatening (butterflies, rabbits) stimuli, which expanded in size at a rate indicating one of five TTCs. Visual-evoked potentials (VEPs) and oscillatory neural responses measured with electroencephalography were analysed. The arrival time of threatening stimuli was underestimated compared with non-threatening stimuli, though an interaction suggested that this underestimation was not constant across TTCs. Further, both speed of approach and threat modulated both VEPs and oscillatory responses. Speed of approach modulated the N1 parietal and oscillations in the beta band. Threat modulated several VEP components (P1, N1 frontal, N1 occipital, early posterior negativity and late positive potential) and oscillations in the alpha and high gamma band. The results for the high gamma band suggest an interaction between these two factors. Previous evidence suggests that looming stimuli activate sensorimotor areas, even in the absence of an intended action. The current results show that threat disrupts the synchronization over the sensorimotor areas that are likely activated by the presentation of a looming stimulus. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.
S. Shaun Ho
Full Text Available Mothers need to make caregiving decisions to meet the needs of children, which may or may not result in positive child feedback. Variations in caregivers’ emotional reactivity to unpleasant child-feedback may be partially explained by their dispositional empathy levels. Furthermore, empathic response to the child’s unpleasant feedback likely helps mothers to regulate their own stress. We investigated the relationship between maternal dispositional empathy, stress reactivity, and neural correlates of child feedback to caregiving decisions. In Part 1 of the study, 33 female participants were recruited to undergo a lab-based mild stressor, the Social Evaluation Test (SET, and then in Part 2 of the study, a subset of the participants, fourteen mothers, performed a Parenting Decision Making Task (PDMT in an fMRI setting. Four dimensions of dispositional empathy based on the Interpersonal Reactivity Index were measured in all participants – Personal Distress, Empathic Concern, Perspective Taking, and Fantasy. Overall, we found that the Personal Distress and Perspective Taking were associated with greater and lesser cortisol reactivity, respectively. The four types of empathy were distinctly associated with the negative (versus positive child feedback activation in the brain. Personal Distress was associated with amygdala and hypothalamus activation, Empathic Concern with the left ventral striatum, ventrolateral prefrontal cortex (VLPFC, and supplemental motor area (SMA activation, and Fantasy with the septal area, right SMA and VLPFC activation. Interestingly, hypothalamus-septal coupling during the negative feedback condition was associated with less PDMT-related cortisol reactivity. The roles of distinct forms of dispositional empathy in neural and stress responses are discussed.
Zioga, Ioanna; Di Bernardi Luft, Caroline; Bhattacharya, Joydeep
Current research on music processing and syntax or semantics in language suggests that music and language share partially overlapping neural resources. Pitch also constitutes a common denominator, forming melody in music and prosody in language. Further, pitch perception is modulated by musical training. The present study investigated how music and language interact on pitch dimension and whether musical training plays a role in this interaction. For this purpose, we used melodies ending on an expected or unexpected note (melodic expectancy being estimated by a computational model) paired with prosodic utterances which were either expected (statements with falling pitch) or relatively unexpected (questions with rising pitch). Participants' (22 musicians, 20 nonmusicians) ERPs and behavioural responses in a statement/question discrimination task were recorded. Participants were faster for simultaneous expectancy violations in the melodic and linguistic stimuli. Further, musicians performed better than nonmusicians, which may be related to their increased pitch tracking ability. At the neural level, prosodic violations elicited a front-central positive ERP around 150ms after the onset of the last word/note, while musicians presented reduced P600 in response to strong incongruities (questions on low-probability notes). Critically, musicians' P800 amplitudes were proportional to their level of musical training, suggesting that expertise might shape the pitch processing of language. The beneficial aspect of expertise could be attributed to its strengthening effect of general executive functions. These findings offer novel contributions to our understanding of shared higher-order mechanisms between music and language processing on pitch dimension, and further demonstrate a potential modulation by musical expertise. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.
Sroka, M Claire; Vannest, Jennifer; Maloney, Thomas C; Horowitz-Kraus, Tzipi; Byars, Anna W; Holland, Scott K
A left-lateralized fronto-temporo-parietal language network has been well-characterized in adults; however, the neural basis of this fundamental network has hardly been explored in the preschool years, despite this being a time for rapid language development and vocabulary growth. We examined the functional imaging correlates associated with vocabulary ability and narrative comprehension in 30 preschool children ages 3 to 5. Bilateral auditory cortex and superior temporal activation as well as left angular and supramarginal gyrus activation were observed during a passive listening-to-stories task. Boys showed greater activation than girls in the right anterior cingulate and right superior frontal gyrus (SFG). Finally, children with higher vocabulary scores showed increased grey matter left-lateralization and greater activation in bilateral thalamus, hippocampus, and left angular gyrus. This study is novel in its approach to relate left-hemisphere language regions and vocabulary scores in preschool-aged children using fMRI.
Anna Luisa Klahn
Group independent neural activity in the right dlPFC increased with decreasing threat predictability. PD patients showed a sustained hyperactivation of the vmPFC under threat and safety conditions. The magnitude of hyperactivation was inversely correlated with PDs subjective arousal and anxiety sensitivity. Both PD and SP patients revealed decreased parietal processing of affective stimuli. Findings indicate overgeneralization between threat and safety conditions and increased need for emotion regulation via the vmPFC in PD, but not SP patients. Both anxiety disorders showed decreased activation in parietal networks possibly indicating attentional avoidance of affective stimuli. Present results complement findings from fear conditioning studies and underline overgeneralization of fear, particularly in PD.
Gabriel F Donnay
Full Text Available Interactive generative musical performance provides a suitable model for communication because, like natural linguistic discourse, it involves an exchange of ideas that is unpredictable, collaborative, and emergent. Here we show that interactive improvisation between two musicians is characterized by activation of perisylvian language areas linked to processing of syntactic elements in music, including inferior frontal gyrus and posterior superior temporal gyrus, and deactivation of angular gyrus and supramarginal gyrus, brain structures directly implicated in semantic processing of language. These findings support the hypothesis that musical discourse engages language areas of the brain specialized for processing of syntax but in a manner that is not contingent upon semantic processing. Therefore, we argue that neural regions for syntactic processing are not domain-specific for language but instead may be domain-general for communication.
Peigneux, Philippe; Van der Linden, Martial; Garraux, Gaetan; Laureys, Steven; Degueldre, Christian; Aerts, Joel; Del Fiore, Guy; Moonen, Gustave; Luxen, Andre; Salmon, Eric
The present study aimed to ascertain the neuroanatomical basis of an influential neuropsychological model for upper limb apraxia [Rothi LJ, et al. The Neuropsychology of Action. 1997. Hove, UK: Psychology Press]. Regional cerebral blood flow was measured in healthy volunteers using H2 15O PET during performance of four tasks commonly used for testing upper limb apraxia, i.e., pantomime of familiar gestures on verbal command, imitation of familiar gestures, imitation of novel gestures, and an action-semantic task that consisted in matching objects for functional use. We also re-analysed data from a previous PET study in which we investigated the neural basis of the visual analysis of gestures. First, we found that two sets of discrete brain areas are predominantly engaged in the imitation of familiar and novel gestures, respectively. Segregated brain activation for novel gesture imitation concur with neuropsychological reports to support the hypothesis that knowledge about the organization of the human body mediates the transition from visual perception to motor execution when imitating novel gestures [Goldenberg Neuropsychologia 1995;33:63-72]. Second, conjunction analyses revealed distinctive neural bases for most of the gesture-specific cognitive processes proposed in this cognitive model of upper limb apraxia. However, a functional analysis of brain imaging data suggested that one single memory store may be used for "to-be-perceived" and "to-be-produced" gestural representations, departing from Rothi et al.'s proposal. Based on the above considerations, we suggest and discuss a revised model for upper limb apraxia that might best account for both brain imaging findings and neuropsychological dissociations reported in the apraxia literature. Copyright 2004 Wiley-Liss, Inc.
Biyu J He
Full Text Available What neural mechanisms underlie the seamless flow of our waking consciousness? A necessary albeit insufficient condition for such neural mechanisms is that they should be consistently modulated across time were a segment of the conscious stream to be repeated twice. In this study, we experimentally manipulated the content of a story followed by subjects during functional magnetic resonance imaging (fMRI independently from the modality of sensory input (as visual text or auditory speech as well as attentional focus. We then extracted brain activity patterns consistently modulated across subjects by the evolving content of the story regardless of whether it was presented visually or auditorily. Specifically, in one experiment we presented the same story to different subjects via either auditory or visual modality. In a second experiment, we presented two different stories simultaneously, one auditorily, one visually, and manipulated the subjects’ attentional focus. This experimental design allowed us to dissociate brain activities underlying modality-specific sensory processing from modality-independent story processing. We uncovered a network of brain regions consistently modulated by the evolving content of a story regardless of the sensory modality used for stimulus input, including the superior temporal sulcus/gyrus (STS/STG, the inferior frontal gyrus (IFG, the posterior cingulate cortex (PCC, the medial frontal cortex (MFC, the temporal pole (TP and the temporoparietal junction (TPJ. Many of these regions have previously been implicated in semantic processing. Interestingly, different stories elicited similar brain activity patterns, but with subtle differences potentially attributable to varying degrees of emotional valence and self-relevance.
Full Text Available Recently, non-motor symptoms of Parkinson's disease (PD have been considered crucial factors in determining a patient's quality of life and have been proposed as the predominant features of the premotor phase. Researchers have investigated the relationship between non-motor symptoms and the motor laterality; however, this relationship remains disputed. This study investigated the neural connectivity correlates of non-motor and motor symptoms of PD with respect to motor laterality.Eight-seven patients with PD were recruited and classified into left-more-affected PD (n = 44 and right-more affected PD (n = 37 based on their MDS-UPDRS (Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale motor examination scores. The patients underwent MRI scanning, which included resting fMRI. Brain regions were labeled as ipsilateral and contralateral to the more-affected body side. Correlation analysis between the functional connectivity across brain regions and the scores of various symptoms was performed to identify the neural connectivity correlates of each symptom.The resting functional connectivity centered on the ipsilateral inferior orbito-frontal area was negatively correlated with the severity of non-motor symptoms, and the connectivity of the contralateral inferior parietal area was positively correlated with the severity of motor symptoms (p 0.3.These results suggest that the inferior orbito-frontal area may play a crucial role in non-motor dysfunctions, and that the connectivity information may be utilized as a neuroimaging biomarker for the early diagnosis of PD.
Schmaal, L; Goudriaan, A E; Joos, L; Dom, G; Pattij, T; van den Brink, W; Veltman, D J
Impulsive decision making is a hallmark of frequently occurring addiction disorders including alcohol dependence (AD). Therefore, ameliorating impulsive decision making is a promising target for the treatment of AD. Previous studies have shown that modafinil enhances cognitive control functions in various psychiatric disorders. However, the effects of modafinil on delay discounting and its underlying neural correlates have not been investigated as yet. The aim of the current study was to investigate the effects of modafinil on neural correlates of impulsive decision making in abstinent AD patients and healthy control (HC) subjects. A randomized, double-blind, placebo-controlled, within-subjects cross-over study using functional magnetic resonance imaging (fMRI) was conducted in 14 AD patients and 16 HC subjects. All subjects participated in two fMRI sessions in which they either received a single dose of placebo or 200 mg of modafinil 2 h before the session. During fMRI, subjects completed a delay-discounting task to measure impulsive decision making. Modafinil improved impulsive decision making in AD pateints, which was accompanied by enhanced recruitment of frontoparietal regions and reduced activation of the ventromedial prefrontal cortex. Moreover, modafinil-induced enhancement of functional connectivity between the superior frontal gyrus and ventral striatum was specifically associated with improvement in impulsive decision making. These findings indicate that modafinil can improve impulsive decision making in AD patients through an enhanced coupling of prefrontal control regions and brain regions coding the subjective value of rewards. Therefore, the current study supports the implementation of modafinil in future clinical trials for AD.
Shin, Yeon Soon; Kim, Hye-Young; Han, Sanghoon
Accurate person perception is crucial in social decision-making. One of the central elements in successful social perception is the ability to understand another's response bias; this is because the same behavior can represent different inner states depending on whether other people are yea-sayers or naysayers. In the present study, we have tried to investigate how the internal biases of others are perceived. Using a multi-trial learning paradigm, perceivers made predictions about a target's responses to various suggested activities and then received feedback for each prediction trial-by-trial. Our hypotheses were that (1) the internal decision criterion of the targets would be realized through repeated experiences, and (2) due to positive-negative asymmetry, yea-sayers would be recognized more gradually than naysayers through the probabilistic integration of repeated experiences. To find neural evidence that tracks probabilistic integration when forming person knowledge on response biases, we employed a model-based fMRI with a State-Space Model. We discovered that person knowledge about yea-sayers modulated several brain regions, including caudate nucleus, DLPFC, hippocampus, etc. Moreover, when person knowledge was updated with incorrect performance feedback, brain regions including the caudate nucleus, DLPFC, dmPFC, and TPJ were also involved. There were overlapping regions for both processes, caudate nucleus and DLPFC, suggesting that these regions take crucial roles in forming person knowledge with repeated feedback, while reflecting acquired information up to the current prediction. Copyright © 2014 Elsevier Inc. All rights reserved.
Nguyen, Hieu T; Sapp, Shawn; Wei, Claudia; Chow, Jacqueline K; Nguyen, Alvin; Coursen, Jeff; Luebben, Silvia; Chang, Emily; Ross, Robert; Schmidt, Christine E
Nerve guidance conduits (NGCs) are FDA-approved devices used to bridge gaps across severed nerve cables and help direct axons sprouting from the proximal end toward the distal stump. In this article, we present the development of a novel electrically conductive, biodegradable NGC made from a polypyrrole-block-polycaprolactone (PPy-PCL) copolymer material laminated with poly(lactic-co-glycolic acid) (PLGA). The PPy-PCL has a bulk conductivity ranging 10-20 S/cm and loses 40 wt % after 7 months under physiologic conditions. Dorsal root ganglia (DRG) grown on flat PPy-PCL/PLGA material exposed to direct current electric fields (EF) of 100 mV/cm for 2 h increased axon growth by 13% (± 2%) toward either electrode of a 2-electrode setup, compared with control grown on identical substrates without EF exposure. Alternating current increased axon growth by 21% (±3%) without an observable directional preference, compared with the same control group. The results from this study demonstrate PLGA-coated PPy-PCL is a unique biodegradable material that can deliver substrate EF stimulation to improve axon growth for peripheral nerve repair. © 2013 Wiley Periodicals, Inc.
Ereifej, Evon S.
grown on PMMA resembled closely to that of cells grown on the control surface, thus confirming the biocompatibility of PMMA. Additionally, the astrocyte GFAP gene expressions of cells grown on PMMA were lower than the control, signifying a lack of astrocyte reactivity. Based on the findings from the biomaterials study, it was decided to optimize PMMA by changing the surface characteristic of the material. Through the process of hot embossing, nanopatterns were placed on the surface in order to test the hypothesis that nanopatterning can improve the cellular response to the material. Results of this study agreed with current literature showing that topography effects protein and cell behavior. It was concluded that for the use in neural electrode fabrication and design, the 3600mm/gratings pattern feature sizes were optimal. The 3600 mm/gratings pattern depicted cell alignment along the nanopattern, less protein adsorption, less cell adhesion, proliferation and viability, inhibition of GFAP and MAP2k1 compared to all other substrates tested. Results from the initial biomaterials study also indicated platinum was negatively affected the cells and may not be a suitable material for neural electrodes. This lead to pursuing studies with iridium oxide and platinum alloy wires for the glial scar assay. Iridium oxide advantages of lower impedance and higher charge injection capacity would appear to make iridium oxide more favorable for neural electrode fabrication. However, results of this study demonstrate iridium oxide wires exhibited a more significant reactive response as compared to platinum alloy wires. Astrocytes cultured with platinum alloy wires had less GFAP gene expression, lower average GFAP intensity, and smaller glial scar thickness. Results from the nanopatterning PMMA study prompted a more thorough investigation of the nanopatterning effects using an organotypic brain slice model. PDMS was utilized as the substrate due to its optimal physical properties
van der Laan, Laura N.; Barendse, Marjolein E. A.; Viergever, Max A.; Smeets, Paul A. M.
Impulsivity is a personality trait that is linked to unhealthy eating and overweight. A few studies assessed how impulsivity relates to neural responses to anticipating and tasting food, but it is unknown how impulsivity relates to neural responses during food choice. Although impulsivity is a
Full Text Available Relief fits the definition of a reward. Unlike other reward types the pleasantness of relief depends on the violation of a negative expectation, yet this has not been investigated using neuroimaging approaches. We hypothesized that the degree of negative expectation depends on state (dread and trait (pessimism sensitivity. Of the brain regions that are involved in mediating pleasure, the nucleus accumbens also signals unexpected reward and positive prediction error. We hypothesized that accumbens activity reflects the level of negative expectation and subsequent pleasant relief. Using fMRI and two purpose-made tasks, we compared hedonic and BOLD responses to relief with responses during an appetitive reward task in 18 healthy volunteers. We expected some similarities in task responses, reflecting common neural substrates implicated across reward types. However, we also hypothesized that relief responses would differ from appetitive rewards in the nucleus accumbens, since only relief pleasantness depends on negative expectations. The results confirmed these hypotheses. Relief and appetitive reward task activity converged in the ventromedial prefrontal cortex, which also correlated with appetitive reward pleasantness ratings. In contrast, dread and pessimism scores correlated with relief but not with appetitive reward hedonics. Moreover, only relief pleasantness covaried with accumbens activation. Importantly, the accumbens signal appeared to specifically reflect individual differences in anticipation of the adverse event (dread, pessimism but was uncorrelated to appetitive reward hedonics. In conclusion, relief differs from appetitive rewards due to its reliance on negative expectations, the violation of which is reflected in relief-related accumbens activation.
Daniel Hart Baker
Full Text Available White pixel noise is widely used to estimate the level of internal noise in a system by injecting external variance into the detecting mechanism. Recent work (Baker & Meese, 2012, J Vis, 12(10:20 has provided psychophysical evidence that such noise masks might also cause suppression that could invalidate estimates of internal noise. Here we measure neural population responses directly, using steady-state visual evoked potentials, elicited by target stimuli embedded in different mask types. Sinusoidal target gratings of 1c/deg flickered at 5Hz, and were shown in isolation, or with superimposed orthogonal grating masks or 2D white noise masks, flickering at 7Hz. Compared with responses to a blank screen, the Fourier amplitude at the target frequency increased monotonically as a function of target contrast when no mask was present. Both orthogonal and white noise masks caused rightward shifts of the contrast response function, providing evidence of contrast gain control suppression. We also calculated within-observer amplitude variance across trials. This increased in proportion to the target response, implying signal-dependent (i.e. multiplicative noise at the system level, the implications of which we discuss for behavioural tasks. This measure of variance was reduced by both mask types, consistent with the changes in mean target response. An alternative variety of noise, which we term zero-dimensional noise, involves trial-by-trial jittering of the target contrast. This type of noise produced no gain control suppression, and increased the amplitude variance across trials.
Murielle Ursulla Ferraye
Full Text Available This study examines the cerebral structures involved in dynamic balance using a motor imagery (MI protocol. We recorded cerebral activity with functional magnetic resonance imaging while subjects imagined swaying on a balance board along the sagittal plane to point a laser at target pairs of different sizes (small, large. We used a matched visual imagery (VI control task and recorded imagery durations during scanning. MI and VI durations were differentially influenced by the sway accuracy requirement, indicating that MI of balance is sensitive to the increased motor control necessary to point at a smaller target. Compared to VI, MI of dynamic balance recruited additional cortical and subcortical portions of the motor system, including frontal cortex, basal ganglia, cerebellum and mesencephalic locomotor region, the latter showing increased effective connectivity with the supplementary motor area. The regions involved in MI of dynamic balance were spatially distinct but contiguous to those involved in MI of gait (Bakker et al., 2008; Snijders et al., 2011; Crémers et al., 2012, in a pattern consistent with existing somatotopic maps of the trunk (for balance and legs (for gait. These findings validate a novel, quantitative approach for studying the neural control of balance in humans. This approach extends previous reports on MI of static stance (Jahn et al., 2004, 2008, and opens the way for studying gait and balance impairments in patients with neurodegenerative disorders.
Macedonia, Manuela; Müller, Karsten; Friederici, Angela D
Vocabulary acquisition represents a major challenge in foreign language learning. Research has demonstrated that gestures accompanying speech have an impact on memory for verbal information in the speakers' mother tongue and, as recently shown, also in foreign language learning. However, the neural basis of this effect remains unclear. In a within-subjects design, we compared learning of novel words coupled with iconic and meaningless gestures. Iconic gestures helped learners to significantly better retain the verbal material over time. After the training, participants' brain activity was registered by means of fMRI while performing a word recognition task. Brain activations to words learned with iconic and with meaningless gestures were contrasted. We found activity in the premotor cortices for words encoded with iconic gestures. In contrast, words encoded with meaningless gestures elicited a network associated with cognitive control. These findings suggest that memory performance for newly learned words is not driven by the motor component as such, but by the motor image that matches an underlying representation of the word's semantics. Copyright © 2010 Wiley-Liss, Inc.
Zhang, Wei; He, Xianyou; Lai, Siyan; Wan, Juan; Lai, Shuxian; Zhao, Xueru; Li, Darong
What are the neural mechanisms underlying beauty based on objective parameters and beauty based on subjective social construction? This study scanned participants with fMRI while they performed aesthetic judgments on concrete pictographs and abstract oracle bone scripts. Behavioral results showed both pictographs and oracle bone scripts were judged to be more beautiful when they referred to beautiful objects and positive social meanings, respectively. Imaging results revealed regions associated with perceptual, cognitive, emotional and reward processing were commonly activated both in beautiful judgments of pictographs and oracle bone scripts. Moreover, stronger activations of orbitofrontal cortex (OFC) and motor-related areas were found in beautiful judgments of pictographs, whereas beautiful judgments of oracle bone scripts were associated with putamen activity, implying stronger aesthetic experience and embodied approaching for beauty were elicited by the pictographs. In contrast, only visual processing areas were activated in the judgments of ugly pictographs and negative oracle bone scripts. Results provide evidence that the sense of beauty is triggered by two processes: one based on the objective parameters of stimuli (embodied natural beauty) and the other based on the subjective social construction (social endowed beauty).
Cohn, Melanie; St-Laurent, Marie; Barnett, Alexander; McAndrews, Mary Pat
In temporal lobe epilepsy and lobectomy, deficits in emotion identification have been found consistently, but there is limited evidence for complex social inference skills such as theory of mind. Furthermore, risk factors and the specific neural underpinnings of these deficits in this population are unclear. We investigated these issues using a comprehensive range of social inference tasks (emotion identification and comprehension of sincere, deceitful and sarcastic social exchanges) in individuals with temporal lobe epilepsy or lobectomy (n = 87). We observed deficits across patient groups which were partly related to the presence of mesial temporal lobe sclerosis, early age of seizure onset and left lobectomy. A voxel-based morphometry analysis conducted in the pre-operative group confirmed the importance of the temporal lobe by showing a relationship between left hippocampal atrophy and overall social inference abilities, and between left anterior neocortex atrophy and sarcasm comprehension. These findings are in keeping with theoretical proposals that the hippocampus is critical for binding diverse elements in cognitive domains beyond canonical episodic memory operations, and that the anterior temporal cortex is a convergence zone of higher-order perceptual and emotional processes, and of stored representations. As impairments were frequent, we require further investigation of this behavioural domain and its impact on the lives of people with epilepsy. © The Author (2014). Published by Oxford University Press. For Permissions, please email: email@example.com.
O'Dhaniel A Mullette-Gillman
Full Text Available Contingency learning is fundamental to cognition. Knowledge about environmental contingencies allows behavioral flexibility, as executive control processes accommodate the demands of novel or changing environments. Studies of experiential learning have focused on the relationship between actions and the values of associated outcomes. However, outcome values have often been confounded with the physical changes in the outcomes themselves. Here, we dissociated contingency learning into valuative and non-valuative forms, using a novel version of the two-alternative choice task, while measuring the neural effects of contingency changes using functional magnetic resonance imaging (fMRI. Changes in value-relevant contingencies evoked activation in the lateral prefrontal cortex (LPFC, posterior parietal cortex (PPC, and dorsomedial prefrontal cortex (DMPFC consistent with prior results (e.g., reversal-learning paradigms. Changes in physical contingencies unrelated to value or to action produced similar activations within the LPFC, indicating that LPFC may engage in generalized contingency learning that is not specific to valuation. In contrast, contingency changes that required behavioral shifts evoked activation localized to the DMPFC, supplementary motor, and precentral cortices, suggesting that these regions play more specific roles within the executive control of behavior.
Ferraye, Murielle Ursulla; Debû, Bettina; Heil, Lieke; Carpenter, Mark; Bloem, Bastiaan Roelof; Toni, Ivan
This study examines the cerebral structures involved in dynamic balance using a motor imagery (MI) protocol. We recorded cerebral activity with functional magnetic resonance imaging while subjects imagined swaying on a balance board along the sagittal plane to point a laser at target pairs of different sizes (small, large). We used a matched visual imagery (VI) control task and recorded imagery durations during scanning. MI and VI durations were differentially influenced by the sway accuracy requirement, indicating that MI of balance is sensitive to the increased motor control necessary to point at a smaller target. Compared to VI, MI of dynamic balance recruited additional cortical and subcortical portions of the motor system, including frontal cortex, basal ganglia, cerebellum and mesencephalic locomotor region, the latter showing increased effective connectivity with the supplementary motor area. The regions involved in MI of dynamic balance were spatially distinct but contiguous to those involved in MI of gait (Bakker et al., 2008; Snijders et al., 2011; Crémers et al., 2012), in a pattern consistent with existing somatotopic maps of the trunk (for balance) and legs (for gait). These findings validate a novel, quantitative approach for studying the neural control of balance in humans. This approach extends previous reports on MI of static stance (Jahn et al., 2004, 2008), and opens the way for studying gait and balance impairments in patients with neurodegenerative disorders.
Lacey, Elizabeth H; Skipper-Kallal, Laura M; Xing, Shihui; Fama, Mackenzie E; Turkeltaub, Peter E
Understanding the relationships between clinical tests, the processes they measure, and the brain networks underlying them, is critical in order for clinicians to move beyond aphasia syndrome classification toward specification of individual language process impairments. To understand the cognitive, language, and neuroanatomical factors underlying scores of commonly used aphasia tests. Twenty-five behavioral tests were administered to a group of 38 chronic left hemisphere stroke survivors and a high-resolution magnetic resonance image was obtained. Test scores were entered into a principal components analysis to extract the latent variables (factors) measured by the tests. Multivariate lesion-symptom mapping was used to localize lesions associated with the factor scores. The principal components analysis yielded 4 dissociable factors, which we labeled Word Finding/Fluency, Comprehension, Phonology/Working Memory Capacity, and Executive Function. While many tests loaded onto the factors in predictable ways, some relied heavily on factors not commonly associated with the tests. Lesion symptom mapping demonstrated discrete brain structures associated with each factor, including frontal, temporal, and parietal areas extending beyond the classical language network. Specific functions mapped onto brain anatomy largely in correspondence with modern neural models of language processing. An extensive clinical aphasia assessment identifies 4 independent language functions, relying on discrete parts of the left middle cerebral artery territory. A better understanding of the processes underlying cognitive tests and the link between lesion and behavior may lead to improved aphasia diagnosis, and may yield treatments better targeted to an individual's specific pattern of deficits and preserved abilities.
Melrose, A James; Bailer, Ursula; Wierenga, Christina E; Bischoff-Grethe, Amanda; Paulus, Martin P; Kaye, Walter H
Amphetamine, likely via action on the brain's dopaminergic systems, induces anorectic eating behavior and blunts dopaminergic midbrain activation to rewards. Past work has hypothesized that this blunted reward responsivity is a result of increasing tonic over phasic DA activity. We sought to extend past findings to sweet taste during fMRI following single-blind administration of dextroamphetamine and placebo in 11 healthy women. We hypothesized that neural response in both limbic and cognitive sweet taste circuits would mirror past work with monetary rewards by effectively blunting sweet taste reward, and 'equalizing' it's rewarding taste with receipt of water. Behavioral results showed that amphetamine reduced self-reported hunger (supporting the existence of amphetamine anorexia) and increased self-report euphoria. In addition, region of Interest analysis revealed significant treatment by taste interactions in the middle insula and dorsal anterior cingulate confirming the 'equalizing' hypothesis in the cingulate, but unlike monetary reinforcers, the insula actually evinced enhanced separation between tastes on the amphetamine day. These results suggest a divergence from prior research using monetary reinforcers when extended to primary reinforcers, and may hint that altering dopaminergic signaling in the insula and anterior cingulate may be a target for pharmacological manipulation of appetite, and the treatment of obesity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Flowers, D. A.; Ayres, V. M.; Delgado-Rivera, R.; Ahmed, I.; Meiners, S. A.
Preliminary data from in-vivo investigations (rat model) suggest that a nanofiber prosthetic device of fibroblast growth factor-2 (FGF-2)-modified nanofibers can correctly guide regenerating axons across an injury gap with aligned functional recovery. Scanning Probe Recognition Microscopy (SPRM) with auto-tracking of individual nanofibers is used for investigation of the key nanoscale properties of the nanofiber prosthetic device for central nervous system tissue engineering and repair. The key properties under SPRM investigation include nanofiber stiffness and surface roughness, nanofiber curvature, nanofiber mesh density and porosity, and growth factor presentation and distribution. Each of these factors has been demonstrated to have global effects on cell morphology, function, proliferation, morphogenesis, migration, and differentiation. The effect of FGF-2 modification on the key nanoscale properties is investigated. Results from the nanofiber prosthetic properties investigations are correlated with astrocyte response to unmodified and FGF-2 modified scaffolds, using 2D planar substrates as a control.
Luca Francesco Ticini
Full Text Available Brain damage may induce a dysfunction of upright body position termed "pusher syndrome". Patients with such disorder suffer from an alteration of their sense of body verticality. They experience their body as oriented upright when actually tilted nearly 20 degrees to the ipsilesional side. Pusher syndrome typically is associated with posterior thalamic stroke; less frequently with extra-thalamic lesions. This argued for a fundamental role of these structures in our control of upright body posture. Here we investigated whether such patients may show additional functional or metabolic abnormalities outside the areas of brain lesion. We investigated 19 stroke patients with thalamic or with extra-thalamic lesions showing versus not showing misperception of body orientation. We measured fluid-attenuated inversion-recovery (FLAIR imaging, diffusion-weighted imaging (DWI, and perfusion-weighted imaging (PWI. This allowed us to determine the structural damage as well as to identify the malperfused but structural intact tissue. Pusher patients with thalamic lesions did not show dysfunctional brain areas in addition to the ones found to be structurally damaged. In the pusher patients with extra-thalamic lesions, the thalamus was neither structurally damaged nor malperfused. Rather, these patients showed small regions of abnormal perfusion in the structurally intact inferior frontal gyrus, middle temporal gyrus, inferior parietal lobule, and parietal white matter. The results indicate that these extra-thalamic brain areas contribute to the network controlling upright body posture. The data also suggest that damage of the neural tissue in the posterior thalamus itself rather than additional malperfusion in distant cortical areas is associated with pusher syndrome. Hence, it seems as if the normal functioning of both extra-thalamic as well as posterior thalamic structures is integral to perceiving gravity and controlling upright body orientation in humans.
Thaler, Lore; Goodale, Melvyn A.
Neuropsychological evidence suggests that different brain areas may be involved in movements that are directed at visual targets (e.g., pointing or reaching), and movements that are based on allocentric visual information (e.g., drawing or copying). Here we used fMRI to investigate the neural correlates of these two types of movements in healthy volunteers. Subjects (n = 14) performed right hand movements in either a target-directed task (moving a cursor to a target dot) or an allocentric task (moving a cursor to reproduce the distance and direction between two distal target dots) with or without visual feedback about their hand movement. Movements were monitored with an MR compatible touch panel. A whole brain analysis revealed that movements in allocentric conditions led to an increase in activity in the fundus of the left intra-parietal sulcus (IPS), in posterior IPS, in bilateral dorsal premotor cortex (PMd), and in the lateral occipital complex (LOC). Visual feedback in both target-directed and allocentric conditions led to an increase in activity in area MT+, superior parietal–occipital cortex (SPOC), and posterior IPS (all bilateral). In addition, we found that visual feedback affected brain activity differently in target-directed as compared to allocentric conditions, particularly in the pre-supplementary motor area, PMd, IPS, and parieto-occipital cortex. Our results, in combination with previous findings, suggest that the LOC is essential for allocentric visual coding and that SPOC is involved in visual feedback control. The differences in brain activity between target-directed and allocentric visual feedback conditions may be related to behavioral differences in visual feedback control. Our results advance the understanding of the visual coordinate frame used by the LOC. In addition, because of the nature of the allocentric task, our results have relevance for the understanding of neural substrates of magnitude estimation and vector coding of
Matsushita, Atsuko; Pyon, Grace; Kawasaki, Masashi
Roles of the time coding electrosensory system in the novelty responses of a pulse-type gymnotiform electric fish, Brachyhypopomus, were examined behaviorally, physiologically, and anatomically. Brachyhypopomus responded with the novelty responses to small changes (100 μs) in time difference between electrosensory stimulus pulses applied to different parts of the body, as long as these pulses were given within a time period of ~500 μs. Physiological recording revealed neurons in the hindbrain and midbrain that fire action potentials time-locked to stimulus pulses with short latency (500-900 μs). These time-locked neurons, along with other types of neurons, were labeled with intracellular and extracellular marker injection techniques. Light and electron microscopy of the labeled materials revealed neural connectivity within the time coding system. Two types of time-locked neurons, the pear-shaped cells and the large cells converge onto the small cells in a hypertrophied structure, the mesencephalic magnocellular nucleus. The small cells receive a calyx synapse from a large cell at their somata and an input from a pear-shaped cell at the tip of their dendrites via synaptic islands. The small cells project to the torus semicircularis. We hypothesized that the time-locked neural signals conveyed by the pear-shaped cells and the large cells are decoded by the small cells for detection of time shifts occurring across body areas.
Campbell, Luke; Kaicer, Arielle; Briggs, Robert; O'Leary, Stephen
To record cochlear responses to acoustic stimulation (electrocochleography) directly from a cochlear implant (CI) in awake recipients with residual hearing, using an adaptation of Neural Response Telemetry (NRT) that achieves a 10-ms recording window. Modern cochlear implants contain circuitry for recording neural responses to electrical stimulation, which is known in Cochlear Ltd systems as NRT. We adapted NRT to achieve an extended recording window long enough to record an acoustic electrocochleogram. This paper reports recordings made with this system in recipients with residual hearing. Subjects were adults with CI422 CIs who retained audiometric thresholds between 75 and 90 dB HL at 500 Hz in their implanted ear. The CI was interfaced to a laptop via a Freedom speech processor connected by USB. Calibrated acoustic stimuli (clicks and tone bursts between 500 and 1,500 Hz) were presented via insert tube phones to the implanted ear. Responses were acquired through the adapted NRT system. Recordings were made from apical, mid-array, and basal electrodes. Electrocochleography responses were compared with audiometric thresholds. Electrocochleography could be recorded from all five subjects. The compound action potential, cochlear microphonic, and summating potentials were identified. Good quality recordings were most reliably attained from apical electrodes using 40 to 100 repetitions. Audiometric thresholds were similar to compound action potential thresholds. Intracochlear responses to acoustic stimulation can be recorded directly from the CI in awake recipients with residual hearing. This may prove useful for monitoring postoperative hearing and for device fitting.
Full Text Available The main purpose of this study to increase the optimal conditions for biogas yield from anaerobic digestion of agricultural waste (Rice Straw using Response Surface Methodology (RSM and Artificial Neural Network (ANN. In the development of predictive models temperature, pH, substrate concentration and agitation time are conceived as model variables. The experimental results show that the liner model terms of temperature, substrate concentration and pH, agitation time have significance of interactive effects (p < 0.05. The results manifest that the optimum process parameters affected on biogas yield increase from the ANN model when compared to RSM model. The ANN model indicates that it is much more accurate and reckons the values of maximum biogas yield when compared to RSM model.
Acheson, Daniel J.; Hamidi, Massihullah; Binder, Jeffrey R.; Postle, Bradley R.
Verbal working memory (VWM), the ability to maintain and manipulate representations of speech sounds over short periods, is held by some influential models to be independent from the systems responsible for language production and comprehension [e.g., Baddeley, A. D. "Working memory, thought, and action." New York, NY: Oxford University Press,…
Rosling, Anna; Lindahl, Björn D; Taylor, Andy F S; Finlay, Roger D
A colorimetric method was developed to permit semi-quantitative measurement of substrate acidification by different ectomycorrhizal and one saprotrophic fungus growing on media containing one of five different minerals. Overall, substrate acidification differed between fungal species and the degree of variation in acidification in response to different minerals was highly species-dependent. Mycena galopus and Cortinarius glaucopus produced the least biomass of all tested species and produced the highest amount of acidification per unit mycelial density. Substrate acidification by C. glaucopus was inversely related to mycelial density, with particularly high acidification at low mycelial density on medium enriched with tri-calcium phosphate. Substrate acidification by M. galopus was constant irrespective of mycelial density and varied only according to mineral treatment, with higher substrate acidification on tri-calcium phosphate compared to the other minerals.
Chopra, Anuj; Bayraktar, Muharrem; Nijland, Maarten; Ten Elshof, Johan E; Bijkerk, Fred; Rijnders, Guus
Renewed interest has been witnessed in utilizing the piezoelectric response of PbZr 0.52 Ti 0.48 O 3 (PZT) films on glass substrates for applications such as adaptive optics. Accordingly, new methodologies are being explored to grow well-oriented PZT thin films to harvest a large piezoelectric response. However, thin film piezoelectric response is significantly reduced compared to intrinsic response due to substrate induced clamping, even when films are well-oriented. Here, a novel method is presented to grow preferentially (100)-oriented PZT films on glass substrates by utilizing crystalline nanosheets as seed layers. Furthermore, increasing the repetition frequency up to 20 Hz during pulsed laser deposition helps to tune the film microstructure to hierarchically ordered columns that leads to reduced clamping and enhanced piezoelectric response evidenced by transmission electron microscopy and analytical calculations. A large piezoelectric coefficient of 250 pm/V is observed in optimally tuned structure which is more than two times the highest reported piezoelectric response on glass. To confirm that the clamping compromises the piezoelectric response, denser films are deposited using a lower repetition frequency and a BiFeO 3 buffer layer resulting in significantly reduced piezoelectric responses. This paper demonstrates a novel method for PZT integration on glass substrates without compromising the large piezoelectric response.
Gillihan, Seth J; Detre, John A; Farah, Martha J; Rao, Hengyi
Daily variations in weather are known to be associated with variations in mood. However, little is known about the specific brain regions that instantiate weather-related mood changes. We used a data-driven approach and ASL perfusion fMRI to assess the neural substrates associated with weather-induced mood variability. The data-driven approach was conducted with mood ratings under various weather conditions (N = 464). Forward stepwise regression was conducted to develop a statistical model of mood as a function of weather conditions. The model results were used to calculate the mood-relevant weather index which served as the covariate in the regression analysis of the resting CBF (N = 42) measured by ASL perfusion fMRI under various weather conditions. The resting CBF activities in the left insula-prefrontal cortex and left superior parietal lobe were negatively correlated (corrected pweather index, indicating that better mood-relevant weather conditions were associated with lower CBF in these regions within the brain's emotional network. The present study represents a first step toward the investigation of the effect of natural environment on baseline human brain function, and suggests the feasibility of ASL perfusion fMRI for such study.
Liebenthal, Einat; Silbersweig, David A; Stern, Emily
Rapid assessment of emotions is important for detecting and prioritizing salient input. Emotions are conveyed in spoken words via verbal and non-verbal channels that are mutually informative and unveil in parallel over time, but the neural dynamics and interactions of these processes are not well understood. In this paper, we review the literature on emotion perception in faces, written words, and voices, as a basis for understanding the functional organization of emotion perception in spoken words. The characteristics of visual and auditory routes to the amygdala-a subcortical center for emotion perception-are compared across these stimulus classes in terms of neural dynamics, hemispheric lateralization, and functionality. Converging results from neuroimaging, electrophysiological, and lesion studies suggest the existence of an afferent route to the amygdala and primary visual cortex for fast and subliminal processing of coarse emotional face cues. We suggest that a fast route to the amygdala may also function for brief non-verbal vocalizations (e.g., laugh, cry), in which emotional category is conveyed effectively by voice tone and intensity. However, emotional prosody which evolves on longer time scales and is conveyed by fine-grained spectral cues appears to be processed via a slower, indirect cortical route. For verbal emotional content, the bulk of current evidence, indicating predominant left lateralization of the amygdala response and timing of emotional effects attributable to speeded lexical access, is more consistent with an indirect cortical route to the amygdala. Top-down linguistic modulation may play an important role for prioritized perception of emotions in words. Understanding the neural dynamics and interactions of emotion and language perception is important for selecting potent stimuli and devising effective training and/or treatment approaches for the alleviation of emotional dysfunction across a range of neuropsychiatric states.
Chambers, Christopher D; Garavan, Hugh; Bellgrove, Mark A
Neural mechanisms of cognitive control enable us to initiate, coordinate and update behaviour. Central to successful control is the ability to suppress actions that are no longer relevant or required. In this article, we review the contribution of cognitive neuroscience, molecular genetics and clinical investigations to understanding how response inhibition is mediated in the human brain. In Section 1, we consider insights into the neural basis of inhibitory control from the effects of neural interference, neural dysfunction, and drug addiction. In Section 2, we explore the functional specificity of inhibitory mechanisms among a range of related processes, including response selection, working memory, and attention. In Section 3, we focus on the contribution of response inhibition to understanding flexible behaviour, including the effects of learning and individual differences. Finally, in Section 4, we propose a series of technical and conceptual objectives for future studies addressing the neural basis of inhibition.
Riem, M.M.E.; van IJzendoorn, M.H.; De Carli, P.; Vingerhoets, A.J.J.M.; Bakermans-Kranenburg, M. J.
The current study examined behavioral and neural responses to infant and adult tears, taking into account childhood experiences with parental love-withdrawal. With functional MRI (fMRI), we measured neural reactivity to pictures of infants and adults with and without tears on their faces in
Ladeby, Rune; Wirenfeldt, Martin; Dalmau, Ishar
Reactive microgliosis is a highly characteristic response to neural injury and disease, which may influence neurodegenerative processes and neural plasticity. We have investigated the origin and characteristics of reactive microglia in the acute phase of their activation in the dentate gyrus...
Martin William F; Pikosky Matthew A; Gaine P Courtney; Vislocky Lisa M; Rodriguez Nancy R
Abstract Background Although several studies have investigated gender differences in the substrate and endocrine responses during and following endurance exercise, few have studied sex differences during a more prolonged recovery period post endurance exercise. The purpose of this study was to compare and characterize the endocrine and substrate profiles of trained male and female adult runners during the three-and-a-half hour recovery period from an endurance run. Methods After consuming a e...
Chopra, A.; Bayraktar, Muharrem; Nijland, Maarten; ten Elshof, Johan E.; Bijkerk, Frederik; Rijnders, Augustinus J.H.M.
Renewed interest has been witnessed in utilizing the piezoelectric response of PbZr0.52Ti0.48O3 (PZT) films on glass substrates for applications such as adaptive optics. Accordingly, new methodologies are being explored to grow well-oriented PZT thin films to harvest a large piezoelectric response.
Alarcón, Gabriela; Cservenka, Anita; Nagel, Bonnie J
Risky decision making is prominent during adolescence, perhaps contributed to by heightened sensation seeking and ongoing maturation of reward and dopamine systems in the brain, which are, in part, modulated by sex hormones. In this study, we examined sex differences in the neural substrates of reward sensitivity during a risky decision-making task and hypothesized that compared with girls, boys would show heightened brain activation in reward-relevant regions, particularly the nucleus accumbens, during reward receipt. Further, we hypothesized that testosterone and estradiol levels would mediate this sex difference. Moreover, we predicted boys would make more risky choices on the task. While boys showed increased nucleus accumbens blood oxygen level-dependent (BOLD) response relative to girls, sex hormones did not mediate this effect. As predicted, boys made a higher percentage of risky decisions during the task. Interestingly, boys also self-reported more motivation to perform well and earn money on the task, while girls self-reported higher state anxiety prior to the scan session. Motivation to earn money partially mediated the effect of sex on nucleus accumbens activity during reward. Previous research shows that increased motivation and salience of reinforcers is linked with more robust striatal BOLD response, therefore psychosocial factors, in addition to sex, may play an important role in reward sensitivity. Elucidating neurobiological mechanisms that support adolescent sex differences in risky decision making has important implications for understanding individual differences that lead to advantageous and adverse behaviors that affect health outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.
Boccia, M; Barbetti, S; Piccardi, L; Guariglia, C; Ferlazzo, F; Giannini, A M; Zaidel, D W
Here we aimed at finding the neural correlates of the general aspect of visual aesthetic experience (VAE) and those more strictly correlated with the content of the artworks. We applied a general activation likelihood estimation (ALE) meta-analysis to 47 fMRI experiments described in 14 published studies. We also performed four separate ALE analyses in order to identify the neural substrates of reactions to specific categories of artworks, namely portraits, representation of real-world-visual-scenes, abstract paintings, and body sculptures. The general ALE revealed that VAE relies on a bilateral network of areas, and the individual ALE analyses revealed different maximal activation for the artworks' categories as function of their content. Specifically, different content-dependent areas of the ventral visual stream are involved in VAE, but a few additional brain areas are involved as well. Thus, aesthetic-related neural responses to art recruit widely distributed networks in both hemispheres including content-dependent brain areas of the ventral visual stream. Together, the results suggest that aesthetic responses are not independent of sensory, perceptual, and cognitive processes. Copyright © 2015 Elsevier Ltd. All rights reserved.
Tlustos, Sarah J; Peter Chiu, C Y; Walz, Nicolay C; Wade, Shari L
Disturbances of emotional regulation and social difficulties are common in children and adolescents with traumatic brain injury (TBI). Recent research suggests that developments within ``socio-emotional'' brain systems during early adolescence and more protracted development of "cognitive control'' systems have implications for emotional and behavioral regulation during adolescence. However, few functional neuroimaging studies have directly examined the interaction of these neuropsychological processes in adolescents with TBI. The current study examined how affective processing might modulate inhibitory processing in an Emotional Go/NoGo paradigm. The study uses a cross-sectional, age, gender, and maternal education matched design.A response inhibition paradigm (i.e., the Go/NoGo task with emotional faces) was used to examine emotional-cognition interaction in 11 adolescents with complicated mild to moderate TBI, at least 12 months post injury, and 14 typically-developing (TD) adolescents using functional magnetic resonance imaging (fMRI). Participants saw adult facial expressions of emotions (happy, sad, fearful, and angry) and were instructed to respond (``go'') on all expressions other than angry (``no-go''). Preliminary results (p= 0.001 uncorrected, cluster size = 50) showed higher levels of inhibition-related activation in TD adolescents than in adolescents with TBI in several brain regions including anterior cingulate and motor/premotor regions. These results suggest that TBI in adolescence might alter brain activation patterns and interrupt the development of brain networks governing emotion-cognition interactions.
Full Text Available Human morning and evening chronotypes differ in their preferred timing for sleep and wakefulness, as well as in optimal daytime periods to cope with cognitive challenges. Recent evidence suggests that these preferences are not a simple by-product of socio-professional timing constraints, but can be driven by inter-individual differences in the expression of circadian and homeostatic sleep-wake promoting signals. Chronotypes thus constitute a unique tool to access the interplay between those processes under normally entrained day-night conditions, and to investigate how they impinge onto higher cognitive control processes. Using functional magnetic resonance imaging (fMRI, we assessed the influence of chronotype and time-of-day on conflict processing-related cerebral activity throughout a normal waking day. Sixteen morning and 15 evening types were recorded at two individually adapted time points (1.5 versus 10.5 hours spent awake while performing the Stroop paradigm. Results show that interference-related hemodynamic responses are maintained or even increased in evening types from the subjective morning to the subjective evening in a set of brain areas playing a pivotal role in successful inhibitory functioning, whereas they decreased in morning types under the same conditions. Furthermore, during the evening hours, activity in a posterior hypothalamic region putatively involved in sleep-wake regulation correlated in a chronotype-specific manner with slow wave activity at the beginning of the night, an index of accumulated homeostatic sleep pressure. These results shed light into the cerebral mechanisms underlying inter-individual differences of higher-order cognitive state maintenance under normally entrained day-night conditions.
Schmidt, Christina; Peigneux, Philippe; Leclercq, Yves; Sterpenich, Virginie; Vandewalle, Gilles; Phillips, Christophe; Berthomier, Pierre; Berthomier, Christian; Tinguely, Gilberte; Gais, Steffen; Schabus, Manuel; Desseilles, Martin; Dang-Vu, Thanh; Salmon, Eric; Degueldre, Christian; Balteau, Evelyne; Luxen, André; Cajochen, Christian; Maquet, Pierre; Collette, Fabienne
Human morning and evening chronotypes differ in their preferred timing for sleep and wakefulness, as well as in optimal daytime periods to cope with cognitive challenges. Recent evidence suggests that these preferences are not a simple by-product of socio-professional timing constraints, but can be driven by inter-individual differences in the expression of circadian and homeostatic sleep-wake promoting signals. Chronotypes thus constitute a unique tool to access the interplay between those processes under normally entrained day-night conditions, and to investigate how they impinge onto higher cognitive control processes. Using functional magnetic resonance imaging (fMRI), we assessed the influence of chronotype and time-of-day on conflict processing-related cerebral activity throughout a normal waking day. Sixteen morning and 15 evening types were recorded at two individually adapted time points (1.5 versus 10.5 hours spent awake) while performing the Stroop paradigm. Results show that interference-related hemodynamic responses are maintained or even increased in evening types from the subjective morning to the subjective evening in a set of brain areas playing a pivotal role in successful inhibitory functioning, whereas they decreased in morning types under the same conditions. Furthermore, during the evening hours, activity in a posterior hypothalamic region putatively involved in sleep-wake regulation correlated in a chronotype-specific manner with slow wave activity at the beginning of the night, an index of accumulated homeostatic sleep pressure. These results shed light into the cerebral mechanisms underlying inter-individual differences of higher-order cognitive state maintenance under normally entrained day-night conditions.
Kaustubh Supekar; Anna G. Swigart; Caitlin Tenison; Dietsje D. Jolles; Miriam Rosenberg-Lee; Lynn Fuchs; Vinod Menon
... some children to acquire these skills faster than others. Here we investigate the behavioral and neural predictors of individual differences in arithmetic skill acquisition in response to 8-wk of one-to-one math tutoring...
Full Text Available How natural communication sounds are spatially represented across the inferior colliculus, the main center of convergence for auditory information in the midbrain, is not known. The neural representation of the acoustic stimuli results from the interplay of locally differing input and the organization of spectral and temporal neural preferences that change gradually across the nucleus. This raises the question how similar the neural representation of the communication sounds is across these gradients of neural preferences, and whether it also changes gradually. Analyzed neural recordings were multi-unit cluster spike trains from guinea pigs presented with a spectrotemporally rich set of eleven species-specific communication sounds. Using cross-correlation, we analyzed the response similarity of spiking activity across a broad frequency range for neurons of similar and different frequency tuning. Furthermore, we separated the contribution of the stimulus to the correlations to investigate whether similarity is only attributable to the stimulus, or, whether interactions exist between the multi-unit clusters that lead to neural correlations and whether these follow the same representation as the response correlations. We found that similarity of responses is dependent on the neurons' spatial distance for similarly and differently frequency-tuned neurons, and that similarity decreases gradually with spatial distance. Significant neural correlations exist, and contribute to the total response similarity. Our findings suggest that for multi-unit clusters in the mammalian inferior colliculus, the gradual response similarity with spatial distance to natural complex sounds is shaped by neural interactions and the gradual organization of neural preferences.
Abbas, Paul J; Tejani, Viral D; Scheperle, Rachel A; Brown, Carolyn J
This report describes the results of a series of experiments where we use the neural response telemetry (NRT) system of the Nucleus cochlear implant (CI) to measure the response of the peripheral auditory system to acoustic stimulation in Nucleus Hybrid CI users. The objectives of this study were to determine whether they could separate responses from hair cells and neurons and to evaluate the stability of these measures over time. Forty-four CI users participated. They all had residual acoustic hearing and used a Nucleus Hybrid S8, S12, or L24 CI or the standard lateral wall CI422 implant. The NRT system of the CI was used to trigger an acoustic stimulus (500-Hz tone burst or click), which was presented at a low stimulation rate (10, 15, or 50 per second) to the implanted ear via an insert earphone and to record the cochlear microphonic, the auditory nerve neurophonic and the compound action potential (CAP) from an apical intracochlear electrode. To record acoustically evoked responses, a longer time window than is available with the commercial NRT software is required. This limitation was circumvented by making multiple recordings for each stimulus using different time delays between the onset of stimulation and the onset of averaging. These recordings were then concatenated off-line. Matched recordings elicited using positive and negative polarity stimuli were added off-line to emphasize neural potentials (SUM) and subtracted off-line to emphasize potentials primarily generated by cochlear hair cells (DIF). These assumptions regarding the origin of the SUM and DIF components were tested by comparing the magnitude of these derived responses recorded using various stimulation rates. Magnitudes of the SUM and DIF components were compared with each other and with behavioral thresholds. SUM and DIF components were identified for most subjects, consistent with both hair cell and neural responses to acoustic stimulation. For a subset of the study participants, the DIF
Khalighinejad, Bahar; Cruzatto da Silva, Guilherme; Mesgarani, Nima
Humans are unique in their ability to communicate using spoken language. However, it remains unclear how the speech signal is transformed and represented in the brain at different stages of the auditory pathway. In this study, we characterized electroencephalography responses to continuous speech by obtaining the time-locked responses to phoneme instances (phoneme-related potential). We showed that responses to different phoneme categories are organized by phonetic features. We found that each instance of a phoneme in continuous speech produces multiple distinguishable neural responses occurring as early as 50 ms and as late as 400 ms after the phoneme onset. Comparing the patterns of phoneme similarity in the neural responses and the acoustic signals confirms a repetitive appearance of acoustic distinctions of phonemes in the neural data. Analysis of the phonetic and speaker information in neural activations revealed that different time intervals jointly encode the acoustic similarity of both phonetic and speaker categories. These findings provide evidence for a dynamic neural transformation of low-level speech features as they propagate along the auditory pathway, and form an empirical framework to study the representational changes in learning, attention, and speech disorders.SIGNIFICANCE STATEMENT We characterized the properties of evoked neural responses to phoneme instances in continuous speech. We show that each instance of a phoneme in continuous speech produces several observable neural responses at different times occurring as early as 50 ms and as late as 400 ms after the phoneme onset. Each temporal event explicitly encodes the acoustic similarity of phonemes, and linguistic and nonlinguistic information are best represented at different time intervals. Finally, we show a joint encoding of phonetic and speaker information, where the neural representation of speakers is dependent on phoneme category. These findings provide compelling new evidence for
Hess, A. E.; Capadona, J. R.; Shanmuganathan, K.; Hsu, L.; Rowan, S. J.; Weder, C.; Tyler, D. J.; Zorman, C. A.
This paper reports the development of micromachining processes and mechanical evaluation of a stimuli-responsive, mechanically dynamic polymer nanocomposite for biomedical microsystems. This nanocomposite consists of a cellulose nanofiber network encased in a polyvinyl acetate matrix. Micromachined tensile testing structures fabricated from the nanocomposite displayed a reversible and switchable stiffness comparable to bulk samples, with a Young's modulus of 3420 MPa when dry, reducing to ~20 MPa when wet, and a stiff-to-flexible transition time of ~300 s. This mechanically dynamic behavior is particularly attractive for the development of adaptive intracortical probes that are sufficiently stiff to insert into the brain without buckling, but become highly compliant upon insertion. Along these lines, a micromachined neural probe incorporating parylene insulating/moisture barrier layers and Ti/Au electrodes was fabricated from the nanocomposite using a fabrication process designed specifically for this chemical- and temperature-sensitive material. It was found that the parylene layers only slightly increased the stiffness of the probe in the wet state in spite of its much higher Young's modulus. Furthermore, the Ti/Au electrodes exhibited impedance comparable to Au electrodes on conventional substrates. Swelling of the nanocomposite was highly anisotropic favoring the thickness dimension by a factor of 8 to 12, leading to excellent adhesion between the nanocomposite and parylene layers and no discernable deformation of the probes when deployed in deionized water.
Christiansen, Niels Hørbye; Høgsberg, Jan Becker; Winther, Ole
It is shown how artificial neural networks can be trained to predict dynamic response of a simple nonlinear structure. Data generated using a nonlinear finite element model of a simplified wind turbine is used to train a one layer artificial neural network. When trained properly the network is ab...... to perform accurate response prediction much faster than the corresponding finite element model. Initial result indicate a reduction in cpu time by two orders of magnitude.......It is shown how artificial neural networks can be trained to predict dynamic response of a simple nonlinear structure. Data generated using a nonlinear finite element model of a simplified wind turbine is used to train a one layer artificial neural network. When trained properly the network is able...
Full Text Available Emotion regulation is crucial for successfully engaging in social interactions. Yet, little is known about the neural mechanisms controlling behavioral responses to emotional expressions perceived in the face of other people, which constitute a key element of interpersonal communication. Here, we investigated brain systems involved in social emotion perception and regulation, using functional magnetic resonance imaging (fMRI in 20 healthy participants who saw dynamic facial expressions of either happiness or sadness, and were asked to either imitate the expression or to suppress any expression on their own face (in addition to a gender judgment control task. fMRI results revealed higher activity in regions associated with emotion (e.g., the insula, motor function (e.g., motor cortex, and theory of mind during imitation. Activity in dorsal cingulate cortex was also increased during imitation, possibly reflecting greater action monitoring or conflict with own feeling states. In addition, premotor regions were more strongly activated during both imitation and suppression, suggesting a recruitment of motor control for both the production and inhibition of emotion expressions. Expressive suppression produced increases in dorsolateral and lateral prefrontal cortex typically related to cognitive control. These results suggest that voluntary imitation and expressive suppression modulate brain responses to emotional signals perceived from faces, by up- and down-regulating activity in distributed subcortical and cortical networks that are particularly involved in emotion, action monitoring, and cognitive control.
van Rooij, Sanne J H; Geuze, Elbert; Kennis, Mitzy; Rademaker, Arthur R|info:eu-repo/dai/nl/304836427; Vink, Matthijs
Thirty to fifty percent of posttraumatic stress disorder (PTSD) patients do not respond to treatment. Understanding the neural mechanisms underlying treatment response could contribute to improve response rates. PTSD is often associated with decreased inhibition of fear responses in a safe
Kim, Pilyoung; Capistrano, Christian G; Erhart, Andrew; Gray-Schiff, Rachel; Xu, Nanxi
During the early postpartum period, mothers exhibit increased amygdala responses to positive infant expressions, which are important for positive mother-infant relationships. Socioeconomic disadvantage is associated with altered amygdala response to emotional stimuli as well as more negative mother-infant relationships. However, little is known about the role of socioeconomic disadvantage in neural responses specifically to infants. Thus, we examined whether socioeconomic disadvantage (indexed by lower income-to-needs ratio) is associated with neural responses to infant emotions and parenting behaviors among new mothers. Using fMRI, neural responses to infants' emotional expressions (positive, negative, and neutral faces) were assessed among 39 low- and middle-income first-time mothers during 0-6 postpartum months. Lower income-to-needs ratio was associated with dampened amygdala responses to positive infant faces, but increased amygdala responses to negative infant faces. An indirect effect of socioeconomic disadvantage on emotional availability via amygdala activation suggests that socioeconomic disadvantage is associated with heightened neural sensitivity to infants' negative emotions, which is further associated with mothers' intrusiveness observed during interactions with their own infant. The findings suggest that low-income mothers may be more vulnerable to altered neural processing of infants' emotional expressions which may further influence mothers' emotional availability during interactions with their own infants. Copyright © 2017 Elsevier B.V. All rights reserved.
Full Text Available Neural activity of behaving animals, especially in the prefrontal cortex, is highly heterogeneous, with selective responses to diverse aspects of the executed task. We propose a general model of recurrent neural networks that perform complex rule-based tasks, and we show that the diversity of neuronal responses plays a fundamental role when the behavioral responses are context dependent. Specifically, we found that when the inner mental states encoding the task rules are represented by stable patterns of neural activity (attractors of the neural dynamics, the neurons must be selective for combinations of sensory stimuli and inner mental states. Such mixed selectivity is easily obtained by neurons that connect with random synaptic strengths both to the recurrent network and to neurons encoding sensory inputs. The number of randomly connected neurons needed to solve a task is on average only three times as large as the number of neurons needed in a network designed ad hoc. Moreover, the number of needed neurons grows only linearly with the number of task-relevant events and mental states, provided that each neuron responds to a large proportion of events (dense/distributed coding. A biologically realistic implementation of the model captures several aspects of the activity recorded from monkeys performing context dependent tasks. Our findings explain the importance of the diversity of neural responses and provide us with simple and general principles for designing attractor neural networks that perform complex computation.
Fang, Yanshan; Soares, Lorena; Bonini, Nancy M
Live-imaging technology has markedly advanced in the field of neural injury and axon degeneration; however, studies are still predominantly performed in in vitro settings such as cultured neuronal cells or in model organisms such as Caenorhabditis elegans in which axons lack glial wrappings. We recently developed a new in vivo model for adult-stage neural injury in Drosophila melanogaster, using the highly accessible wing of the animal. Because the Drosophila wing is translucent and dispensable for survival, it allows clear and direct visualization of injury-induced progressive responses of axons and glia highlighted by fluorescent protein (FP) markers in live animals over time. Moreover, unlike previous Drosophila models of neural injury, this procedure does not require dissection of the CNS. Thus, the key preparation steps for in vivo imaging of the neural injury response described in this protocol can be completed within 30 min.
Tkačik, Gašper; Granot-Atedgi, Einat; Segev, Ronen; Schneidman, Elad
The ability of an organism to distinguish between various stimuli is limited by the structure and noise in the population code of its sensory neurons. Here we infer a distance measure on the stimulus space directly from the recorded activity of 100 neurons in the salamander retina. In contrast to previously used measures of stimulus similarity, this "neural metric" tells us how distinguishable a pair of stimulus clips is to the retina, based on the similarity between the induced distributions of population responses. We show that the retinal distance strongly deviates from Euclidean, or any static metric, yet has a simple structure: we identify the stimulus features that the neural population is jointly sensitive to, and show the support-vector-machine-like kernel function relating the stimulus and neural response spaces. We show that the non-Euclidean nature of the retinal distance has important consequences for neural decoding.
is connected to thousands of other neurons. The rst question is: how to model neural networks through stochastic processes? A multivariate Ornstein-Uhlenbeck process, obtained as a diffusion approximation of a jump process, is the proposed answer. Obviously, dependencies between neurons imply dependencies......Stochastic processes and their rst passage times have been widely used to describe the membrane potential dynamics of single neurons and to reproduce neuronal spikes, respectively.However, cerebral cortex in human brains is estimated to contain 10-20 billions of neurons and each of them...... between their spike times. Therefore, the second question is: how to detect neural network connectivity from simultaneously recorded spike trains? Answering this question corresponds to investigate the joint distribution of sequences of rst passage times. A non-parametric method based on copulas...
Full Text Available Objectives: An important subset of patients with schizophrenia present clinically significant persistent negative symptoms (PNS. Identifying the neural substrates of PNS could help improve our understanding and treatment of these symptoms. Methods: This study included 64 non-affective first-episode of psychosis (FEP patients and 60 healthy controls; 16 patients displayed PNS (i.e., at least 1 primary negative symptom at moderate or worse severity sustained for at least 6 consecutive months. Using voxel-based morphometry (VBM, we explored for grey matter differences between PNS and non-PNS patients; patient groups were also compared to controls. All comparisons were performed at p<0.05, corrected for multiple comparisons.Results: PNS patients had smaller grey matter in the right frontal medial-orbital gyrus (extending into the inferior frontal gyrus and right parahippocampal gyrus (extending into the fusiform gyrus compared to non-PNS patients. Compared to controls, PNS patients had smaller grey matter in the right parahippocampal gyrus (extending into the fusiform gyrus and superior temporal gyrus; non-PNS patients showed no significant differences to controls. Conclusions: Neural substrates of persistent negative symptoms are evident in FEP patients. A better understanding of the neural etiology of PNS may encourage the search for new medications and/or alternative treatments to better help those affected.
Sin, G.; Vanrolleghem, P.A.; Gernaey, Krist
The state-of-the-art understanding of activated sludge processes as summarized in activated sludge models (ASMs) predicts an instantaneous increase in the biomass activity (which is measured, e.g., by the corresponding respiration rate OUR, NUR, etc.) under sudden substrate concentration changes...... process. That transient phenomenon exhibits itself immediately upon addition of a substrate source to an endogenously respiring activated sludge sample and it usually takes a few minutes until the activated sludge reaches its maximum possible rate under given environmental conditions. This discrepancy...... response of the activated sludge most likely results from the sequence of intracellular reactions involved in substrate degradation by the activated sludge. Results from studies performed elsewhere with pure cultures (S. cerevisae and E. coli) support the hypothesis. The transient phenomenon can...
Hu, Prof Pingan [Harbin Institute of Technology; Wang, Lifeng [Harbin Institute of Technology; Yoon, Mina [ORNL; Zhang, Jia [Harbin Institute of Technology; Feng, Wei [Harbin Institute of Technology; Wang, Xiaona [Harbin Institute of Technology; Wen, Zhenzhong [Harbin Institute of Technology; Idrobo Tapia, Juan C [ORNL; Miyamoto, Yoshiyuki [National Institute of Advanced Industrial Science and Technology, Japan; Geohegan, David B [ORNL; Xiao, Kai [ORNL
The first GaS nanosheet-based photodetectors are demonstrated on both mechanically rigid and flexible substrates. Highly-crystalline, exfoliated GaS nanosheets are promising for optoelectronics due to strong absorption in the UV-visible wavelength region. Photocurrent measurements of GaS nanosheet photodetectors made on SiO2/Si substrates and flexible polyethylene terephthalate (PET) substrates exhibit a photo-responsivity at 254nm up to 4.2 AW-1 and 19.2 AW-1, respectively, which exceeds that of graphene, MoS2, or other 2D materials-based devices. Additionally, the linear dynamic range of the devices on SiO2/Si and PET substrates are 97.7dB and 78.73 dB, respectively. Both surpass that of currently-exploited InGaAs photodetectors (66 dB). Theoretical modeling of the electronic structures indicates that the reduction of the effective mass at the valence band maximum (VBM) with decreasing sheet thickness enhances the carrier mobility of the GaS nanosheets, contributing to the high photocurrents. Double-peak VBMs are theoretically predicted for ultrathin GaS nanosheets (thickness less than 5 monolayers), which is found to promote photon absorption. These theoretical and experimental results show that GaS nanosheets are promising materials for high performance photodetectors on both conventional silicon and flexible substrates.
Wang, Chao; Trongnetrpunya, Amy; Samuel, Immanuel Babu Henry; Ding, Mingzhou; Kluger, Benzi M
Prolonged continuous performance of a cognitively demanding task induces cognitive fatigue and is associated with a time-related deterioration of objective performance, the degree of which is referred to cognitive fatigability. Although the neural underpinnings of cognitive fatigue are poorly understood, prior studies report changes in neural activity consistent with deterioration of task-related networks over time. While compensatory brain activity is reported to maintain motor task performance in the face of motor fatigue and cognitive performance in the face of other stressors (e.g., aging) and structural changes, there are no studies to date demonstrating compensatory activity for cognitive fatigue. High-density electroencephalography was recorded from human subjects during a 160 min continuous performance of a cognitive control task. While most time-varying neural activity showed a linear decline over time, we identified an evoked potential over the anterior frontal region which demonstrated an inverted U-shaped time-on-task profile. This evoked brain activity peaked between 60 and 100 min into the task and was positively associated with better behavioral performance only during this interval. Following the peak and during subsequent decline of this anterior frontal activity, the rate of performance decline also accelerated. These findings demonstrate that this anterior frontal brain activity, which is not part of the primary task-related activity at baseline, is recruited to compensate for fatigue-induced impairments in the primary task-related network, and that this compensation terminates as cognitive fatigue further progresses. These findings may be relevant to understanding individual differences in cognitive fatigability and developing interventions for clinical conditions afflicted by fatigue. Fatigue refers to changes in objective performance and subjective effort induced by continuous task performance. We examined the neural underpinnings of cognitive
Franco, Vanina G; Perín, Juan C; Mantovani, Víctor E; Goicoechea, Héctor C
An experiment was developed as a simple alternative to existing analytical methods for the simultaneous quantitation of glucose (substrate) and glucuronic acid (main product) in the bioprocesses Kombucha by using FTIR spectroscopy coupled to multivariate calibration (partial least-squares, PLS-1 and artificial neural networks, ANNs). Wavelength selection through a novel ranked regions genetic algorithm (RRGA) was used to enhance the predictive ability of the chemometric models. Acceptable results were obtained by using the ANNs models considering the complexity of the sample and the speediness and simplicity of the method. The accuracy on the glucuronic acid determination was calculated by analysing spiked real fermentation samples (recoveries ca. 115%).
Krok, A.; Waszczyszyn, Z. [Cracow University of Technology, Krakow (Poland)
Acceleration response spectra (ARS) for mining tremors in the Upper Silesian Coalfield, Poland are generated using neural networks trained by means of Kalman filtering. The target ARS were computed on the base of measured accelerograms. It was proved that the standard feed-forward, layered neural network, trained by the DEFK (decoupled extended Kalman filter) algorithm is numerically much less efficient than the standard recurrent NN learnt by Recurrent DEKF, cf. (Haykin S, (editor). Kalman filtering and neural networks. New York: John Wiley & Sons; 2001). It is also shown that the studied KF algorithms are better than the traditional Resilient-Propagation learning method. The improvement of the training process and neural prediction due to introduction of an autoregressive input is also discussed in the paper.
Full Text Available Experiments that study neural encoding of stimuli at the level of individual neurons typically choose a small set of features present in the world-contrast and luminance for vision, pitch and intensity for sound-and assemble a stimulus set that systematically varies along these dimensions. Subsequent analysis of neural responses to these stimuli typically focuses on regression models, with experimenter-controlled features as predictors and spike counts or firing rates as responses. Unfortunately, this approach requires knowledge in advance about the relevant features coded by a given population of neurons. For domains as complex as social interaction or natural movement, however, the relevant feature space is poorly understood, and an arbitrary a priori choice of features may give rise to confirmation bias. Here, we present a Bayesian model for exploratory data analysis that is capable of automatically identifying the features present in unstructured stimuli based solely on neuronal responses. Our approach is unique within the class of latent state space models of neural activity in that it assumes that firing rates of neurons are sensitive to multiple discrete time-varying features tied to the stimulus, each of which has Markov (or semi-Markov dynamics. That is, we are modeling neural activity as driven by multiple simultaneous stimulus features rather than intrinsic neural dynamics. We derive a fast variational Bayesian inference algorithm and show that it correctly recovers hidden features in synthetic data, as well as ground-truth stimulus features in a prototypical neural dataset. To demonstrate the utility of the algorithm, we also apply it to cluster neural responses and demonstrate successful recovery of features corresponding to monkeys and faces in the image set.
Neural substrates of normal and impaired preattentive sensory discrimination in large cohorts of nonpsychiatric subjects and schizophrenia patients as indexed by MMN and P3a change detection responses☆
Takahashi, Hidetoshi; Rissling, Anthony J.; Pascual-Marqui, Roberto; Kirihara, Kenji; Pela, Marlena; Sprock, Joyce; Braff, David L.; Light, Gregory A.
Objective Schizophrenia (SZ) patients have information processing deficits, spanning from low level sensory processing to higher-order cognitive functions. Mismatch negativity (MMN) and P3a are event-related potential (ERP) components that are automatically elicited in response to unattended changes in ongoing, repetitive stimuli that provide a window into abnormal information processing in SZ. MMN and P3a are among the most robust and consistently identified deficits in SZ, yet the neural substrates of these responses and their associated deficits in SZ are not fully understood. This study examined the neural sources of MMN and P3a components in a large cohort of SZ and nonpsychiatric control subjects (NCS) using Exact Low Resolution Electromagnetic Tomography Analyses (eLORETA) in order to identify the neural sources of MMN and P3a as well as the brain regions associated with deficits commonly observed among SZ patients. Methods 410 SZ and 247 NCS underwent EEG testing using a duration-deviant auditory oddball paradigm (1-kHz tones, 500 ms SOA; standard p=0.90, 50-ms duration; deviant tones P=0.10, 100-ms duration) while passively watching a silent video. Voxel-by-voxel within- (MMN vs. P3a) and between-group (SZ vs. NCS) comparisons were performed using eLORETA. Results SZ had robust deficits in MMN and P3a responses measured at scalp electrodes consistent with other studies. These components mapped onto neural sources broadly distributed across temporal, frontal, and parietal regions. MMN deficits in SZ were associated with reduced activations in discrete medial frontal brain regions, including the anterior–posterior cingulate and medial frontal gyri. These early sensory discriminatory MMN impairments were followed by P3a deficits associated with widespread reductions in the activation of attentional networks (frontal, temporal, parietal regions), reflecting impaired orienting or shifts of attention to the infrequent stimuli. Conclusions MMN and P3a are
Smid, B.E.; Ferraz, M.J.; Verhoek, M.; Mirzaian, M.; Wisse, P.; Overkleeft, H.S.; Hollak, C.E.; Aerts, J.M.
Background We retrospectively compared biochemical responses in type 1 Gaucher disease patients to treatment with glycosphingolipid synthesis inhibitors miglustat and eliglustat and ERT. Methods Seventeen GD1 patients were included (n?=?6 eliglustat, (two switched from ERT), n?=?9 miglustat (seven switchers), n?=?4 ERT (median dose 60U/kg/m). Plasma protein markers reflecting disease burden (chitotriosidase, CCL18) and lipids reflecting substrate accumulation (glucosylsphingosine, glucosylcer...
Sihi, Debjani; Gerber, Stefan; Inglett, Patrick W.; Sharma Inglett, Kanika
Recent developments in modelling soil organic carbon decomposition include the explicit incorporation of enzyme and microbial dynamics. A characteristic of these models is a positive feedback between substrate and consumers, which is absent in traditional first-order decay models. With sufficiently large substrate, this feedback allows an unconstrained growth of microbial biomass. We explore mechanisms that curb unrestricted microbial growth by including finite potential sites where enzymes can bind and by allowing microbial scavenging for enzymes. We further developed a model where enzyme synthesis is not scaled to microbial biomass but associated with a respiratory cost and microbial population adjusts enzyme production in order to optimise their growth. We then tested short- and long-term responses of these models to a step increase in temperature and find that these models differ in the long-term when short-term responses are harmonised. We show that several mechanisms, including substrate limitation, variable production of microbial enzymes, and microbes feeding on extracellular enzymes eliminate oscillations arising from a positive feedback between microbial biomass and depolymerisation. The model where enzyme production is optimised to yield maximum microbial growth shows the strongest reduction in soil organic carbon in response to warming, and the trajectory of soil carbon largely follows that of a first-order decomposition model. Modifications to separate growth and maintenance respiration generally yield short-term differences, but results converge over time because microbial biomass approaches a quasi-equilibrium with the new conditions of carbon supply and temperature.
Madipakkam, Apoorva Rajiv; Rothkirch, Marcus; Guggenmos, Matthias; Heinz, Andreas; Sterzer, Philipp
Gaze direction and especially direct gaze is a powerful nonverbal cue that plays an important role in social interactions. Here we studied the neural mechanisms underlying the privileged access of direct gaze to visual awareness. We performed functional magnetic resonance imaging in healthy human volunteers who were exposed to faces with direct or averted gaze under continuous flash suppression, thereby manipulating their awareness of the faces. A gaze processing network comprising fusiform face area (FFA), superior temporal sulcus, amygdala, and intraparietal sulcus showed overall reduced neural responses when participants reported to be unaware of the faces. Interestingly, direct gaze elicited greater responses than averted gaze when participants were aware of the faces, but smaller responses when they were unaware. Additional between-subject correlation and single-trial analyses indicated that this pattern of results was due to a modulation of the relationship between neural responses and awareness by gaze direction: with increasing neural activation in the FFA, direct-gaze faces entered awareness more readily than averted-gaze faces. These findings suggest that for direct gaze, lower levels of neural activity are sufficient to give rise to awareness than for averted gaze, thus providing a neural basis for privileged access of direct gaze to awareness. Significance statement: Another person's eye gaze directed at oneself is a powerful social signal acting as a catalyst for further communication. Here, we studied the neural mechanisms underlying the prioritized access of direct gaze to visual awareness in healthy human volunteers and show that with increasing neural activation, direct-gaze faces enter awareness more readily than averted-gaze faces. This suggests that for a socially highly relevant cue like direct gaze, lower levels of neural activity are sufficient to give rise to awareness compared with averted gaze, possibly because the human brain is attuned
Full Text Available In this study, the capabilities of response surface methodology (RSM and artificial neural networks (ANN for modeling and optimization of ethanol production from glucoseusing Saccharomyces cerevisiae in batch fermentation process were investigated. Effect of three independent variables in a defined range of pH (4.2-5.8, temperature (20-40ºC and glucose concentration (20-60 g/l on the cell growth and ethanol production was evaluated. Results showed that prediction accuracy of ANN was apparently similar to RSM. At optimum condition of temperature (32°C, pH (5.2 and glucose concentration (50 g/l suggested by the statistical methods, the maximum cell dry weight and ethanol concentration obtained from RSM were 12.06 and 16.2 g/l whereas experimental values were 12.09 and 16.53 g/l, respectively. The present study showed that using ANN as fitness function, the maximum cell dry weight and ethanol concentration were 12.05 and 16.16 g/l, respectively. Also, the coefficients of determination for biomass and ethanol concentration obtained from RSM were 0.9965 and 0.9853 and from ANN were 0.9975 and 0.9936, respectively. The process parameters optimization was successfully conducted using RSM and ANN; however prediction by ANN was slightly more precise than RSM. Based on experimental data maximum yield of ethanol production of 0.5 g ethanol/g substrate (97 % of theoretical yield was obtained.
Matthias C. Krantz
Full Text Available Resonant bending-mode magnetoelectric (ME coefficients of magnetostrictive-piezoelectric multilayer cantilevers are calculated analytically using a model developed for arbitrary multilayers on a substrate. Without quality factor effects the ME coefficient maxima in the four-dimensional parameter space of layer numbers, layer sequences, piezoelectric volume fractions, and substrate thicknesses are found to be essentially constant for nonzero substrate thickness. Global maxima occur for bilayers without substrates. Vanishing magnetoelectric response regions result from voltage cancellation in piezoelectric layers or absence of bending-mode excitation. They are determined by the neutral plane position in the multilayer stack. With Q-factor effects dominated by viscous air damping ME coefficients strongly increase with cantilever thickness primarily due to increasing resonance frequencies. The results yield a layer specific prediction of ME coefficients, resonance frequencies, and Q-factors in arbitrary multilayers and thus distinction of linear-coupling and Q-factor effects from exchange interaction, interface, or nonlinear ME effects.
Shirdar, Mostafa Rezazadeh; Golshan, Abolfazl; Izman, Sudin; Ghodsiyeh, Danial
High cobalt (Co) content greater than 10% in tungsten carbide is desirable because Co improves the toughness of the cutting tool. However, the additional Co poses a huge challenge in surface preparation given that the Co content must be reduced to less than 1% on the substrate surface prior to applying a diamond coating. The excessive presence of Co on the substrate surface during coating suppresses diamond nucleation and causes the deterioration of diamond film adhesion. Many attempts have been made to overcome this issue, including the use of chemical etching, mechanical blasting, and heat treatment, but the successful pretreatment of WC-12%Co is still very limited. In this paper, a single-step chemical pretreatment using a mixture of sulfuric acid and hydrogen peroxide solutions was carried out on WC-12%Co. Two independent variables, i.e., etching time and acid temperature, were varied in the experiments to reduce Co contents as well as to roughen the substrate surface. The experimental plan was based on a central composite design. Variance analysis was employed to verify the precision of the mathematical models and their relative parameters. The predicted models generated by the response surface methodology (RSM) were compared with the experimental results, and close agreement was observed. The models demonstrated the significance of both factors, namely, acid temperature and etching time, in reducing Co contents to less than 1% as well as a roughening of the substrate surface within the desirable range.
Cascio Carissa J
Full Text Available Abstract Background One hypothesis for the social deficits that characterize autism spectrum disorders (ASD is diminished neural reward response to social interaction and attachment. Prior research using established monetary reward paradigms as a test of non-social reward to compare with social reward may involve confounds in the ability of individuals with ASD to utilize symbolic representation of money and the abstraction required to interpret monetary gains. Thus, a useful addition to our understanding of neural reward circuitry in ASD includes a characterization of the neural response to primary rewards. Method We asked 17 children with ASD and 18 children without ASD to abstain from eating for at least four hours before an MRI scan in which they viewed images of high-calorie foods. We assessed the neural reward network for increases in the blood oxygenation level dependent (BOLD signal in response to the food images Results We found very similar patterns of increased BOLD signal to these images in the two groups; both groups showed increased BOLD signal in the bilateral amygdala, as well as in the nucleus accumbens, orbitofrontal cortex, and insula. Direct group comparisons revealed that the ASD group showed a stronger response to food cues in bilateral insula along the anterior-posterior gradient and in the anterior cingulate cortex than the control group, whereas there were no neural reward regions that showed higher activation for controls than for ASD. Conclusion These results suggest that neural response to primary rewards is not diminished but in fact shows an aberrant enhancement in children with ASD.
Gilman, Jodi M; Ramchandani, Vijay A.; Crouss, Tess; Hommer, Daniel W.
Heavy alcohol consumption during young adulthood is a risk factor for the development of serious alcohol use disorders. Research has shown that individual differences in subjective responses to alcohol may affect individuals' vulnerability to developing alcoholism. Studies comparing the subjective and objective response to alcohol between light and heavy drinkers (HDs), however, have yielded inconsistent results, and neural responses to alcohol in these groups have not been characterized. We ...
Junius, D.; Dau, Torsten
), disparities occurred between the responses, reflecting a nonlinearity in the processing when neural activity is integrated across frequency. In the third experiment, the effect of within-train rate on wave-V response was investigated. The response to the chirp presented at a within-train rate of 95 Hz...... processing in the human auditory system. The findings might also be useful for the development of effective stimulation paradigms in clinical applications....
Zhou, Ke; Geng, Yaohui; Liu, Hongpeng; Wang, Shichan; Mao, Dongyao; Yu, Dan
A novel substrate-free acrylamide photopolymer was proposed to improve holographic sensing characterization. The diffraction spectrum response of reflection volume grating recorded in the medium was characterized for exploring the improvement of sensitivity. The compared result indicated that the response rate and sensitivity were evidently improved by absorption of double surface in substrate-free polymer. The thickness of the sample as a significant factor was discussed in detail experimentally. During the sensing process, the inhibition concentration and concentration constant of organic vapor were extracted to evaluate the significance of sample thickness. Simultaneously, optimization of thickness could be considered as an effective approach to improve the response rate of holographic sensing. The reversibility of a novel holographic sensor with double surface was demonstrated by recovery measurement. The swelling ratio indicated that the peak wavelength shift was attributed to the expansion of binder induced by absorption of organic vapor. Theoretically, the sensing physical mechanism and the dynamic swelling process were analyzed and simulated using a diffusional model with nonlocal response. These experimental results provide an effective strategy for improving the response of a holographic sensor and accelerate the development of the holographic optical element based on photopolymer.
Mascaro, Jennifer S.; Hackett, Patrick D.; Rilling, James K.
Despite the well-documented importance of paternal caregiving for positive child development, little is known about the neural changes that accompany the transition to fatherhood in humans, or about how changes in hormone levels affect paternal brain function. We compared fathers of children aged 1–2 with non-fathers in terms of hormone levels (oxytocin and testosterone), neural responses to child picture stimuli, and neural responses to visual sexual stimuli. Compared to non-fathers, fathers...
Sproule, Michael K J; Chacron, Maurice J
Neural heterogeneities are seen ubiquitously within the brain and greatly complicate classification efforts. Here we tested whether the responses of an anatomically well-characterized sensory neuron population to natural stimuli could be used for functional classification. To do so, we recorded from pyramidal cells within the electrosensory lateral line lobe (ELL) of the weakly electric fish Apteronotus leptorhynchus in response to natural electro-communication stimuli as these cells can be anatomically classified into six different types. We then used two independent methodologies to functionally classify responses: one relies of reducing the dimensionality of a feature space while the other directly compares the responses themselves. Both methodologies gave rise to qualitatively similar results: while ON and OFF-type cells could easily be distinguished from one another, ELL pyramidal neuron responses are actually distributed along a continuum rather than forming distinct clusters due to heterogeneities. We discuss the implications of our results for neural coding and highlight some potential advantages.
H.M. de Souza
Full Text Available Hepatic responsiveness to gluconeogenic substrates during insulin-induced hypoglycemia was investigated. For this purpose, livers were perfused with a saturating concentration of 2 mM glycerol, 5 mM L-alanine or 5 mM L-glutamine as gluconeogenic substrates. All experiments were performed 1 h after an ip injection of saline (CN group or 1 IU/kg of insulin (IN group. The IN group showed higher (P<0.05 hepatic glucose production from glycerol, L-alanine and L-glutamine and higher (P<0.05 production of L-lactate, pyruvate and urea from L-alanine and L-glutamine. In addition, ip injection of 100 mg/kg glycerol, L-alanine and L-glutamine promoted glucose recovery. The results indicate that the hepatic capacity to produce glucose from gluconeogenic precursors was increased during insulin-induced hypoglycemia.
Yeo, S.; Rosen, B.; Bosch, M.P.C.; Noort, M.W.M.L. van den; Lim, S.
Objective: To examine gender differences and similarities in the psychophysical and brain responses to acupuncture at GB34, a point that is frequently used to treat motor function issues in Traditional Chinese Medicine. Methods: Functional MRI (fMRI) was used to measure brain activation in response
Berthrong, S. T.; Buckley, D. H.; Drinkwater, L. E.
Fertilizer application in conventional agriculture leads to N saturation and decoupled soil C and N cycling, whereas organic practices, e.g. complex rotations and legume incorporation, often results in increased SOM and tightly coupled cycles of C and N. These legacy effects of management on soils likely affect microbial community composition and microbial process rates. This project tested if agricultural management practices led to distinct microbial communities and if those communities differed in ability to utilize labile plant carbon substrates and to produce more plant available N. We addressed several specific questions in this project. 1) Do organic and conventional management legacies on similar soils produce distinct soil bacterial and fungal community structures and abundances? 2) How do these microbial community structures change in response to carbon substrate addition? 3) How do the responses of the microbial communities influence N cycling? To address these questions we conducted a laboratory incubation of organically and conventionally managed soils. We added C-13 labelled glucose either in one large dose or several smaller pulses. We extracted genomic DNA from soils before and after incubation for TRFLP community fingerprinting. We measured C in soil pools and respiration and N in soil extracts and leachates. Management led to different compositions of bacteria and fungi driven by distinct components in organic soils. Biomass did not differ across treatments indicating that differences in cycling were due to composition rather than abundance. C substrate addition led to convergence in bacterial communities; however management still strongly influenced the difference in communities. Fungal communities were very distinct between managements and plots with substrate addition not altering this pattern. Organic soils respired 3 times more of the glucose in the first week than conventional soils (1.1% vs 0.4%). Organic soils produced twice as much
Chen, Zhencai; De Beuckelaer, A.; Wang, Xu; Liu, Jia
Recent studies revealed spontaneous neural activity to be associated with fluid intelligence (gF) which is commonly assessed by Raven’s Advanced Progressive Matrices, and embeds two types of reasoning: visuospatial and verbal-analytic reasoning. With resting-state fMRI data, using global brain
Buchsbaum, Bradley R.; Padmanabhan, Aarthi; Berman, Karen Faith
One of the classic categorical divisions in the history of memory research is that between short-term and long-term memory. Indeed, because memory for the immediate past (a few seconds) and memory for the relatively more remote past (several seconds and beyond) are assumed to rely on distinct neural systems, more often than not, memory research…
Sui, Jie; Chechlacz, Magdalena; Humphreys, Glyn W.
Facial self-awareness is a basic human ability dependent on a distributed bilateral neural network and revealed through prioritized processing of our own over other faces. Using non-prosopagnosic patients we show, for the first time, that facial self-awareness can be fractionated into different component processes. Patients performed two face…
Son, Taeyoon; Wang, Benquan; Lu, Yiming; Chen, Yanjun; Cao, Dingcai; Yao, Xincheng
It is well established that major retinal diseases involve distortions of the retinal neural physiology and blood vascular structures. However, the details of distortions in retinal neurovascular coupling associated with major eye diseases are not well understood. In this study, a multi-modal optical coherence tomography (OCT) imaging system was developed to enable concurrent imaging of retinal neural activity and vascular hemodynamics. Flicker light stimulation was applied to mouse retinas to evoke retinal neural responses and hemodynamic changes. The OCT images were acquired continuously during the pre-stimulation, light-stimulation, and post-stimulation phases. Stimulus-evoked intrinsic optical signals (IOSs) and hemodynamic changes were observed over time in blood-free and blood regions, respectively. Rapid IOSs change occurred almost immediately after stimulation. Both positive and negative signals were observed in adjacent retinal areas. The hemodynamic changes showed time delays after stimulation. The signal magnitudes induced by light stimulation were observed in blood regions and did not show significant changes in blood-free regions. These differences may arise from different mechanisms in blood vessels and neural tissues in response to light stimulation. These characteristics agreed well with our previous observations in mouse retinas. Further development of the multimodal OCT may provide a new imaging method for studying how retinal structures and metabolic and neural functions are affected by age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), and other diseases, which promises novel noninvasive biomarkers for early disease detection and reliable treatment evaluations of eye diseases.
Hulsey, Daniel R; Riley, Jonathan R; Loerwald, Kristofer W; Rennaker, Robert L; Kilgard, Michael P; Hays, Seth A
Vagus nerve stimulation (VNS) has emerged as a therapy to treat a wide range of neurological disorders, including epilepsy, depression, stroke, and tinnitus. Activation of neurons in the locus coeruleus (LC) is believed to mediate many of the effects of VNS in the central nervous system. Despite the importance of the LC, there is a dearth of direct evidence characterizing neural activity in response to VNS. A detailed understanding of the brain activity evoked by VNS across a range of stimulation parameters may guide selection of stimulation regimens for therapeutic use. In this study, we recorded neural activity in the LC and the mesencephalic trigeminal nucleus (Me5) in response to VNS over a broad range of current amplitudes, pulse frequencies, train durations, inter-train intervals, and pulse widths. Brief 0.5s trains of VNS drive rapid, phasic firing of LC neurons at 0.1mA. Higher current intensities and longer pulse widths drive greater increases in LC firing rate. Varying the pulse frequency substantially affects the timing, but not the total amount, of phasic LC activity. VNS drives pulse-locked neural activity in the Me5 at current levels above 1.2mA. These results provide insight into VNS-evoked phasic neural activity in multiple neural structures and may be useful in guiding the selection of VNS parameters to enhance clinical efficacy. Copyright © 2016 Elsevier Inc. All rights reserved.
Liu, Qin; Ulloa, Antonio; Horwitz, Barry
Many cognitive and computational models have been proposed to help understand working memory. In this article, we present a simulation study of cortical processing of visual objects during several working memory tasks using an extended version of a previously constructed large-scale neural model [Tagamets, M. A., & Horwitz, B. Integrating electrophysiological and anatomical experimental data to create a large-scale model that simulates a delayed match-to-sample human brain imaging study. Cerebral Cortex, 8, 310-320, 1998]. The original model consisted of arrays of Wilson-Cowan type of neuronal populations representing primary and secondary visual cortices, inferotemporal (IT) cortex, and pFC. We added a module representing entorhinal cortex, which functions as a gating module. We successfully implemented multiple working memory tasks using the same model and produced neuronal patterns in visual cortex, IT cortex, and pFC that match experimental findings. These working memory tasks can include distractor stimuli or can require that multiple items be retained in mind during a delay period (Sternberg's task). Besides electrophysiology data and behavioral data, we also generated fMRI BOLD time series from our simulation. Our results support the involvement of IT cortex in working memory maintenance and suggest the cortical architecture underlying the neural mechanisms mediating particular working memory tasks. Furthermore, we noticed that, during simulations of memorizing a list of objects, the first and last items in the sequence were recalled best, which may implicate the neural mechanism behind this important psychological effect (i.e., the primacy and recency effect).
Canterberry, Melanie; Peltier, MacKenzie R; Brady, Kathleen T; Hanlon, Colleen A
Cocaine users often report a loss of arousal for nondrug-related stimuli, which may contribute to their response to drug-related rewards. However, little is known about users' neural reactivity to emotional nondrug-related stimuli and the potential influence of gender. Test the hypotheses that cocaine-dependent individuals have an attenuated neural response to arousing stimuli relative to controls and that this difference is amplified in women. The brain response to typically arousing positive and negative images as well as neutral images from the International Affective Picture System was measured in 40 individuals (20 non-treatment seeking cocaine-dependent and 20 age- and gender-matched control participants; 50% of whom were women). Images were displayed for 4 s each in blocks of five across two 270-second runs. General linear models assessed within and between group activation differences for the emotional images. Cocaine-dependent individuals had a significantly lower response to typically arousing positive and negative images than controls, with attenuated neural activity present in the medial prefrontal cortex (mPFC) and anterior cingulate cortex (ACC). Analyses by gender revealed less mPFC/ACC activation among female users, but not males, for both positive and negative images. The dampened neural response to typically arousing stimuli among cocaine-dependent polydrug users suggests decreased salience processing for nondrug stimuli, particularly among female users. This decreased responding is consistent with data from other substance using populations and suggests that this may be a general feature of addiction. Amplifying the neural response to naturally arousing nondrug-related reinforcers may present an opportunity for unique behavioral and brain stimulation therapies.
Full Text Available Functional MRI analyses commonly rely on the assumption that the temporal dynamics of hemodynamic response functions (HRFs are independent of the amplitude of the neural signals that give rise to them. The validity of this assumption is particularly important for techniques that use fMRI to resolve sub-second timing distinctions between responses, in order to make inferences about the ordering of neural processes. Whether or not the detailed shape of the HRF is independent of neural response amplitude remains an open question, however. We performed experiments in which we measured responses in primary visual cortex (V1 to large, contrast-reversing checkerboards at a range of contrast levels, which should produce varying amounts of neural activity. Ten subjects (ages 22-52 were studied in each of two experiments using 3 Tesla scanners. We used rapid, 250 msec, temporal sampling (repetition time, or TR and both short and long inter-stimulus interval (ISI stimulus presentations. We tested for a systematic relationship between the onset of the HRF and its amplitude across conditions, and found a strong negative correlation between the two measures when stimuli were separated in time (long- and medium-ISI experiments, but not the short-ISI experiment. Thus, stimuli that produce larger neural responses, as indexed by HRF amplitude, also produced HRFs with shorter onsets. The relationship between amplitude and latency was strongest in voxels with lowest mean-normalized variance (i.e., parenchymal voxels. The onset differences observed in the longer-ISI experiments are likely attributable to mechanisms of neurovascular coupling, since they are substantially larger than reported differences in the onset of action potentials in V1 as a function of response amplitude.
Lau, Jennifer Y. F.; Guyer, Amanda E.; Tone, Erin B.; Jenness, Jessica; Parrish, Jessica M.; Pine, Daniel S.; Nelson, Eric E.
Peer rejection powerfully predicts adolescent anxiety. While cognitive differences influence anxious responses to social feedback, little is known about neural contributions. Twelve anxious and twelve age-, gender- and IQ-matched, psychiatrically healthy adolescents received "not interested" and "interested" feedback from unknown peers during a…
Metting, H.J; Coenegracht, P.M J
The usefulness of artificial neural networks for response surface modeling in HPLC optimization is compared with (non-)linear regression methods. The number of hidden nodes is optimized by a lateral inhibition method. Overfitting is controlled by cross-validation using the leave one out method
Will, G.J.; Van, Lier P.A.; Crone, E.A.; Guroglu, B.
This functional Magnetic Resonance Imaging (fMRI) study examined subjective and neural responses to social exclusion in adolescents (age 12-15) who either had a stable accepted (n = 27; 14 males) or a chronic rejected (n = 19; 12 males) status among peers from age 6 to 12. Both groups of adolescents
Caseras, X.; Mataix-Cols, D.; An, S.K.; Lawrence, N.S.; Speckens, A.E.M.; Giampietro, V.; Brammer, M.J.; Phillips, M.L.
BACKGROUND: A majority of patients with disgust-related psychiatric disorders such as animal phobias and contamination-related obsessive-compulsive disorder are women. The aim of this functional magnetic resonance imaging (fMRI) study was to examine possible sex differences in neural responses to
Masten, Carrie L.; Eisenberger, Naomi I.; Pfeifer, Jennifer H.; Colich, Natalie L.; Dapretto, Mirella
Links among concurrent and longitudinal changes in pubertal development and empathic ability from ages 10 to 13 and neural responses while witnessing peer rejection at age 13 were examined in 16 participants. More advanced pubertal development at age 13, and greater longitudinal increases in pubertal development, related to increased activity in…
Full Text Available Alcohol impairs inhibitory control, including the ability to terminate an initiated action. While there is increasing knowledge about neural mechanisms involved in response inhibition, the level at which alcohol impairs such mechanisms remains poorly understood. Thirty-nine healthy social drinkers received either 0.4 g/kg or 0.8 g/kg of alcohol, or placebo, and performed two variants of a Visual Stop-signal task during acquisition of functional magnetic resonance imaging (fMRI data. The two task variants differed only in their instructions: in the classic variant (VSST, participants inhibited their response to a "Go-stimulus" when it was followed by a "Stop-stimulus". In the control variant (VSST_C, participants responded to the "Go-stimulus" even if it was followed by a "Stop-stimulus". Comparison of successful Stop-trials (Sstop>Go, and unsuccessful Stop-trials (Ustop>Sstop between the three beverage groups enabled the identification of alcohol effects on functional neural circuits supporting inhibitory behaviour and error processing. Alcohol impaired inhibitory control as measured by the Stop-signal reaction time, but did not affect other aspects of VSST performance, nor performance on the VSST_C. The low alcohol dose evoked changes in neural activity within prefrontal, temporal, occipital and motor cortices. The high alcohol dose evoked changes in activity in areas affected by the low dose but importantly induced changes in activity within subcortical centres including the globus pallidus and thalamus. Alcohol did not affect neural correlates of perceptual processing of infrequent cues, as revealed by conjunction analyses of VSST and VSST_C tasks. Alcohol ingestion compromises the inhibitory control of action by modulating cortical regions supporting attentional, sensorimotor and action-planning processes. At higher doses the impact of alcohol also extends to affect subcortical nodes of fronto-basal ganglia- thalamo-cortical motor circuits
Nikolaou, Kyriaki; Critchley, Hugo; Duka, Theodora
Alcohol impairs inhibitory control, including the ability to terminate an initiated action. While there is increasing knowledge about neural mechanisms involved in response inhibition, the level at which alcohol impairs such mechanisms remains poorly understood. Thirty-nine healthy social drinkers received either 0.4 g/kg or 0.8 g/kg of alcohol, or placebo, and performed two variants of a Visual Stop-signal task during acquisition of functional magnetic resonance imaging (fMRI) data. The two task variants differed only in their instructions: in the classic variant (VSST), participants inhibited their response to a "Go-stimulus" when it was followed by a "Stop-stimulus". In the control variant (VSST_C), participants responded to the "Go-stimulus" even if it was followed by a "Stop-stimulus". Comparison of successful Stop-trials (Sstop)>Go, and unsuccessful Stop-trials (Ustop)>Sstop between the three beverage groups enabled the identification of alcohol effects on functional neural circuits supporting inhibitory behaviour and error processing. Alcohol impaired inhibitory control as measured by the Stop-signal reaction time, but did not affect other aspects of VSST performance, nor performance on the VSST_C. The low alcohol dose evoked changes in neural activity within prefrontal, temporal, occipital and motor cortices. The high alcohol dose evoked changes in activity in areas affected by the low dose but importantly induced changes in activity within subcortical centres including the globus pallidus and thalamus. Alcohol did not affect neural correlates of perceptual processing of infrequent cues, as revealed by conjunction analyses of VSST and VSST_C tasks. Alcohol ingestion compromises the inhibitory control of action by modulating cortical regions supporting attentional, sensorimotor and action-planning processes. At higher doses the impact of alcohol also extends to affect subcortical nodes of fronto-basal ganglia- thalamo-cortical motor circuits. In contrast
Goodchild, Martin; Janes, Stuart; Jenkins, Malcolm; Nicholl, Chris; Kühn, Karl
The aim of this work is to assess the use of temperature corrected substrate moisture data to improve the relationship between environmental drivers and the measurement of substrate moisture content in high porosity soil-free growing environments such as coir. Substrate moisture sensor data collected from strawberry plants grown in coir bags installed in a table-top system under a polytunnel illustrates the impact of temperature on capacitance-based moisture measurements. Substrate moisture measurements made in our coir arrangement possess the negative temperature coefficient of the permittivity of water where diurnal changes in moisture content oppose those of substrate temperature. The diurnal substrate temperature variation was seen to range from 7° C to 25° C resulting in a clearly observable temperature effect in substrate moisture content measurements during the 23 day test period. In the laboratory we measured the ML3 soil moisture sensor (ThetaProbe) response to temperature in Air, dry glass beads and water saturated glass beads and used a three-phase alpha (α) mixing model, also known as the Complex Refractive Index Model (CRIM), to derive the permittivity temperature coefficients for glass and water. We derived the α value and estimated the temperature coefficient for water - for sensors operating at 100MHz. Both results are good agreement with published data. By applying the CRIM equation with the temperature coefficients of glass and water the moisture temperature coefficient of saturated glass beads has been reduced by more than an order of magnitude to a moisture temperature coefficient of
Icenhour, A; Labrenz, F; Ritter, C; Theysohn, N; Forsting, M; Bingel, U; Elsenbruch, S
Studies investigating mechanisms underlying nocebo responses in pain have mainly focused on negative expectations induced by verbal suggestions. Herein, we addressed neural and behavioral correlates of nocebo responses induced by classical conditioning in a visceral pain model. In two independent studies, a total of 40 healthy volunteers underwent classical conditioning, consisting of repeated pairings of one visual cue (CS High ) with rectal distensions of high intensity, while a second cue (CS Low ) was always followed by low-intensity distensions. During subsequent test, only low-intensity distensions were delivered, preceded by either CS High or CS Low . Distension intensity ratings were assessed in both samples and functional magnetic resonance imaging data were available from one study (N=16). As a consequence of conditioning, we hypothesized CS High -cued distensions to be perceived as more intense and expected enhanced cue- and distension-related neural responses in regions encoding sensory and affective dimensions of pain and in structures associated with pain-related fear memory. During test, distension intensity ratings did not differ depending on preceding cue. Greater distension-induced neural activation was observed in somatosensory, prefrontal, and cingulate cortices and caudate when preceded by CS High . Analysis of cue-related responses revealed strikingly similar activation patterns. We report changes in neural activation patterns during anticipation and visceral stimulation induced by prior conditioning. In the absence of behavioral effects, markedly altered neural responses may indicate conditioning with visceral signals to induce hypervigilance rather than hyperalgesia, involving altered attention, reappraisal, and perceptual acuity as processes contributing to the pathophysiology of visceral pain. © 2017 John Wiley & Sons Ltd.
Bagherifard, Sara; Ghelichi, Ramin; Khademhosseini, Ali; Guagliano, Mario
Cell-substrate interface is known to control the cell response and subsequent cell functions. Among the various biophysical signals, grain structure, which indicates the repeating arrangement of atoms in the material, has also proved to play a role of significant importance in mediating the cell activities. Moreover, refining the grain size through severe plastic deformation is known to provide the processed material with novel mechanical properties. The potential application of such advanced materials as biomedical implants has recently been evaluated by investigating the effect of different substrate grain sizes on a wide variety of cell activities. In this review, recent advances in biomedical applications of severe plastic deformation techniques are highlighted with special attention to the effect of the obtained nano/ultra-fine-grain size on cell-substrate interactions. Various severe plastic deformation techniques used for this purpose are discussed presenting a brief description of the mechanism for each process. The results obtained for each treatment on cell morphology, adhesion, proliferation, and differentiation, as well as the in vivo studies, are discussed. Finally, the advantages and challenges regarding the application of these techniques to produce multifunctional bio-implant materials are addressed.
Ketchum, Christina; Sun, Xiaoyu; Fourkas, John; Song, Wenxia; Upadhyaya, Arpita
B cells become activated upon physical contact with antigen on the surface of antigen presenting cells, such as dendritic cells. Binding of the B cell receptor with antigen initiates actin-mediated spreading of B cells, signaling cascades and eventually infection fighting antibodies. Lymphocytes, including B cells and T cells, have been shown to be responsive to the physical parameters of the contact surface, such as antigen mobility and substrate stiffness. However the roll of surface topography on lymphocyte function is unknown. Here we investigate the degree to which substrate topography controls actin-mediated spreading and B cell activation using nano-fabricated surfaces and live cell imaging. The model topographical system consists of 600 nanometer tall ridges with spacing varying between 800 nanometers and 5 micrometers. Using TIRF imaging we observe actin dynamics, B cell receptor motion and calcium signaling of B cells as they spread on the ridged substrates. We show that the spacing between ridges had a strong effect on the dynamics of actin and calcium influx on B cells. Our results indicate that B cells are highly sensitive to surface topography during cell spreading and signaling activation.
Jürimäe, J; Vaiksaar, S; Purge, P; Jürimäe, T
This study investigated the effects of acute exercise and menstrual phase on adiponectin and osteocalcin concentrations, and the possible role of these biomarkers in exercise-induced substrate oxidation in rowers. Thirteen female rowers (19.3 ± 2.3 years; height: 172.7 ± 3.9 cm; body mass: 66.5 ± 7.9 kg) performed 1-h rowing ergometer exercise at 70% of maximal oxygen consumption (VO2max) during follicular phase and luteal phase of the menstrual cycle. Oxygen consumption (VO2), total energy expenditure (EE), carbohydrate EE, and lipid EE were assessed during the exercise. Venous blood samples were collected before and after ergometer exercise. No differences (p > 0.05) were observed in substrate oxidation values during exercise across menstrual cycle. Exercise resulted in an acute rise in osteocalcin and no changes in adiponectin at both menstrual cycle phases. Adiponectin and osteocalcin were not related across phase or time (r 0.05). Post-exercise adiponectin was related (p menstrual cycle phase had no effect on substrate oxidation, and adiponectin and osteocalcin responses to acute exercise. It appears that adiponectin and osteocalcin may serve as signals for metabolic reaction to the energy cost of the acute exercise in female rowers.
Jagiellowicz, Jadzia; Xu, Xiaomeng; Aron, Arthur; Aron, Elaine; Cao, Guikang; Feng, Tingyong; Weng, Xuchu
This exploratory study examined the extent to which individual differences in sensory processing sensitivity (SPS), a temperament/personality trait characterized by social, emotional and physical sensitivity, are associated with neural response in visual areas in response to subtle changes in visual scenes. Sixteen participants completed the Highly Sensitive Person questionnaire, a standard measure of SPS. Subsequently, they were tested on a change detection task while undergoing functional m...
Sekiguchi, Atsushi; Sugiura, Motoaki; Yokoyama, Satoru; Sassa, Yuko; Horie, Kaoru; Sato, Shigeru; Kawashima, Ryuta
Background Frustrating situations are encountered daily, and it is necessary to respond in an adaptive fashion. A psychological definition states that adaptive social behaviors are ?self-performing? and ?contain a solution.? The present study investigated the neural correlates of adaptive social responses to frustrating situations by assessing the dimension of causal attribution. Based on attribution theory, internal causality refers to one?s aptitudes that cause natural responses in real-lif...
Lillian eMay; Krista eByers-Heinlein; Judit eGervain; Werker, Janet F.
Previous research has shown that by the time of birth, the neonate brain responds specially to the native language when compared to acoustically similar non-language stimuli. In the current study, we use Near Infrared Spectroscopy to ask how prenatal language experience might shape the brain response to language in newborn infants. To do so, we examine the neural response of neonates when listening to familiar versus unfamiliar language, as well as to non-linguistic backwards language. Twenty...
Hamilton, Lisa Dawn; Meston, Cindy M
In non-human animal research, studies comparing socially monogamous and promiscuous species of voles (Microtus) have identified some key neural differences related to monogamy and non-monogamy. Specifically, densities of the vasopressin V1a receptor and dopamine D2 receptors in subcortical reward-related and limbic areas of the brain have been linked to monogamous behavior in prairie voles (Microtus ochrogaster). Similar brain areas have been shown to be correlated with feelings of romantic love in monogamously pair-bonded humans. Humans vary in the degree to which they engage in (non-)monogamous behaviors. The present study examined the differences in neural activation in response to sexual and romantic stimuli in monogamous (n = 10) and non-monogamous (n = 10) men. Results indicated that monogamous men showed more reward-related neural activity when viewing romantic pictures compared to non-monogamous men. Areas with increased activation for monogamous men were all in the right hemisphere and included the thalamus, accumbens, striatum, pallidum, insula, and orbitofrontal cortex. There were no significant differences between groups in activation to sexual stimuli. These results demonstrate that the neural processing of romantic images is different for monogamous and non-monogamous men. There is some overlap in the neural areas showing increased activation in monogamous men in the present study and the neural areas that show differences in the vole models of monogamy and affiliation. Future research will be needed to clarify whether similar factors are contributing to the neural differences seen in monogamous and non-monogamous humans and voles.
Mathur, Vani A; Cheon, Bobby K; Harada, Tokiko; Scimeca, Jason M; Chiao, Joan Y
Interpersonal pain perception is a fundamental and evolutionarily beneficial social process. While critical for navigating the social world, whether or not people rely on similar processes to perceive and respond to the harm of the non-human biological world remains largely unknown. Here we investigate whether neural reactivity toward the suffering of other people is distinct from or overlapping with the neural response to pain and harm inflicted upon non-human entities, specifically animals and nature. We used fMRI to measure neural activity while participants (n=15) perceived and reported how badly they felt for the pain or harm of humans, animals, and nature, relative to neutral situations. Neural regions associated with perceiving the pain of other people (e.g. dorsal anterior cingulate cortex, bilateral anterior insula) were similarly recruited when perceiving and responding to painful scenes across people, animals, and nature. These results suggest that similar brain responses are relied upon when perceiving the harm of social and non-social biological entities, broadly construed, and that activity within the dorsal anterior cingulate cortex and bilateral anterior insula in response to pain-relevant stimuli is not uniquely specific to humans. Copyright © 2016 Elsevier Ltd. All rights reserved.
Yeo, Sujung; Lim, Sabina; Choe, Il-Hwan; Choi, Yeong-Gon; Chung, Kyung-Cheon; Jahng, Geon-Ho; Kim, Sung-Hoon
Parkinson's disease (PD) is a degenerative brain disorder that is caused by neural defects in the substantia nigra. Numerous studies have reported that acupuncture treatment on GB34 (Yanglingquan) leads to significant improvements in patients with PD and in PD animal models. Studies using functional magnetic resonance imaging (fMRI) have shown that patients with PD, compared to healthy participants, have lower neural responses in extensive brain regions including the putamen, thalamus, and the supplementary motor area. This study investigated the reported association between acupuncture point GB34 and PD. Using fMRI, neural responses of 12 patients with PD and 12 healthy participants were examined before and after acupuncture stimulation. Acupuncture stimulation increased neural responses in regions including the substantia nigra, caudate, thalamus, and putamen, which are impaired caused by PD. Areas associated with PD were activated by the acupuncture stimulation on GB34. This shows that acupuncture treatment on GB34 may be effective in improving the symptoms of PD. Although more randomized controlled trials on the topic will be needed, this study shows that acupuncture may be helpful in the treatment of symptoms involving PD. © 2012 Blackwell Publishing Ltd.
Li, Xiaoyang; Liu, Yi; Luo, Siyang; Wu, Bing; Wu, Xinhuai; Han, Shihui
Behavioral research suggests that mortality salience (MS) leads to increased in-group identification and in-group favoritism in prosocial behavior. What remains unknown is whether and how MS influences brain activity that mediates emotional resonance with in-group and out-group members and is associated with in-group favoritism in helping behavior. The current work investigated MS effects on empathic neural responses to racial in-group and out-group members' suffering. Experiments 1 and 2 respectively recorded event related potentials (ERPs) and blood oxygen level dependent signals to pain/neutral expressions of Asian and Caucasian faces from Chinese adults who had been primed with MS or negative affect (NA). Experiment 1 found that an early frontal/central activity (P2) was more strongly modulated by pain vs. neutral expressions of Asian than Caucasian faces, but this effect was not affected by MS vs. NA priming. However, MS relative to NA priming enhanced racial in-group bias in long-latency neural response to pain expressions over the central/parietal regions (P3). Experiment 2 found that MS vs. NA priming increased racial in-group bias in empathic neural responses to pain expression in the anterior and mid-cingulate cortex. Our findings indicate that reminding mortality enhances brain activity that differentiates between racial in-group and out-group members' emotional states and suggest a neural basis of in-group favoritism under mortality threat. Copyright © 2015 Elsevier Inc. All rights reserved.
Jun Nakanishi, Hidekazu Nakayama, Kazuo Yamaguchi, Andres J Garcia and Yasuhiro Horiike
Full Text Available The development of methods for the off–on switching of immobilization or presentation of cell-adhesive peptides and proteins during cell culture is important because such surfaces are useful for the analysis of the dynamic processes of cell adhesion and migration. This paper describes a chemically functionalized gold substrate that captures a genetically tagged extracellular matrix protein in response to light. The substrate was composed of mixed self-assembled monolayers (SAMs of three disulfide compounds containing (i a photocleavable poly(ethylene glycol (PEG, (ii nitrilotriacetic acid (NTA and (iii hepta(ethylene glycol (EG7. Although the NTA group has an intrinsic high affinity for oligohistidine tag (His-tag sequences in its Ni2+-ion complex, the interaction was suppressed by the steric hindrance of coexisting PEG on the substrate surface. Upon photoirradiation of the substrate to release the PEG chain from the surface, this interaction became possible and hence the protein was captured at the irradiated regions, while keeping the non-specific adsorption of non-His-tagged proteins blocked by the EG7 underbrush. In this way, we selectively immobilized a His-tagged fibronectin fragment (FNIII7–10 to the irradiated regions. In contrast, when bovine serum albumin—a major serum protein—was added as a non-His-tagged protein, the surface did not permit its capture, with or without irradiation. In agreement with these results, cells were selectively attached to the irradiated patterns only when a His-tagged FNIII7-10 was added to the medium. These results indicate that the present method is useful for studying the cellular behavior on the specific extracellular matrix protein in cell-culturing environments.
Martin William F
Full Text Available Abstract Background Although several studies have investigated gender differences in the substrate and endocrine responses during and following endurance exercise, few have studied sex differences during a more prolonged recovery period post endurance exercise. The purpose of this study was to compare and characterize the endocrine and substrate profiles of trained male and female adult runners during the three-and-a-half hour recovery period from an endurance run. Methods After consuming a euenergetic diet (1.8 g·kg-1·d-1 protein, 26% fat, 58% carbohydrates, 42.8 ± 1.2 kcal/kg body weight for 8 days, blood was collected from trained male (n = 6, 21 yrs, 70 kg, 180 cm, 9% body fat, VO2peak 78.0 ± 3.4 mL·kg FFM-1·min-1 and female (n = 6, 23 y, 66 kg, 170 cm, 29% body fat, VO2peak 71.6 ± 4.5 mL·kg FFM-1·min-1 endurance runners at rest and during recovery from a 75 min run at 70% VO2peak. Circulating levels of glucose, lactate, free fatty acids (FFAs, insulin, cortisol, growth hormone (GH, and free insulin-like growth factor I (IGF-I were measured. Results During the recovery period, females experienced increases in glucose, lactate and insulin while no changes were noted in men (P P Conclusion These data further document gender differences in substrate and endocrine changes during a prolonged recovery period following endurance exercise. Future studies are needed to evaluate the effect of differing diets and nutritional supplements on these gender-specific post-exercise substrate and endocrine differences.
Vislocky, Lisa M; Gaine, P Courtney; Pikosky, Matthew A; Martin, William F; Rodriguez, Nancy R
Although several studies have investigated gender differences in the substrate and endocrine responses during and following endurance exercise, few have studied sex differences during a more prolonged recovery period post endurance exercise. The purpose of this study was to compare and characterize the endocrine and substrate profiles of trained male and female adult runners during the three-and-a-half hour recovery period from an endurance run. After consuming a euenergetic diet (1.8 g.kg-1.d-1 protein, 26% fat, 58% carbohydrates, 42.8 +/- 1.2 kcal/kg body weight) for 8 days, blood was collected from trained male (n = 6, 21 yrs, 70 kg, 180 cm, 9% body fat, VO(2peak) 78.0 +/- 3.4 mL.kg FFM-1.min-1) and female (n = 6, 23 y, 66 kg, 170 cm, 29% body fat, VO(2peak) 71.6 +/- 4.5 mL.kg FFM-1.min-1) endurance runners at rest and during recovery from a 75 min run at 70% VO(2peak). Circulating levels of glucose, lactate, free fatty acids (FFAs), insulin, cortisol, growth hormone (GH), and free insulin-like growth factor I (IGF-I) were measured. During the recovery period, females experienced increases in glucose, lactate and insulin while no changes were noted in men (P recovery from endurance exercise, but changes were not different between genders. These data further document gender differences in substrate and endocrine changes during a prolonged recovery period following endurance exercise. Future studies are needed to evaluate the effect of differing diets and nutritional supplements on these gender-specific post-exercise substrate and endocrine differences.
Cowdrey, Felicity A; Harmer, Catherine J; Park, Rebecca J; McCabe, Ciara
Impairments in emotional processing have been associated with anorexia nervosa. However, it is unknown whether neural and behavioural differences in the processing of emotional stimuli persist following recovery. The aim of this study was to investigate the neural processing of emotional faces in individuals recovered from anorexia nervosa compared with healthy controls. Thirty-two participants (16 recovered anorexia nervosa, 16 healthy controls) underwent a functional magnetic resonance imaging (fMRI) scan. Participants viewed fearful and happy emotional faces and indicated the gender of the face presented. Whole brain analysis revealed no significant differences between the groups to the contrasts of fear versus happy and vice versa. Region of interest analysis demonstrated no significant differences in the neural response to happy or fearful stimuli between the groups in the amygdala or fusiform gyrus. These results suggest that processing of emotional faces may not be aberrant after recovery from anorexia nervosa. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Pires, Filipa; Ferreira, Quirina; Rodrigues, Carlos A V; Morgado, Jorge; Ferreira, Frederico Castelo
The use of conjugated polymers allows versatile interactions between cells and flexible processable materials, while providing a platform for electrical stimulation, which is particularly relevant when targeting differentiation of neural stem cells and further application for therapy or drug screening. Materials were tested for cytotoxicity following the ISO10993-5. PSS was cross-linked. ReNcellVM neural stem cells (NSC) were seeded in laminin coated surfaces, cultured for 4 days in the presence of EGF (20 ng/mL), FGF-2 (20 ng/mL) and B27 (20 μg/mL) and differentiated over eight additional days in the absence of those factors under 100Hz pulsed DC electrical stimulation, 1V with 10 ms pulses. NSC and neuron elongation aspect ratio as well as neurite length were assessed using ImageJ. Cells were immune-stained for Tuj1 and GFAP. F8T2, MEH-PPV, P3HT and cross-linked PSS (x PSS) were assessed as non-cytotoxic. L929 fibroblast population was 1.3 higher for x PSS than for glass control, while F8T2 presents moderate proliferation. The population of neurons (Tuj1) was 1.6 times higher with longer neurites (73 vs 108 μm) for cells cultured under electrical stimulus, with cultured NSC. Such stimulus led also to longer neurons. x PSS was, for the first time, used to elongate human NSC through the application of pulsed current, impacting on their differentiation towards neurons and contributing to longer neurites. The range of conductive conjugated polymers known as non-cytotoxic was expanded. x PSS was introduced as a stable material, easily processed from solution, to interface with biological systems, in particular NSC, without the need of in-situ polymerization. Copyright © 2015 Elsevier B.V. All rights reserved.
Sebastian, Catherine L; McCrory, Eamon J P; Cecil, Charlotte A M; Lockwood, Patricia L; De Brito, Stéphane A; Fontaine, Nathalie M G; Viding, Essi
Reduced neural responses to others' distress is hypothesized to play a critical role in conduct problems coupled with callous-unemotional traits, whereas increased neural responses to affective stimuli may accompany conduct problems without callous-unemotional traits. Heterogeneity of affective profiles in conduct problems may account for inconsistent neuroimaging findings in this population. To broaden understanding of neural processing in conduct problems using an affective processing task including an empathy component as well as to explore dimensional contributions of conduct problems symptoms and callous-unemotional traits to variance in affective neural responses. Case-control study. On-campus neuroimaging facility. Thirty-one boys with conduct problems (mean age, 14.34 years) and 16 typically developing control subjects (mean age, 13.51 years) matched for age (range, 10-16 years), IQ, socioeconomic status, handedness, and race/ethnicity. Participants were recruited using screening questionnaires in a community-based volunteer sample. Functional magnetic resonance imaging of a task contrasting affective and cognitive theory of mind judgments. Relative to typically developing children, children with conduct problems showed reduced activation in right amygdala and anterior insula for affective vs cognitive theory of mind judgments. Furthermore, in the right amygdala, regression analysis within the conduct-problems group showed suppressor effects between ratings of conduct problems and callous-unemotional traits. Specifically, unique variance associated with conduct problems was positively correlated with amygdala reactivity, whereas unique variance associated with callous-unemotional traits was negatively correlated with amygdala reactivity. These associations were not explained by hyperactivity, depression/anxiety symptoms, or alcohol use ratings. Childhood conduct problems are associated with amygdala and anterior insula hypoactivity during a complex
Sekiguchi, Atsushi; Sugiura, Motoaki; Yokoyama, Satoru; Sassa, Yuko; Horie, Kaoru; Sato, Shigeru; Kawashima, Ryuta
Frustrating situations are encountered daily, and it is necessary to respond in an adaptive fashion. A psychological definition states that adaptive social behaviors are "self-performing" and "contain a solution." The present study investigated the neural correlates of adaptive social responses to frustrating situations by assessing the dimension of causal attribution. Based on attribution theory, internal causality refers to one's aptitudes that cause natural responses in real-life situations, whereas external causality refers to environmental factors, such as experimental conditions, causing such responses. To investigate the issue, we developed a novel approach that assesses causal attribution under experimental conditions. During fMRI scanning, subjects were required to engage in virtual frustrating situations and play the role of protagonists by verbalizing social responses, which were socially adaptive or non-adaptive. After fMRI scanning, the subjects reported their causal attribution index of the psychological reaction to the experimental condition. We performed a correlation analysis between the causal attribution index and brain activity. We hypothesized that the brain region whose activation would have a positive and negative correlation with the self-reported index of the causal attributions would be regarded as neural correlates of internal and external causal attribution of social responses, respectively. We found a significant negative correlation between external causal attribution and neural responses in the right anterior temporal lobe for adaptive social behaviors. This region is involved in the integration of emotional and social information. These results suggest that, particularly in adaptive social behavior, the social demands of frustrating situations, which involve external causality, may be integrated by a neural response in the right anterior temporal lobe.
Kim Elmer K
Full Text Available Abstract Background The next generation of prosthetic limbs will restore sensory feedback to the nervous system by mimicking how skin mechanoreceptors, innervated by afferents, produce trains of action potentials in response to compressive stimuli. Prior work has addressed building sensors within skin substitutes for robotics, modeling skin mechanics and neural dynamics of mechanotransduction, and predicting response timing of action potentials for vibration. The effort here is unique because it accounts for skin elasticity by measuring force within simulated skin, utilizes few free model parameters for parsimony, and separates parameter fitting and model validation. Additionally, the ramp-and-hold, sustained stimuli used in this work capture the essential features of the everyday task of contacting and holding an object. Methods This systems integration effort computationally replicates the neural firing behavior for a slowly adapting type I (SAI afferent in its temporally varying response to both intensity and rate of indentation force by combining a physical force sensor, housed in a skin-like substrate, with a mathematical model of neuronal spiking, the leaky integrate-and-fire. Comparison experiments were then conducted using ramp-and-hold stimuli on both the spiking-sensor model and mouse SAI afferents. The model parameters were iteratively fit against recorded SAI interspike intervals (ISI before validating the model to assess its performance. Results Model-predicted spike firing compares favorably with that observed for single SAI afferents. As indentation magnitude increases (1.2, 1.3, to 1.4 mm, mean ISI decreases from 98.81 ± 24.73, 54.52 ± 6.94, to 41.11 ± 6.11 ms. Moreover, as rate of ramp-up increases, ISI during ramp-up decreases from 21.85 ± 5.33, 19.98 ± 3.10, to 15.42 ± 2.41 ms. Considering first spikes, the predicted latencies exhibited a decreasing trend as stimulus rate increased, as is
Full Text Available Lehky et al. (2011 provided a statistical analysis on the responses of the recorded 674 neurons to 806 image stimuli in anterior inferotemporalm (AIT cortex of two monkeys. In terms of kurtosis and Pareto tail index, they observed that the population sparseness of both unnormalized and normalized responses is always larger than their single-neuron selectivity, hence concluded that the critical features for individual neurons in primate AIT cortex are not very complex, but there is an indefinitely large number of them. In this work, we explore an “inverse problem” by simulation, that is, by simulating each neuron indeed only responds to a very limited number of stimuli among a very large number of neurons and stimuli, to assess whether the population sparseness is always larger than the single-neuron selectivity. Our simulation results show that the population sparseness exceeds the single-neuron selectivity in most cases even if the number of neurons and stimuli are much larger than several hundreds, which confirms the observations in Lehky et al. (2011. In addition, we found that the variances of the computed kurtosis and Pareto tail index are quite large in some cases, which reveals some limitations of these two criteria when used for neuron response evaluation.
Full Text Available Mothers are important to all humans. Research has established that maternal information affects individuals' cognition, emotion, and behavior. We measured event-related potentials (ERPs to examine attentional and evaluative processing of maternal stimuli while participants completed a Go/No-go Association Task that paired mother or others words with good or bad evaluative words. Behavioral data showed that participants responded faster to mother words paired with good than the mother words paired with bad but showed no difference in response to these others across conditions, reflecting a positive evaluation of mother. ERPs showed larger P200 and N200 in response to mother than in response to others, suggesting that mother attracted more attention than others. In the subsequent time window, mother in the mother + bad condition elicited a later and larger late positive potential (LPP than it did in the mother + good condition, but this was not true for others, also suggesting a positive evaluation of mother. These results suggest that people differentiate mother from others during initial attentional stage, and evaluative mother positively during later stage.
Peciña, Marta; Bohnert, Amy S. B.; Sikora, Magdalena; Avery, Erich T.; Langenecker, Scott A.; Mickey, Brian J.; Zubieta, Jon-Kar
Importance High placebo responses have been observed across a wide range of pathologies, severely impacting drug development. Objective Here we examined neurochemical mechanisms underlying the formation of placebo effects in patients with Major Depressive Disorder (MDD). Participants Thirty-five medication-free MDD patients. Design and Intervention We performed a single-blinded two-week cross-over randomized controlled trial of two identical oral placebos (described as having either “active” or “inactive” fast-acting antidepressant-like effects) followed by a 10-week open-label treatment with a selective serotonin reuptake inhibitor (SSRI) or in some cases, another agent as clinically indicated. The volunteers were studied with PET and the μ-opioid receptor (MOR)-selective radiotracer [11C]carfentanil after each 1-week “inactive” and “active” oral placebo treatment. In addition, 1 mL of isotonic saline was administered intravenously (i.v.) within sight of the volunteer during PET scanning every 4 min over 20 min only after the 1-week active placebo treatment, with instructions that the compound may be associated with the activation of brain systems involved in mood improvement. This challenge stimulus was utilized to test the individual capacity to acutely activate endogenous opioid neurotransmision under expectations of antidepressant effect. Setting A University Health System. Main Outcomes and Measures Changes in depressive symptoms in response to “active” placebo and antidepressant. Baseline and activation measures of MOR binding. Results Higher baseline MOR binding in the nucleus accumbens (NAc) was associated with better response to antidepressant treatment (r=0.48; p=0.02). Reductions in depressive symptoms after 1-week of “active” placebo treatment, compared to the “inactive”, were associated with increased placebo-induced μ-opioid neurotransmission in a network of regions implicated in emotion, stress regulation, and the
Mohamed A. Korany
Full Text Available This paper discusses the usefulness of artificial neural networks (ANNs for response surface modelling in HPLC method development. In this study, the combined effect of pH and mobile phase composition on the reversed-phase liquid chromatographic behaviour of a mixture of salbutamol (SAL and guaiphenesin (GUA, combination I, and a mixture of ascorbic acid (ASC, paracetamol (PAR and guaiphenesin (GUA, combination II, was investigated. The results were compared with those produced using multiple regression (REG analysis. To examine the respective predictive power of the regression model and the neural network model, experimental and predicted response factor values, mean of squares error (MSE, average error percentage (Er%, and coefficients of correlation (r were compared. It was clear that the best networks were able to predict the experimental responses more accurately than the multiple regression analysis.
Krizman, Jennifer; Skoe, Erika; Marian, Viorica; Kraus, Nina
Auditory processing is presumed to be influenced by cognitive processes – including attentional control – in a top-down manner. In bilinguals, activation of both languages during daily communication hones inhibitory skills, which subsequently bolster attentional control. We hypothesize that the heightened attentional demands of bilingual communication strengthens connections between cognitive (i.e., attentional control) and auditory processing, leading to greater across-trial consistency in the auditory evoked response (i.e., neural consistency) in bilinguals. To assess this, we collected passively-elicited auditory evoked responses to the syllable [da] and separately obtained measures of attentional control and language ability in adolescent Spanish-English bilinguals and English monolinguals. Bilinguals demonstrated enhanced attentional control and more consistent brainstem and cortical responses. In bilinguals, but not monolinguals, brainstem consistency tracked with language proficiency and attentional control. We interpret these enhancements in neural consistency as the outcome of strengthened attentional control that emerged from experience communicating in two languages. PMID:24413593
Yokum, Sonja; Stice, Eric; Harris, Jennifer L.; Brownell, Kelly D.
Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean to obese in response to food and non-food commercials imbedded in a television show. Adolescents exhibited greater activation in regions implicated in visual processing (e.g. occipital gyrus), attention (e.g. parietal lobes), cognition (e.g. temporal gyrus and posterior cerebellar lobe), movement (e.g. anterior cerebellar cortex), somatosensory response (e.g. postcentral gyrus) and reward [e.g. orbitofrontal cortex and anterior cingulate cortex (ACC)] during food commercials. Obese participants exhibited less activation during food relative to non-food commercials in neural regions implicated in visual processing (e.g. cuneus), attention (e.g. posterior cerebellar lobe), reward (e.g. ventromedial prefrontal cortex and ACC) and salience detection (e.g. precuneus). Obese participants did exhibit greater activation in a region implicated in semantic control (e.g. medial temporal gyrus). These findings may inform current policy debates regarding the impact of food advertising to minors. PMID:23576811
Gearhardt, Ashley N; Yokum, Sonja; Stice, Eric; Harris, Jennifer L; Brownell, Kelly D
Adolescents view thousands of food commercials annually, but the neural response to food advertising and its association with obesity is largely unknown. This study is the first to examine how neural response to food commercials differs from other stimuli (e.g. non-food commercials and television show) and to explore how this response may differ by weight status. The blood oxygen level-dependent functional magnetic resonance imaging activation was measured in 30 adolescents ranging from lean to obese in response to food and non-food commercials imbedded in a television show. Adolescents exhibited greater activation in regions implicated in visual processing (e.g. occipital gyrus), attention (e.g. parietal lobes), cognition (e.g. temporal gyrus and posterior cerebellar lobe), movement (e.g. anterior cerebellar cortex), somatosensory response (e.g. postcentral gyrus) and reward [e.g. orbitofrontal cortex and anterior cingulate cortex (ACC)] during food commercials. Obese participants exhibited less activation during food relative to non-food commercials in neural regions implicated in visual processing (e.g. cuneus), attention (e.g. posterior cerebellar lobe), reward (e.g. ventromedial prefrontal cortex and ACC) and salience detection (e.g. precuneus). Obese participants did exhibit greater activation in a region implicated in semantic control (e.g. medial temporal gyrus). These findings may inform current policy debates regarding the impact of food advertising to minors. © The Author (2013). Published by Oxford University Press. For Permissions, please email: firstname.lastname@example.org.
Faghihi, Shahab; Zia, Sonia; Taha, Masoumeh Fakhr
Stainless steel (SS) is one of the most applicable materials in fabrication of cardiac implants. The aim of this study is to investigate the effect of atomic structure of polycrystalline stainless steel on the response of adipose tissue-derived stem cells (ADSCs). Samples are prepared from differently processed extruded rod and rolled sheet of 316L SS having different crystallographic structure. X-ray diffraction analysis indicated (200) and (111) orientations with distinct volume fractions in the specimens. Morphology and ADSCs behavior including adhesion, proliferation and differentiation are assessed. The expression of cardiac specific protein (cardiac troponin I) and genes of differentiating cardiomyocytes is analyzed by immunofluorescence and RT-PCR. The number of attached and grown cells on the rod sample is higher than the sheet sample also the scanning electron microscopy (SEM) analysis of ADSCs grown on the samples demonstrates higher cell density and spreading pattern on the surface of rod sample. In differentiated ADSCs on the rod sample the expression of all genes except ANF are detectable, while on the sheet sample only the MEF2C and β-MHC are expressed. This study shows that the cellular response is influenced by the crystal structure of the substrate therefore; the skill to alter the structure of substrate may lend itself to engineer a biomaterial which could be suitable for differentiation of stem cells into a definite lineage. Copyright © 2012 Elsevier Ltd. All rights reserved.
Babo-Rebelo, Mariana; Richter, Craig G; Tallon-Baudry, Catherine
The default network (DN) has been consistently associated with self-related cognition, but also to bodily state monitoring and autonomic regulation. We hypothesized that these two seemingly disparate functional roles of the DN are functionally coupled, in line with theories proposing that selfhood is grounded in the neural monitoring of internal organs, such as the heart. We measured with magnetoencephalograhy neural responses evoked by heartbeats while human participants freely mind-wandered. When interrupted by a visual stimulus at random intervals, participants scored the self-relatedness of the interrupted thought. They evaluated their involvement as the first-person perspective subject or agent in the thought ("I"), and on another scale to what degree they were thinking about themselves ("Me"). During the interrupted thought, neural responses to heartbeats in two regions of the DN, the ventral precuneus and the ventromedial prefrontal cortex, covaried, respectively, with the "I" and the "Me" dimensions of the self, even at the single-trial level. No covariation between self-relatedness and peripheral autonomic measures (heart rate, heart rate variability, pupil diameter, electrodermal activity, respiration rate, and phase) or alpha power was observed. Our results reveal a direct link between selfhood and neural responses to heartbeats in the DN and thus directly support theories grounding selfhood in the neural monitoring of visceral inputs. More generally, the tight functional coupling between self-related processing and cardiac monitoring observed here implies that, even in the absence of measured changes in peripheral bodily measures, physiological and cognitive functions have to be considered jointly in the DN. The default network (DN) has been consistently associated with self-processing but also with autonomic regulation. We hypothesized that these two functions could be functionally coupled in the DN, inspired by theories according to which selfhood is
Romens, Sarah E; Casement, Melynda D; McAloon, Rose; Keenan, Kate; Hipwell, Alison E; Guyer, Amanda E; Forbes, Erika E
Children who experience socioeconomic disadvantage are at heightened risk for developing depression; however, little is known about neurobiological mechanisms underlying this association. Low socioeconomic status (SES) during childhood may confer risk for depression through its stress-related effects on the neural circuitry associated with processing monetary rewards. In a prospective study, we examined the relationships among the number of years of household receipt of public assistance from age 5-16 years, neural activation during monetary reward anticipation and receipt at age 16, and depression symptoms at age 16 in 123 girls. Number of years of household receipt of public assistance was positively associated with heightened response in the medial prefrontal cortex during reward anticipation, and this heightened neural response mediated the relationship between socioeconomic disadvantage and current depression symptoms, controlling for past depression. Chronic exposure to socioeconomic disadvantage in childhood may alter neural circuitry involved in reward anticipation in adolescence, which in turn may confer risk for depression. © 2015 Association for Child and Adolescent Mental Health.
Romens, Sarah E.; Casement, Melynda D.; McAloon, Rose; Keenan, Kate; Hipwell, Alison E.; Guyer, Amanda E.; Forbes, Erika E.
Background Children who experience socioeconomic disadvantage are at heightened risk for developing depression; however, little is known about neurobiological mechanisms underlying this association. Low socioeconomic status (SES) during childhood may confer risk for depression through its stress-related effects on the neural circuitry associated with processing monetary rewards. Methods In a prospective study, we examined the relationships among the number of years of household receipt of public assistance from age 5–16 years, neural activation during monetary reward anticipation and receipt at age 16, and depression symptoms at age 16 in 123 girls. Results Number of years of household receipt of public assistance was positively associated with heightened response in the medial prefrontal cortex during reward anticipation, and this heightened neural response mediated the relationship between socioeconomic disadvantage and current depression symptoms, controlling for past depression. Conclusions Chronic exposure to socioeconomic disadvantage in childhood may alter neural circuitry involved in reward anticipation in adolescence, which in turn may confer risk for depression. PMID:25846746
Chen, Yongshuo; Li, Shizhong; Berezin, Vladimir
Activation of fibroblast growth factor (FGF) receptors (FGFRs) both by FGFs and by the neural cell adhesion molecule (NCAM) is crucial in the development and function of the nervous system. We found that FGFR substrate 2alpha (FRS2alpha), Src homologous and collagen A (ShcA), and phospholipase......-Cgamma (PLCgamma) were all required for neurite outgrowth from cerebellar granule neurons (CGNs) induced by FGF1 and FGL (an NCAM-derived peptide agonist of FGFR1). Like FGF1, FGL induced tyrosine phosphorylation of FGFR1, FRS2alpha, ShcA, and PLCgamma in a time- and dose-dependent manner. However, the activation...... of FRS2alpha by FGL was significantly lower than the activation by FGF1, indicating a differential signaling profile induced by NCAM compared with the cognate growth factor....
McAdams, Carrie J.; Lohrenz, Terry; Montague, P. Read
In anorexia nervosa, problems with social relationships contribute to illness, and improvements in social support are associated with recovery. Using the multiround trust game and 3T MRI, we compare neural responses in a social relationship in three groups of women: women with anorexia nervosa, women in long-term weight recovery from anorexia nervosa, and healthy comparison women. Surrogate markers related to social signals in the game were computed each round to assess whether the relationship was improving (benevolence) or deteriorating (malevolence) for each subject. Compared with healthy women, neural responses to benevolence were diminished in the precuneus and right angular gyrus in both currently-ill and weight-recovered subjects with anorexia, but neural responses to malevolence differed in the left fusiform only in currently-ill subjects. Next, using a whole-brain regression, we identified an office assessment, the positive personalizing bias, that was inversely correlated with neural activity in the occipital lobe, the precuneus and posterior cingulate, the bilateral temporoparietal junctions, and dorsal anterior cingulate, during benevolence for all groups of subjects. The positive personalizing bias is a self-report measure that assesses the degree with which a person attributes positive experiences to other people. These data suggest that problems in perceiving kindness may be a consistent trait related to the development of anorexia nervosa, whereas recognizing malevolence may be related to recovery. Future work on social brain function, in both healthy and psychiatric populations, should consider positive personalizing biases as a possible marker of neural differences related to kindness perception. PMID:26416161
McAdams, Carrie J; Lohrenz, Terry; Montague, P Read
In anorexia nervosa, problems with social relationships contribute to illness, and improvements in social support are associated with recovery. Using the multiround trust game and 3T MRI, we compare neural responses in a social relationship in three groups of women: women with anorexia nervosa, women in long-term weight recovery from anorexia nervosa, and healthy comparison women. Surrogate markers related to social signals in the game were computed each round to assess whether the relationship was improving (benevolence) or deteriorating (malevolence) for each subject. Compared with healthy women, neural responses to benevolence were diminished in the precuneus and right angular gyrus in both currently-ill and weight-recovered subjects with anorexia, but neural responses to malevolence differed in the left fusiform only in currently-ill subjects. Next, using a whole-brain regression, we identified an office assessment, the positive personalizing bias, that was inversely correlated with neural activity in the occipital lobe, the precuneus and posterior cingulate, the bilateral temporoparietal junctions, and dorsal anterior cingulate, during benevolence for all groups of subjects. The positive personalizing bias is a self-report measure that assesses the degree with which a person attributes positive experiences to other people. These data suggest that problems in perceiving kindness may be a consistent trait related to the development of anorexia nervosa, whereas recognizing malevolence may be related to recovery. Future work on social brain function, in both healthy and psychiatric populations, should consider positive personalizing biases as a possible marker of neural differences related to kindness perception. © 2015 Wiley Periodicals, Inc.
Bari, Andrea; Robbins, Trevor W
In many circumstances alternative courses of action and thoughts have to be inhibited to allow the emergence of goal-directed behavior. However, this has not been the accepted view in the past and only recently has inhibition earned its own place in the neurosciences as a fundamental cognitive function. In this review we first introduce the concept of inhibition from early psychological speculations based on philosophical theories of the human mind. The broad construct of inhibition is then reduced to its most readily observable component which necessarily is its behavioral manifestation. The study of 'response inhibition' has the advantage of dealing with a relatively simple and straightforward process, the overriding of a planned or already initiated action. Deficient inhibitory processes profoundly affect everyday life, causing impulsive conduct which is generally detrimental for the individual. Impulsivity has been consistently linked to several types of addiction, attention deficit/hyperactivity disorder, mania and other psychiatric conditions. Our discussion of the behavioral assessment of impulsivity will focus on objective laboratory tasks of response inhibition that have been implemented in parallel for humans and other species with relatively few qualitative differences. The translational potential of these measures has greatly improved our knowledge of the neurobiological basis of behavioral inhibition and impulsivity. We will then review the current models of behavioral inhibition along with their expression via underlying brain regions, including those involved in the activation of the brain's emergency 'brake' operation, those engaged in more controlled and sustained inhibitory processes and other ancillary executive functions. Copyright © 2013 Elsevier Ltd. All rights reserved.
Wen, Ming-Ching; Ng, Samuel Y E; Heng, Hannah S E; Chao, Yin Xia; Chan, Ling Ling; Tan, Eng King; Tan, Louis C S
Excessive daytime sleepiness (EDS) is a common non-motor symptom in Parkinson's disease (PD), but its neuropathology remains elusive due to the limited studies and the inclusion of medicated patients. This current study examined the neural substrates of EDS in drug naïve PD patients. A total of 76 PD patients in the early disease stages were recruited; 16 of them had EDS, while the remaining 60 did not. Resting state functional magnetic resonance imaging (rs-fMRI) was used to determine group differences (patients with EDS vs. patients without EDS) in spontaneous neural activity indicated by regional homogeneity (ReHo). Additionally, functional connectivity (FC) of the regions showing group differences in ReHo with the entire brain was performed. ReHo analysis controlling for gray matter volume, age, gender, general cognition, depression, postural instability gait difficulty, and rapid eye movement sleep behavior disorder showed decreased ReHo in the left cerebellum and inferior frontal gyrus, but increased ReHo in the left paracentral lobule in PD-EDS patients, compared with patients without EDS. FC analysis controlling for the same variables as in the analysis of ReHo revealed that the three regions showing ReHo differences had decreased FC with regions in the frontal, temporal, insular and limbic lobes and cerebellum in PDs with EDS. While decreases in ReHo and FC were found, increases in ReHo were also noted, implying both neural downregulation and compensatory mechanisms in early PD patients with EDS. Longitudinal studies are warranted to clarify the long-term impact of EDS in PD. Copyright © 2016 Elsevier Ltd. All rights reserved.
Full Text Available Abstract Background Impairments in executive function and language processing are characteristic of both schizophrenia and bipolar disorder. Their functional neuroanatomy demonstrate features that are shared as well as specific to each disorder. Determining the distinct pattern of neural responses in schizophrenia and bipolar disorder may provide biomarkers for their diagnoses. Methods 104 participants underwent functional magnetic resonance imaging (fMRI scans while performing a phonological verbal fluency task. Subjects were 32 patients with schizophrenia in remission, 32 patients with bipolar disorder in an euthymic state, and 40 healthy volunteers. Neural responses to verbal fluency were examined in each group, and the diagnostic potential of the pattern of the neural responses was assessed with machine learning analysis. Results During the verbal fluency task, both patient groups showed increased activation in the anterior cingulate, left dorsolateral prefrontal cortex and right putamen as compared to healthy controls, as well as reduced deactivation of precuneus and posterior cingulate. The magnitude of activation was greatest in patients with schizophrenia, followed by patients with bipolar disorder and then healthy individuals. Additional recruitment in the right inferior frontal and right dorsolateral prefrontal cortices was observed in schizophrenia relative to both bipolar disorder and healthy subjects. The pattern of neural responses correctly identified individual patients with schizophrenia with an accuracy of 92%, and those with bipolar disorder with an accuracy of 79% in which mis-classification was typically of bipolar subjects as healthy controls. Conclusions In summary, both schizophrenia and bipolar disorder are associated with altered function in prefrontal, striatal and default mode networks, but the magnitude of this dysfunction is particularly marked in schizophrenia. The pattern of response to verbal fluency is highly
Yamano, Emi; Ishii, Akira; Tanaka, Masaaki; Nomura, Shusaku; Watanabe, Yasuyoshi
Stress is a risk factor for the onset of mental disorders. Although stress response varies across individuals, the mechanism of individual differences remains unclear. Here, we investigated the neural basis of individual differences in response to mental stress using magnetoencephalography (MEG). Twenty healthy male volunteers completed the Temperament and Character Inventory (TCI). The experiment included two types of tasks: a non-stress-inducing task and a stress-inducing task. During these tasks, participants passively viewed non-stress-inducing images and stress-inducing images, respectively, and MEG was recorded. Before and after each task, MEG and electrocardiography were recorded and subjective ratings were obtained. We grouped participants according to Novelty seeking (NS) - tendency to be exploratory, and Harm avoidance (HA) - tendency to be cautious. Participants with high NS and low HA (n = 10) assessed by TCI had a different neural response to stress than those with low NS and high HA (n = 10). Event-related desynchronization (ERD) in the beta frequency band was observed only in participants with high NS and low HA in the brain region extending from Brodmann's area 31 (including the posterior cingulate cortex and precuneus) from 200 to 350 ms after the onset of picture presentation in the stress-inducing task. Individual variation in personality traits (NS and HA) was associated with the neural response to mental stress. These findings increase our understanding of the psychological and neural basis of individual differences in the stress response, and will contribute to development of the psychotherapeutic approaches to stress-related disorders.
Smith, Imogen; Silveirinha, Vasco; Stein, Jason L; de la Torre-Ubieta, Luis; Farrimond, Jonathan A; Williamson, Elizabeth M; Whalley, Benjamin J
Differentiated human neural stem cells were cultured in an inert three-dimensional (3D) scaffold and, unlike two-dimensional (2D) but otherwise comparable monolayer cultures, formed spontaneously active, functional neuronal networks that responded reproducibly and predictably to conventional pharmacological treatments to reveal functional, glutamatergic synapses. Immunocytochemical and electron microscopy analysis revealed a neuronal and glial population, where markers of neuronal maturity were observed in the former. Oligonucleotide microarray analysis revealed substantial differences in gene expression conferred by culturing in a 3D vs a 2D environment. Notable and numerous differences were seen in genes coding for neuronal function, the extracellular matrix and cytoskeleton. In addition to producing functional networks, differentiated human neural stem cells grown in inert scaffolds offer several significant advantages over conventional 2D monolayers. These advantages include cost savings and improved physiological relevance, which make them better suited for use in the pharmacological and toxicological assays required for development of stem cell-based treatments and the reduction of animal use in medical research. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
Devaud, Jean-Marc; Papouin, Thomas; Carcaud, Julie; Sandoz, Jean-Christophe; Grünewald, Bernd; Giurfa, Martin
Learning theories distinguish elemental from configural learning based on their different complexity. Although the former relies on simple and unambiguous links between the learned events, the latter deals with ambiguous discriminations in which conjunctive representations of events are learned as being different from their elements. In mammals, configural learning is mediated by brain areas that are either dispensable or partially involved in elemental learning. We studied whether the insect brain follows the same principles and addressed this question in the honey bee, the only insect in which configural learning has been demonstrated. We used a combination of conditioning protocols, disruption of neural activity, and optophysiological recording of olfactory circuits in the bee brain to determine whether mushroom bodies (MBs), brain structures that are essential for memory storage and retrieval, are equally necessary for configural and elemental olfactory learning. We show that bees with anesthetized MBs distinguish odors and learn elemental olfactory discriminations but not configural ones, such as positive and negative patterning. Inhibition of GABAergic signaling in the MB calyces, but not in the lobes, impairs patterning discrimination, thus suggesting a requirement of GABAergic feedback neurons from the lobes to the calyces for nonelemental learning. These results uncover a previously unidentified role for MBs besides memory storage and retrieval: namely, their implication in the acquisition of ambiguous discrimination problems. Thus, in insects as in mammals, specific brain regions are recruited when the ambiguity of learning tasks increases, a fact that reveals similarities in the neural processes underlying the elucidation of ambiguous tasks across species.
Michael H. Thaut
Full Text Available Rhythm as the time structure of music is composed of distinct temporal components such as pattern, meter, and tempo. Each feature requires different computational processes: meter involves representing repeating cycles of strong and weak beats; pattern involves representing intervals at each local time point which vary in length across segments and are linked hierarchically; and tempo requires representing frequency rates of underlying pulse structures. We explored whether distinct rhythmic elements engage different neural mechanisms by recording brain activity of adult musicians and non-musicians with positron emission tomography (PET as they made covert same-different discriminations of (a pairs of rhythmic, monotonic tone sequences representing changes in pattern, tempo, and meter, and (b pairs of isochronous melodies. Common to pattern, meter, and tempo tasks were focal activities in right, or bilateral, areas of frontal, cingulate, parietal, prefrontal, temporal, and cerebellar cortices. Meter processing alone activated areas in right prefrontal and inferior frontal cortex associated with more cognitive and abstract representations. Pattern processing alone recruited right cortical areas involved in different kinds of auditory processing. Tempo processing alone engaged mechanisms subserving somatosensory and premotor information (e.g., posterior insula, postcentral gyrus. Melody produced activity different from the rhythm conditions (e.g., right anterior insula and various cerebellar areas. These exploratory findings suggest the outlines of some distinct neural components underlying the components of rhythmic structure.
Thaut, Michael H; Trimarchi, Pietro Davide; Parsons, Lawrence M
Rhythm as the time structure of music is composed of distinct temporal components such as pattern, meter, and tempo. Each feature requires different computational processes: meter involves representing repeating cycles of strong and weak beats; pattern involves representing intervals at each local time point which vary in length across segments and are linked hierarchically; and tempo requires representing frequency rates of underlying pulse structures. We explored whether distinct rhythmic elements engage different neural mechanisms by recording brain activity of adult musicians and non-musicians with positron emission tomography (PET) as they made covert same-different discriminations of (a) pairs of rhythmic, monotonic tone sequences representing changes in pattern, tempo, and meter, and (b) pairs of isochronous melodies. Common to pattern, meter, and tempo tasks were focal activities in right, or bilateral, areas of frontal, cingulate, parietal, prefrontal, temporal, and cerebellar cortices. Meter processing alone activated areas in right prefrontal and inferior frontal cortex associated with more cognitive and abstract representations. Pattern processing alone recruited right cortical areas involved in different kinds of auditory processing. Tempo processing alone engaged mechanisms subserving somatosensory and premotor information (e.g., posterior insula, postcentral gyrus). Melody produced activity different from the rhythm conditions (e.g., right anterior insula and various cerebellar areas). These exploratory findings suggest the outlines of some distinct neural components underlying the components of rhythmic structure.
Dedovic, Katarina; Slavich, George M.; Jarcho, Michael R.; Breen, Elizabeth C.; Bower, Julienne E.; Irwin, Michael R.; Eisenberger, Naomi I.
Social stratification has important implications for health and well-being, with individuals lower in standing in a hierarchy experiencing worse outcomes than those higher up the social ladder. Separate lines of past research suggest that alterations in inflammatory processes and neural responses to threat may link lower social status with poorer outcomes. This study was designed to bridge these literatures to investigate the neurocognitive mechanisms linking subjective social status and inflammation. Thirty-one participants reported their subjective social status, and underwent a functional magnetic resonance imaging scan while they were socially evaluated. Participants also provided blood samples before and after the stressor, which were analysed for changes in inflammation. Results showed that lower subjective social status was associated with greater increases in inflammation. Neuroimaging data revealed lower subjective social status was associated with greater neural activity in the dorsomedial prefrontal cortex (DMPFC) in response to negative feedback. Finally, results indicated that activation in the DMPFC in response to negative feedback mediated the relation between social status and increases in inflammatory activity. This study provides the first evidence of a neurocognitive pathway linking subjective social status and inflammation, thus furthering our understanding of how social hierarchies shape neural and physiological responses to social interactions. PMID:26979965
Verma, Rohit; Guex, Amelie A.; Hancock, Kenneth E.; Durakovic, Nedim; McKay, Colette M.; Slama, Michaël C. C.; Brown, M. Christian; Lee, Daniel J.
In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported “optophonic” effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach. PMID:24508368
Verma, Rohit U; Guex, Amélie A; Hancock, Kenneth E; Durakovic, Nedim; McKay, Colette M; Slama, Michaël C C; Brown, M Christian; Lee, Daniel J
In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported "optophonic" effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach. Copyright © 2014 Elsevier B.V. All rights reserved.
Casement, Melynda D.; Guyer, Amanda E.; Hipwell, Alison; McAloon, Rose L.; Hoffmann, Amy M.; Keenan, Kathryn; Forbes, Erika E.
Developmental models of psychopathology posit that exposure to social stressors may confer risk for depression in adolescent girls by disrupting neural reward circuitry. The current study tested this hypothesis by examining the relationship between early adolescent social stressors and later neural reward processing and depressive symptoms. Participants were 120 girls from an ongoing longitudinal study of precursors to depression across adolescent development. Low parental warmth, peer victimization, and depressive symptoms were assessed when the girls were 11 and 12 years old, and participants completed a monetary reward guessing fMRI task and assessment of depressive symptoms at age 16. Results indicate that low parental warmth was associated with increased response to potential rewards in the medial prefrontal cortex (mPFC), striatum, and amygdala, whereas peer victimization was associated with decreased response to potential rewards in the mPFC. Furthermore, concurrent depressive symptoms were associated with increased reward anticipation response in mPFC and striatal regions that were also associated with early adolescent psychosocial stressors, with mPFC and striatal response mediating the association between social stressors and depressive symptoms. These findings are consistent with developmental models that emphasize the adverse impact of early psychosocial stressors on neural reward processing and risk for depression in adolescence. PMID:24397999
Casement, Melynda D; Guyer, Amanda E; Hipwell, Alison E; McAloon, Rose L; Hoffmann, Amy M; Keenan, Kathryn E; Forbes, Erika E
Developmental models of psychopathology posit that exposure to social stressors may confer risk for depression in adolescent girls by disrupting neural reward circuitry. The current study tested this hypothesis by examining the relationship between early adolescent social stressors and later neural reward processing and depressive symptoms. Participants were 120 girls from an ongoing longitudinal study of precursors to depression across adolescent development. Low parental warmth, peer victimization, and depressive symptoms were assessed when the girls were 11 and 12 years old, and participants completed a monetary reward guessing fMRI task and assessment of depressive symptoms at age 16. Results indicate that low parental warmth was associated with increased response to potential rewards in the medial prefrontal cortex (mPFC), striatum, and amygdala, whereas peer victimization was associated with decreased response to potential rewards in the mPFC. Furthermore, concurrent depressive symptoms were associated with increased reward anticipation response in mPFC and striatal regions that were also associated with early adolescent psychosocial stressors, with mPFC and striatal response mediating the association between social stressors and depressive symptoms. These findings are consistent with developmental models that emphasize the adverse impact of early psychosocial stressors on neural reward processing and risk for depression in adolescence. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.
Melynda D. Casement
Full Text Available Developmental models of psychopathology posit that exposure to social stressors may confer risk for depression in adolescent girls by disrupting neural reward circuitry. The current study tested this hypothesis by examining the relationship between early adolescent social stressors and later neural reward processing and depressive symptoms. Participants were 120 girls from an ongoing longitudinal study of precursors to depression across adolescent development. Low parental warmth, peer victimization, and depressive symptoms were assessed when the girls were 11 and 12 years old, and participants completed a monetary reward guessing fMRI task and assessment of depressive symptoms at age 16. Results indicate that low parental warmth was associated with increased response to potential rewards in the medial prefrontal cortex (mPFC, striatum, and amygdala, whereas peer victimization was associated with decreased response to potential rewards in the mPFC. Furthermore, concurrent depressive symptoms were associated with increased reward anticipation response in mPFC and striatal regions that were also associated with early adolescent psychosocial stressors, with mPFC and striatal response mediating the association between social stressors and depressive symptoms. These findings are consistent with developmental models that emphasize the adverse impact of early psychosocial stressors on neural reward processing and risk for depression in adolescence.
Patricia Z. Tan
Full Text Available Parenting is often implicated as a potential source of individual differences in youths’ emotional information processing. The present study examined whether parental affect is related to an important aspect of adolescent emotional development, response to peer evaluation. Specifically, we examined relations between maternal negative affect, observed during parent–adolescent discussion of an adolescent-nominated concern with which s/he wants parental support, and adolescent neural responses to peer evaluation in 40 emotionally healthy and depressed adolescents. We focused on a network of ventral brain regions involved in affective processing of social information: the amygdala, anterior insula, nucleus accumbens, and subgenual anterior cingulate, as well as the ventrolateral prefrontal cortex. Maternal negative affect was not associated with adolescent neural response to peer rejection. However, longer durations of maternal negative affect were associated with decreased responsivity to peer acceptance in the amygdala, left anterior insula, subgenual anterior cingulate, and left nucleus accumbens. These findings provide some of the first evidence that maternal negative affect is associated with adolescents’ neural processing of social rewards. Findings also suggest that maternal negative affect could contribute to alterations in affective processing, specifically, dampening the saliency and/or reward of peer interactions during adolescence.
Muscatell, Keely A; Dedovic, Katarina; Slavich, George M; Jarcho, Michael R; Breen, Elizabeth C; Bower, Julienne E; Irwin, Michael R; Eisenberger, Naomi I
Social stratification has important implications for health and well-being, with individuals lower in standing in a hierarchy experiencing worse outcomes than those higher up the social ladder. Separate lines of past research suggest that alterations in inflammatory processes and neural responses to threat may link lower social status with poorer outcomes. This study was designed to bridge these literatures to investigate the neurocognitive mechanisms linking subjective social status and inflammation. Thirty-one participants reported their subjective social status, and underwent a functional magnetic resonance imaging scan while they were socially evaluated. Participants also provided blood samples before and after the stressor, which were analysed for changes in inflammation. Results showed that lower subjective social status was associated with greater increases in inflammation. Neuroimaging data revealed lower subjective social status was associated with greater neural activity in the dorsomedial prefrontal cortex (DMPFC) in response to negative feedback. Finally, results indicated that activation in the DMPFC in response to negative feedback mediated the relation between social status and increases in inflammatory activity. This study provides the first evidence of a neurocognitive pathway linking subjective social status and inflammation, thus furthering our understanding of how social hierarchies shape neural and physiological responses to social interactions. © The Author (2016). Published by Oxford University Press. For Permissions, please email: email@example.com.
Nawijn, Laura; van Zuiden, Mirjam; Koch, Saskia B J; Frijling, Jessie L; Veltman, Dick J; Olff, Miranda
Therapeutic alliance and perceived social support are important predictors of treatment response for post-traumatic stress disorder (PTSD). Intranasal oxytocin administration may enhance treatment response by increasing sensitivity for social reward and thereby therapeutic alliance and perceived social support. As a first step to investigate this therapeutical potential, we investigated whether intranasal oxytocin enhances neural sensitivity to social reward in PTSD patients. Male and female police officers with (n = 35) and without PTSD (n = 37) were included in a double-blind, randomized, placebo-controlled cross-over fMRI study. After intranasal oxytocin (40 IU) and placebo administration, a social incentive delay task was conducted to investigate neural responses during social reward and punishment anticipation and feedback. Under placebo, PTSD patients showed reduced left anterior insula (AI) responses to social rewards (i.e. happy faces) compared with controls. Oxytocin administration increased left AI responses during social reward in PTSD patients, such that PTSD patients no longer differed from controls under placebo. Furthermore, in PTSD patients, oxytocin increased responses to social reward in the right putamen. By normalizing abberant insula responses and increasing putamen responses to social reward, oxytocin administration may enhance sensitivity for social support and therapeutic alliance in PTSD patients. Future studies are needed to investigate clinical effects of oxytocin. © The Author (2016). Published by Oxford University Press.
Heather L Chapin
Full Text Available The aim of this study was to explore the role of attention in pulse and meter perception using complex rhythms. We used a selective attention paradigm in which participants attended to either a complex auditory rhythm or a visually presented word list. Performance on a reproduction task was used to gauge whether participants were attending to the appropriate stimulus. We hypothesized that attention to complex rhythms – which contain no energy at the pulse frequency – would lead to activations in motor areas involved in pulse perception. Moreover, because multiple repetitions of a complex rhythm are needed to perceive a pulse, activations in pulse related areas would be seen only after sufficient time had elapsed for pulse perception to develop. Selective attention was also expected to modulate activity in sensory areas specific to the modality. We found that selective attention to rhythms led to increased BOLD responses in basal ganglia, and basal ganglia activity was observed only after the rhythms had cycled enough times for a stable pulse percept to develop. These observations suggest that attention is needed to recruit motor activations associated with the perception of pulse in complex rhythms. Moreover, attention to the auditory stimulus enhanced activity in an attentional sensory network including primary auditory, insula, anterior cingulate, and prefrontal cortex, and suppressed activity in sensory areas associated with attending to the visual stimulus.
Larissa Felicidade Werkhauser Demarco
Full Text Available Abstract This paper presents an evaluation of the response of seismic reflection attributes in different types of marine substrate (rock, shallow gas, sediments using seafloor samples for ground-truth statistical comparisons. The data analyzed include seismic reflection profiles collected using two CHIRP subbottom profilers (Edgetech Model 3100 SB-216S, with frequency ranging between 2 and 16 kHz, and a number (38 of sediment samples collected from the seafloor. The statistical method used to discriminate between different substratum responses was the non-parametric Kruskal-Wallis analysis, carried out in two steps: 1 comparison of Seismic Attributes between different marine substrates (unconsolidated sediments, rock and shallow gas; 2 comparison of Seismic Attributes between different sediment classes in seafloors characterized by unconsolidated sediments (subdivided according to sorting. These analyses suggest that amplitude-related attributes were effective in discriminating between sediment and gassy/rocky substratum, but did not differentiate between rocks and shallow gas. On the other hand, the Instantaneous Frequency attribute was effective in differentiating sediments, rocks and shallow gas, with sediment showing higher frequency range, rock an intermediate range, and shallow gas the lowest response. Regarding grain-size classes and sorting, statistical analysis discriminated between two distinct groups of samples, the SVFS (silt and very fine sand and the SFMC (fine, medium and coarse sand groups. Using a Spearman coefficient, it was found that the Instantaneous Amplitude was more efficient in distinguishing between the two groups. None of the attributes was able to distinguish between the closest grain size classes such as those of silt and very fine sand.
Iris I A Groen
Full Text Available The visual world is complex and continuously changing. Yet, our brain transforms patterns of light falling on our retina into a coherent percept within a few hundred milliseconds. Possibly, low-level neural responses already carry substantial information to facilitate rapid characterization of the visual input. Here, we computationally estimated low-level contrast responses to computer-generated naturalistic images, and tested whether spatial pooling of these responses could predict image similarity at the neural and behavioral level. Using EEG, we show that statistics derived from pooled responses explain a large amount of variance between single-image evoked potentials (ERPs in individual subjects. Dissimilarity analysis on multi-electrode ERPs demonstrated that large differences between images in pooled response statistics are predictive of more dissimilar patterns of evoked activity, whereas images with little difference in statistics give rise to highly similar evoked activity patterns. In a separate behavioral experiment, images with large differences in statistics were judged as different categories, whereas images with little differences were confused. These findings suggest that statistics derived from low-level contrast responses can be extracted in early visual processing and can be relevant for rapid judgment of visual similarity. We compared our results with two other, well- known contrast statistics: Fourier power spectra and higher-order properties of contrast distributions (skewness and kurtosis. Interestingly, whereas these statistics allow for accurate image categorization, they do not predict ERP response patterns or behavioral categorization confusions. These converging computational, neural and behavioral results suggest that statistics of pooled contrast responses contain information that corresponds with perceived visual similarity in a rapid, low-level categorization task.
Zachary B Gaber
Full Text Available Distinct classes of neurons and glial cells in the developing spinal cord arise at specific times and in specific quantities from spatially discrete neural progenitor domains. Thus, adjacent domains can exhibit marked differences in their proliferative potential and timing of differentiation. However, remarkably little is known about the mechanisms that account for this regional control. Here, we show that the transcription factor Promyelocytic Leukemia Zinc Finger (PLZF plays a critical role shaping patterns of neuronal differentiation by gating the expression of Fibroblast Growth Factor (FGF Receptor 3 and responsiveness of progenitors to FGFs. PLZF elevation increases FGFR3 expression and STAT3 pathway activity, suppresses neurogenesis, and biases progenitors towards glial cell production. In contrast, PLZF loss reduces FGFR3 levels, leading to premature neuronal differentiation. Together, these findings reveal a novel transcriptional strategy for spatially tuning the responsiveness of distinct neural progenitor groups to broadly distributed mitogenic signals in the embryonic environment.
Full Text Available During neural tissue genesis, neural stem/progenitor cells are exposed to bioelectric stimuli well before synaptogenesis and neural circuit formation. Fluctuations in the electrochemical potential in the vicinity of developing cells influence the genesis, migration and maturation of neuronal precursors. The complexity of the in vivo environment and the coexistence of various progenitor populations hinder the understanding of the significance of ionic/bioelectric stimuli in the early phases of neuronal differentiation. Using optogenetic stimulation, we investigated the in vitro motility responses of radial glia-like neural stem/progenitor populations to ionic stimuli. Radial glia-like neural stem cells were isolated from CAGloxpStoploxpChR2(H134-eYFP transgenic mouse embryos. After transfection with Cre-recombinase, ChR2(channelrhodopsin-2-expressing and non-expressing cells were separated by eYFP fluorescence. Expression of light-gated ion channels were checked by patch clamp and fluorescence intensity assays. Neurogenesis by ChR2-expressing and non-expressing cells was induced by withdrawal of EGF from the medium. Cells in different (stem cell, migrating progenitor and maturing precursor stages of development were illuminated with laser light (λ = 488 nm; 1.3 mW/mm2; 300 ms in every 5 min for 12 h. The displacement of the cells was analyzed on images taken at the end of each light pulse. Results demonstrated that the migratory activity decreased with the advancement of neuronal differentiation regardless of stimulation. Light-sensitive cells, however, responded on a differentiation-dependent way. In non-differentiated ChR2-expressing stem cell populations, the motility did not change significantly in response to light-stimulation. The displacement activity of migrating progenitors was enhanced, while the motility of differentiating neuronal precursors was markedly reduced by illumination.
Guyer, Amanda E.; Jarcho, Johanna M.; Pérez-Edgar, Koraly; Degnan, Kathryn A.; Pine, Daniel S.; Fox, Nathan A.; Nelson, Eric E.
Behavioral inhibition (BI) is a temperament characterized by social reticence and withdrawal from unfamiliar or novel contexts and conveys risk for social anxiety disorder. Developmental outcomes associated with this temperament can be influenced by children’s caregiving context. The convergence of a child’s temperamental disposition and rearing environment is ultimately expressed at both the behavioral and neural levels in emotional and cognitive response patterns to social challenges. The p...
Full Text Available Substance abuse in pregnant and recently postpartum women is a major public health concern because of effects on the infant and on the ability of the adult to care for the infant. In addition to the negative health effects of teratogenic substances on fetal development, substance use can contribute to difficulties associated with the social and behavioral aspects of parenting. Neural circuits associated with parenting behavior overlap with circuits involved in addiction (e.g., frontal, striatal and limbic systems and thus may be co-opted for the craving/reward cycle associated with substance use and abuse and be less available for parenting. The current study investigates the degree to which neural circuits associated with parenting are disrupted in mothers who are substance-using. Specifically, we used functional magnetic resonance imaging to examine the neural response to emotional infant cues (faces and cries in substance-using compared to non-using mothers. In response to both faces (of varying emotional valence and cries (of varying distress levels, substance-using mothers evidenced reduced neural activation in regions that have been previously implicated in reward and motivation as well as regions involved in cognitive control. Specifically, in response to faces, substance users showed reduced activation in prefrontal regions, including the dorsolateral and ventromedial prefrontal cortex, as well as visual processing (occipital lobes and limbic regions (parahippocampus and amygdala. Similarly, in response to infant cries substance-using mothers showed reduced activation relative to non-using mothers in prefrontal regions, auditory sensory processing regions, insula and limbic regions (parahippocampus and amygdala. These findings suggest that infant stimuli may be less salient for substance-using mothers, and such reduced saliency may impair developing infant-caregiver attachment and the ability of mothers to respond appropriately to their
Park, Mi-Sook; Lee, Bae Hwan; Sohn, Jin-Hun
Very little is known about the neural circuitry underlying anger processing among alcoholics. The purpose of this study was to examine the altered brain activity of alcoholic individuals during transient anger emotion. Using functional magnetic resonance imaging (fMRI), 18 male patients diagnosed with alcohol dependence in an inpatient alcohol treatment facility and 16 social drinkers with similar demographics were scanned during the viewing of anger-provoking film clips. While there was no significant difference in the level of experienced anger between alcohol-dependent patients and non-alcoholic controls, significantly greater activation was observed in the bilateral dorsal anterior cingulate cortex (dACC) and the right precentral gyrus among alcoholic patients compared to the normal controls. In summary, specific brain regions were identified that are associated with anger among patients with alcohol dependency.
Full Text Available The questions whether and how empathy for pain can be modulated by acute alcohol intoxication in the non-dependent population remain unanswered. To address these questions, a double-blind, placebo-controlled, within-subject study design was adopted in this study, in which healthy social drinkers were asked to complete a pain-judgment task using pictures depicting others' body parts in painful or non-painful situations during fMRI scanning, either under the influence of alcohol intoxication or placebo conditions. Empathic neural activity for pain was reduced by alcohol intoxication only in the dorsal anterior cingulate cortex (dACC. More interestingly, we observed that empathic neural activity for pain in the right anterior insula (rAI was significantly correlated with trait empathy only after alcohol intoxication, along with impaired functional connectivity between the rAI and the fronto-parietal attention network. Our results reveal that alcohol intoxication not only inhibits empathic neural responses for pain but also leads to trait empathy inflation, possibly via impaired top-down attentional control. These findings help to explain the neural mechanism underlying alcohol-related social problems.
Joni N Saby
Full Text Available Human infants rapidly learn new skills and customs via imitation, but the neural linkages between action perception and production are not well understood. Neuroscience studies in adults suggest that a key component of imitation-identifying the corresponding body part used in the acts of self and other-has an organized neural signature. In adults, perceiving someone using a specific body part (e.g., hand vs. foot is associated with activation of the corresponding area of the sensory and/or motor strip in the observer's brain-a phenomenon called neural somatotopy. Here we examine whether preverbal infants also exhibit somatotopic neural responses during the observation of others' actions. 14-month-old infants were randomly assigned to watch an adult reach towards and touch an object using either her hand or her foot. The scalp electroencephalogram (EEG was recorded and event-related changes in the sensorimotor mu rhythm were analyzed. Mu rhythm desynchronization was greater over hand areas of sensorimotor cortex during observation of hand actions and was greater over the foot area for observation of foot actions. This provides the first evidence that infants' observation of someone else using a particular body part activates the corresponding areas of sensorimotor cortex. We hypothesize that this somatotopic organization in the developing brain supports imitation and cultural learning. The findings connect developmental cognitive neuroscience, adult neuroscience, action representation, and behavioral imitation.
ter Hofstede, Hannah M; Goerlitz, Holger R; Montealegre-Z, Fernando; Robert, Daniel; Holderied, Marc W
Ears evolved in many groups of moths to detect the echolocation calls of predatory bats. Although the neurophysiology of bat detection has been intensively studied in moths for decades, the relationship between sound-induced movement of the noctuid tympanic membrane and action potentials in the auditory sensory cells (A1 and A2) has received little attention. Using laser Doppler vibrometry, we measured the velocity and displacement of the tympanum in response to pure tone pulses for moths that were intact or prepared for neural recording. When recording from the auditory nerve, the displacement of the tympanum at the neural threshold remained constant across frequencies, whereas velocity varied with frequency. This suggests that the key biophysical parameter for triggering action potentials in the sensory cells of noctuid moths is tympanum displacement, not velocity. The validity of studies on the neurophysiology of moth hearing rests on the assumption that the dissection and recording procedures do not affect the biomechanics of the ear. There were no consistent differences in tympanal velocity or displacement when moths were intact or prepared for neural recordings for sound levels close to neural threshold, indicating that this and other neurophysiological studies provide good estimates of what intact moths hear at threshold.
Samantha J Brooks
Full Text Available 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.
Dean, Z; Horndasch, S; Giannopoulos, P; McCabe, C
We have previously shown that the selective serotonergic reuptake inhibitor, citalopram, reduces the neural response to reward and aversion in healthy volunteers. We suggest that this inhibitory effect might underlie the emotional blunting reported by patients on these medications. Bupropion is a dopaminergic and noradrenergic reuptake inhibitor and has been suggested to have more therapeutic effects on reward-related deficits. However, how bupropion affects the neural responses to reward and aversion is unclear. Seventeen healthy volunteers (9 female, 8 male) received 7 days bupropion (150 mg/day) and 7 days placebo treatment, in a double-blind crossover design. Our functional magnetic resonance imaging task consisted of three phases; an anticipatory phase (pleasant or unpleasant cue), an effort phase (button presses to achieve a pleasant taste or to avoid an unpleasant taste) and a consummatory phase (pleasant or unpleasant tastes). Volunteers also rated wanting, pleasantness and intensity of the tastes. Relative to placebo, bupropion increased activity during the anticipation phase in the ventral medial prefrontal cortex (vmPFC) and caudate. During the effort phase, bupropion increased activity in the vmPFC, striatum, dorsal anterior cingulate cortex and primary motor cortex. Bupropion also increased medial orbitofrontal cortex, amygdala and ventral striatum activity during the consummatory phase. Our results are the first to show that bupropion can increase neural responses during the anticipation, effort and consummation of rewarding and aversive stimuli. This supports the notion that bupropion might be beneficial for depressed patients with reward-related deficits and blunted affect.
Burkhouse, Katie L; Kujawa, Autumn; Kennedy, Amy E; Shankman, Stewart A; Langenecker, Scott A; Phan, K Luan; Klumpp, Heide
Cognitive behavioral therapy (CBT) is a well-established treatment for anxiety and depression; however, response to CBT is heterogeneous across patients and many remain symptomatic after therapy, raising the need to identify prospective predictors for treatment planning. Altered neural processing of reward has been implicated in both depression and anxiety, and improving hedonic capacity is a goal of CBT. However, little is known about how neural response to reward relates to CBT outcomes in depression and anxiety. The current study used the reward positivity (RewP) event-related potential (ERP) component to examine whether neural reactivity to reward would predict CBT response in a sample of patients with anxiety without depression (n = 30) and comorbid anxiety and depression (CAD, n = 22). Participants completed a guessing reward ERP paradigm before completing 12 weeks of standard CBT. The majority of the sample (68%; 35 out of 52 patients) responded to treatment, and those with a reduced RewP at baseline were more likely to respond to treatment. A reduced RewP was also associated with a greater pre-to-post CBT reduction in depressive symptoms among individuals with CAD, but not among individuals with pure anxiety. CBT may be most beneficial in reducing depressive symptoms for individuals who demonstrate decreased reward reactivity prior to treatment. CBT may target reward brain function, leading to greater improvement in symptoms. These effects may be strongest, and therefore most meaningful, for individuals with reward-processing deficits prior to treatment. © 2016 Wiley Periodicals, Inc.
Full Text Available Recent research suggests that conceptual or emotional factors could influence the perceptual processing of stimuli. In this article, we aimed to evaluate the effect of social information (positive, negative, or no information related to the character of the target on subjective (perceived and felt valence and arousal, physiological (facial mimicry as well as on neural (P100 and N170 responses to dynamic emotional facial expressions (EFE that varied from neutral to one of the six basic emotions. Across three studies, the results showed reduced ratings of valence and arousal of EFE associated with incongruent social information (Study 1, increased electromyographical responses (Study 2, and significant modulation of P100 and N170 components (Study 3 when EFE were associated with social (positive and negative information (vs. no information. These studies revealed that positive or negative social information reduces subjective responses to incongruent EFE and produces a similar neural and physiological boost of the early perceptual processing of EFE irrespective of their congruency. In conclusion, the article suggests that the presence of positive or negative social context modulates early physiological and neural activity preceding subsequent behavior.
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.
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
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
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.
Burger, Kyle S; Stice, Eric
Although soft drinks are heavily advertised, widely consumed, and have been associated with obesity, little is understood regarding neural responsivity to soft drink intake, anticipated intake, and advertisements. Functional MRI was used to assess examine neural response to carbonated soft drink intake, anticipated intake and advertisement exposure as well as milkshake intake in 27 adolescents that varied on soft drink consumer status. Intake and anticipated intake of carbonated Coke® activated regions implicated in gustatory, oral somatosensory, and reward processing, yet high-fat/sugar milkshake intake elicited greater activation in these regions vs. Coke intake. Advertisements highlighting the Coke product vs. nonfood control advertisements, but not the Coke logo, activated gustatory and visual brain regions. Habitual Coke consumers vs. nonconsumers showed greater posterior cingulate responsivity to Coke logo ads, suggesting that the logo is a conditioned cue. Coke consumers exhibited less ventrolateral prefrontal cortex responsivity during anticipated Coke intake relative to nonconsumers. Results indicate that soft drinks activate reward and gustatory regions, but are less potent in activating these regions than high-fat/sugar beverages, and imply that habitual soft drink intake promotes hyper-responsivity of regions encoding salience/attention toward brand specific cues and hypo-responsivity of inhibitory regions while anticipating intake. Copyright © 2013 The Obesity Society.
Maupin, Angela N; Rutherford, Helena J V; Landi, Nicole; Potenza, Marc N; Mayes, Linda C
Understanding the maternal neural response to infant affective cues has important implications for parent-child relationships. The current study employed event-related potentials (ERPs) to examine patterns in mothers' responses to infant affective cues, and evaluated the influence of maternal experience, defined by parity (i.e., the number of children a mother has) on ERP responses. Eighty-three mothers, three months postpartum, viewed photographs of displays of infant emotional faces (sad or happy) and listened to infant cries of different distress levels and a control tone. Maternal neural response was modulated by the emotional content of the auditory stimulus, as indexed by the N100 amplitude and latency. However, response to infant faces was not modulated by the emotional content of the stimuli as indexed by the N170. Neither N100 nor N170 were affected by parity. Maternal engagement with auditory stimuli, as indexed by the P300, was modulated by the emotional content of the cry and was affected by parity. A similar parity effect was observed for the P300 response to infant faces. Results suggest that parity may play an important role at later stages of maternal infant cue perception.
Miskowiak, K W; Glerup, L; Vestbo, C; Harmer, C J; Reinecke, A; Macoveanu, J; Siebner, H R; Kessing, L V; Vinberg, M
Negative cognitive bias and aberrant neural processing of emotional faces are trait-marks of depression. Yet it is unclear whether these changes constitute an endophenotype for depression and are also present in healthy individuals with hereditary risk for depression. Thirty healthy, never-depressed monozygotic (MZ) twins with a co-twin history of depression (high risk group: n = 13) or without co-twin history of depression (low-risk group: n = 17) were enrolled in a functional magnetic resonance imaging (fMRI) study. During fMRI, participants viewed fearful and happy faces while performing a gender discrimination task. After the scan, they were given a faces dot-probe task, a facial expression recognition task and questionnaires assessing mood, personality traits and coping strategies. High-risk twins showed increased neural response to happy and fearful faces in dorsal anterior cingulate cortex (ACC), dorsomedial prefrontal cortex (dmPFC), pre-supplementary motor area and occipito-parietal regions compared to low-risk twins. They also displayed stronger negative coupling between amygdala and pregenual ACC, dmPFC and temporo-parietal regions during emotional face processing. These task-related changes in neural responses in high-risk twins were accompanied by impaired gender discrimination performance during face processing. They also displayed increased attention vigilance for fearful faces and were slower at recognizing facial expressions relative to low-risk controls. These effects occurred in the absence of differences between groups in mood, subjective state or coping. Different neural response and functional connectivity within fronto-limbic and occipito-parietal regions during emotional face processing and enhanced fear vigilance may be key endophenotypes for depression.
Zhang, Yifeng; Min, Booki; Huang, L.
The effect of substrate changes on the performance and microbial community of two-chamber microbial fuel cells (MFCs) was investigated in this study. The MFCs enriched with a single substrate (e.g., acetate, glucose, or butyrate) had different acclimatization capability to substrate changes. The ...
Feng, C; Lori, A; Waldman, I. D; Binder, E. B; Haroon, E; Rilling, J. K
.... However, OT effects are often heterogeneous across individuals. Here we explore individual differences in OT effects on the neural response to social cooperation as a function of the rs53576 polymorphism of the oxytocin receptor gene ( OXTR...
Baeken, Chris; De Raedt, Rudi; Van Schuerbeek, Peter; De Mey, Johan; Bossuyt, Axel; Luypaert, Robert
Events coupled with an emotional context seem to be better retained than non-emotional events. The aim of our study was to investigate whether an emotional context could influence the neural substrates of memory associations with novel portrait art stimuli. In the current prospective fMRI study, we have investigated for one specific visual art form (modern artistic portraits with a high degree of abstraction) whether memory is influenced by priming with emotional facial pictures. In total forty healthy female volunteers in the same age range were recruited for the study. Twenty of these women participated in a prospective brain imaging memory paradigm and were asked to memorize a series of similar looking, but different portraits. After randomization, for twelve participants (Group 1), a third of the portraits was emotionally primed with approach-related pictures (smiling baby faces), a third with withdrawal-related pictures (baby faces with severe dermatological conditions), and another third with neutral images. Group 2 consisted of eight participants and they were not primed. Then, during an fMRI session 2h later, these portraits were viewed in random order intermixed with a set of new (previously unseen) ones, and the participants had to decide for each portrait whether or not they had already been seen. In a separate experiment, a different sample of twenty healthy females (Group 3) rated their mood after being exposed to the same art stimuli, without priming. The portraits did not evoke significant mood changes by themselves, supporting their initial neutral emotional character (Group 3). The correct decision on whether the portraits were Familiar of Unfamiliar led to similar neuronal activations in brain areas implicated in visual and attention processing for both groups (Groups 1 and 2). In contrast, whereas primed participants showed significant higher neuronal activities in the left midline superior frontal cortex (Brodmann area (BA) 6), unprimed
Full Text Available In humans, emotions from music serve important communicative roles. Despite a growing interest in the neural basis of music perception, action and emotion, the majority of previous studies in this area have focused on the auditory aspects of music performances. Here we investigate how the brain processes the emotions elicited by audiovisual music performances. We used event-related functional magnetic resonance imaging, and in Experiment 1 we defined the areas responding to audiovisual (musician's movements with music, visual (musician's movements only, and auditory emotional (music only displays. Subsequently a region of interest analysis was performed to examine if any of the areas detected in Experiment 1 showed greater activation for emotionally mismatching performances (combining the musician's movements with mismatching emotional sound than for emotionally matching music performances (combining the musician's movements with matching emotional sound as presented in Experiment 2 to the same participants. The insula and the left thalamus were found to respond consistently to visual, auditory and audiovisual emotional information and to have increased activation for emotionally mismatching displays in comparison with emotionally matching displays. In contrast, the right thalamus was found to respond to audiovisual emotional displays and to have similar activation for emotionally matching and mismatching displays. These results suggest that the insula and left thalamus have an active role in detecting emotional correspondence between auditory and visual information during music performances, whereas the right thalamus has a different role.
Petrini, Karin; Crabbe, Frances; Sheridan, Carol; Pollick, Frank E
In humans, emotions from music serve important communicative roles. Despite a growing interest in the neural basis of music perception, action and emotion, the majority of previous studies in this area have focused on the auditory aspects of music performances. Here we investigate how the brain processes the emotions elicited by audiovisual music performances. We used event-related functional magnetic resonance imaging, and in Experiment 1 we defined the areas responding to audiovisual (musician's movements with music), visual (musician's movements only), and auditory emotional (music only) displays. Subsequently a region of interest analysis was performed to examine if any of the areas detected in Experiment 1 showed greater activation for emotionally mismatching performances (combining the musician's movements with mismatching emotional sound) than for emotionally matching music performances (combining the musician's movements with matching emotional sound) as presented in Experiment 2 to the same participants. The insula and the left thalamus were found to respond consistently to visual, auditory and audiovisual emotional information and to have increased activation for emotionally mismatching displays in comparison with emotionally matching displays. In contrast, the right thalamus was found to respond to audiovisual emotional displays and to have similar activation for emotionally matching and mismatching displays. These results suggest that the insula and left thalamus have an active role in detecting emotional correspondence between auditory and visual information during music performances, whereas the right thalamus has a different role.
Zhang, Jin-Tao; Yao, Yuan-Wei; Potenza, Marc N; Xia, Cui-Cui; Lan, Jing; Liu, Lu; Wang, Ling-Jiao; Liu, Ben; Ma, Shan-Shan; Fang, Xiao-Yi
Internet gaming disorder (IGD) is characterized by high levels of craving for online gaming and related cues. Since addiction-related cues can evoke increased activation in brain areas involved in motivational and reward processing and may engender gaming behaviors or trigger relapse, ameliorating cue-induced craving may be a promising target for interventions for IGD. This study compared neural activation between 40 IGD and 19 healthy control (HC) subjects during an Internet-gaming cue-reactivity task and found that IGD subjects showed stronger activation in multiple brain areas, including the dorsal striatum, brainstem, substantia nigra, and anterior cingulate cortex, but lower activation in the posterior insula. Furthermore, twenty-three IGD subjects (CBI + group) participated in a craving behavioral intervention (CBI) group therapy, whereas the remaining 17 IGD subjects (CBI - group) did not receive any intervention, and all IGD subjects were scanned during similar time intervals. The CBI + group showed decreased IGD severity and cue-induced craving, enhanced activation in the anterior insula and decreased insular connectivity with the lingual gyrus and precuneus after receiving CBI. These findings suggest that CBI is effective in reducing craving and severity in IGD, and it may exert its effects by altering insula activation and its connectivity with regions involved in visual processing and attention bias.
Full Text Available Internet gaming disorder (IGD is characterized by high levels of craving for online gaming and related cues. Since addiction-related cues can evoke increased activation in brain areas involved in motivational and reward processing and may engender gaming behaviors or trigger relapse, ameliorating cue-induced craving may be a promising target for interventions for IGD. This study compared neural activation between 40 IGD and 19 healthy control (HC subjects during an Internet-gaming cue-reactivity task and found that IGD subjects showed stronger activation in multiple brain areas, including the dorsal striatum, brainstem, substantia nigra, and anterior cingulate cortex, but lower activation in the posterior insula. Furthermore, twenty-three IGD subjects (CBI+ group participated in a craving behavioral intervention (CBI group therapy, whereas the remaining 17 IGD subjects (CBI− group did not receive any intervention, and all IGD subjects were scanned during similar time intervals. The CBI+ group showed decreased IGD severity and cue-induced craving, enhanced activation in the anterior insula and decreased insular connectivity with the lingual gyrus and precuneus after receiving CBI. These findings suggest that CBI is effective in reducing craving and severity in IGD, and it may exert its effects by altering insula activation and its connectivity with regions involved in visual processing and attention bias.
Insel, Catherine; Reinen, Jenna; Weber, Jochen; Wager, Tor D; Jarskog, L Fredrik; Shohamy, Daphna; Smith, Edward E
Schizophrenia is characterized by an abnormal dopamine system, and dopamine blockade is the primary mechanism of antipsychotic treatment. Consistent with the known role of dopamine in reward processing, prior research has demonstrated that patients with schizophrenia exhibit impairments in reward-based learning. However, it remains unknown how treatment with antipsychotic medication impacts the behavioral and neural signatures of reinforcement learning in schizophrenia. The goal of this study was to examine whether antipsychotic medication modulates behavioral and neural responses to prediction error coding during reinforcement learning. Patients with schizophrenia completed a reinforcement learning task while undergoing functional magnetic resonance imaging. The task consisted of two separate conditions in which participants accumulated monetary gain or avoided monetary loss. Behavioral results indicated that antipsychotic medication dose was associated with altered behavioral approaches to learning, such that patients taking higher doses of medication showed increased sensitivity to negative reinforcement. Higher doses of antipsychotic medication were also associated with higher learning rates (LRs), suggesting that medication enhanced sensitivity to trial-by-trial feedback. Neuroimaging data demonstrated that antipsychotic dose was related to differences in neural signatures of feedback prediction error during the loss condition. Specifically, patients taking higher doses of medication showed attenuated prediction error responses in the striatum and the medial prefrontal cortex. These findings indicate that antipsychotic medication treatment may influence motivational processes in patients with schizophrenia.
Reed, Darrin K.; Tóth, Brigitta; Best, Virginia; Majdak, Piotr; Colburn, H. Steven; Shinn-Cunningham, Barbara
Studies of auditory looming bias have shown that sources increasing in intensity are more salient than sources decreasing in intensity. Researchers have argued that listeners are more sensitive to approaching sounds compared with receding sounds, reflecting an evolutionary pressure. However, these studies only manipulated overall sound intensity; therefore, it is unclear whether looming bias is truly a perceptual bias for changes in source distance, or only in sound intensity. Here we demonstrate both behavioral and neural correlates of looming bias without manipulating overall sound intensity. In natural environments, the pinnae induce spectral cues that give rise to a sense of externalization; when spectral cues are unnatural, sounds are perceived as closer to the listener. We manipulated the contrast of individually tailored spectral cues to create sounds of similar intensity but different naturalness. We confirmed that sounds were perceived as approaching when spectral contrast decreased, and perceived as receding when spectral contrast increased. We measured behavior and electroencephalography while listeners judged motion direction. Behavioral responses showed a looming bias in that responses were more consistent for sounds perceived as approaching than for sounds perceived as receding. In a control experiment, looming bias disappeared when spectral contrast changes were discontinuous, suggesting that perceived motion in distance and not distance itself was driving the bias. Neurally, looming bias was reflected in an asymmetry of late event-related potentials associated with motion evaluation. Hence, both our behavioral and neural findings support a generalization of the auditory looming bias, representing a perceptual preference for approaching auditory objects. PMID:28827336
Baumgartner, Robert; Reed, Darrin K; Tóth, Brigitta; Best, Virginia; Majdak, Piotr; Colburn, H Steven; Shinn-Cunningham, Barbara
Studies of auditory looming bias have shown that sources increasing in intensity are more salient than sources decreasing in intensity. Researchers have argued that listeners are more sensitive to approaching sounds compared with receding sounds, reflecting an evolutionary pressure. However, these studies only manipulated overall sound intensity; therefore, it is unclear whether looming bias is truly a perceptual bias for changes in source distance, or only in sound intensity. Here we demonstrate both behavioral and neural correlates of looming bias without manipulating overall sound intensity. In natural environments, the pinnae induce spectral cues that give rise to a sense of externalization; when spectral cues are unnatural, sounds are perceived as closer to the listener. We manipulated the contrast of individually tailored spectral cues to create sounds of similar intensity but different naturalness. We confirmed that sounds were perceived as approaching when spectral contrast decreased, and perceived as receding when spectral contrast increased. We measured behavior and electroencephalography while listeners judged motion direction. Behavioral responses showed a looming bias in that responses were more consistent for sounds perceived as approaching than for sounds perceived as receding. In a control experiment, looming bias disappeared when spectral contrast changes were discontinuous, suggesting that perceived motion in distance and not distance itself was driving the bias. Neurally, looming bias was reflected in an asymmetry of late event-related potentials associated with motion evaluation. Hence, both our behavioral and neural findings support a generalization of the auditory looming bias, representing a perceptual preference for approaching auditory objects.
Chapin, Heather; Jantzen, Kelly; Kelso, J A Scott; Steinberg, Fred; Large, Edward
Apart from its natural relevance to cognition, music provides a window into the intimate relationships between production, perception, experience, and emotion. Here, emotional responses and neural activity were observed as they evolved together with stimulus parameters over several minutes. Participants listened to a skilled music performance that included the natural fluctuations in timing and sound intensity that musicians use to evoke emotional responses. A mechanical performance of the same piece served as a control. Before and after fMRI scanning, participants reported real-time emotional responses on a 2-dimensional rating scale (arousal and valence) as they listened to each performance. During fMRI scanning, participants listened without reporting emotional responses. Limbic and paralimbic brain areas responded to the expressive dynamics of human music performance, and both emotion and reward related activations during music listening were dependent upon musical training. Moreover, dynamic changes in timing predicted ratings of emotional arousal, as well as real-time changes in neural activity. BOLD signal changes correlated with expressive timing fluctuations in cortical and subcortical motor areas consistent with pulse perception, and in a network consistent with the human mirror neuron system. These findings show that expressive music performance evokes emotion and reward related neural activations, and that music's affective impact on the brains of listeners is altered by musical training. Our observations are consistent with the idea that music performance evokes an emotional response through a form of empathy that is based, at least in part, on the perception of movement and on violations of pulse-based temporal expectancies.
Full Text Available Apart from its natural relevance to cognition, music provides a window into the intimate relationships between production, perception, experience, and emotion. Here, emotional responses and neural activity were observed as they evolved together with stimulus parameters over several minutes. Participants listened to a skilled music performance that included the natural fluctuations in timing and sound intensity that musicians use to evoke emotional responses. A mechanical performance of the same piece served as a control. Before and after fMRI scanning, participants reported real-time emotional responses on a 2-dimensional rating scale (arousal and valence as they listened to each performance. During fMRI scanning, participants listened without reporting emotional responses. Limbic and paralimbic brain areas responded to the expressive dynamics of human music performance, and both emotion and reward related activations during music listening were dependent upon musical training. Moreover, dynamic changes in timing predicted ratings of emotional arousal, as well as real-time changes in neural activity. BOLD signal changes correlated with expressive timing fluctuations in cortical and subcortical motor areas consistent with pulse perception, and in a network consistent with the human mirror neuron system. These findings show that expressive music performance evokes emotion and reward related neural activations, and that music's affective impact on the brains of listeners is altered by musical training. Our observations are consistent with the idea that music performance evokes an emotional response through a form of empathy that is based, at least in part, on the perception of movement and on violations of pulse-based temporal expectancies.
Bunford, Nora; Kujawa, Autumn; Fitzgerald, Kate D; Swain, James E; Hanna, Gregory L; Koschmann, Elizabeth; Simpson, David; Connolly, Sucheta; Monk, Christopher S; Phan, K Luan
Although cognitive-behavioral psychotherapy (CBT) and pharmacotherapy are evidence-based treatments for pediatric anxiety, many youth with anxiety disorders fail to respond to these treatments. Given limitations of clinical measures in predicting treatment response, identifying neural predictors is timely. In this study, 35 anxious youth (ages 7-19 years) completed an emotional face-matching task during which the late positive potential (LPP), an event-related potential (ERP) component that indexes sustained attention towards emotional stimuli, was measured. Following the ERP measurement, youth received CBT or selective serotonin reuptake inhibitor (SSRI) treatment, and the LPP was examined as a predictor of treatment response. Findings indicated that, accounting for pre-treatment anxiety severity, neural reactivity to emotional faces predicted anxiety severity post- CBT and SSRI treatment such that enhanced electrocortical response to angry faces was associated with better treatment response. An enhanced LPP to angry faces may predict treatment response insofar as it may reflect greater emotion dysregulation or less avoidance and/or enhanced engagement with environmental stimuli in general, including with treatment.
Edelen, Auralee [Fermilab; Biedron, Sandra [Colorado State U., Fort Collins; Bowring, Daniel [Fermilab; Chase, Brian [Fermilab; Edelen, Jonathan [Fermilab; Milton, Stephen [Colorado State U., Fort Collins; Steimel, Jim [Fermilab
As part of the PIP-II Injector Experiment (PXIE) accel-erator, a four-vane radio frequency quadrupole (RFQ) accelerates a 30-keV, 1-mA to 10-mA H' ion beam to 2.1 MeV. It is designed to operate at a frequency of 162.5 MHz with arbitrary duty factor, including continuous wave (CW) mode. The resonant frequency is controlled solely by a water-cooling system. We present an initial neural network model of the RFQ frequency response to changes in the cooling system and RF power conditions during pulsed operation. A neural network model will be used in a model predictive control scheme to regulate the resonant frequency of the RFQ.
Full Text Available Infants' sensitivity to ostensive signals, such as direct eye contact and infant-directed speech, is well documented in the literature. We investigated how infants interpret such signals by assessing common processing mechanisms devoted to them and by measuring neural responses to their compounds. In Experiment 1, we found that ostensive signals from different modalities display overlapping electrophysiological activity in 5-month-old infants, suggesting that these signals share neural processing mechanisms independently of their modality. In Experiment 2, we found that the activation to ostensive signals from different modalities is not additive to each other, but rather reflects the presence of ostension in either stimulus stream. These data support the thesis that ostensive signals obligatorily indicate to young infants that communication is directed to them.
Tan, Sze-Yen; Peh, Elaine; Lau, Evelyn; Marangoni, Alejandro G; Henry, Christiani Jeyakumar
Background: Dietary fats elicit various physiological responses, with the physical form of fat reported to alter fat digestion and absorption.Objectives: The primary aims were to compare the effects of dietary fat in 2 physical forms (liquid and oleogel) and 2 degrees of saturation (saturated and polyunsaturated) on postprandial energy expenditure (EE) and substrate oxidation, glycemia, and appetite.Methods: The study was a randomized, controlled crossover trial. Sixteen normal-weight, healthy Chinese men completed the study [mean ± SD age: 28 ± 6 y; body mass index (in kg/m(2)): 22.9 ± 3.1]. After an overnight fast, participants had their body weight measured and entered an indirect whole-room calorimeter (WRC). After baseline measurements, participants consumed orange juice and rice porridge alone (control), with 22.25 g coconut oil or sunflower oil or with 25 g coconut oleogel or sunflower oleogel in random order with a 5-d washout period between treatments. EE, substrate oxidation, capillary blood glucose, and appetite were measured over 195 min in a WRC. Participants completed a meal challenge to assess appetite. Test meals effects were compared by using repeated-measures ANOVA.Results: Fat saturation did not affect all study outcomes significantly. When data were pooled based on the physical form of dietary fat, EE did not differ. However, significantly higher carbohydrate oxidation (P = 0.03) and a trend of lower fat oxidation (P = 0.07) were found after the liquid oil than after the oleogel or control treatments. Postprandial capillary glucose was also significantly lower after the liquid oil than after the oleogel or control treatments (P fats.Conclusions: The saturation of dietary fat did not affect postprandial glucose, EE, substrate oxidation, or appetite. However, oleogel prevented the glycemic-lowering and fat-oxidation effects induced by liquid oil in Chinese men. Future work on oleogel should focus on cardiometabolic risk factors. This study was
Carrus, Elisa; Pearce, Marcus T; Bhattacharya, Joydeep
Current behavioural and electrophysiological evidence suggests that music and language syntactic processing depends on at least partly shared neural resources. Existing studies using a simultaneous presentation paradigm are limited to the effects of violations of harmonic structure in Western tonal music on processing of single syntactic or semantic violations. Because melody is a universal property of music as it is emphasized also by non-western musical traditions, it is fundamental to investigate interactions between melodic expectation and language processing. The present study investigates the effect of melodically unexpected notes on neural responses elicited by linguistic violations. Sentences with or without a violation in the last word were presented on screen simultaneously with melodies whose last note had a high- or low-probability, as estimated by a computational model of melodic expectation. Violations in language could be syntactic, semantic or combined. The electroencephalogram (EEG) was recorded while participants occasionally responded to language stimuli. Confirming previous studies, low-probability notes elicited an enhanced N1 compared to high-probability notes. Further, syntactic violations elicited a left anterior negativity (LAN) and P600 component, and semantic violations elicited an N400. Combined violations elicited components which resembled neural responses to both syntactic and semantic incongruities. The LAN amplitude was decreased when language syntactic violations were presented simultaneously with low-probability notes compared to when they were presented with high-probability notes. The N400 was not influenced by the note-probability. These findings show support for the neural interaction between language and music processing, including novel evidence for melodic processing which can be incorporated in a computational framework of melodic expectation. Copyright © 2012 Elsevier Ltd. All rights reserved.
Liu, Taosheng; Cable, Dylan; Gardner, Justin L
Channel-encoding models offer the ability to bridge different scales of neuronal measurement by interpreting population responses, typically measured with BOLD imaging in humans, as linear sums of groups of neurons (channels) tuned for visual stimulus properties. Inverting these models to form predicted channel responses from population measurements in humans seemingly offers the potential to infer neuronal tuning properties. Here, we test the ability to make inferences about neural tuning width from inverted encoding models. We examined contrast invariance of orientation selectivity in human V1 (both sexes) and found that inverting the encoding model resulted in channel response functions that became broader with lower contrast, thus apparently violating contrast invariance. Simulations showed that this broadening could be explained by contrast-invariant single-unit tuning with the measured decrease in response amplitude at lower contrast. The decrease in response lowers the signal-to-noise ratio of population responses that results in poorer population representation of orientation. Simulations further showed that increasing signal to noise makes channel response functions less sensitive to underlying neural tuning width, and in the limit of zero noise will reconstruct the channel function assumed by the model regardless of the bandwidth of single units. We conclude that our data are consistent with contrast-invariant orientation tuning in human V1. More generally, our results demonstrate that population selectivity measures obtained by encoding models can deviate substantially from the behavior of single units because they conflate neural tuning width and noise and are therefore better used to estimate the uncertainty of decoded stimulus properties.SIGNIFICANCE STATEMENT It is widely recognized that perceptual experience arises from large populations of neurons, rather than a few single units. Yet, much theory and experiment have examined links between single
Luu, N Thin; Glen, Katie E; Egginton, Stuart; Rainger, G Ed; Nash, Gerard B
Conditioning of endothelial cells by shear stress suppresses their response to inflammatory cytokines. We questioned whether signalling through different integrin-matrix interactions, previously associated with the pathogenic effects of disturbed flow, supported the anti-inflammatory action of steady shear. Primary human endothelial cells were cultured on different substrates and exposed to shear stress (2.0Pa) for varying periods before stimulation with tumour necrosis factor-α (TNF). Shear-conditioning inhibited cytokine-induced recruitment of flowing neutrophils. However, the effect was similar for culture on collagen, laminin or fibronectin, even when seeding was reduced to 2 hours, and shear to 3 hours before TNF treatment (to minimise deposition of endothelial matrix). Nevertheless, in short- or longer-term cultures, reduction in expression of β(1)-integrin (but not β(3)-integrin) using siRNA essentially ablated the effect of shear-conditioning on neutrophil recruitment. Studies of focal adhesion kinase (FAK) phosphorylation, siRNA against FAK and a FAK-inhibitor (PF573228) indicated that FAK activity was an essential component downstream of β(1)-integrin. In addition, MAP-kinase p38 was phosphorylated downstream of FAK and also required for functional modification. Mechanotransduction through β(1)-integrins, FAK and p38 is required for anti-inflammatory effects of steady shear stress. Separation of the pathways which underlie pathological versus protective responses of different patterns of flow is required to enable therapeutic modification or mimicry, respectively.
Genchi, Giada Graziana; Ciofani, Gianni; Polini, Alessandro; Liakos, Ioannis; Iandolo, Donata; Athanassiou, Athanassia; Pisignano, Dario; Mattoli, Virgilio; Menciassi, Arianna
In the last decade, the importance of topographic properties of extracellular environments has been shown to be essential to addressing cell response, especially when replacing damaged tissues with functional constructs obtained in vitro. In the current study, densely packed sub-micron poly(3-hydroxybutyrate) (PHB) fibres were electrospun with random and parallel orientations. PC12 pheochromocytoma cells that mimic central dopaminergic neurons and represent a model for neuronal differentiation were cultured on collagen-coated fibres to evaluate cell response dependence on substrate topography. Cell adhesion, viability and proliferation, as well as dopamine production were evaluated after three days since seeding. Cell differentiation was examined in terms of neurite number, orientation and length 6 days after administration of nerve growth factor (NGF). Results showed that proliferating PC12 cells secreted a higher quantity of dopamine on fibres with respect to control cultures and as a result, a possible use of PHB fibres was considered for cell transplantation in the central nervous system when local production of dopamine is impaired. Differentiated PC12 cells were characterized by highly aligned and longer neurites on parallel PHB fibres with respect to random fibres, thereby demonstrating the suitability of parallel PHB fibres for further studies in peripheral nervous system regeneration. Copyright © 2012 John Wiley & Sons, Ltd.
Khadempour, Lily [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Zoology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA; Burnum-Johnson, Kristin E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Baker, Erin S. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Nicora, Carrie D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Webb-Robertson, Bobbie-Jo M. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; White, Richard A. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Monroe, Matthew E. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Huang, Eric L. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Smith, Richard D. [Biological Sciences Division, Pacific Northwest National Laboratory, Richland WA 99352 USA; Currie, Cameron R. [Department of Bacteriology, University of Wisconsin-Madison, Madison WI 53706 USA; Department of Energy Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison WI 53706 USA
Herbivores use symbiotic microbes to help gain access to energy and nutrients from plant material. Leaf-cutter ants are a paradigmatic example, having tremendous impact on their ecosystems as dominant generalist herbivores through cultivation of a fungus, Leucoagaricus gongylophorous. Here we examine how this mutualism could facilitate the flexible substrate incorporation of the ants by providing leaf-cutter ant subcolonies four substrate types: leaves, flowers, oats, and a mixture of all three. Through metaproteomic analysis of the fungus gardens, we were able to identify and quantify 1766 different fungal proteins, including 161 biomass-degrading enzymes. This analysis revealed that fungal protein profiles were significantly different between subcolonies fed different substrates with the highest abundance of cellulolytic enzymes observed in the leaf and flower treatments. When the fungus garden is provided with leaves and flowers, which contain the majority of their energy in recalcitrant material, it increases its production of proteins that break down cellulose: endoglucanases, exoglucanase and β-glucosidase. Further, the complete metaproteomes for the leaves and flowers treatments were very similar, the mixed treatment closely resembled the treatment with oats alone. This suggests that when provided a mixture of substrates, the fungus garden preferentially produces enzymes necessary for breakdown of simpler, more digestible substrates. This flexible, substrate-specific response of the fungal cultivar allows the leaf-cutter ants to derive energy from a wide range of substrates, which may contribute to their ability to be dominant generalist herbivores.
Full Text Available Most previous studies investigating the neural correlates of reading have presented text using serial visual presentation (SVP, which may not fully reflect the underlying processes of natural reading. In the present study, eye movements and BOLD data were collected while subjects either read normal paragraphs naturally or moved their eyes through paragraphs of pseudo-text (pronounceable pseudowords or consonant letter strings in two pseudo-reading conditions. Eye movement data established that subjects were reading and scanning the stimuli normally. A conjunction fMRI analysis across natural- and pseudo-reading showed that a common eye-movement network including frontal eye fields, supplementary eye fields, and intraparietal sulci was activated, consistent with previous studies using simpler eye movement tasks. In addition, natural reading versus pseudo-reading showed different patterns of brain activation: normal reading produced activation in a well-established language network that included superior temporal gyrus/sulcus, middle temporal gyrus, angular gyrus, inferior frontal gyrus, and middle frontal gyrus, whereas pseudo-reading produced activation in an attentional network that included anterior/posterior cingulate and parietal cortex. These results are consistent with results found in previous single-saccade eye movement tasks and SVP reading studies, suggesting that component processes of eye-movement control and language processing observed in past fMRI research generalize to natural reading. The results also suggest that combining eyetracking and fMRI is a suitable method for investigating the component processes of natural reading in fMRI research.
Choi, Wonil; Desai, Rutvik H; Henderson, John M
Most previous studies investigating the neural correlates of reading have presented text using serial visual presentation (SVP), which may not fully reflect the underlying processes of natural reading. In the present study, eye movements and BOLD data were collected while subjects either read normal paragraphs naturally or moved their eyes through "paragraphs" of pseudo-text (pronounceable pseudowords or consonant letter strings) in two pseudo-reading conditions. Eye movement data established that subjects were reading and scanning the stimuli normally. A conjunction fMRI analysis across natural- and pseudo-reading showed that a common eye-movement network including frontal eye fields (FEF), supplementary eye fields (SEF), and intraparietal sulci was activated, consistent with previous studies using simpler eye movement tasks. In addition, natural reading versus pseudo-reading showed different patterns of brain activation: normal reading produced activation in a well-established language network that included superior temporal gyrus/sulcus, middle temporal gyrus (MTG), angular gyrus (AG), inferior frontal gyrus, and middle frontal gyrus, whereas pseudo-reading produced activation in an attentional network that included anterior/posterior cingulate and parietal cortex. These results are consistent with results found in previous single-saccade eye movement tasks and SVP reading studies, suggesting that component processes of eye-movement control and language processing observed in past fMRI research generalize to natural reading. The results also suggest that combining eyetracking and fMRI is a suitable method for investigating the component processes of natural reading in fMRI research.
Quinti, Luisa; Dayalan Naidu, Sharadha; Träger, Ulrike; Chen, Xiqun; Kegel-Gleason, Kimberly; Llères, David; Connolly, Colúm; Chopra, Vanita; Low, Cho; Moniot, Sébastien; Sapp, Ellen; Tousley, Adelaide R.; Vodicka, Petr; Van Kanegan, Michael J.; Kaltenbach, Linda S.; Crawford, Lisa A.; Fuszard, Matthew; Higgins, Maureen; Miller, James R. C.; Farmer, Ruth E.; Potluri, Vijay; Samajdar, Susanta; Meisel, Lisa; Zhang, Ningzhe; Snyder, Andrew; Stein, Ross; Hersch, Steven M.; Ellerby, Lisa M.; Schwarzschild, Michael A.; Steegborn, Clemens; Leavitt, Blair R.; Degterev, Alexei; Tabrizi, Sarah J.; Lo, Donald C.; DiFiglia, Marian; Thompson, Leslie M.; Dinkova-Kostova, Albena T.; Kazantsev, Aleksey G.
The activity of the transcription factor nuclear factor-erythroid 2 p45-derived factor 2 (NRF2) is orchestrated and amplified through enhanced transcription of antioxidant and antiinflammatory target genes. The present study has characterized a triazole-containing inducer of NRF2 and elucidated the mechanism by which this molecule activates NRF2 signaling. In a highly selective manner, the compound covalently modifies a critical stress-sensor cysteine (C151) of the E3 ligase substrate adaptor protein Kelch-like ECH-associated protein 1 (KEAP1), the primary negative regulator of NRF2. We further used this inducer to probe the functional consequences of selective activation of NRF2 signaling in Huntington's disease (HD) mouse and human model systems. Surprisingly, we discovered a muted NRF2 activation response in human HD neural stem cells, which was restored by genetic correction of the disease-causing mutation. In contrast, selective activation of NRF2 signaling potently repressed the release of the proinflammatory cytokine IL-6 in primary mouse HD and WT microglia and astrocytes. Moreover, in primary monocytes from HD patients and healthy subjects, NRF2 induction repressed expression of the proinflammatory cytokines IL-1, IL-6, IL-8, and TNFα. Together, our results demonstrate a multifaceted protective potential of NRF2 signaling in key cell types relevant to HD pathology. PMID:28533375
Kam, Julia W Y; Boyd, Lara A; Hsu, Chun L; Liu-Ambrose, Teresa; Handy, Todd C; Lim, Howard J; Hayden, Sherri; Campbell, Kristin L
While impairments in executive functions have been reported in breast cancer survivors (BCS) who have undergone adjuvant chemotherapy, only a limited number of functional neuroimaging studies have associated alterations in cerebral activity with executive functions deficits in BCS. Using fMRI, the current study assessed the neural basis underlying a specific facet of executive function, namely prepotent response inhibition. 12 BCS who self-reported cognitive problems up to 3 years following cancer treatment and 12 female healthy comparisons (HC) performed the Stroop task. We compared their neural activation between the incongruent and neutral experimental conditions. Relative to the HC group, BCS showed lower blood-oxygen level dependent signal in several frontal regions, including the anterior cingulate cortex, a region critical for response inhibition. Our data indicates reduced neural activation in BCS during a prepotent response inhibition task, providing support for the prevailing notion of neural alterations observed in BCS treated with chemotherapy.
Kim, Junkyeong; Lee, Chaggil; Park, Seunghee
Concrete is one of the most common materials used to construct a variety of civil infrastructures. However, since concrete might be susceptible to brittle fracture, it is essential to confirm the strength of concrete at the early-age stage of the curing process to prevent unexpected collapse. To address this issue, this study proposes a novel method to estimate the early-age strength of concrete, by integrating an artificial neural network algorithm with a dynamic response measurement of the concrete material. The dynamic response signals of the concrete, including both electromechanical impedances and guided ultrasonic waves, are obtained from an embedded piezoelectric sensor module. The cross-correlation coefficient of the electromechanical impedance signals and the amplitude of the guided ultrasonic wave signals are selected to quantify the variation in dynamic responses according to the strength of the concrete. Furthermore, an artificial neural network algorithm is used to verify a relationship between the variation in dynamic response signals and concrete strength. The results of an experimental study confirm that the proposed approach can be effectively applied to estimate the strength of concrete material from the early-age stage of the curing process.
Dedovic, Katarina; Duchesne, Annie; Engert, Veronika; Lue, Sonja Damika; Andrews, Julie; Efanov, Simona I; Beaudry, Thomas; Pruessner, Jens C
This study aimed to identify vulnerability patterns in psychological, physiological and neural responses to mild psychosocial challenge in a population that is at a direct risk of developing depression, but who has not as yet succumbed to the full clinical syndrome. A group of healthy and a group of subclinically depressed participants underwent a modified Montreal Imaging Stress task (MIST), a mild neuroimaging psychosocial task and completed state self-esteem and mood measures. Cortisol levels were assessed throughout the session. All participants showed a decrease in performance self-esteem levels following the MIST. Yet, the decline in performance self-esteem levels was associated with increased levels of anxiety and confusion in the healthy group, but increased levels of depression in the subclinical group, following the MIST. The subclinical group showed overall lower cortisol levels compared with the healthy group. The degree of change in activity in the subgenual anterior cingulate cortex in response to negative evaluation was associated with increased levels of depression in the whole sample. Findings suggest that even in response to a mild psychosocial challenge, those individuals vulnerable to depression already show important maladaptive response patterns at psychological and neural levels. The findings point to important targets for future interventions. © The Author (2013). Published by Oxford University Press. For Permissions, please email: firstname.lastname@example.org.
Guyer, Amanda E; Jarcho, Johanna M; Pérez-Edgar, Koraly; Degnan, Kathryn A; Pine, Daniel S; Fox, Nathan A; Nelson, Eric E
Behavioral inhibition (BI) is a temperament characterized by social reticence and withdrawal from unfamiliar or novel contexts and conveys risk for social anxiety disorder. Developmental outcomes associated with this temperament can be influenced by children's caregiving context. The convergence of a child's temperamental disposition and rearing environment is ultimately expressed at both the behavioral and neural levels in emotional and cognitive response patterns to social challenges. The present study used functional neuroimaging to assess the moderating effects of different parenting styles on neural response to peer rejection in two groups of adolescents characterized by their early childhood temperament (M(age) = 17.89 years, N = 39, 17 males, 22 females; 18 with BI; 21 without BI). The moderating effects of authoritarian and authoritative parenting styles were examined in three brain regions linked with social anxiety: ventrolateral prefrontal cortex (vlPFC), striatum, and amygdala. In youth characterized with BI in childhood, but not in those without BI, diminished responses to peer rejection in vlPFC were associated with higher levels of authoritarian parenting. In contrast, all youth showed decreased caudate response to peer rejection at higher levels of authoritative parenting. These findings indicate that BI in early life relates to greater neurobiological sensitivity to variance in parenting styles, particularly harsh parenting, in late adolescence. These results are discussed in relation to biopsychosocial models of development.
Berlin, Heather A; Schulz, Kurt P; Zhang, Sam; Turetzky, Rachel; Rosenthal, David; Goodman, Wayne
Failure to inhibit recurrent anxiety-provoking thoughts is a central symptom of obsessive-compulsive disorder (OCD). Neuroimaging studies suggest inhibitory control and disgust processing abnormalities in patients with OCD. However, the emotional modulation of response inhibition deficits in OCD and their neural correlates remain to be elucidated. For this preliminary study we administered an adapted affective response inhibition paradigm, an emotional go/no-go task, during fMRI to characterize the neural systems underlying disgust-related and fear-related inhibition in nine adults with contamination-type OCD compared to ten matched healthy controls. Participants with OCD had significantly greater anterior insula cortex activation when inhibiting responses to both disgusting (bilateral), and fearful (right-sided) images, compared to healthy controls. They also had increased activation in several frontal, temporal, and parietal regions, but there was no evidence of amygdala activation in OCD or healthy participants and no significant between-group differences in performance on the emotion go/no-go task. The anterior insula appears to play a central role in the emotional modulation of response inhibition in contamination-type OCD to both fearful and disgusting images. The insula may serve as a potential treatment target for contamination-type OCD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Smid, Bouwien E; Ferraz, Maria J; Verhoek, Marri; Mirzaian, Mina; Wisse, Patrick; Overkleeft, Herman S; Hollak, Carla E; Aerts, Johannes M
We retrospectively compared biochemical responses in type 1 Gaucher disease patients to treatment with glycosphingolipid synthesis inhibitors miglustat and eliglustat and ERT. Seventeen GD1 patients were included (n = 6 eliglustat, (two switched from ERT), n = 9 miglustat (seven switchers), n = 4 ERT (median dose 60U/kg/m). Plasma protein markers reflecting disease burden (chitotriosidase, CCL18) and lipids reflecting substrate accumulation (glucosylsphingosine, glucosylceramide) were determined. Also, liver and spleen volumes, hemoglobin, platelets, and fat fraction were measured. In patients naïve to treatment, chitotriosidase, CCL18 and glucosylsphingosine decreased comparably upon eliglustat and ERT treatment, while the response to miglustat was less. After 2 years, median decrease of chitotriosidase was 89% (range 77-98), 88% (78-92) and 37% (29-46) for eliglustat, ERT and miglustat naïve patients respectively; decrease of CCL18 was 73% (63-78), 54% (43-86), and 10% (3-18); decrease of glucosylsphingosine was 86% (78-93), 78% (65-91), 48% (46-50). Plasma glucosylceramide in eliglustat treated patients (n = 4) reached values below the normal range (n = 20 healthy controls). Biochemical markers decreased or stabilized in switchers from ERT to eliglustat (n = 2), but less in miglustat switchers (n = 7). Clinical parameters responded comparably upon eliglustat and ERT treatment. Our explorative study provides evidence that biochemical markers respond comparably in patients receiving eliglustat treatment and ERT, while the corresponding response to miglustat treatment is less.
Chervyakov, Alexander V; Sinitsyn, Dmitry O; Piradov, Michael A
HIGHLIGHTS We suggest classifying variability of neuronal responses as follows: false (associated with a lack of knowledge about the influential factors), "genuine harmful" (noise), "genuine neutral" (synonyms, repeats), and "genuine useful" (the basis of neuroplasticity and learning).The genuine neutral variability is considered in terms of the phenomenon of degeneracy.Of particular importance is the genuine useful variability that is considered as a potential basis for neuroplasticity and learning. This type of variability is considered in terms of the neural Darwinism theory. In many cases, neural signals detected under the same external experimental conditions significantly change from trial to trial. The variability phenomenon, which complicates extraction of reproducible results and is ignored in many studies by averaging, has attracted attention of researchers in recent years. In this paper, we classify possible types of variability based on its functional significance and describe features of each type. We describe the key adaptive significance of variability at the neural network level and the degeneracy phenomenon that may be important for learning processes in connection with the principle of neuronal group selection.
de Water, Erik; Mies, Gabry W; Ma, Ili; Mennes, Maarten; Cillessen, Antonius H N; Scheres, Anouk
We examined whether adolescents' neural responses to social exclusion and inclusion are influenced by their own popularity and acceptance and by the popularity of their excluders and includers. Accepted adolescents are highly prosocial. In contrast, popular adolescents, who are central and influential, show prosocial as well as antisocial behaviors, such as peer exclusion. Fifty-two 12-16 year-old adolescents underwent an functional magnetic resonance imaging (fMRI) scan while playing the ball-tossing game Cyberball in which they received or did not receive the ball from other virtual players. The other virtual players were described as either highly popular or average in popularity. Participants' own popularity and acceptance were assessed with peer nominations at school (n = 31). Participants' acceptance was positively correlated with activity of the dorsal anterior cingulate cortex (ACC) during exclusion. Participants' popularity was positively associated with ventral striatum and medial prefrontal cortex activity during exclusion, but only when the excluders were popular virtual players. Participants showed increased rostral ACC activation to inclusion by players who were average in popularity. These findings indicate that peer status plays an important role in adolescents' neural processing of social exclusion and inclusion. Moreover, these findings underscore that popularity and acceptance are distinct types of high peer status in adolescence, with not only distinct behavioral correlates, but also distinct neural correlates. Copyright © 2017 Elsevier Ltd. All rights reserved.
Background Social anxiety disorder (SAD) is thought to involve deficits in emotion regulation, and more specifically, deficits in cognitive reappraisal. However, evidence for such deficits is mixed. Methods Using functional magnetic resonance imaging (fMRI) of blood oxygen-level dependent (BOLD) signal, we examined reappraisal-related behavioral and neural responses in 27 participants with generalized SAD and 27 healthy controls (HC) during three socio-emotional tasks: (1) looming harsh faces (Faces); (2) videotaped actors delivering social criticism (Criticism); and (3) written autobiographical negative self-beliefs (Beliefs). Results Behaviorally, compared to HC, participants with SAD had lesser reappraisal-related reduction in negative emotion in the Beliefs task. Neurally, compared to HC, participants with SAD had lesser BOLD responses in reappraisal-related brain regions when reappraising faces, in visual and attention related regions when reappraising criticism, and in the left superior temporal gyrus when reappraising beliefs. Examination of the temporal dynamics of BOLD responses revealed late reappraisal-related increased responses in HC, compared to SAD. In addition, the dorsomedial prefrontal cortex (DMPFC), which showed reappraisal-related increased activity in both groups, had similar temporal dynamics in SAD and HC during the Faces and Criticism tasks, but greater late response increases in HC, compared to SAD, during the Beliefs task. Reappraisal-related greater late DMPFC responses were associated with greater percent reduction in negative emotion ratings in SAD patients. Conclusions These results suggest a dysfunction of cognitive reappraisal in SAD patients, with overall reduced late brain responses in prefrontal regions, particularly when reappraising faces. Decreased late activity in the DMPFC might be associated with deficient reappraisal and greater negative reactivity. Trial registration ClinicalTrials.gov identifier: NCT00380731 PMID
Clinard, Christopher G; Hodgson, Sarah L; Scherer, Mary Ellen
The binaural masking level difference (BMLD) is an auditory phenomenon where binaural tone-in-noise detection is improved when the phase of either signal or noise is inverted in one of the ears (SπNo or SoNπ, respectively), relative to detection when signal and noise are in identical phase at each ear (SoNo). Processing related to BMLDs and interaural time differences has been confirmed in the auditory brainstem of non-human mammals; in the human auditory brainstem, phase-locked neural responses elicited by BMLD stimuli have not been systematically examined across signal-to-noise ratio. Behavioral and physiological testing was performed in three binaural stimulus conditions: SoNo, SπNo, and SoNπ. BMLDs at 500 Hz were obtained from 14 young, normal-hearing adults (ages 21-26). Physiological BMLDs used the frequency-following response (FFR), a scalp-recorded auditory evoked potential dependent on sustained phase-locked neural activity; FFR tone-in-noise detection thresholds were used to calculate physiological BMLDs. FFR BMLDs were significantly smaller (poorer) than behavioral BMLDs, and FFR BMLDs did not reflect a physiological release from masking, on average. Raw FFR amplitude showed substantial reductions in the SπNo condition relative to SoNo and SoNπ conditions, consistent with negative effects of phase summation from left and right ear FFRs. FFR amplitude differences between stimulus conditions (e.g., SoNo amplitude-SπNo amplitude) were significantly predictive of behavioral SπNo BMLDs; individuals with larger amplitude differences had larger (better) behavioral B MLDs and individuals with smaller amplitude differences had smaller (poorer) behavioral B MLDs. These data indicate a role for sustained phase-locked neural activity in BMLDs of humans and are the first to show predictive relationships between behavioral BMLDs and human brainstem responses.
Shin, Na Young; Park, Hye Yoon; Jung, Wi Hoon; Park, Jin Woo; Yun, Je-Yeon; Jang, Joon Hwan; Kim, Sung Nyun; Han, Hyun Jung; Kim, So-Yeon; Kang, Do-Hyung; Kwon, Jun Soo
Impaired facial emotion recognition is a core deficit in schizophrenia. Oxytocin has been shown to improve social perception in patients with schizophrenia; however, the effect of oxytocin on the neural activity underlying facial emotion recognition has not been investigated. This study was aimed to assess the effect of a single dose of intranasal oxytocin on brain activity in patients with schizophrenia using an implicit facial emotion-recognition paradigm. Sixteen male patients with schizophrenia and 16 age-matched healthy male control subjects participated in a randomized, double-blind, placebo-controlled crossover trial at Seoul National University Hospital. Delivery of a single dose of 40 IU intranasal oxytocin and the placebo was separated by 1 week. Drug conditions were compared by performing a region of interest (ROI) analysis of the bilateral amygdala on responses to the emotion recognition test. It was found that nasal spray decreased amygdala activity for fearful emotion and increased activity for happy faces. Further, oxytocin elicited differential effects between the patient and control groups. Intranasal oxytocin attenuated amygdala activity for emotional faces in patients with schizophrenia, whereas intranasal oxytocin significantly increased amygdala activity in healthy controls. Oxytocin-induced BOLD signal changes in amygdala in response to happy faces was related to attachment style in the control group. Our result provides new evidence of a modulatory effect of oxytocin on neural response to emotional faces for patients with schizophrenia. Future studies are needed to investigate the effectiveness of long-term treatment with intranasal oxytocin on neural activity in patients with schizophrenia.
Miskowiak, K W; Glerup, L; Vestbo, C
healthy, never-depressed monozygotic (MZ) twins with a co-twin history of depression (high risk group: n = 13) or without co-twin history of depression (low-risk group: n = 17) were enrolled in a functional magnetic resonance imaging (fMRI) study. During fMRI, participants viewed fearful and happy faces...... while performing a gender discrimination task. After the scan, they were given a faces dot-probe task, a facial expression recognition task and questionnaires assessing mood, personality traits and coping strategies. RESULTS: High-risk twins showed increased neural response to happy and fearful faces...
Will, G.J.; Van, Lier P.A.; Crone, E.A.; Guroglu, B.
This functional Magnetic Resonance Imaging (fMRI) study examined subjective and neural responses to social exclusion in adolescents (age 12?15) who either had a stable accepted (n?=?27; 14 males) or a chronic rejected (n?=?19; 12 males) status among peers from age 6 to 12. Both groups of adolescents reported similar increases in distress after being excluded in a virtual ball-tossing game (Cyberball), but adolescents with a history of chronic peer rejection showed higher activity in brain reg...
Full Text Available Transcranial direct current stimulation (tDCS is a non-invasive technique recently employed in disorders of consciousness, and determining a transitory recovery of signs of consciousness in almost half of minimally conscious state (MCS patients. Although the rising evidences about its possible role in the treatment of many neurological and psychiatric conditions, no evidences exist about brain functional connectivity substrates underlying tDCS response. We retrospectively evaluated resting state functional Magnetic Resonance Imaging (fMRI of 16 sub-acute and chronic MCS patients (6 tDCS responders who successively received a single left dorsolateral prefrontal cortex (DLPFC tDCS in a double-blind randomized cross-over trial. A seed-based approach for regions of left extrinsic control network and default-mode network was performed.TDCS responders showed an increased left intra-network connectivity for regions co-activated with left DLPFC, and significantly with left inferior frontal gyrus. Non-responders MCS patients showed an increased connectivity between left DLPFC and midline cortical structures, including anterior cingulate cortex and precuneus.Our findings suggest that a prior high connectivity with regions belonging to extrinsic control network can facilitate transitory recovery of consciousness in a subgroup of MCS patients that underwent tDCS treatment. Therefore, resting state-fMRI could be very valuable in detecting the neuronal conditions necessary for tDCS to improve behavior in MCS.
Baseler, Heidi A; Harris, Richard J; Young, Andrew W; Andrews, Timothy J
Neural models of human face perception propose parallel pathways. One pathway (including posterior superior temporal sulcus, pSTS) is responsible for processing changeable aspects of faces such as gaze and expression, and the other pathway (including the fusiform face area, FFA) is responsible for relatively invariant aspects such as identity. However, to be socially meaningful, changes in expression and gaze must be tracked across an individual face. Our aim was to investigate how this is achieved. Using functional magnetic resonance imaging, we found a region in pSTS that responded more to sequences of faces varying in gaze and expression in which the identity was constant compared with sequences in which the identity varied. To determine whether this preferential response to same identity faces was due to the processing of identity in the pSTS or was a result of interactions between pSTS and other regions thought to code face identity, we measured the functional connectivity between face-selective regions. We found increased functional connectivity between the pSTS and FFA when participants viewed same identity faces compared with different identity faces. Together, these results suggest that distinct neural pathways involved in expression and identity interact to process the changeable features of the face in a socially meaningful way.
Krizman, Jennifer; Skoe, Erika; Marian, Viorica; Kraus, Nina
Auditory processing is presumed to be influenced by cognitive processes - including attentional control - in a top-down manner. In bilinguals, activation of both languages during daily communication hones inhibitory skills, which subsequently bolster attentional control. We hypothesize that the heightened attentional demands of bilingual communication strengthens connections between cognitive (i.e., attentional control) and auditory processing, leading to greater across-trial consistency in the auditory evoked response (i.e., neural consistency) in bilinguals. To assess this, we collected passively-elicited auditory evoked responses to the syllable [da] in adolescent Spanish-English bilinguals and English monolinguals and separately obtained measures of attentional control and language ability. Bilinguals demonstrated enhanced attentional control and more consistent brainstem and cortical responses. In bilinguals, but not monolinguals, brainstem consistency tracked with language proficiency and attentional control. We interpret these enhancements in neural consistency as the outcome of strengthened attentional control that emerged from experience communicating in two languages. Copyright © 2013 Elsevier Inc. All rights reserved.
Garrido, Marta I; Rowe, Elise G; Halász, Veronika; Mattingley, Jason B
Predictive coding posits that the human brain continually monitors the environment for regularities and detects inconsistencies. It is unclear, however, what effect attention has on expectation processes, as there have been relatively few studies and the results of these have yielded contradictory findings. Here, we employed Bayesian model comparison to adjudicate between 2 alternative computational models. The "Opposition" model states that attention boosts neural responses equally to predicted and unpredicted stimuli, whereas the "Interaction" model assumes that attentional boosting of neural signals depends on the level of predictability. We designed a novel, audiospatial attention task that orthogonally manipulated attention and prediction by playing oddball sequences in either the attended or unattended ear. We observed sensory prediction error responses, with electroencephalography, across all attentional manipulations. Crucially, posterior probability maps revealed that, overall, the Opposition model better explained scalp and source data, suggesting that attention boosts responses to predicted and unpredicted stimuli equally. Furthermore, Dynamic Causal Modeling showed that these Opposition effects were expressed in plastic changes within the mismatch negativity network. Our findings provide empirical evidence for a computational model of the opposing interplay of attention and expectation in the brain. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: email@example.com.
Orfanidou, Eleni; Marslen-Wilson, William D; Davis, Matthew H
An important method for studying how the brain processes familiar stimuli is to present the same item on more than one occasion and measure how responses change with repetition. Here we use repetition priming in a sparse functional magnetic resonance imaging (fMRI) study to probe the neuroanatomical basis of spoken word recognition and the representations of spoken words that mediate repetition priming effects. Participants made lexical decisions to words and pseudowords spoken by a male or female voice that were presented twice, with half of the repetitions in a different voice. Behavioral and neural priming was observed for both words and pseudowords and was not affected by voice changes. The fMRI data revealed an elevated response to words compared to pseudowords in both posterior and anterior temporal regions, suggesting that both contribute to word recognition. Both reduced and elevated activation for second presentations (repetition suppression and enhancement) were observed in frontal and posterior regions. Correlations between behavioral priming and neural repetition suppression were observed in frontal regions, suggesting that repetition priming effects for spoken words reflect changes within systems involved in generating behavioral responses. Based on the current results, these processes are sufficiently abstract to display priming despite changes in the physical form of the stimulus and operate equivalently for words and pseudowords.
Harriet A Allen
response to parental teaching and modelling of behaviour. Parental restrictive feeding and parental teaching and modelling affected neural responses to food cues in different ways, depending on motivations and diagnoses, illustrating a social influence on neural responses to food cues.
Allen, Harriet A; Chambers, Alison; Blissett, Jacqueline; Chechlacz, Magdalena; Barrett, Timothy; Higgs, Suzanne; Nouwen, Arie
parental teaching and modelling of behaviour. Parental restrictive feeding and parental teaching and modelling affected neural responses to food cues in different ways, depending on motivations and diagnoses, illustrating a social influence on neural responses to food cues.
Swain, James E
Interacting parenting thoughts and behaviors critically shape human infants' current and future behavior. Indeed, the parent-infant relationship provides infants with their first social environment, forming templates for what they can expect from others and how best to interact with them. This paper focuses on the functional magnetic resonance imaging (fMRI) experiments relevant to the study of the brain-basis of parenting. First there is a brief introduction to techniques and a selective review of functional neuroimaging studies that examine fMRI responses to infant stimuli: baby sounds or visuals. Next, there is a sample single-subject set of brain imaging data of brain response to own-baby-cry. Finally, there is a proposed model of how infant stimuli activate parent brain circuits, including sensory analysis brain regions, as well as corticolimbic circuits that regulate motivation, reward, and learning about their infants, and ultimately organize parenting impulses, thoughts, and emotions into coordinated behaviors. It is argued that an integrated understanding of the brain basis of parenting has profound implications for understanding long-term parent and infant mental health risk and resilience.
Robert J Martinez
Full Text Available BACKGROUND: Radionuclide- and heavy metal-contaminated subsurface sediments remain a legacy of Cold War nuclear weapons research and recent nuclear power plant failures. Within such contaminated sediments, remediation activities are necessary to mitigate groundwater contamination. A promising approach makes use of extant microbial communities capable of hydrolyzing organophosphate substrates to promote mineralization of soluble contaminants within deep subsurface environments. METHODOLOGY/PRINCIPAL FINDINGS: Uranium-contaminated sediments from the U.S. Department of Energy Oak Ridge Field Research Center (ORFRC Area 2 site were used in slurry experiments to identify microbial communities involved in hydrolysis of 10 mM organophosphate amendments [i.e., glycerol-2-phosphate (G2P or glycerol-3-phosphate (G3P] in synthetic groundwater at pH 5.5 and pH 6.8. Following 36 day (G2P and 20 day (G3P amended treatments, maximum phosphate (PO4(3- concentrations of 4.8 mM and 8.9 mM were measured, respectively. Use of the PhyloChip 16S rRNA microarray identified 2,120 archaeal and bacterial taxa representing 46 phyla, 66 classes, 110 orders, and 186 families among all treatments. Measures of archaeal and bacterial richness were lowest under G2P (pH 5.5 treatments and greatest with G3P (pH 6.8 treatments. Members of the phyla Crenarchaeota, Euryarchaeota, Bacteroidetes, and Proteobacteria demonstrated the greatest enrichment in response to organophosphate amendments and the OTUs that increased in relative abundance by 2-fold or greater accounted for 9%-50% and 3%-17% of total detected Archaea and Bacteria, respectively. CONCLUSIONS/SIGNIFICANCE: This work provided a characterization of the distinct ORFRC subsurface microbial communities that contributed to increased concentrations of extracellular phosphate via hydrolysis of organophosphate substrate amendments. Within subsurface environments that are not ideal for reductive precipitation of uranium
Leeuw, de J.A.; Ekkel, E.D.
The effects of feeding level (unrestricted, UR and restricted, R) and the presence of a foraging substrate (no substrate, NS and substrate, S; wood chips on the floor) on both the behaviour and stress physiological response were studied in a 2 x 2 factorial design. In three batches and two rooms, 96
Mascaro, Jennifer S; Hackett, Patrick D; Rilling, James K
Despite the well-documented importance of paternal caregiving for positive child development, little is known about the neural changes that accompany the transition to fatherhood in humans, or about how changes in hormone levels affect paternal brain function. We compared fathers of children aged 1-2 with non-fathers in terms of hormone levels (oxytocin and testosterone), neural responses to child picture stimuli, and neural responses to visual sexual stimuli. Compared to non-fathers, fathers had significantly higher levels of plasma oxytocin and lower levels of plasma testosterone. In response to child picture stimuli, fathers showed stronger activation than non-fathers within regions important for face emotion processing (caudal middle frontal gyrus [MFG]), mentalizing (temporo-parietal junction [TPJ]) and reward processing (medial orbitofrontal cortex [mOFC]). On the other hand, non-fathers had significantly stronger neural responses to sexually provocative images in regions important for reward and approach-related motivation (dorsal caudate and nucleus accumbens). Testosterone levels were negatively correlated with responses to child stimuli in the MFG. Surprisingly, neither testosterone nor oxytocin levels predicted neural responses to sexual stimuli. Our results suggest that the decline in testosterone that accompanies the transition to fatherhood may be important for augmenting empathy toward children. Copyright © 2014 Elsevier Ltd. All rights reserved.
Josef, Noam; Berenshtein, Igal; Rousseau, Meghan; Scata, Gabriella; Fiorito, Graziano; Shashar, Nadav
Camouflage is common throughout the phylogenetic tree and is largely used to minimize detection by predator or prey. Cephalopods, and in particular Sepia officinalis cuttlefish, are common models for camouflage studies. Predator avoidance behavior is particularly important in this group of soft-bodied animals that lack significant physical defenses. While previous studies have suggested that immobile cephalopods selectively camouflage to objects in their immediate surroundings, the camouflage characteristics of cuttlefish during movement are largely unknown. In a heterogenic environment, the visual background and substrate feature changes quickly as the animal swim across it, wherein substrate patch is a distinctive and high contrast patch of substrate in the animal's trajectory. In the current study, we examine the effect of substrate patch size on cuttlefish camouflage, and specifically the minimal size of an object for eliciting intensity matching response while moving. Our results indicated that substrate patch size has a positive effect on animal's reflectance change, and that the threshold patch size resulting in camouflage response falls between 10 and 19 cm (width). These observations suggest that the animal's length (7.2–12.3 cm mantle length in our case) serves as a possible threshold filter below which objects are considered irrelevant for camouflage, reducing the frequency of reflectance changes—which may lead to detection. Accordingly, we have constructed a computational model capturing the main features of the observed camouflaging behavior, provided for cephalopod camouflage during movement. PMID:28144221
Park, Hyeong-Dong; Bernasconi, Fosco; Bello-Ruiz, Javier; Pfeiffer, Christian; Salomon, Roy; Blanke, Olaf
Recent research has investigated self-consciousness associated with the multisensory processing of bodily signals (e.g., somatosensory, visual, vestibular signals), a notion referred to as bodily self-consciousness, and these studies have shown that the manipulation of bodily inputs induces changes in bodily self-consciousness such as self-identification. Another line of research has highlighted the importance of signals from the inside of the body (e.g., visceral signals) and proposed that neural representations of internal bodily signals underlie self-consciousness, which to date has been based on philosophical inquiry, clinical case studies, and behavioral studies. Here, we investigated the relationship of bodily self-consciousness with the neural processing of internal bodily signals. By combining electrical neuroimaging, analysis of peripheral physiological signals, and virtual reality technology in humans, we show that transient modulations of neural responses to heartbeats in the posterior cingulate cortex covary with changes in bodily self-consciousness induced by the full-body illusion. Additional analyses excluded that measured basic cardiorespiratory parameters or interoceptive sensitivity traits could account for this finding. These neurophysiological data link experimentally the cortical mapping of the internal body to self-consciousness. What are the brain mechanisms of self-consciousness? Prominent views propose that the neural processing associated with signals from the internal organs (such as the heart and the lung) plays a critical role in self-consciousness. Although this hypothesis dates back to influential views in philosophy and psychology (e.g., William James), definitive experimental evidence supporting this idea is lacking despite its recent impact in neuroscience. In the present study, we show that posterior cingulate activities responding to heartbeat signals covary with changes in participants' conscious self-identification with a body
Mitchell, Jere H
During both dynamic (e.g., endurance) and static (e.g., strength) exercise there are exaggerated cardiovascular responses in hypertension. This includes greater increases in blood pressure, heart rate, and efferent sympathetic nerve activity than in normal controls. Two of the known neural factors that contribute to this abnormal cardiovascular response are the exercise pressor reflex (EPR) and functional sympatholysis. The EPR originates in contracting skeletal muscle and reflexly increases sympathetic efferent nerve activity to the heart and blood vessels as well as decreases parasympathetic efferent nerve activity to the heart. These changes in autonomic nerve activity cause an increase in blood pressure, heart rate, left ventricular contractility, and vasoconstriction in the arterial tree. However, arterial vessels in the contracting skeletal muscle have a markedly diminished vasoconstrictor response. The markedly diminished vasoconstriction in contracting skeletal muscle has been termed functional sympatholysis. It has been shown in hypertension that there is an enhanced EPR, including both its mechanoreflex and metaboreflex components, and an impaired functional sympatholysis. These conditions set up a positive feedback or vicious cycle situation that causes a progressively greater decrease in the blood flow to the exercising muscle. Thus these two neural mechanisms contribute significantly to the abnormal cardiovascular response to exercise in hypertension. In addition, exercise training in hypertension decreases the enhanced EPR, including both mechanoreflex and metaboreflex function, and improves the impaired functional sympatholysis. These two changes, caused by exercise training, improve the muscle blood flow to exercising muscle and cause a more normal cardiovascular response to exercise in hypertension. Copyright © 2017 the American Physiological Society.
Sagomonyants, Karen B; Jarman-Smith, Marcus L; Devine, John N; Aronow, Michael S; Gronowicz, Gloria A
on all the different substrates. The varied response reported here at different time points during the study suggests that material formulation (unfilled PEEK or CFR-PEEK), subjection to industrial processing, surface roughness and topography may all influence the cellular response of osteoblasts to PEEK. Thus, differences in human osteoblast responses were found to the various samples of PEEK, but implantable grade PEEK, in general, was comparable in vitro to the bone forming capacity of rough titanium.
Hahn, Tim; Kircher, Tilo; Straube, Benjamin; Wittchen, Hans-Ulrich; Konrad, Carsten; Ströhle, Andreas; Wittmann, André; Pfleiderer, Bettina; Reif, Andreas; Arolt, Volker; Lueken, Ulrike
Although neuroimaging research has made substantial progress in identifying the large-scale neural substrate of anxiety disorders, its value for clinical application lags behind expectations. Machine-learning approaches have predictive potential for individual-patient prognostic purposes and might thus aid translational efforts in psychiatric research. To predict treatment response to cognitive behavioral therapy (CBT) on an individual-patient level based on functional magnetic resonance imaging data in patients with panic disorder with agoraphobia (PD/AG). We included 49 patients free of medication for at least 4 weeks and with a primary diagnosis of PD/AG in a longitudinal study performed at 8 clinical research institutes and outpatient centers across Germany. The functional magnetic resonance imaging study was conducted between July 2007 and March 2010. Twelve CBT sessions conducted 2 times a week focusing on behavioral exposure. Treatment response was defined as exceeding a 50% reduction in Hamilton Anxiety Rating Scale scores. Blood oxygenation level-dependent signal was measured during a differential fear-conditioning task. Regional and whole-brain gaussian process classifiers using a nested leave-one-out cross-validation were used to predict the treatment response from data acquired before CBT. Although no single brain region was predictive of treatment response, integrating regional classifiers based on data from the acquisition and the extinction phases of the fear-conditioning task for the whole brain yielded good predictive performance (accuracy, 82%; sensitivity, 92%; specificity, 72%; P < .001). Data from the acquisition phase enabled 73% correct individual-patient classifications (sensitivity, 80%; specificity, 67%; P < .001), whereas data from the extinction phase led to an accuracy of 74% (sensitivity, 64%; specificity, 83%; P < .001). Conservative reanalyses under consideration of potential confounders yielded nominally lower but comparable
Full Text Available Abstract Background It has yet to be determined whether visual-tactile cross-modal plasticity due to visual deprivation, particularly in the primary visual cortex (V1, is solely due to visual deprivation or if it is a result of long-term tactile training. Here we conducted an fMRI study with normally-sighted participants who had undergone long-term training on the tactile shape discrimination of the two dimensional (2D shapes on Mah-Jong tiles (Mah-Jong experts. Eight Mah-Jong experts and twelve healthy volunteers who were naïve to Mah-Jong performed a tactile shape matching task using Mah-Jong tiles with no visual input. Furthermore, seven out of eight experts performed a tactile shape matching task with unfamiliar 2D Braille characters. Results When participants performed tactile discrimination of Mah-Jong tiles, the left lateral occipital cortex (LO and V1 were activated in the well-trained subjects. In the naïve subjects, the LO was activated but V1 was not activated. Both the LO and V1 of the well-trained subjects were activated during Braille tactile discrimination tasks. Conclusion The activation of V1 in subjects trained in tactile discrimination may represent altered cross-modal responses as a result of long-term training.
Skoe, Erika; Krizman, Jennifer; Kraus, Nina
Despite the prevalence of poverty worldwide, little is known about how early socioeconomic adversity affects auditory brain function. Socioeconomically disadvantaged children are underexposed to linguistically and cognitively stimulating environments and overexposed to environmental toxins, including noise pollution. This kind of sensory impoverishment, we theorize, has extensive repercussions on how the brain processes sound. To characterize how this impoverishment affects auditory brain function, we compared two groups of normal-hearing human adolescents who attended the same schools and who were matched in age, sex, and ethnicity, but differed in their maternal education level, a correlate of socioeconomic status (SES). In addition to lower literacy levels and cognitive abilities, adolescents from lower maternal education backgrounds were found to have noisier neural activity than their classmates, as reflected by greater activity in the absence of auditory stimulation. Additionally, in the lower maternal education group, the neural response to speech was more erratic over repeated stimulation, with lower fidelity to the input signal. These weaker, more variable, and noisier responses are suggestive of an inefficient auditory system. By studying SES within a neuroscientific framework, we have the potential to expand our understanding of how experience molds the brain, in addition to informing intervention research aimed at closing the achievement gap between high-SES and low-SES children.
Bruce, Amanda S; Bruce, Jared M; Black, William R; Lepping, Rebecca J; Henry, Janice M; Cherry, Joseph Bradley C; Martin, Laura E; Papa, Vlad B; Davis, Ann M; Brooks, William M; Savage, Cary R
Branding and advertising have a powerful effect on both familiarity and preference for products, yet no neuroimaging studies have examined neural response to logos in children. Food advertising is particularly pervasive and effective in manipulating choices in children. The purpose of this study was to examine how healthy children's brains respond to common food and other logos. A pilot validation study was first conducted with 32 children to select the most culturally familiar logos, and to match food and non-food logos on valence and intensity. A new sample of 17 healthy weight children were then scanned using functional magnetic resonance imaging. Food logos compared to baseline were associated with increased activation in orbitofrontal cortex and inferior prefrontal cortex. Compared to non-food logos, food logos elicited increased activation in posterior cingulate cortex. Results confirmed that food logos activate some brain regions in children known to be associated with motivation. This marks the first study in children to examine brain responses to culturally familiar logos. Considering the pervasiveness of advertising, research should further investigate how children respond at the neural level to marketing.
Riem, Madelon M E; van IJzendoorn, Marinus H; De Carli, Pietro; Vingerhoets, Ad J J M; Bakermans-Kranenburg, Marian J
The current study examined behavioral and neural responses to infant and adult tears, taking into account childhood experiences with parental love-withdrawal. With functional MRI (fMRI), we measured neural reactivity to pictures of infants and adults with and without tears on their faces in nulliparous women with varying childhood experiences of maternal use of love withdrawal. Behavioral responses to infant and adult tears were measured with an approach-avoidance task. We found that individuals with experiences of love withdrawal showed less amygdala and insula reactivity to adult tears, but love withdrawal did not affect amygdala and insula reactivity to infant tears. During the approach-avoidance task, individuals responded faster to adult tears in the approach condition compared with the avoidance condition, indicating that adult tears facilitate approach behavior. Individuals responded faster to infant tears than to adult tears, regardless of approach or avoidance condition. Our findings suggest that infant tears are highly salient and may, therefore, overrule the effects of contextual and personal characteristics that influence the perception of adult crying. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Gentili, Claudio; Cristea, Ioana Alina; Angstadt, Mike; Klumpp, Heide; Tozzi, Leonardo; Phan, K Luan; Pietrini, Pietro
Patients with social anxiety disorder (SAD) experience anxiety and avoidance in face-to-face interactions. We performed a meta-analysis of functional magnetic resonance imaging (fMRI) studies in SAD to provide a comprehensive understanding of the neural underpinnings of face perception in this disorder. To this purpose, we adopted an innovative approach, asking authors for unpublished data. This is a common procedure for behavioral meta-analyses, which, however has never been used in neuroimaging studies. We searched Pubmed with the key words "Social Anxiety AND faces" and "Social Phobia AND faces." Then, we selected those fMRI studies for which we were able to obtain data for the comparison between SAD and healthy controls (HC) in a face perception task, either from the published papers or from the authors themselves. In this way, we obtained 23 studies (totaling 449 SAD and 424 HC individuals). We identified significant clusters in which faces evoked a higher response in SAD in bilateral amygdala, globus pallidus, superior temporal sulcus, visual cortex, and prefrontal cortex. We also found a higher activity for HC in the lingual gyrus and in the posterior cingulate. Our findings show that altered neural response to face in SAD is not limited to emotional structures but involves a complex network. These results may have implications for the understanding of SAD pathophysiology, as they suggest that a dysfunctional face perception process may bias patient person-to-person interactions. © 2015 by the Society for Experimental Biology and Medicine.
Will, Geert-Jan; van Lier, Pol A C; Crone, Eveline A; Güroğlu, Berna
This functional Magnetic Resonance Imaging (fMRI) study examined subjective and neural responses to social exclusion in adolescents (age 12-15) who either had a stable accepted (n = 27; 14 males) or a chronic rejected (n = 19; 12 males) status among peers from age 6 to 12. Both groups of adolescents reported similar increases in distress after being excluded in a virtual ball-tossing game (Cyberball), but adolescents with a history of chronic peer rejection showed higher activity in brain regions previously linked to the detection of, and the distress caused by, social exclusion. Specifically, compared with stably accepted adolescents, chronically rejected adolescents displayed: 1) higher activity in the dorsal anterior cingulate cortex (dACC) during social exclusion and 2) higher activity in the dACC and anterior prefrontal cortex when they were incidentally excluded in a social interaction in which they were overall included. These findings demonstrate that chronic childhood peer rejection is associated with heightened neural responses to social exclusion during adolescence, which has implications for understanding the processes through which peer rejection may lead to adverse effects on mental health over time.
Wang, Xiaoyan; Zheng, Li; Cheng, Xuemei; Li, Lin; Sun, Lining; Wang, Qianfeng; Guo, Xiuyan
People often take either the role of an actor or that of recipient in positive and negative interpersonal events when they interact with others. The present study investigated how the actor-recipient role affected the neural responses to self in emotional situations. Twenty-five participants were scanned while they were presented with positive and negative interpersonal events and were asked to rate the degree to which the actor/the recipient was that kind of person who caused the interpersonal event. Half of the trials were self-relevant events and the other half were other-relevant events. Results showed that people were more likely to isolate self from negative events when they played the role of actor relative to recipient. Pregenual anterior cingulate cortex (pgACC) and posterior dorsal anterior cingulate cortex (pdACC) were more active for self than other only in negative events. More importantly, also in negative interpersonal events, dorsal medial prefrontal cortex (dmPFC) showed greater self-related activations (self-other) when participants played the role of recipient relative to actor, while activities in orbitofrontal cortex (OFC) were greater for self than other only when the evaluation target played the role of recipient. These results showed that the actor-recipient role affected neural responses to self in emotional situations, especially when a recipient role was played in negative situations.
Full Text Available Previous studies have demonstrated that the brain responds differentially to others' gains and losses relative to one's own, moderated by social context factors such as competition and interpersonal relationships. In the current study, we tested the hypothesis that the neural response to others' outcomes could be modulated by a short-term induced affective preference. We engaged 17 men and 18 women in a social-exchange game, in which two confederates played fairly or unfairly. Both men and women rated the fair player as likable and the unfair players as unlikable. Afterwards, ERPs were recorded while participants observed each confederates playing a gambling game individually. This study examines feedback related negativity (FRN, an ERP component sensitive to negative feedback. ANOVA showed a significant interaction in which females but not males displayed stronger FRNs when observing likable players' outcomes compared to unlikable ones'. However, males did not respond differently under either circumstance. These findings suggest that, at least in females, the neural response is influenced by a short-term induced affective preference.
Wang, Yang; Qu, Chen; Luo, Qiuling; Qu, Lulu; Li, Xuebing
Previous studies have demonstrated that the brain responds differentially to others' gains and losses relative to one's own, moderated by social context factors such as competition and interpersonal relationships. In the current study, we tested the hypothesis that the neural response to others' outcomes could be modulated by a short-term induced affective preference. We engaged 17 men and 18 women in a social-exchange game, in which two confederates played fairly or unfairly. Both men and women rated the fair player as likable and the unfair players as unlikable. Afterwards, ERPs were recorded while participants observed each confederates playing a gambling game individually. This study examines feedback related negativity (FRN), an ERP component sensitive to negative feedback. ANOVA showed a significant interaction in which females but not males displayed stronger FRNs when observing likable players' outcomes compared to unlikable ones'. However, males did not respond differently under either circumstance. These findings suggest that, at least in females, the neural response is influenced by a short-term induced affective preference.
Gómez-Nieto, Ricardo; Horta-Júnior, José de Anchieta C.; Castellano, Orlando; Millian-Morell, Lymarie; Rubio, Maria E.; López, Dolores E.
The acoustic startle reflex (ASR) is a survival mechanism of alarm, which rapidly alerts the organism to a sudden loud auditory stimulus. In rats, the primary ASR circuit encompasses three serially connected structures: cochlear root neurons (CRNs), neurons in the caudal pontine reticular nucleus (PnC), and motoneurons in the medulla and spinal cord. It is well-established that both CRNs and PnC neurons receive short-latency auditory inputs to mediate the ASR. Here, we investigated the anatomical origin and functional role of these inputs using a multidisciplinary approach that combines morphological, electrophysiological and behavioral techniques. Anterograde tracer injections into the cochlea suggest that CRNs somata and dendrites receive inputs depending, respectively, on their basal or apical cochlear origin. Confocal colocalization experiments demonstrated that these cochlear inputs are immunopositive for the vesicular glutamate transporter 1 (VGLUT1). Using extracellular recordings in vivo followed by subsequent tracer injections, we investigated the response of PnC neurons after contra-, ipsi-, and bilateral acoustic stimulation and identified the source of their auditory afferents. Our results showed that the binaural firing rate of PnC neurons was higher than the monaural, exhibiting higher spike discharges with contralateral than ipsilateral acoustic stimulations. Our histological analysis confirmed the CRNs as the principal source of short-latency acoustic inputs, and indicated that other areas of the cochlear nucleus complex are not likely to innervate PnC. Behaviorally, we observed a strong reduction of ASR amplitude in monaural earplugged rats that corresponds with the binaural summation process shown in our electrophysiological findings. Our study contributes to understand better the role of neuronal mechanisms in auditory alerting behaviors and provides strong evidence that the CRNs-PnC pathway mediates fast neurotransmission and binaural summation
Full Text Available The acoustic startle reflex (ASR is a survival mechanism of alarm, which rapidly alerts the organism to a sudden loud auditory stimulus. In rats, the primary ASR circuit encompasses three serially connected structures: cochlear root neurons (CRNs, neurons in the caudal pontine reticular nucleus (PnC, and motoneurons in the medulla and spinal cord. It is well established that both CRNs and PnC neurons receive short-latency auditory inputs to mediate the ASR. Here, we investigated the anatomical origin and functional role of these inputs using a multidisciplinary approach that combines morphological, electrophysiological and behavioural techniques. Anterograde tracer injections into the cochlea suggest that CRNs somata and dendrites receive inputs depending, respectively, on their basal or apical cochlear origin. Confocal colocalization experiments demonstrated that these cochlear inputs are immunopositive for the vesicular glutamate transporter 1. Using extracellular recordings in vivo followed by subsequent tracer injections, we investigated the response of PnC neurons after contra-, ipsi-, and bilateral acoustic stimulation and identified the source of their auditory afferents. Our results showed that the binaural firing rate of PnC neurons was higher than the monaural, exhibiting higher spike discharges with contralateral than ipsilateral acoustic stimulations. Our histological analysis confirmed the CRNs as the principal source of short-latency acoustic inputs, and indicated that other areas of the cochlear nucleus complex are not likely to innervate PnC. Behaviourally, we observed a strong reduction of ASR amplitude in monaural earplugged rats that corresponds with the binaural summation process shown in our electrophysiological findings. Our study contributes to understand better the role of neuronal mechanisms in auditory alerting behaviours and provides strong evidence that the CRNs-PnC pathway mediates fast neurotransmission and binaural
Robin L. Aupperle
Conclusions: Results support a relationship between anxiety and depressive symptoms and prefrontal-amygdala responses to maternal feedback. The lateralization of amygdala findings suggests separate neural targets for interventions reducing reactivity to negative feedback or increasing salience of positive feedback. Exploratory analyses suggest that parents' OXTR genetic profile influences parent-child interactions and related adolescent brain responses.
Matthias C. Krantz
Full Text Available A theory is derived for the bending-mode magnetoelectric coefficients at resonance for magnetostrictive and piezoelectric layers on opposite sides of a substrate. Results are given for the transverse ME coefficient in the Metglas-Si-AlN system with magnetic field excitation parallel and electric polarization perpendicular to the cantilever. The center-substrate layer sequence is found to produce about 50 % enhancement of the magnetoelectric effect compared to magnetoelectric bilayers on one side of a substrate. Up to about 10 % additional enhancement of the ME effect is predicted if the magnetostrictive and piezoelectric layers are separated from the substrate by spacer layers with lower Youngs modulus. Lowest order bending mode resonance frequencies are given.
Goodman, Jarid; Gabriele, Amanda; Packard, Mark G
The present study examined the role of the dorsolateral striatum (DLS) in extinction behavior. Male Long-Evans rats were initially trained on the straight alley maze, in which they were reinforced to traverse a straight runway and retrieve food reward at the opposite end of the maze. After initial acquisition, animals were given extinction training using 1 of 2 distinct protocols: response extinction or latent extinction. For response extinction, the animal was released from the same starting position and had the opportunity to perform the originally reinforced approach response to the goal end of the maze, which no longer contained food. For latent extinction, the animal was confined to the original goal location without food, allowing the animal to form a new cognitive expectation (i.e., that the goal location is no longer reinforced). Immediately before response or latent extinction training, animals received bilateral intra-DLS administration of the sodium channel blocker bupivacaine or control injections of physiological saline. Results indicated that neural inactivation of the DLS with bupivacaine impaired response extinction, but did not influence latent extinction. The dissociation observed indicates that the DLS selectively mediates extinction mechanisms involving suppression of the original response, as opposed to cognitive mechanisms involving a change in expectation. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Full Text Available An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users whereas others are discontent (dissonant users. Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli and stimuli associated with the terminal stage (END-smoking-stimuli of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant
Kate A. Woodcock
Full Text Available Background: Emotional responding is sensitive to social context; however, little emphasis has been placed on the mechanisms by which social context effects changes in emotional responding. Objective: We aimed to investigate the effects of social context on neural responses to emotional stimuli to inform on the mechanisms underpinning context-linked changes in emotional responding. Design: We measured event-related potential (ERP components known to index specific emotion processes and self-reports of explicit emotion regulation strategies and emotional arousal. Female Chinese university students observed positive, negative, and neutral photographs, whilst alone or accompanied by a culturally similar (Chinese or dissimilar researcher (British. Results: There was a reduction in the positive versus neutral differential N1 amplitude (indexing attentional capture by positive stimuli in the dissimilar relative to alone context. In this context, there was also a corresponding increase in amplitude of a frontal late positive potential (LPP component (indexing engagement of cognitive control resources. In the similar relative to alone context, these effects on differential N1 and frontal LPP amplitudes were less pronounced, but there was an additional decrease in the amplitude of a parietal LPP component (indexing motivational relevance in response to positive stimuli. In response to negative stimuli, the differential N1 component was increased in the similar relative to dissimilar and alone (trend context. Conclusion: These data suggest that neural processes engaged in response to emotional stimuli are modulated by social context. Possible mechanisms for the social-context-linked changes in attentional capture by emotional stimuli include a context-directed modulation of the focus of attention, or an altered interpretation of the emotional stimuli based on additional information proportioned by the context.
Yan, Yuanwei; Bejoy, Julie; Xia, Junfei; Guan, Jingjiao; Zhou, Yi; Li, Yan
Appropriate neural patterning of human induced pluripotent stem cells (hiPSCs) is critical to generate specific neural cells/tissues and even mini-brains that are physiologically relevant to model neurological diseases. However, the capacity of signaling factors that regulate 3-D neural tissue patterning in vitro and differential responses of the resulting neural populations to various biomolecules have not yet been fully understood. By tuning neural patterning of hiPSCs with small molecules targeting sonic hedgehog (SHH) signaling, this study generated different 3-D neuronal cultures that were mainly comprised of either cortical glutamatergic neurons or motor neurons. Abundant glutamatergic neurons were observed following the treatment with an antagonist of SHH signaling, cyclopamine, while Islet-1 and HB9-expressing motor neurons were enriched by an SHH agonist, purmorphamine. In neurons derived with different neural patterning factors, whole-cell patch clamp recordings showed similar voltage-gated Na(+)/K(+) currents, depolarization-evoked action potentials and spontaneous excitatory post-synaptic currents. Moreover, these different neuronal populations exhibited differential responses to three classes of biomolecules, including (1) matrix metalloproteinase inhibitors that affect extracellular matrix remodeling; (2) N-methyl-d-aspartate that induces general neurotoxicity; and (3) amyloid β (1-42) oligomers that cause neuronal subtype-specific neurotoxicity. This study should advance our understanding of hiPSC self-organization and neural tissue development and provide a transformative approach to establish 3-D models for neurological disease modeling and drug discovery. Appropriate neural patterning of human induced pluripotent stem cells (hiPSCs) is critical to generate specific neural cells, tissues and even mini-brains that are physiologically relevant to model neurological diseases. However, the capability of sonic hedgehog-related small molecules to tune
Costalago Meruelo, Alicia; Simpson, David M; Veres, Sandor M; Newland, Philip L
Mathematical modelling is used routinely to understand the coding properties and dynamics of responses of neurons and neural networks. Here we analyse the effectiveness of Artificial Neural Networks (ANNs) as a modelling tool for motor neuron responses. We used ANNs to model the synaptic responses of an identified motor neuron, the fast extensor motor neuron, of the desert locust in response to displacement of a sensory organ, the femoral chordotonal organ, which monitors movements of the tibia relative to the femur of the leg. The aim of the study was threefold: first to determine the potential value of ANNs as tools to model and investigate neural networks, second to understand the generalisation properties of ANNs across individuals and to different input signals and third, to understand individual differences in responses of an identified neuron. A metaheuristic algorithm was developed to design the ANN architectures. The performance of the models generated by the ANNs was compared with those generated through previous mathematical models of the same neuron. The results suggest that ANNs are significantly better than LNL and Wiener models in predicting specific neural responses to Gaussian White Noise, but not significantly different when tested with sinusoidal inputs. They are also able to predict responses of the same neuron in different individuals irrespective of which animal was used to develop the model, although notable differences between some individuals were evident. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Lo, Yu-Chun; Chen, Yu-Jen; Hsu, Yung-Chin; Tseng, Wen-Yih Isaac; Gau, Susan Shur-Fen
Autism spectrum disorder (ASD) is a neurodevelopmental disorder with social communication deficits as one of the core symptoms. Recently, a five-level model for the social communication has been proposed in which white matter tracts corresponding to each level of the model are identified. Given that the model for social communication subserves social language functions, we hypothesized that the tract integrity of the model for social communication may be reduced in ASD, and the reduction may be related to social communication deficits. Sixty-two right-handed boys with ASD and 55 typically developing (TD) boys received clinical evaluations, intelligence tests, the Social Communication Questionnaire (SCQ), and MRI scans. Generalized fractional anisotropy (GFA) was measured by diffusion spectrum imaging to indicate the microstructural integrity of the tracts for each level of the social communication model. Group difference in the tract integrity and its relationship with the SCQ subscales of social communication and social interaction were investigated. We found that the GFA values of the superior longitudinal fasciculus III (SLF III, level 1) and the frontal aslant tracts (FAT, level 2) were decreased in ASD compared to TD. Moreover, the GFA values of the SLF III and the FAT were associated with the social interaction subscale in ASD. The tract integrity of the model for social communication is reduced in ASD, and the reduction is associated with impaired social interaction. Our results support that reduced tract integrity of the model for social communication might be a neural substrate of social communication deficits in ASD. © 2016 Association for Child and Adolescent Mental Health.
Demos, Kathryn E; Sweet, Lawrence H; Hart, Chantelle N; McCaffery, Jeanne M; Williams, Samantha E; Mailloux, Kimberly A; Trautvetter, Jennifer; Owens, Max M; Wing, Rena R
Despite growing literature on neural food cue responsivity in obesity, little is known about how the brain processes food cues following partial sleep deprivation and whether short sleep leads to changes similar to those observed in obesity. We used functional magnetic resonance imaging (fMRI) to test the hypothesis that short sleep leads to increased reward-related and decreased inhibitory control-related processing of food cues.In a within-subject design, 30 participants (22 female, mean age = 36.7 standard deviation = 10.8 years, body mass index range 20.4-40.7) completed four nights of 6 hours/night time-in-bed (TIB; short sleep) and four nights of 9 hours/night TIB (long sleep) in random counterbalanced order in their home environments. Following each sleep condition, participants completed an fMRI scan while viewing food and nonfood images.A priori region of interest analyses revealed increased activity to food in short versus long sleep in regions of reward processing (eg, nucleus accumbens/putamen) and sensory/motor signaling (ie, right paracentral lobule, an effect that was most pronounced in obese individuals). Contrary to the hypothesis, whole brain analyses indicated greater food cue responsivity during short sleep in an inhibitory control region (right inferior frontal gyrus) and ventral medial prefrontal cortex, which has been implicated in reward coding and decision-making (false discovery rate corrected q = 0.05).These findings suggest that sleep restriction leads to both greater reward and control processing in response to food cues. Future research is needed to understand the dynamic functional connectivity between these regions during short sleep and whether the interplay between these neural processes determines if one succumbs to food temptation. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail firstname.lastname@example.org.
Louise R Manfredi
Full Text Available Because tactile perception relies on the response of large populations of receptors distributed across the skin, we seek to characterize how a mechanical deformation of the skin at one location affects the skin at another. To this end, we introduce a novel non-contact method to characterize the surface waves produced in the skin under a variety of stimulation conditions. Specifically, we deliver vibrations to the fingertip using a vibratory actuator and measure, using a laser Doppler vibrometer, the surface waves at different distances from the locus of stimulation. First, we show that a vibration applied to the fingertip travels at least the length of the finger and that the rate at which it decays is dependent on stimulus frequency. Furthermore, the resonant frequency of the skin matches the frequency at which a subpopulation of afferents, namely Pacinian afferents, is most sensitive. We show that this skin resonance can lead to a two-fold increase in the strength of the response of a simulated afferent population. Second, the rate at which vibrations propagate across the skin is dependent on the stimulus frequency and plateaus at 7 m/s. The resulting delay in neural activation across locations does not substantially blur the temporal patterning in simulated populations of afferents for frequencies less than 200 Hz, which has important implications about how vibratory frequency is encoded in the responses of somatosensory neurons. Third, we show that, despite the dependence of decay rate and propagation speed on frequency, the waveform of a complex vibration is well preserved as it travels across the skin. Our results suggest, then, that the propagation of surface waves promotes the encoding of spectrally complex vibrations as the entire neural population is exposed to essentially the same stimulus. We also discuss the implications of our results for biomechanical models of the skin.
Full Text Available Imaging of cancer with 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET has become a standard component of diagnosis and staging in oncology, and is becoming more important as a quantitative monitor of individual response to therapy. In this article we investigate the challenging problem of predicting a patient's response to neoadjuvant chemotherapy from a single 18F-FDG PET scan taken prior to treatment. We take a "radiomics" approach whereby a large amount of quantitative features is automatically extracted from pretherapy PET images in order to build a comprehensive quantification of the tumor phenotype. While the dominant methodology relies on hand-crafted texture features, we explore the potential of automatically learning low- to high-level features directly from PET scans. We report on a study that compares the performance of two competing radiomics strategies: an approach based on state-of-the-art statistical classifiers using over 100 quantitative imaging descriptors, including texture features as well as standardized uptake values, and a convolutional neural network, 3S-CNN, trained directly from PET scans by taking sets of adjacent intra-tumor slices. Our experimental results, based on a sample of 107 patients with esophageal cancer, provide initial evidence that convolutional neural networks have the potential to extract PET imaging representations that are highly predictive of response to therapy. On this dataset, 3S-CNN achieves an average 80.7% sensitivity and 81.6% specificity in predicting non-responders, and outperforms other competing predictive models.
Full Text Available BackgroundPatients with obsessive-compulsive disorder (OCD have highly idiosyncratic triggers. To fully understand which role this idiosyncrasy plays in the neurobiological mechanisms behind OCD, it is necessary to elucidate the impact of individualization regarding the applied investigation methods.This functional magnetic resonance imaging (fMRI study explores the neural correlates of contamination/washing-related OCD with a highly individualized symptom provocation paradigm. Additionally, it is the first study to directly compare individualized and standardized symptom provocation. MethodsNineteen patients with washing compulsions created individual OCD hierarchies, which later served as instructions to photograph their own individualized stimulus sets. The patients and 19 case-by-case matched healthy controls participated in a symptom provocation fMRI experiment with individualized and standardized stimulus sets created for each patient. ResultsOCD patients compared to healthy controls displayed stronger activation in the basal ganglia (nucleus accumbens, nucleus caudatus, pallidum for individualized symptom provocation. Using standardized symptom provocation, this group comparison led to stronger activation in the nucleus caudatus. The direct comparison of between-group effects for both symptom provocation approaches revealed stronger activation of the orbitofronto-striatal network for individualized symptom provocation.ConclusionsThe present study provides insight into the differential impact of individualized and standardized symptom provocation on the orbitofronto-striatal network of OCD washers. Behavioral and neural responses imply a higher symptom-specificity of individualized symptom provocation.
Kapania, Rakesh K.; Liu, Youhua
At the preliminary design stage of a wing structure, an efficient simulation, one needing little computation but yielding adequately accurate results for various response quantities, is essential in the search of optimal design in a vast design space. In the present paper, methods of using sensitivities up to 2nd order, and direct application of neural networks are explored. The example problem is how to decide the natural frequencies of a wing given the shape variables of the structure. It is shown that when sensitivities cannot be obtained analytically, the finite difference approach is usually more reliable than a semi-analytical approach provided an appropriate step size is used. The use of second order sensitivities is proved of being able to yield much better results than the case where only the first order sensitivities are used. When neural networks are trained to relate the wing natural frequencies to the shape variables, a negligible computation effort is needed to accurately determine the natural frequencies of a new design.
Erguzel, Turker Tekin; Ozekes, Serhat; Gultekin, Selahattin; Tarhan, Nevzat; Hizli Sayar, Gokben; Bayram, Ali
The combination of repetitive transcranial magnetic stimulation (rTMS), a non-pharmacological form of therapy for treating major depressive disorder (MDD), and electroencephalogram (EEG) is a valuable tool for investigating the functional connectivity in the brain. This study aims to explore whether pre-treating frontal quantitative EEG (QEEG) cordance is associated with response to rTMS treatment among MDD patients by using an artificial intelligence approach, artificial neural network (ANN). The artificial neural network using pre-treatment cordance of frontal QEEG classification was carried out to identify responder or non-responder to rTMS treatment among 55 MDD subjects. The classification performance was evaluated using k-fold cross-validation. The ANN classification identified responders to rTMS treatment with a sensitivity of 93.33%, and its overall accuracy reached to 89.09%. Area under Receiver Operating Characteristic (ROC) curve (AUC) value for responder detection using 6, 8 and 10 fold cross validation were 0.917, 0.823 and 0.894 respectively. Potential utility of ANN approach method can be used as a clinical tool in administering rTMS therapy to a targeted group of subjects suffering from MDD. This methodology is more potentially useful to the clinician as prediction is possible using EEG data collected before this treatment process is initiated. It is worth using feature selection algorithms to raise the sensitivity and accuracy values.
Bolling, Danielle Z; Pitskel, Naomi B; Deen, Ben; Crowley, Michael J; McPartland, James C; Kaiser, Martha D; Wyk, Brent C Vander; Wu, Jia; Mayes, Linda C; Pelphrey, Kevin A
The present study aimed to explore the neural correlates of two characteristic deficits in autism spectrum disorders (ASD); social impairment and restricted, repetitive behavior patterns. To this end, we used comparable experiences of social exclusion and rule violation to probe potentially atypical neural networks in ASD. In children and adolescents with and without ASD, we used the interactive ball-toss game (Cyberball) to elicit social exclusion and a comparable game (Cybershape) to elicit a non-exclusive rule violation. Using functional magnetic resonance imaging (fMRI), we identified group differences in brain responses to social exclusion and rule violation. Though both groups reported equal distress following exclusion, the right insula and ventral anterior cingulate cortex were hypoactive during exclusion in children with ASD. In rule violation, right insula and dorsal prefrontal cortex were hyperactive in ASD. Right insula showed a dissociation in activation; it was hypoactive to social exclusion and hyperactive to rule violation in the ASD group. Further probed, different regions of right insula were modulated in each game, highlighting differences in regional specificity for which subsequent analyses revealed differences in patterns of functional connectivity. These results demonstrate neurobiological differences in processing social exclusion and rule violation in children with ASD.
Full Text Available Large networks of sparsely coupled, excitatory and inhibitory cells occur throughout the brain. For many models of these networks, a striking feature is that their dynamics are chaotic and thus, are sensitive to small perturbations. How does this chaos manifest in the neural code? Specifically, how variable are the spike patterns that such a network produces in response to an input signal? To answer this, we derive a bound for a general measure of variability -- spike-train entropy. This leads to important insights on the variability of multi-cell spike pattern distributions in large recurrent networks of spiking neurons responding to fluctuating inputs. The analysis is based on results from random dynamical systems theory and is complemented by detailed numerical simulations. We find that the spike pattern entropy is an order of magnitude lower than what would be extrapolated from single cells. This holds despite the fact that network coupling becomes vanishingly sparse as network size grows -- a phenomenon that depends on ``extensive chaos, as previously discovered for balanced networks without stimulus drive. Moreover, we show how spike pattern entropy is controlled by temporal features of the inputs. Our findings provide insight into how neural networks may encode stimuli in the presence of inherently chaotic dynamics.
Hoyniak, Caroline P; Bates, John E; Petersen, Isaac T; Yang, Chung-Lin; Darcy, Isabelle; Fontaine, Nathalie M G
Callous-unemotional (CU) traits are characterized by a lack of guilt and empathy, and low responsiveness to distress and fear in others. Children with CU traits are at-risk for engaging in early and persistent conduct problems. Individuals showing CU traits have been shown to have reduced neural responses to others' distress (e.g., fear). However, the neural components of distress responses in children with CU traits have not been investigated in early childhood. In the current study, we examined neural responses that underlie the processing of emotionally valenced vocal stimuli using the event-related potential technique in a group of preschoolers. Participants between 2 and 5 years old took part in an auditory oddball task containing English-based pseudowords spoken with either a fearful, happy, or a neutral prosody while electroencephalography data were collected. The mismatch negativity (MMN) component, an index of the automatic detection of deviant stimuli within a series of stimuli, was examined in association with two dimensions of CU traits (i.e., callousness-uncaring and unemotional dimensions) reported by primary caregivers. Findings suggest that the callousness-uncaring dimension of CU traits in early childhood is associated with reduced responses to fearful vocal stimuli. Reduced neural responses to vocal fear could be a biomarker for callous-uncaring traits in early childhood. These findings are relevant for clinicians and researchers attempting to identify risk factors for early callous-uncaring traits. © 2017 John Wiley & Sons Ltd.
Rodgers, John W.
The development of high aspect ratio large feature density polymer microarrays requires the synergistic optimization of design, material, mold tooling, and processing. A conventional mold base with steel inserts and controllable resistance heating was assembled to incorporate interchangeable inserts with microfeatured silicon inlays. Ultraviolet (UV) lithography with dry etching was used to impart microfeatures into silicon wafers with a variety of different geometries containing aspect ratios ranging from 0.92 to 6. Multiple polymer resins, including polystyrene (PS), low density polyethylene (LDPE), cyclic olefin copolymer (COC), and thermoplastic polyurethane (TPU), were used to test replication and cellular response to materials with different bulk stiffness and topography-modified surface stiffness. The maximum achieved microfeature aspect ratio was 9.3 (high impact polystyrene), owed to tensile stretching during part ejection. For non-stretched substrates, the maximum molded aspect ratio was 4.5 (LDPE) and highest replication quotient (RQ = feature height / tooling feature depth) was 0.97 (COC). The maximum aspect ratio molded with consistent features across the entire surface was 2.1 (TPU). Parameters shown to enhance replication were mold temperature (T mold = Tg was a critical replication transition point), injection velocity at higher mold temperatures, holding time, holding pressure, and nozzle temperature. The importance of certain parameters was material dependent, but mold temperature consistently had a relatively large impact. A concern that was addressed for a high density array of microfeatures was the consistency of replication, which is vital for the intended application and seldom address in published literature. Increased consistency was attained through strategic placement of temperature control, modification of the main cavity design, and optimized silicon tooling with reduced microcavity nanoroughness. Silicon tooling was fabricated with the
Goldfarb, K.C.; Karaoz, U.; Hanson, C.A.; Santee, C.A.; Bradford, M.A.; Treseder, K.K.; Wallenstein, M.D.; Brodie, E.L.
Soils are immensely diverse microbial habitats with thousands of co-existing bacterial, archaeal, and fungal species. Across broad spatial scales, factors such as pH and soil moisture appear to determine the diversity and structure of soil bacterial communities. Within any one site however, bacterial taxon diversity is high and factors maintaining this diversity are poorly resolved. Candidate factors include organic substrate availability and chemical recalcitrance, and given that they appear to structure bacterial communities at the phylum level, we examine whether these factors might structure bacterial communities at finer levels of taxonomic resolution. Analyzing 16S rRNA gene composition of nucleotide analog-labeled DNA by PhyloChip microarrays, we compare relative growth rates on organic substrates of increasing chemical recalcitrance of >2,200 bacterial taxa across 43 divisions/phyla. Taxa that increase in relative abundance with labile organic substrates (i.e., glycine, sucrose) are numerous (>500), phylogenetically clustered, and occur predominantly in two phyla (Proteobacteria and Actinobacteria) including orders Actinomycetales, Enterobacteriales, Burkholderiales, Rhodocyclales, Alteromonadales, and Pseudomonadales. Taxa increasing in relative abundance with more chemically recalcitrant substrates (i.e., cellulose, lignin, or tannin-protein) are fewer (168) but more phylogenetically dispersed, occurring across eight phyla and including Clostridiales, Sphingomonadalaes, Desulfovibrionales. Just over 6% of detected taxa, including many Burkholderiales increase in relative abundance with both labile and chemically recalcitrant substrates. Estimates of median rRNA copy number per genome of responding taxa demonstrate that these patterns are broadly consistent with bacterial growth strategies. Taken together, these data suggest that changes in availability of intrinsically labile substrates may result in predictable shifts in soil bacterial composition.
Full Text Available The processes of cellular differentiation and phenotypic maintenance can be influenced by stimuli from a variety of different factors. One commonly overlooked factor is the mechanical properties of the growth substrate in which stem cells are maintained or differentiated down various lineages. Here we explored the effect that growth on an elastic silicone substrate had on the myogenic expression and cytoskeletal morphology of periodontal ligament derived stem cells. Cells were grown on either collagen I coated tissue culture polystyrene plates or collagen I coated elastic silicone membranes for a period of 4 days without further induction from soluble factors in the culture media. Following the 4-day growth, gene expression and immunohistochemical analysis for key cardiomyogenic markers was performed along with a morphological assessment of cytoskeletal organization. Results show that cells grown on the elastic substrate significantly upregulate key markers associated with contractile activity in muscle tissues. Namely, the myosin light chain polypeptides 2 and 7, as well as the myosin heavy chain polypeptide 7 genes underwent a statistically significant upregulation in the cells grown on elastic silicone membranes. Similarly, the cells on the softer elastic substrate stained positive for both sarcomeric actin and cardiac troponin t proteins following just 4 days of growth on the softer material. Cytoskeletal analysis showed that substrate stiffness had a marked effect on the organization and distribution of filamentous actin fibers within the cell body. Growth on silicone membranes produced flatter and shorter cellular morphologies with filamentous actin fibers projecting anisotropically throughout the cell body. These results demonstrate how crucial the mechanical properties of the growth substrate of cells can be on the ultimate cellular phenotype. These observations highlight the need to further optimize differentiation protocols to enhance
Singer, Tania; Seymour, Ben; O'Doherty, John P.; Stephan, Klaas E.; Dolan, Raymond J.; Frith, Chris D.
The neural processes underlying empathy are a subject of intense interest within the social neurosciences1-3. However, very little is known about how brain empathic responses are modulated by the affective link between individuals. We show here that empathic responses are modulated by learned preferences, a result consistent with economic models of social preferences4-7. We engaged male and female volunteers in an economic game, in which two confederates played fairly or unfairly, and then measured brain activity with functional magnetic resonance imaging while these same volunteers observed the confederates receiving pain. Both sexes exhibited empathy-related activation in pain-related brain areas (fronto-insular and anterior cingulate cortices) towards fair players. However, these empathy-related responses were significantly reduced in males when observing an unfair person receiving pain. This effect was accompanied by increased activation in reward-related areas, correlated with an expressed desire for revenge. We conclude that in men (at least) empathic responses are shaped by valuation of other people's social behaviour, such that they empathize with fair opponents while favouring the physical punishment of unfair opponents, a finding that echoes recent evidence for altruistic punishment. PMID:16421576
Larsen, Peter E; Cseke, Leland J; Miller, R Michael; Collart, Frank R
Rising atmospheric levels of carbon dioxide and ozone will impact productivity and carbon sequestration in forest ecosystems. The scale of this process and the potential economic consequences provide an incentive for the development of models to predict the types and rates of ecosystem responses and feedbacks that result from and influence of climate change. In this paper, we use phenotypic and molecular data derived from the Aspen Free Air CO2 Enrichment site (Aspen-FACE) to evaluate modeling approaches for ecosystem responses to changing conditions. At FACE, it was observed that different aspen clones exhibit clone-specific responses to elevated atmospheric levels of carbon dioxide and ozone. To identify the molecular basis for these observations, we used artificial neural networks (ANN) to examine above and below-ground community phenotype responses to elevated carbon dioxide, elevated ozone and gene expression profiles. The aspen community models generated using this approach identified specific genes and subnetworks of genes associated with variable sensitivities for aspen clones. The ANN model also predicts specific co-regulated gene clusters associated with differential sensitivity to elevated carbon dioxide and ozone in aspen species. The results suggest ANN is an effective approach to predict relevant gene expression changes resulting from environmental perturbation and provides useful information for the rational design of future biological experiments. Copyright © 2014 Elsevier Ltd. All rights reserved.
Chakraverty, S.; Sahoo, Deepti Moyi
Present paper uses powerful technique of interval neural network (INN) to simulate and estimate structural response of multi-storey shear buildings subject to earthquake motion. The INN is first trained for a real earthquake data, viz., the ground acceleration as input and the numerically generated responses of different floors of multi-storey buildings as output. Till date, no model exists to handle positive and negative data in the INN. As such here, the bipolar data in [ -1, 1] are converted first to unipolar form, i.e., to [0, 1] by means of a novel transformation for the first time to handle the above training patterns in normalized form. Once the training is done, again the unipolar data are converted back to its bipolar form by using the inverse transformation. The trained INN architecture is then used to simulate and test the structural response of different floors for various intensity earthquake data and it is found that the predicted responses given by INN model are good for practical purposes.
Ghimire, Rajan; Norton, Jay B; Stahl, Peter D; Norton, Urszula
Changes in soil microbiotic properties such as microbial biomass and community structure in response to alternative management systems are driven by microbial substrate quality and substrate utilization. We evaluated irrigated crop and forage production in two separate four-year experiments for differences in microbial substrate quality, microbial biomass and community structure, and microbial substrate utilization under conventional, organic, and reduced-tillage management systems. The six different management systems were imposed on fields previously under long-term, intensively tilled maize production. Soils under crop and forage production responded to conversion from monocropping to crop rotation, as well as to the three different management systems, but in different ways. Under crop production, four years of organic management resulted in the highest soil organic C (SOC) and microbial biomass concentrations, while under forage production, reduced-tillage management most effectively increased SOC and microbial biomass. There were significant increases in relative abundance of bacteria, fungi, and protozoa, with two- to 36-fold increases in biomarker phospholipid fatty acids (PLFAs). Under crop production, dissolved organic C (DOC) content was higher under organic management than under reduced-tillage and conventional management. Perennial legume crops and organic soil amendments in the organic crop rotation system apparently favored greater soil microbial substrate availability, as well as more microbial biomass compared with other management systems that had fewer legume crops in rotation and synthetic fertilizer applications. Among the forage production management systems with equivalent crop rotations, reduced-tillage management had higher microbial substrate availability and greater microbial biomass than other management systems. Combined crop rotation, tillage management, soil amendments, and legume crops in rotations considerably influenced soil
Moura, Amanda Christina Gomes de
Full Text Available Introduction Currently the cochlear implant allows access to sounds in individuals with profound hearing loss. The objective methods used to verify the integrity of the cochlear device and the electrophysiologic response of users have noted these improvements. Objective To establish whether the evoked compound action potential of the auditory nerve can appear after electrical stimulation when it is absent intraoperatively. Methods The clinical records of children implanted with the Nucleus Freedom (Cochlear Ltd., Australia (CI24RE cochlear implant between January 2009 and January 2010 with at least 6 months of use were evaluated. The neural response telemetry (NRT thresholds of electrodes 1, 6, 11, 16, and 22 during surgery and after at least 3 months of implant use were analyzed and correlated with etiology, length of auditory deprivation, and chronological age. These data were compared between a group of children exhibiting responses in all of the tested electrodes and a group of children who had at least one absent response. Results The sample was composed of clinical records of 51 children. From these, 21% (11 showed no NRT in at least one of the tested electrodes. After an average of 4.9 months of stimulation, the number of individuals exhibiting absent responses decreased from 21 to 11% (n = 6. Conclusion It is feasible that absent responses present after a period of electrical stimulation. In our sample, 45% (n = 5 of the patients with intraoperative absence exhibited a positive response after an average of 4.9 months of continued electrical stimulation.
van der Vegt, Joyce P M; Hulme, Oliver J; Zittel, Simone
resulting in impulse control disorders. To circumvent this treatment confound, we assayed the neural basis of reward processing in a group of newly diagnosed patients with Parkinson's disease that had never been treated with dopaminergic drugs. Thirteen drug-naive patients with Parkinson's disease and 12......Parkinson's disease results from the degeneration of dopaminergic neurons in the substantia nigra, manifesting as a spectrum of motor, cognitive and affective deficits. Parkinson's disease also affects reward processing, but disease-related deficits in reinforcement learning are thought to emerge...... at a slower pace than motor symptoms as the degeneration progresses from dorsal to ventral striatum. Dysfunctions in reward processing are difficult to study in Parkinson's disease as most patients have been treated with dopaminergic drugs, which sensitize reward responses in the ventral striatum, commonly...
Miskowiak, Kamilla W; Kessing, Lars V; Ott, Caroline V
Negative neurocognitive bias is a core feature of major depressive disorder that is reversed by pharmacological and psychological treatments. This double-blind functional magnetic resonance imaging study investigated for the first time whether electroconvulsive therapy modulates negative neurocog......Negative neurocognitive bias is a core feature of major depressive disorder that is reversed by pharmacological and psychological treatments. This double-blind functional magnetic resonance imaging study investigated for the first time whether electroconvulsive therapy modulates negative...... to fearful versus happy faces as well as in fear-specific functional connectivity between amygdala and occipito-temporal regions. Across all patients, greater fear-specific amygdala - occipital coupling correlated with lower fear vigilance. Despite no statistically significant shift in neural response...
Full Text Available Adult neurogenesis plays increasingly recognized roles in brain homeostasis and repair and is profoundly affected by energy balance and nutrients. We found that the expression of Hes-1 (hairy and enhancer of split 1 is modulated in neural stem and progenitor cells (NSCs by extracellular glucose through the coordinated action of CREB (cyclic AMP responsive element binding protein and Sirt-1 (Sirtuin 1, two cellular nutrient sensors. Excess glucose reduced CREB-activated Hes-1 expression and results in impaired cell proliferation. CREB-deficient NSCs expanded poorly in vitro and did not respond to glucose availability. Elevated glucose also promoted Sirt-1-dependent repression of the Hes-1 promoter. Conversely, in low glucose, CREB replaced Sirt-1 on the chromatin associated with the Hes-1 promoter enhancing Hes-1 expression and cell proliferation. Thus, the glucose-regulated antagonism between CREB and Sirt-1 for Hes-1 transcription participates in the metabolic regulation of neurogenesis.
Rutherford, Helena J V; Byrne, Simon P; Austin, Grace M; Lee, Jonathan D; Crowley, Michael J; Mayes, Linda C
Women are vulnerable to anxiety during pregnancy and postpartum. However, little is known about antenatal anxiety and neural processing of infant-relevant information. In this experiment, the N170, P300, and LPP (late positive potential) event-related potentials were measured from 43 pregnant women as they viewed infant and adult faces, which were either neutral or distressed in expression. Mother's self-reported anxiety levels were also assessed. The N170 was comparable across face conditions and was not associated with anxiety. However, our central finding was that greater levels of antenatal anxiety were associated with a larger LPP, but only for neutral infant faces. Results suggest that antenatal anxiety may result in deeper processing of neutral, emotionally ambiguous, infant faces during pregnancy. These findings are discussed in light of other work indicating an interpretive bias toward threat in response to neutral stimuli in anxiety. Copyright © 2017 Elsevier B.V. All rights reserved.
Supekar, Kaustubh; Swigart, Anna G; Tenison, Caitlin; Jolles, Dietsje D; Rosenberg-Lee, Miriam; Fuchs, Lynn; Menon, Vinod
Now, more than ever, the ability to acquire mathematical skills efficiently is critical for academic and professional success, yet little is known about the behavioral and neural mechanisms that drive some children to acquire these skills faster than others. Here we investigate the behavioral and neural predictors of individual differences in arithmetic skill acquisition in response to 8-wk of one-to-one math tutoring. Twenty-four children in grade 3 (ages 8-9 y), a critical period for acquisition of basic mathematical skills, underwent structural and resting-state functional MRI scans pretutoring. A significant shift in arithmetic problem-solving strategies from counting to fact retrieval was observed with tutoring. Notably, the speed and accuracy of arithmetic problem solving increased with tutoring, with some children improving significantly more than others. Next, we examined whether pretutoring behavioral and brain measures could predict individual differences in arithmetic performance improvements with tutoring. No behavioral measures, including intelligence quotient, working memory, or mathematical abilities, predicted performance improvements. In contrast, pretutoring hippocampal volume predicted performance improvements. Furthermore, pretutoring intrinsic functional connectivity of the hippocampus with dorsolateral and ventrolateral prefrontal cortices and the basal ganglia also predicted performance improvements. Our findings provide evidence that individual differences in morphometry and connectivity of brain regions associated with learning and memory, and not regions typically involved in arithmetic processing, are strong predictors of responsiveness to math tutoring in children. More generally, our study suggests that quantitative measures of brain structure and intrinsic brain organization can provide a more sensitive marker of skill acquisition than behavioral measures.
Unhjem, Runar; Lundestad, Raymond; Fimland, Marius Steiro; Mosti, Mats Peder; Wang, Eivind
Although reductions in resting H-reflex responses and maximal firing frequency suggest that reduced efferent drive may limit muscle strength in elderly, there are currently no reports of V-wave measurements in elderly, reflecting the magnitude of efferent output to the muscle during maximal contraction. Furthermore, it is uncertain whether potential age-related neural deficiencies can be restored by resistance training. We assessed evoked reflex recordings in the triceps surae muscles during rest and maximal voluntary contraction (MVC), rate of force development (RFD), and muscle mass in seven elderly (74 ± 6 years) males before and after 8 weeks of heavy resistance training, contrasted by seven young (24 ± 4 years) male controls. At baseline, m. soleus (SOL) V/M ratio (0.124 ± 0.082 vs. 0.465 ± 0.197, p elderly compared to young. Also, SOL H-reflex latency (33.29 ± 2.41 vs. 30.29 ± 0.67 ms, p elderly. The reduced neural drive was, despite similar leg muscle mass (10.7 ± 1.2 vs. 11.5 ± 1.4 kg), mirrored by lower MVC (158 ± 48 vs. 240 ± 54 Nm, p elderly. In response to training SOL V/M ratio (0.184 ± 0.092, p elderly, yet only to a level ~40 % of the young. This was accompanied by increased MVC (190 ± 70 Nm, p muscle strength. Furthermore, this motor system impairment can to some extent be improved by heavy resistance training.
Atwater, Brett D; Wagner, Galen S; Kisslo, Joseph
BACKGROUND: Some patients with RBBB may respond to cardiac resynchronization therapy (CRT). However, little is known regarding the electromechanical substrate for CRT and whether this is the optimal pacing strategy. METHODS: This was a pilot prospective double crossover randomized controlled clin...
Blaak, E E; Saris, W H; Wolffenbuttel, B H
OBJECTIVE: This study intended to investigate disturbances in beta-adrenergically-mediated substrate utilization and thermogenesis in obese subjects with mild non insulin-dependent diabetes mellitus (NIDDM). DESIGN: Following a baseline period of 30 min, the beta-agonist isoproterenol (ISO) was
Pullan, Steven T; Daly, Paul; Delmas, Stéphane; Ibbett, Roger; Kokolski, Matthew; Neiteler, Almar; van Munster, Jolanda M; Wilson, Raymond; Blythe, Martin J; Gaddipati, Sanyasi; Tucker, Gregory A; Archer, David B
Saprobic fungi are the predominant industrial sources of Carbohydrate Active enZymes (CAZymes) used for the saccharification of lignocellulose during the production of second generation biofuels. The production of more effective enzyme cocktails is a key objective for efficient biofuel production. To achieve this objective, it is crucial to understand the response of fungi to lignocellulose substrates. Our previous study used RNA-seq to identify the genes induced in Aspergillus niger in response to wheat straw, a biofuel feedstock, and showed that the range of genes induced was greater than previously seen with simple inducers. In this work we used RNA-seq to identify the genes induced in A. niger in response to short rotation coppice willow and compared this with the response to wheat straw from our previous study, at the same time-point. The response to willow showed a large increase in expression of genes encoding CAZymes. Genes encoding the major activities required to saccharify lignocellulose were induced on willow such as endoglucanases, cellobiohydrolases and xylanases. The transcriptome response to willow had many similarities with the response to straw with some significant differences in the expression levels of individual genes which are discussed in relation to differences in substrate composition or other factors. Differences in transcript levels include higher levels on wheat straw from genes encoding enzymes classified as members of GH62 (an arabinofuranosidase) and CE1 (a feruloyl esterase) CAZy families whereas two genes encoding endoglucanases classified as members of the GH5 family had higher transcript levels when exposed to willow. There were changes in the cocktail of enzymes secreted by A. niger when cultured with willow or straw. Assays for particular enzymes as well as saccharification assays were used to compare the enzyme activities of the cocktails. Wheat straw induced an enzyme cocktail that saccharified wheat straw to a greater extent
Wood, Kimberly H; Ver Hoef, Lawrence W; Knight, David C
Recognizing cues that predict an aversive event allows one to react more effectively under threatening conditions, and minimizes the reaction to the threat itself. This is demonstrated during Pavlovian fear conditioning when the unconditioned response (UCR) to a predictable unconditioned stimulus (UCS) is diminished compared to the UCR to an unpredictable UCS. The present study investigated the functional magnetic resonance imaging (fMRI) signal response associated with Pavlovian conditioned UCR diminution to better understand the relationship between individual differences in behavior and the neural mechanisms of the threat-related emotional response. Healthy volunteers participated in a fear conditioning study in which trait anxiety, skin conductance response (SCR), UCS expectancy, and the fMRI signal were assessed. During acquisition trials, a tone (CS+) was paired with a white noise UCS and a second tone (CS-) was presented without the UCS. Test trials consisted of the CS+ paired with the UCS, CS- paired with the UCS, and presentations of the UCS alone to assess conditioned UCR diminution. UCR diminution was observed within the dorsolateral PFC, dorsomedial PFC, cingulate cortex, inferior parietal lobule (IPL), anterior insula, and amygdala. The threat-related activity within the dorsolateral PFC, dorsomedial PFC, posterior cingulate cortex, and IPL varied with individual differences in trait anxiety. In addition, anticipatory (i.e. CS elicited) activity within the PFC showed an inverse relationship with threat-related (i.e. UCS elicited) activity within the PFC, IPL, and amygdala. Further, the emotional response (indexed via SCR) elicited by the threat was closely linked to amygdala activity. These findings are consistent with the view that the amygdala and PFC support learning-related processes that influence the emotional response evoked by a threat. Copyright © 2011 Elsevier Inc. All rights reserved.
Di Russo, Francesco; Taddei, Francesco; Apnile, Teresa; Spinelli, Donatella
Flexible adaptation of behaviour is highly required in some sports, such as fencing. In particular, stimulus discrimination and motor response selection and inhibition processes are crucial. We investigated the neural mechanisms responsible for fencers' fast and flexible behaviour recording event-related potentials (ERPs) in discriminative reaction task (DRT, Go/No-go task) and simple reaction task (SRT) to visual stimuli. In the DRT, in addition to faster RTs measured in fencers with respect to control subjects, three main electrophysiological differences were found. First, attentional modulation of the visual processing taking place in the occipital lobes and reaching a peak at 170 ms was enhanced in the athletes group. Second, the activity in the posterior cingulate gyrus, associated with the stimulus discrimination stage, started earlier in fencers than controls (150 ms versus 200 ms) and the peak had larger amplitude. Third, the activity at the level of the prefrontal cortex (time range: 250-350 ms), associated with response selection stage and particularly with motor inhibition process, was stronger in fencers. No differences between athletes and controls were found in the SRT for both ERPs and RTs. Concluding, the fencers' ability to cope to the opponent feint switching quickly from an intended action to a new more appropriate action is likely due to a faster stimulus discrimination facilitated by higher attention and by stronger inhibition activity in prefrontal cortex.
Goerlich-Dobre, Katharina Sophia; Witteman, Jurriaan; Schiller, Niels O; van Heuven, Vincent J P; Aleman, André; Martens, Sander
How we perceive emotional signals from our environment depends on our personality. Alexithymia, a personality trait characterized by difficulties in emotion regulation has been linked to aberrant brain activity for visual emotional processing. Whether alexithymia also affects the brain's perception of emotional speech prosody is currently unknown. We used functional magnetic resonance imaging to investigate the impact of alexithymia on hemodynamic activity of three a priori regions of the prosody network: the superior temporal gyrus (STG), the inferior frontal gyrus and the amygdala. Twenty-two subjects performed an explicit task (emotional prosody categorization) and an implicit task (metrical stress evaluation) on the same prosodic stimuli. Irrespective of task, alexithymia was associated with a blunted response of the right STG and the bilateral amygdalae to angry, surprised and neutral prosody. Individuals with difficulty describing feelings deactivated the left STG and the bilateral amygdalae to a lesser extent in response to angry compared with neutral prosody, suggesting that they perceived angry prosody as relatively more salient than neutral prosody. In conclusion, alexithymia may be associated with a generally blunted neural response to speech prosody. Such restricted prosodic processing may contribute to problems in social communication associated with this personality trait. © The Author (2013). Published by Oxford University Press. For Permissions, please email: email@example.com.
Hinaut, Xavier; Lance, Florian; Droin, Colas; Petit, Maxime; Pointeau, Gregoire; Dominey, Peter Ford
Language production requires selection of the appropriate sentence structure to accommodate the communication goal of the speaker - the transmission of a particular meaning. Here we consider event meanings, in terms of predicates and thematic roles, and we address the problem that a given event can be described from multiple perspectives, which poses a problem of response selection. We present a model of response selection in sentence production that is inspired by the primate corticostriatal system. The model is implemented in the context of reservoir computing where the reservoir - a recurrent neural network with fixed connections - corresponds to cortex, and the readout corresponds to the striatum. We demonstrate robust learning, and generalization properties of the model, and demonstrate its cross linguistic capabilities in English and Japanese. The results contribute to the argument that the corticostriatal system plays a role in response selection in language production, and to the stance that reservoir computing is a valid potential model of corticostriatal processing. Copyright © 2015 Elsevier Inc. All rights reserved.
Hillyard, Stanley D; Baula, Victor; Tuttle, Wendy
low, V(b) transiently hyperpolarized to values near the equilibrium potential for K(+) and corresponded with the reduced neural response. These results support the hypothesis that chemosensory function of the skin is analogous to that of mammalian taste cells but utilizes paracellular ion transport...
Andreasson, E.; Jenkins, T.; Brodersen, P.
-dependent resistance, but does not interfere with induction of a defense gene by JA. Further yeast two-hybrid screening revealed that MKS1 interacts with the WRKY transcription factors WRKY25 and WRKY33. WRKY25 and WRKY33 were shown to be in vitro substrates of MPK4, and a wrky33 knockout mutant was found to exhibit...... increased expression of the SA-related defense gene PR1. MKS1 may therefore contribute to MPK4-regulated defense activation by coupling the kinase to specific WRKY transcription factors....... yeast two-hybrid screening to identify the MPK4 substrate MKS1. Analyses of transgenic plants and genome-wide transcript profiling indicated that MKS1 is required for full SA-dependent resistance in mpk4 mutants, and that overexpression of MKS1 in wild-type plants is sufficient to activate SA...
Dunn, Christopher P.; Scott, Michael L.
The influence of thermal disturbance and site characteristics on distribution of herbs was studied in portions of a 3020 ha wetland in the southeastern USA. Presence-absence of 52 species in 130 0.25 m2 plots was determined from four sites with different disturbance histories and from an undisturbed site. Data from the four disturbed sites were ordinated by detrended correspondence analysis. Differences in species composition among sites (coarse scale) were associated with water depth, light, and substrate type. Within a site (at a fine scale), correlation of environmental variables with ordination scores at a chronically disturbed site was weakly correlated with light (r=0.50). At two sites with episodic disturbance, species composition correlated significantly and positively with substrate and water depth. At a recovering site, vegetation patterns were moderately correlated with water depth (r=−0.52). Species richness was correlated with substrate type along the disturbance gradient. Our results are consistent the intermediate disturbance hypothesis and the subsidy-stress gradient concept.
When we experience an error during a movement, we update our motor commands to partially correct for this error on the next trial. How does experience of error produce the improvement in the subsequent motor commands? During the course of an erroneous reaching movement, proprioceptive and visual sensory pathways not only sense the error, but also engage feedback mechanisms, resulting in corrective motor responses that continue until the hand arrives at its goal. One possibility is that this feedback response is co-opted by the learning system and used as a template to improve performance on the next attempt. Here we used electromyography (EMG) to compare neural correlates of learning and feedback to test the hypothesis that the feedback response to error acts as a template for learning. We designed a task in which mixtures of error-clamp and force-field perturbation trials were used to deconstruct EMG time courses into error-feedback and learning components. We observed that the error-feedback response was composed of excitation of some muscles, and inhibition of others, producing a complex activation/deactivation pattern during the reach. Despite this complexity, across muscles the learning response was consistently a scaled version of the error-feedback response, but shifted 125 ms earlier in time. Across people, individuals who produced a greater feedback response to error, also learned more from error. This suggests that the feedback response to error serves as a teaching signal for the brain. Individuals who learn faster have a better teacher in their feedback control system. SIGNIFICANCE STATEMENT Our sensory organs transduce errors in behavior. To improve performance, we must generate better motor commands. How does the nervous system transform an error in sensory coordinates into better motor commands in muscle coordinates? Here we show that when an error occurs during a movement, the reflexes transform the sensory representation of error into motor
Phan, Mimi L.; Vicario, David S.
How do social interactions form and modulate the neural representations of specific complex signals? This question can be addressed in the songbird auditory system. Like humans, songbirds learn to vocalize by imitating tutors heard during development. These learned vocalizations are important in reproductive and social interactions and in individual recognition. As a model for the social reinforcement of particular songs, male zebra finches were trained to peck for a food reward in response to one song stimulus (GO) and to withhold responding for another (NoGO). After performance reached criterion, single and multiunit neural responses to both trained and novel stimuli were obtained from multiple electrodes inserted bilaterally into two songbird auditory processing areas [caudomedial mesopallium (CMM) and caudomedial nidopallium (NCM)] of awake, restrained birds. Neurons in these areas undergo stimulus-specific adaptation to repeated song stimuli, and responses to familiar stimuli adapt more slowly than to novel stimuli. The results show that auditory responses differed in NCM and CMM for trained (GO and NoGO) stimuli vs. novel song stimuli. When subjects were grouped by the number of training days required to reach criterion, fast learners showed larger neural responses and faster stimulus-specific adaptation to all stimuli than slow learners in both areas. Furthermore, responses in NCM of fast learners were more strongly left-lateralized than in slow learners. Thus auditory responses in these sensory areas not only encode stimulus familiarity, but also reflect behavioral reinforcement in our paradigm, and can potentially be modulated by social interactions. PMID:25475353
Morgan-Short, Kara; Finger, Ingrid; Grey, Sarah; Ullman, Michael T
Although learning a second language (L2) as an adult is notoriously difficult, research has shown that adults can indeed attain native language-like brain processing and high proficiency levels. However, it is important to then retain what has been attained, even in the absence of continued exposure to the L2--particularly since periods of minimal or no L2 exposure are common. This event-related potential (ERP) study of an artificial language tested performance and neural processing following a substantial period of no exposure. Adults learned to speak and comprehend the artificial language to high proficiency with either explicit, classroom-like, or implicit, immersion-like training, and then underwent several months of no exposure to the language. Surprisingly, proficiency did not decrease during this delay. Instead, it remained unchanged, and there was an increase in native-like neural processing of syntax, as evidenced by several ERP changes--including earlier, more reliable, and more left-lateralized anterior negativities, and more robust P600s, in response to word-order violations. Moreover, both the explicitly and implicitly trained groups showed increased native-like ERP patterns over the delay, indicating that such changes can hold independently of L2 training type. The results demonstrate that substantial periods with no L2 exposure are not necessarily detrimental. Rather, benefits may ensue from such periods of time even when there is no L2 exposure. Interestingly, both before and after the delay the implicitly trained group showed more native-like processing than the explicitly trained group, indicating that type of training also affects the attainment of native-like processing in the brain. Overall, the findings may be largely explained by a combination of forgetting and consolidation in declarative and procedural memory, on which L2 grammar learning appears to depend. The study has a range of implications, and suggests a research program with
Patel, Sona; Lodhavia, Anjli; Frankford, Saul; Korzyukov, Oleg; Larson, Charles R
It is known that singers are able to control their voice to maintain a relatively constant vocal quality while transitioning between vocal registers; however, the neural mechanisms underlying this effect are not understood. It was hypothesized that greater attention to the acoustical feedback of the voice and increased control of the vocal musculature during register transitions compared with singing within a register would be represented as neurological differences in event-related potentials. Nine singers sang musical notes at the high end of the modal register (the boundary between the modal and the head/falsetto registers) and at the low end (the boundary between the modal and the fry/pulse registers). While singing, the pitch of the voice auditory feedback was unexpectedly shifted either into the adjacent register ("toward" the register boundary) or within the modal register ("away from" the boundary). Singers were instructed to maintain a constant pitch and ignore any changes to their voice feedback. Vocal response latencies and magnitude of the accompanying N1 and P2 event-related potentials were greatest at the lower (modal-to-fry) boundary when the pitch shift carried the subjects' voices into the fry register as opposed to remaining within the modal register. These findings suggest that when a singer lowers the pitch of his or her voice such that it enters the fry register from the modal register, there is increased sensory-motor control of the voice, reflected as increased magnitude of the neura