Abstract Representations of Object-Directed Action in the Left Inferior Parietal Lobule.

Science.gov (United States)

Chen, Quanjing; Garcea, Frank E; Jacobs, Robert A; Mahon, Bradford Z

2018-06-01

Prior neuroimaging and neuropsychological research indicates that the left inferior parietal lobule in the human brain is a critical substrate for representing object manipulation knowledge. In the present functional MRI study we used multivoxel pattern analyses to test whether action similarity among objects can be decoded in the inferior parietal lobule independent of the task applied to objects (identification or pantomime) and stimulus format in which stimuli are presented (pictures or printed words). Participants pantomimed the use of objects, cued by printed words, or identified pictures of objects. Classifiers were trained and tested across task (e.g., training data: pantomime; testing data: identification), stimulus format (e.g., training data: word format; testing format: picture) and specific objects (e.g., training data: scissors vs. corkscrew; testing data: pliers vs. screwdriver). The only brain region in which action relations among objects could be decoded across task, stimulus format and objects was the inferior parietal lobule. By contrast, medial aspects of the ventral surface of the left temporal lobe represented object function, albeit not at the same level of abstractness as actions in the inferior parietal lobule. These results suggest compulsory access to abstract action information in the inferior parietal lobe even when simply identifying objects.

High Frequency rTMS over the Left Parietal Lobule Increases Non-Word Reading Accuracy

Science.gov (United States)

Costanzo, Floriana; Menghini, Deny; Caltagirone, Carlo; Oliveri, Massimiliano; Vicari, Stefano

2012-01-01

Increasing evidence in the literature supports the usefulness of Transcranial Magnetic Stimulation (TMS) in studying reading processes. Two brain regions are primarily involved in phonological decoding: the left superior temporal gyrus (STG), which is associated with the auditory representation of spoken words, and the left inferior parietal lobe…

The temporo-parietal junction contributes to global gestalt perception—evidence from studies in chess experts

Science.gov (United States)

Rennig, Johannes; Bilalić, Merim; Huberle, Elisabeth; Karnath, Hans-Otto; Himmelbach, Marc

2013-01-01

In a recent neuroimaging study the comparison of intact vs. disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ) in the intact perception of global gestalt (Huberle and Karnath, 2012). This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2010, 2011a,b, 2012). Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012) and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations. PMID:24009574

The temporo-parietal junction contributes to global gestalt perception-evidence from studies in chess experts.

Science.gov (United States)

Rennig, Johannes; Bilalić, Merim; Huberle, Elisabeth; Karnath, Hans-Otto; Himmelbach, Marc

2013-01-01

In a recent neuroimaging study the comparison of intact vs. disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ) in the intact perception of global gestalt (Huberle and Karnath, 2012). This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2010, 2011a,b, 2012). Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012) and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations.

Abnormal Brain Activation During Theory of Mind Tasks in Schizophrenia: A Meta-Analysis.

Science.gov (United States)

Kronbichler, Lisa; Tschernegg, Melanie; Martin, Anna Isabel; Schurz, Matthias; Kronbichler, Martin

2017-10-21

Social cognition abilities are severely impaired in schizophrenia (SZ). The current meta-analysis used foci of 21 individual studies on functional abnormalities in the schizophrenic brain in order to identify regions that reveal convergent under- or over-activation during theory of mind (TOM) tasks. Studies were included in the analyses when contrasting tasks that require the processing of mental states with tasks which did not. Only studies that investigated patients with an ICD or DSM diagnosis were included. Quantitative voxel-based meta-analyses were done using Seed-based d Mapping software. Common TOM regions like medial-prefrontal cortex and temporo-parietal junction revealed abnormal activation in schizophrenic patients: Under-activation was identified in the medial prefrontal cortex, left orbito-frontal cortex, and in a small section of the left posterior temporo-parietal junction. Remarkably, robust over-activation was identified in a more dorsal, bilateral section of the temporo-parietal junction. Further abnormal activation was identified in medial occipito-parietal cortex, right premotor areas, left cingulate gyrus, and lingual gyrus. The findings of this study suggest that SZ patients simultaneously show over- and under-activation in TOM-related regions. Especially interesting, temporo-parietal junction reveals diverging activation patterns with an under-activating left posterior and an over-activating bilateral dorsal section. In conclusion, SZ patients show less specialized brain activation in regions linked to TOM and increased activation in attention-related networks suggesting compensatory effects. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center.

Dysregulated left inferior parietal activity in schizophrenia and depression: functional connectivity and characterization

Directory of Open Access Journals (Sweden)

Veronika I. Müller

2013-06-01

Full Text Available The inferior parietal cortex (IPC is a heterogeneous region that is known to be involved in a multitude of diverse different tasks and processes, though its contribution to these often-complex functions is yet poorly understood. In a previous study we demonstrated that patients with depression failed to deactivate the left IPC during processing of congruent audiovisual information. We now found the same dysregulation (same region and condition in schizophrenia. By using task-independent (resting state and task-dependent (MACM analyses we aimed at characterizing this particular region with regard to its connectivity and function. Across both approaches, results revealed functional connectivity of the left inferior parietal seed region with bilateral IPC, precuneus and posterior cingulate cortex (PrC/PCC, medial orbitofrontal cortex (mOFC, left middle frontal (MFG as well as inferior frontal (IFG gyrus. Network-level functional characterization further revealed that on the one hand, all interconnected regions are part of a network involved in memory processes. On the other hand, sub-networks are formed when emotion, language, social cognition and reasoning processes are required. Thus, the IPC-region that is dysregulated in both depression and schizophrenia is functionally connected to a network of regions which, depending on task demands may form sub-networks. These results therefore indicate that dysregulation of left IPC in depression and schizophrenia might not only be connected to deficits in audiovisual integration, but is possibly also associated to impaired memory and deficits in emotion processing in these patient groups.

Interpersonal brain synchronization in the right temporo-parietal junction during face-to-face economic exchange.

Science.gov (United States)

Tang, Honghong; Mai, Xiaoqin; Wang, Shun; Zhu, Chaozhe; Krueger, Frank; Liu, Chao

2016-01-01

In daily life, interpersonal interactions are influenced by uncertainty about other people's intentions. Face-to-face (FF) interaction reduces such uncertainty by providing external visible cues such as facial expression or body gestures and facilitates shared intentionality to promote belief of cooperative decisions and actual cooperative behaviors in interaction. However, so far little is known about interpersonal brain synchronization between two people engaged in naturally occurring FF interactions. In this study, we combined an adapted ultimatum game with functional near-infrared spectroscopy (fNIRS) hyperscanning to investigate how FF interaction impacts interpersonal brain synchronization during economic exchange. Pairs of strangers interacted repeatedly either FF or face-blocked (FB), while their activation was simultaneously measured in the right temporo-parietal junction (rTPJ) and the control region, right dorsolateral prefrontal cortex (rDLPFC). Behaviorally, FF interactions increased shared intentionality between strangers, leading more positive belief of cooperative decisions and more actual gains in the game. FNIRS results indicated increased interpersonal brain synchronizations during FF interactions in rTPJ (but not in rDLPFC) with greater shared intentionality between partners. These results highlighted the importance of rTPJ in collaborative social interactions during FF economic exchange and warrant future research that combines FF interactions with fNIRS hyperscanning to study social brain disorders such as autism. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Task-irrelevant memory load induces inattentional blindness without temporo-parietal suppression.

Science.gov (United States)

Matsuyoshi, Daisuke; Ikeda, Takashi; Sawamoto, Nobukatsu; Kakigi, Ryusuke; Fukuyama, Hidenao; Osaka, Naoyuki

2010-08-01

We often fail to consciously detect an unexpected object when we are engaged in an attention-demanding task (inattentional blindness). The inattentional blindness which is induced by visual short-term memory (VSTM) load has been proposed to result from a suppression of temporo-parietal junction (TPJ) activity that involves stimulus-driven attention. However, the fact that, inversely proportional to TPJ activity, intraparietal sulcus (IPS) activity correlates with VSTM load renders questionable the account of inattentional blindness based only on TPJ activity. Here, we investigated whether the TPJ is solely responsible for inattentional blindness by decoupling IPS and TPJ responses to VSTM load and then using the same manipulation to test the behavioral inattentional blindness performance. Experiment 1 showed that TPJ activity was not suppressed by task-irrelevant load while the IPS responded to both task-relevant and task-irrelevant load. Although the TPJ account of inattentional blindness predicts that the degree of inattentional blindness should track TPJ activity, we found in Experiment 2 that inattentional blindness was induced not only by task-relevant load but also by task-irrelevant load, showing inconsistency between the extent of inattentional blindness and TPJ response. These findings suggest that inattentional blindness can be induced without suppression of TPJ activity and seem to offer the possibility that the IPS contributes to conscious perception. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Short and long term effects of left and bilateral repetitive transcranial magnetic stimulation in schizophrenia patients with auditory verbal hallucinations: a randomized controlled trial.

Directory of Open Access Journals (Sweden)

Leonie Bais

Full Text Available BACKGROUND: Repetitive transcranial magnetic stimulation of the left temporo-parietal junction area has been studied as a treatment option for auditory verbal hallucinations. Although the right temporo-parietal junction area has also shown involvement in the genesis of auditory verbal hallucinations, no studies have used bilateral stimulation. Moreover, little is known about durability effects. We studied the short and long term effects of 1 Hz treatment of the left temporo-parietal junction area in schizophrenia patients with persistent auditory verbal hallucinations, compared to sham stimulation, and added an extra treatment arm of bilateral TPJ area stimulation. METHODS: In this randomized controlled trial, 51 patients diagnosed with schizophrenia and persistent auditory verbal hallucinations were randomly allocated to treatment of the left or bilateral temporo-parietal junction area or sham treatment. Patients were treated for six days, twice daily for 20 minutes. Short term efficacy was measured with the Positive and Negative Syndrome Scale (PANSS, the Auditory Hallucinations Rating Scale (AHRS, and the Positive and Negative Affect Scale (PANAS. We included follow-up measures with the AHRS and PANAS at four weeks and three months. RESULTS: The interaction between time and treatment for Hallucination item P3 of the PANSS showed a trend for significance, caused by a small reduction of scores in the left group. Although self-reported hallucination scores, as measured with the AHRS and PANAS, decreased significantly during the trial period, there were no differences between the three treatment groups. CONCLUSION: We did not find convincing evidence for the efficacy of left-sided rTMS, compared to sham rTMS. Moreover, bilateral rTMS was not superior over left rTMS or sham in improving AVH. Optimizing treatment parameters may result in stronger evidence for the efficacy of rTMS treatment of AVH. Moreover, future research should consider

The temporo-parietal junction contributes to global gestalt perception – evidence from studies in chess experts

Directory of Open Access Journals (Sweden)

Johannes eRennig

2013-08-01

Full Text Available In a recent neuroimaging study the comparison of intact versus disturbed perception of global gestalt indicated a significant role of the temporo-parietal junction (TPJ in the intact perception of global gestalt (Huberle and Karnath, 2012. This location corresponded well with the areas known to be damaged or impaired in patients with simultanagnosia after stroke or due to neurodegenerative diseases. It was concluded that the TPJ plays an important role in the integration of individual items to a holistic percept. Thus, increased BOLD signals should be found in this region whenever a task calls for the integration of multiple visual items. Behavioral experiments in chess experts suggested that their superior skills in comparison to chess novices are partly based on fast holistic processing of chess positions with multiple pieces. We thus analyzed BOLD data from four fMRI studies that compared chess experts with chess novices during the presentation of complex chess-related visual stimuli (Bilalić et al., 2011a, 2010, 2011b, 2012. Three regions of interests were defined by significant TPJ clusters in the abovementioned study of global gestalt perception (Huberle and Karnath, 2012 and BOLD signal amplitudes in these regions were compared between chess experts and novices. These cross-paradigm ROI analyses revealed higher signals at the TPJ in chess experts in comparison to novices during presentations of complex chess positions. This difference was consistent across the different tasks in five independent experiments. Our results confirm the assumption that the TPJ region identified in previous work on global gestalt perception plays an important role in the processing of complex visual stimulus configurations.

Temporo-parietal dysfunction in Tourette syndrome: Insights from an fMRI study of Theory of Mind.

Science.gov (United States)

Eddy, Clare M; Cavanna, Andrea E; Rickards, Hugh E; Hansen, Peter C

2016-10-01

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by tics, repetitive movements and vocalizations which are prompted by a sensory-cognitive premonitory urge. Complex tics include environmentally dependent social behaviors such as echoing of other people's speech and actions. Recent studies have suggested that adults with TS can show differences to controls in Theory of Mind (ToM): reasoning about mental states (e.g. beliefs, emotions). In this study, twenty-five adults with uncomplicated TS (no co-morbid disorders, moderate tic severity), and twenty-five healthy age and gender matched controls were scanned with fMRI during an established ToM task. Neural activity was contrasted across ToM trials involving reasoning about false-belief, and matched trials requiring judgments about physical states rather than mental states. Contrasting task conditions uncovered differential fMRI activation in TS during ToM involving the right temporo-parietal junction (TPJ), right amygdala and posterior cingulate. Further analysis revealed that activity within the right TPJ as localised by this task covaried with the severity of symptoms including echophenomena, impulse control problems and premonitory urges in TS. Amygdala activation was also linked to premonitory urges, while activity in the left TPJ during ToM was linked to ratings of non-obscene socially inappropriate symptoms. These findings indicate that patients with TS exhibit atypical functional activation within key neural substrates involved in ToM. More generally, our data could highlight an important role for TPJ dysfunction in driving compulsive behaviors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Differential contribution of right and left temporo-occipital and anterior temporal lesions to face recognition disorders

Directory of Open Access Journals (Sweden)

Guido eGainotti

2011-06-01

Full Text Available In the study of prosopagnosia, several issues (such as the specific or non-specific manifestations of prosopagnosia, the unitary or non-unitary nature of this syndrome and the mechanisms underlying face recognition disorders are still controversial. Two main sources of variance partially accounting for these controversies could be the qualitative differences between the face recognition disorders observed in patients with prevalent lesions of the right or left hemisphere and in those with lesions encroaching upon the temporo-occipital or the (right anterior temporal cortex.Results of our review seem to confirm these suggestions. Indeed, they show that (a the most specific forms of prosopagnosia are due to lesions of a right posterior network including the OFA and the FFA, whereas (b the face identification defects observed in patients with left temporo-occipital lesions seem due to a semantic defect impeding access to person-specific semantic information from the visual modality. Furthermore, face recognition defects resulting from right anterior temporal lesions can usually be considered as part of a multimodal people recognition disorder.The implications of our review are, therefore, the following: (1 to consider the components of visual agnosia often observed in prosopagnosic patients with bilateral temporo-occipital lesions as part of a semantic defect, resulting from left-sided lesions (and not from prosopagnosia proper; (2 to systematically investigate voice recognition disorders in patients with right anterior temporal lesions to determine whether the face recognition defect should be considered a form of ‘associative prosopagnosia’ or a form of the ‘multimodal people recognition disorder’.

Right hemisphere dominance during spatial selective attention and target detection occurs outside the dorsal fronto-parietal network

Science.gov (United States)

Shulman, Gordon L.; Pope, Daniel L. W.; Astafiev, Serguei V.; McAvoy, Mark P.; Snyder, Abraham Z.; Corbetta, Maurizio

2010-01-01

Spatial selective attention is widely considered to be right hemisphere dominant. Previous functional magnetic resonance imaging (fMRI) studies, however, have reported bilateral blood-oxygenation-level-dependent (BOLD) responses in dorsal fronto-parietal regions during anticipatory shifts of attention to a location (Kastner et al., 1999; Corbetta et al., 2000; Hopfinger et al., 2000). Right-lateralized activity has mainly been reported in ventral fronto-parietal regions for shifts of attention to an unattended target stimulus (Arrington et al., 2000; Corbetta et al., 2000). However, clear conclusions cannot be drawn from these studies because hemispheric asymmetries were not assessed using direct voxel-wise comparisons of activity in left and right hemispheres. Here, we used this technique to measure hemispheric asymmetries during shifts of spatial attention evoked by a peripheral cue stimulus and during target detection at the cued location. Stimulus-driven shifts of spatial attention in both visual fields evoked right-hemisphere dominant activity in temporo-parietal junction (TPJ). Target detection at the attended location produced a more widespread right hemisphere dominance in frontal, parietal, and temporal cortex, including the TPJ region asymmetrically activated during shifts of spatial attention. However, hemispheric asymmetries were not observed during either shifts of attention or target detection in the dorsal fronto-parietal regions (anterior precuneus, medial intraparietal sulcus, frontal eye fields) that showed the most robust activations for shifts of attention. Therefore, right hemisphere dominance during stimulus-driven shifts of spatial attention and target detection reflects asymmetries in cortical regions that are largely distinct from the dorsal fronto-parietal network involved in the control of selective attention. PMID:20219998

Functional specialization of the left ventral parietal cortex in working memory

Directory of Open Access Journals (Sweden)

Jennifer Lou Langel

2014-06-01

Full Text Available The function of the ventral parietal cortex (VPC is subject to much debate. Many studies suggest a lateralization of function in the VPC, with the left hemisphere facilitating verbal working memory and the right subserving stimulus-driven attention. However, many attentional tasks elicit activity in the VPC bilaterally. To elucidate the potential divides across the VPC in function, we assessed the pattern of activity in the VPC bilaterally across two tasks that require different demands, an oddball attentional task with low working memory demands and a working memory task. An anterior region of the VPC was bilaterally active during novel targets in the oddball task and during retrieval in WM, while more posterior regions of the VPC displayed dissociable functions in the left and right hemisphere, with the left being active during the encoding and retrieval of WM, but not during the oddball task and the right showing the reverse pattern. These results suggest that bilateral regions of the anterior VPC subserve non-mnemonic processes, such as stimulus-driven attention during WM retrieval and oddball detection. The left posterior VPC may be important for speech-related processing important for both working memory and perception, while the right hemisphere is more lateralized for attention.

Intradiploic encephalocele of the left parietal bone: A case report

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok [Myongji St. Mary' s Hospital, Seoul (Korea, Republic of)

2015-06-15

Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood.

Intradiploic encephalocele of the left parietal bone: A case report

International Nuclear Information System (INIS)

Kim, Hyung Sock; Huh, Choon Woong; Kim, Dal Soo; Mok, Jin Ho; Kim, In Soo; Yang, Geun Seok

2015-01-01

Encephaloceles are generally regarded as midline abnormalities. A 50-year-old man presented with a parietal intradiploic encephalocele manifesting as intermittent headache for the past 6 months. Computed tomography (CT) showed bone destruction associated with a left parietal lesion. Magnetic resonance imaging (MRI) demonstrated brain herniation within the intradiploic space. Cerebral angiographic imaging showed a normal cerebral vessel pattern within the herniated brain lesion. In this case, surgical treatment may not be necessary in the absence of concurrent symptoms and neurologic deficit. We report the CT, MRI, and angiographic findings of an extremely rare case of parietal intradiploic encephalocele in adulthood

Reappraising social emotions: the role of inferior frontal gyrus, temporo-parietal junction and insula in interpersonal emotion regulation.

Science.gov (United States)

Grecucci, Alessandro; Giorgetta, Cinzia; Bonini, Nicolao; Sanfey, Alan G

2013-01-01

Previous studies have reported the effect of emotion regulation (ER) strategies on both individual and social decision-making, however, the effect of regulation on socially driven emotions independent of decisions is still unclear. In the present study, we investigated the neural effects of using reappraisal to both up- and down-regulate socially driven emotions. Participants played the Dictator Game (DG) in the role of recipient while undergoing fMRI, and concurrently applied the strategies of either up-regulation (reappraising the proposer's intentions as more negative), down-regulation (reappraising the proposer's intentions as less negative), as well as a baseline "look" condition. Results showed that regions responding to the implementation of reappraisal (effect of strategy, that is, "regulating regions") were the inferior and middle frontal gyrus, temporo parietal junction and insula bilaterally. Importantly, the middle frontal gyrus activation correlated with the frequency of regulatory strategies in daily life, with the insula activation correlating with the perceived ability to reappraise the emotions elicited by the social situation. Regions regulated by reappraisal (effect of regulation, that is, "regulated regions") were the striatum, the posterior cingulate and the insula, showing increased activation for the up-regulation and reduced activation for down-regulation, both compared to the baseline condition. When analyzing the separate effects of partners' behavior, selfish behavior produced an activation of the insula, not observed when subjects were treated altruistically. Here we show for the first time that interpersonal ER strategies can strongly affect neural responses when experiencing socially driven emotions. Clinical implications of these findings are also discussed to understand how the way we interpret others' intentions may affect the way we emotionally react.

Reappraising social emotions: the role of inferior frontal gyrus, temporo-parietal junction and insula in interpersonal emotion regulation

Directory of Open Access Journals (Sweden)

Alessandro eGrecucci

2013-09-01

Full Text Available Previous studies have reported the effect of emotion regulation strategies on both individual and social decision making, however the effect of regulation on socially driven emotions independent of decisions is still unclear. In the present study, we investigated the neural effects of using reappraisal to both up- and down-regulate socially driven emotions. Participants played the Dictator Game in the role of recipient while undergoing fMRI, and concurrently applied the strategies of either up-regulation (reappraising the proposer’s intentions as more negative, down-regulation (reappraising the proposer’s intentions as less negative, as well as a baseline ‘look’ condition. Results showed that regions responding to the implementation of reappraisal (effect of strategy, that is, regulating regions were the inferior and middle frontal gyrus, temporo parietal junction and insula bilaterally. Importantly, the middle frontal gyrus activation correlated with the frequency of regulatory strategies in daily life, with the insula activation correlating with the perceived ability to reappraise the emotions elicited by the social situation. Regions regulated by reappraisal (effect of regulation, that is, regulated regions were the striatum, the posterior cingulate and the insula, showing increased activation for the up-regulation and reduced activation for down-regulation, both compared to the baseline condition. When analyzing the separate effects of partners’ behavior, selfish behavior produced an activation of the insula, not observed when subjects were treated altruistically. Here we show for the first time that interpersonal emotion regulation strategies can strongly affect neural responses when experiencing socially driven emotions. Clinical implications of these findings are also discussed to understand how the way we interpret others’ intentions may affect the way we emotionally react.

Haptically guided grasping. FMRI shows right-hemisphere parietal stimulus encoding, and bilateral dorso-ventral parietal gradients of object- and action-related processing during grasp execution

Directory of Open Access Journals (Sweden)

Mattia eMarangon

2016-01-01

Full Text Available The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks. None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

Role of the right inferior parietal cortex in auditory selective attention: An rTMS study.

Science.gov (United States)

Bareham, Corinne A; Georgieva, Stanimira D; Kamke, Marc R; Lloyd, David; Bekinschtein, Tristan A; Mattingley, Jason B

2018-02-01

Selective attention is the process of directing limited capacity resources to behaviourally relevant stimuli while ignoring competing stimuli that are currently irrelevant. Studies in healthy human participants and in individuals with focal brain lesions have suggested that the right parietal cortex is crucial for resolving competition for attention. Following right-hemisphere damage, for example, patients may have difficulty reporting a brief, left-sided stimulus if it occurs with a competitor on the right, even though the same left stimulus is reported normally when it occurs alone. Such "extinction" of contralesional stimuli has been documented for all the major sense modalities, but it remains unclear whether its occurrence reflects involvement of one or more specific subregions of the temporo-parietal cortex. Here we employed repetitive transcranial magnetic stimulation (rTMS) over the right hemisphere to examine the effect of disruption of two candidate regions - the supramarginal gyrus (SMG) and the superior temporal gyrus (STG) - on auditory selective attention. Eighteen neurologically normal, right-handed participants performed an auditory task, in which they had to detect target digits presented within simultaneous dichotic streams of spoken distractor letters in the left and right channels, both before and after 20 min of 1 Hz rTMS over the SMG, STG or a somatosensory control site (S1). Across blocks, participants were asked to report on auditory streams in the left, right, or both channels, which yielded focused and divided attention conditions. Performance was unchanged for the two focused attention conditions, regardless of stimulation site, but was selectively impaired for contralateral left-sided targets in the divided attention condition following stimulation of the right SMG, but not the STG or S1. Our findings suggest a causal role for the right inferior parietal cortex in auditory selective attention. Copyright © 2017 Elsevier Ltd. All rights

Haptically Guided Grasping. fMRI Shows Right-Hemisphere Parietal Stimulus Encoding, and Bilateral Dorso-Ventral Parietal Gradients of Object- and Action-Related Processing during Grasp Execution.

Science.gov (United States)

Marangon, Mattia; Kubiak, Agnieszka; Króliczak, Gregory

2015-01-01

The neural bases of haptically-guided grasp planning and execution are largely unknown, especially for stimuli having no visual representations. Therefore, we used functional magnetic resonance imaging (fMRI) to monitor brain activity during haptic exploration of novel 3D complex objects, subsequent grasp planning, and the execution of the pre-planned grasps. Haptic object exploration, involving extraction of shape, orientation, and length of the to-be-grasped targets, was associated with the fronto-parietal, temporo-occipital, and insular cortex activity. Yet, only the anterior divisions of the posterior parietal cortex (PPC) of the right hemisphere were significantly more engaged in exploration of complex objects (vs. simple control disks). None of these regions were re-recruited during the planning phase. Even more surprisingly, the left-hemisphere intraparietal, temporal, and occipital areas that were significantly invoked for grasp planning did not show sensitivity to object features. Finally, grasp execution, involving the re-recruitment of the critical right-hemisphere PPC clusters, was also significantly associated with two kinds of bilateral parieto-frontal processes. The first represents transformations of grasp-relevant target features and is linked to the dorso-dorsal (lateral and medial) parieto-frontal networks. The second monitors grasp kinematics and belongs to the ventro-dorsal networks. Indeed, signal modulations associated with these distinct functions follow dorso-ventral gradients, with left aIPS showing significant sensitivity to both target features and the characteristics of the required grasp. Thus, our results from the haptic domain are consistent with the notion that the parietal processing for action guidance reflects primarily transformations from object-related to effector-related coding, and these mechanisms are rather independent of sensory input modality.

Regional cerebral blood flow in endogenous depression

International Nuclear Information System (INIS)

Sagawa, Katsuo; Morinobu, Shigeru; Kawakatsu, Shinobu

1990-01-01

The subjects were twenty-nine depressed patients who met the DSM-III rd criteria for bipolar disorder or major depression. The rCBF was determined by the Xe-133 inhalation method (HEADTOME: ring type SPECT). There were no significant differences in the rCBF values between the patients with bipolar depression and normal controls. The rCBF values of patients with unipolar depression were significantly lower than those of controls, especially in the left temporo-parietal region (p L) were more noticeable (p<0.01) in unipolar depression patients than in bipolar depression patients. (author)

A postural `stressed` cerebral HMPAO case study

Energy Technology Data Exchange (ETDEWEB)

Williams, R.C.; Jost, G.M.; Bolitho, L.; Grantham, M. [Wangaratta District Hospital, VIC (Australia)

1998-03-01

Full text: This case study represents an example of the utility of postural hypoperfusion stressed HMPAO SPECT. An elderly woman of 78 with a long history of giddiness was referred to our laboratory for examination of possible cerebral ischaemia. She had recurrent dizzy episodes, sometimes posture related, over the past few years and had suffered several falls. Cerebral DSA revealed minimal disease. CT scans were reported as normal. Carotid duplex Doppler studies revealed bilateral plaque disease in the carotid bulbs extending to the origins of the ICAs which were not significant stenoses. Postural symptoms were induced by standing the patient up rapidly and HMPAO was administered at the same time. A SPECT scan of the brain was performed. Quantitative analysis showed a left to right decrease of 10.8% in the temporo-occipital area, 5.6% in the temporo-parietal area and 2.5% in the cerebellar and parietal areas. Images revealed moderately reduced tracer concentration in the left half of the cerebellum and the left occipital region extending as far forward as the temporo-parietal region A repeat HMPAO SPECT scan without stress was normal. This would appear to indicate reversible ischaemia in the left posterior region, and is consistent with the reported symptoms. This case illustrates the usefulness of HMPAO in the diagnosis of reversible cerebral ischaemia.

A postural 'stressed' cerebral HMPAO case study

International Nuclear Information System (INIS)

Williams, R.C.; Jost, G.M.; Bolitho, L.; Grantham, M.

1998-01-01

Full text: This case study represents an example of the utility of postural hypoperfusion stressed HMPAO SPECT. An elderly woman of 78 with a long history of giddiness was referred to our laboratory for examination of possible cerebral ischaemia. She had recurrent dizzy episodes, sometimes posture related, over the past few years and had suffered several falls. Cerebral DSA revealed minimal disease. CT scans were reported as normal. Carotid duplex Doppler studies revealed bilateral plaque disease in the carotid bulbs extending to the origins of the ICAs which were not significant stenoses. Postural symptoms were induced by standing the patient up rapidly and HMPAO was administered at the same time. A SPECT scan of the brain was performed. Quantitative analysis showed a left to right decrease of 10.8% in the temporo-occipital area, 5.6% in the temporo-parietal area and 2.5% in the cerebellar and parietal areas. Images revealed moderately reduced tracer concentration in the left half of the cerebellum and the left occipital region extending as far forward as the temporo-parietal region A repeat HMPAO SPECT scan without stress was normal. This would appear to indicate reversible ischaemia in the left posterior region, and is consistent with the reported symptoms. This case illustrates the usefulness of HMPAO in the diagnosis of reversible cerebral ischaemia

Developmental dyscalculia: compensatory mechanisms in left intraparietal regions in response to nonsymbolic magnitudes.

Science.gov (United States)

Kaufmann, Liane; Vogel, Stephan E; Starke, Marc; Kremser, Christian; Schocke, Michael; Wood, Guilherme

2009-08-05

Functional magnetic resonance imaging (fMRI) studies investigating the neural mechanisms underlying developmental dyscalculia are scarce and results are thus far inconclusive. Main aim of the present study is to investigate the neural correlates of nonsymbolic number magnitude processing in children with and without dyscalculia. 18 children (9 with dyscalculia) were asked to solve a non-symbolic number magnitude comparison task (finger patterns) during brain scanning. For the spatial control task identical stimuli were employed, instructions varying only (judgment of palm rotation). This design enabled us to present identical stimuli with identical visual processing requirements in the experimental and the control task. Moreover, because numerical and spatial processing relies on parietal brain regions, task-specific contrasts are expected to reveal true number-specific activations. Behavioral results during scanning reveal that despite comparable (almost at ceiling) performance levels, task-specific activations were stronger in dyscalculic children in inferior parietal cortices bilaterally (intraparietal sulcus, supramarginal gyrus, extending to left angular gyrus). Interestingly, fMRI signal strengths reflected a group x task interaction: relative to baseline, controls produced significant deactivations in (intra)parietal regions bilaterally in response to number but not spatial processing, while the opposite pattern emerged in dyscalculics. Moreover, beta weights in response to number processing differed significantly between groups in left - but not right - (intra)parietal regions (becoming even positive in dyscalculic children). Overall, findings are suggestive of (a) less consistent neural activity in right (intra)parietal regions upon processing nonsymbolic number magnitudes; and (b) compensatory neural activity in left (intra)parietal regions in developmental dyscalculia.

Specifying the brain anatomy underlying temporo-parietal junction activations for theory of mind: A review using probabilistic atlases from different imaging modalities.

Science.gov (United States)

Schurz, Matthias; Tholen, Matthias G; Perner, Josef; Mars, Rogier B; Sallet, Jerome

2017-09-01

In this quantitative review, we specified the anatomical basis of brain activity reported in the Temporo-Parietal Junction (TPJ) in Theory of Mind (ToM) research. Using probabilistic brain atlases, we labeled TPJ peak coordinates reported in the literature. This was carried out for four different atlas modalities: (i) gyral-parcellation, (ii) sulco-gyral parcellation, (iii) cytoarchitectonic parcellation and (iv) connectivity-based parcellation. In addition, our review distinguished between two ToM task types (false belief and social animations) and a nonsocial task (attention reorienting). We estimated the mean probabilities of activation for each atlas label, and found that for all three task types part of TPJ activations fell into the same areas: (i) Angular Gyrus (AG) and Lateral Occpital Cortex (LOC) in terms of a gyral atlas, (ii) AG and Superior Temporal Sulcus (STS) in terms of a sulco-gyral atlas, (iii) areas PGa and PGp in terms of cytoarchitecture and (iv) area TPJp in terms of a connectivity-based parcellation atlas. Beside these commonalities, we also found that individual task types showed preferential activation for particular labels. Main findings for the right hemisphere were preferential activation for false belief tasks in AG/PGa, and in Supramarginal Gyrus (SMG)/PFm for attention reorienting. Social animations showed strongest selective activation in the left hemisphere, specifically in left Middle Temporal Gyrus (MTG). We discuss how our results (i.e., identified atlas structures) can provide a new reference for describing future findings, with the aim to integrate different labels and terminologies used for studying brain activity around the TPJ. Hum Brain Mapp 38:4788-4805, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Tracing short connections of the temporo-parieto-occipital region in the human brain using diffusion spectrum imaging and fiber dissection.

Science.gov (United States)

Wu, Yupeng; Sun, Dandan; Wang, Yong; Wang, Yunjie; Wang, Yibao

2016-09-01

The temporo-parieto-occipital (TPO) junction plays a unique role in human high-level neurological functions. Long-range fibers from and to this area have been described in detail but little is known about short TPO tracts mediating local connectivity. In this study, we performed high angular diffusion spectrum imaging (DSI) analyses to visualize the short TPO connections in the human brain. Fiber tracking was conducted on a subject-specific approach (10 subjects) and a template of 90 subjects (NTU-90 Atlas). Three tracts were identified: posterior segment of the superior longitudinal fasciculus (SLF-V), connecting the posterior part of the middle and inferior temporal gyri with the angular gyrus and supramarginal gyrus, vertical occipital fasciculus (VOF), connecting the inferior parietal with the lower temporal and occipital lobe, and a novel temporo-parietal (TP) connection, interconnecting the inferior temporal gyrus, middle temporal gyrus and fusiform gyrus, and inferior occipital lobe with the superior parietal lobe. These studies were complemented by fiber dissection techniques. It is the first study that demonstrated the trajectory and connectivity of the VOF using fiber dissection, as well as displayed the spatial relationship of the SLF-V with the cortex and the adjacent fiber bundles on one dissecting hemisphere. By providing a more accurate and detailed description of the local connectivity of the TPO junction, our findings help to develop new insights into its functional role in the human brain. Copyright © 2016 Elsevier B.V. All rights reserved.

Reappraising social emotions: the role of inferior frontal gyrus, temporo-parietal junction and insula in interpersonal emotion regulation

Science.gov (United States)

Grecucci, Alessandro; Giorgetta, Cinzia; Bonini, Nicolao; Sanfey, Alan G.

2013-01-01

Previous studies have reported the effect of emotion regulation (ER) strategies on both individual and social decision-making, however, the effect of regulation on socially driven emotions independent of decisions is still unclear. In the present study, we investigated the neural effects of using reappraisal to both up- and down-regulate socially driven emotions. Participants played the Dictator Game (DG) in the role of recipient while undergoing fMRI, and concurrently applied the strategies of either up-regulation (reappraising the proposer's intentions as more negative), down-regulation (reappraising the proposer's intentions as less negative), as well as a baseline “look” condition. Results showed that regions responding to the implementation of reappraisal (effect of strategy, that is, “regulating regions”) were the inferior and middle frontal gyrus, temporo parietal junction and insula bilaterally. Importantly, the middle frontal gyrus activation correlated with the frequency of regulatory strategies in daily life, with the insula activation correlating with the perceived ability to reappraise the emotions elicited by the social situation. Regions regulated by reappraisal (effect of regulation, that is, “regulated regions”) were the striatum, the posterior cingulate and the insula, showing increased activation for the up-regulation and reduced activation for down-regulation, both compared to the baseline condition. When analyzing the separate effects of partners' behavior, selfish behavior produced an activation of the insula, not observed when subjects were treated altruistically. Here we show for the first time that interpersonal ER strategies can strongly affect neural responses when experiencing socially driven emotions. Clinical implications of these findings are also discussed to understand how the way we interpret others' intentions may affect the way we emotionally react. PMID:24027512

Improving ideomotor limb apraxia by electrical stimulation of the left posterior parietal cortex.

Science.gov (United States)

Bolognini, Nadia; Convento, Silvia; Banco, Elisabetta; Mattioli, Flavia; Tesio, Luigi; Vallar, Giuseppe

2015-02-01

Limb apraxia, a deficit of planning voluntary gestures, is most frequently caused by damage to the left hemisphere, where, according to an influential neurofunctional model, gestures are planned, before being executed through the motor cortex of the hemisphere contralateral to the acting hand. We used anodal transcranial direct current stimulation delivered to the left posterior parietal cortex (PPC), the right motor cortex (M1), and a sham stimulation condition, to modulate the ability of six left-brain-damaged patients with ideomotor apraxia, and six healthy control subjects, to imitate hand gestures, and to perform skilled hand movements using the left hand. Transcranial direct current stimulation delivered to the left PPC reduced the time required to perform skilled movements, and planning, but not execution, times in imitating gestures, in both patients and controls. In patients, the amount of decrease of planning times brought about by left PPC transcranial direct current stimulation was influenced by the size of the parietal lobe damage, with a larger parietal damage being associated with a smaller improvement. Of interest from a clinical perspective, left PPC stimulation also ameliorated accuracy in imitating hand gestures in patients. Instead, transcranial direct current stimulation to the right M1 diminished execution, but not planning, times in both patients and healthy controls. In conclusion, by using a transcranial stimulation approach, we temporarily improved ideomotor apraxia in the left hand of left-brain-damaged patients, showing a role of the left PPC in planning gestures. This evidence opens up novel perspectives for the use of transcranial direct current stimulation in the rehabilitation of limb apraxia. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Using tDCS to Explore the Role of the Right Temporo-Parietal Junction in Theory of Mind and Cognitive Empathy.

Science.gov (United States)

Mai, Xiaoqin; Zhang, Wenli; Hu, Xinmu; Zhen, Zhen; Xu, Zhenhua; Zhang, Jing; Liu, Chao

2016-01-01

The right temporo-parietal junction (rTPJ) is thought to be closely related to theory of mind (ToM) and cognitive empathy. In the present study, we investigated whether these socio-cognitive abilities could be modulated with non-invasive transcranial direct current stimulation (tDCS) of the rTPJ. Participants received anodal (excitatory), cathodal (inhibitory), or sham stimulation before performing a social cognitive task which included inferring other's intention (the ToM condition) and inferring other's emotion (the cognitive empathy condition). Our results showed that the accuracy of both ToM and cognitive empathy decreased after receiving the cathodal stimulation, suggesting that altering the cortical excitability in the rTPJ could influence human's socio-cognitive abilities. The results of this study emphasize the critical role of the rTPJ in ToM and cognitive empathy and demonstrate that these socio-cognitive abilities could be modulated by the tDCS.

[Trigeminal motor paralysis and dislocation of the temporo-mandibular joints].

Science.gov (United States)

Ohkawa, S; Yoshida, T; Ohsumi, Y; Tabuchi, M

1996-07-01

A 64-year-old woman with diabetes mellitus was admitted to our hospital with left hemiparesis of sudden onset. A brain MRI demonstrated a cerebral infarction in the ventral part of the right lower pons. When left hemiparesis worsened, she had dislocation of the temporo-mandibular joints repeatedly. Then, her lower jaw deviated to the right when she opened her mouth. Also, there was decreased contraction of the right masseter when she clenched her teeth. These findings suggest that there was trigeminal motor paralysis on the right side resulting from involvement of the intrapontine trigeminal motor nerve. She has no history of dislocation of the temporo-mandibular joints. An X-ray film showed that the temporo-mandibular joints were intact. Thus, it is possible that deviation of the lower jaw was the cause of this dislocation. We suspect that dislocation of the temporo-mandibular joints may occur as a complication of unilateral trigeminal motor paralysis. This has not been reported to our knowledge.

[Intracranial remote epidural haematoma as a complication after resection of an occipital lobe metastatic tumour from a testicular embryonal carcinoma – a case report].

Science.gov (United States)

Andrusewicz, Wojciech; Limanówka, Bartosz; Sagan, Leszek; Kojder, Ireneusz

We present the case of a patient who suffered from intracranial epidural haematoma in the left fronto -temporo -parietal region as a complication after left parieto -occipital craniotomy and a resection of a metastatic lesion from a testicular embryonal carcinoma to the left occipital lobe. We also discuss possible causes of this complication.

Early sensitivity of left perisylvian cortex to relationality in nouns and verbs.

Science.gov (United States)

Williams, Adina; Reddigari, Samir; Pylkkänen, Liina

2017-06-01

The ability to track the relationality of concepts, i.e., their capacity to encode a relationship between entities, is one of the core semantic abilities humans possess. In language processing, we systematically leverage this ability when computing verbal argument structure, in order to link participants to the events they participate in. Previous work has converged on a large region of left posterior perisylvian cortex as a locus for such processing, but the wide range of experimental stimuli and manipulations has yielded an unclear picture of the region's exact role(s). Importantly, there is a tendency for effects of relationality in single-word studies to localize to posterior temporo-parietal cortex, while argument structure effects in sentences appear in left superior temporal cortex. To characterize these sensitivities, we designed two MEG experiments that cross the factors relationality and eventivity. The first used minimal noun phrases and tested for an effect of semantic composition, while the second employed full sentences and a manipulation of grammatical category. The former identified a region of the left inferior parietal lobe sensitive to relationality, but not eventivity or combination, beginning at 170ms. The latter revealed a similarly-timed effect of relationality in left mid-superior temporal cortex, independent of eventivity and category. The results suggest that i) multiple sub-regions of perisylvian cortex are sensitive to the relationality carried by concepts even in the absence of arguments, ii) linguistic context modulates the locus of this sensitivity, consistent with prior studies, and iii) relationality information is accessed early - before 200ms - regardless of the concept's event status or syntactic category. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of age and sex on developmental neural networks of visual-spatial attention allocation.

Science.gov (United States)

Rubia, Katya; Hyde, Zoe; Halari, Rozmin; Giampietro, Vincent; Smith, Anna

2010-06-01

Compared to our understanding of the functional maturation of brain networks underlying complex cognitive abilities, hardly anything is known of the neurofunctional development of simpler cognitive abilities such as visuo-spatial attention allocation. Furthermore, nothing is known on the effect of gender on the functional development of attention allocation. This study employed event related functional magnetic resonance imaging to investigate effects of age, sex, and sex by age interactions on the brain activation of 63 males and females, between 13 to 38years, during a visual-spatial oddball task. Behaviourally, with increasing age, speed was traded for accuracy, indicative of a less impulsive performance style in older subjects. Increasing age was associated with progressively increased activation in typical areas of selective attention of lateral fronto-striatal and temporo-parietal brain regions. Sex difference analysis showed enhanced activation in right-hemispheric inferior frontal and superior temporal regions in females, and in left-hemispheric inferior temporo-parietal regions in males. Importantly, the age by sex interaction findings showed that these sex-dimorphic patterns of brain activation may be the result of underlying sex differences in the functional maturation of these brain regions, as females had sex-specific progressive age-correlations in the same right inferior fronto-striato-temporal areas, while male-specific age-correlations were in left medial temporal and parietal areas. The findings demonstrate progressive functional maturation of fronto-striato-parieto-temporal networks of the relatively simple function of attention allocation between early adolescence and mid-adulthood. They furthermore show that sex-dimorphic patterns of enhanced reliance on right inferior frontal, striatal and superior temporal regions in females and of left temporo-parietal regions in males during attention allocation may be the result of underlying sex

Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage.

Science.gov (United States)

Lidzba, Karen; de Haan, Bianca; Wilke, Marko; Krägeloh-Mann, Ingeborg; Staudt, Martin

2017-10-01

Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development. Copyright © 2017. Published by Elsevier Inc.

EEG UPPER/LOW ALPHA FREQUENCY POWER RATIO RELATES TO TEMPORO-PARIETAL BRAIN ATROPHY AND MEMORY PERFORMANCES IN MILD COGNITIVE IMPAIRMENT

Directory of Open Access Journals (Sweden)

Davide Vito Moretti

2013-10-01

Full Text Available Objective: temporo-parietal cortex thinning is associated to mild cognitive impairment (MCI due to Alzheimer disease (AD. The increase of EEG upper/low alpha power ratio has been associated with AD-converter MCI subjects. We investigated the association of alpha3/alpha2 ratio with patterns of cortical thickness in MCI.Methods: 74 adult subjects with MCI underwent clinical and neuropsychological evaluation, electroencephalogram (EEG recording and high resolution 3D magnetic resonance imaging (MRI. Alpha3/alpha2 power ratio as well as cortical thickness was computed for each subject. Three MCI groups were detected according to increasing tertile values of upper/low alpha power ratio . Difference of cortical thikness among the groups was estimated. Pearson’s r was used to assess the topography of the correlation between cortical thinning and memory impairment.Results: High upper/low alpha power ratio group had total cortical grey matter (CGM volume reduction of 471 mm2 than low upper/low alpha power ratio group (p

Hyperfamiliarity for unknown faces after left lateral temporo-occipital venous infarction: a double dissociation with prosopagnosia.

Science.gov (United States)

Vuilleumier, Patrik; Mohr, Christine; Valenza, Nathalie; Wetzel, Corinne; Landis, Theodor

2003-04-01

Right hemisphere dominance in face processing is well established and unilateral right inferior temporo-occipital damage can result in prosopagnosia. Here, we describe a 21-year-old right-handed woman with acute impairment in face recognition that selectively concerned unfamiliar faces, following a focal left lateral temporo-occipital venous infarct. She was severely impaired in discerning that unknown people seen in everyday life were unfamiliar, although she had no difficulty recognizing familiar people. Thus, she had no prosopagnosia, but abnormal 'hyperfamiliarity' for unknown faces. Her difficulty was not accompanied by delusions or deficits in discrimination, identification or memory for faces. Standard neuropsychological testing showed that her recognition of familiar faces was entirely normal. By contrast, her sense of personally knowing faces was severely impaired when unknown faces evoked weak signals of familiarity based on spurious cues, to the extent that she would misattribute fame to faces that were unknown but to which she had been incidentally exposed on a prior occasion. Priming experiments also revealed that, unlike normal subjects, she made familiarity judgements without accessing semantic identity representations. Moreover, in face recognition tests, she generally showed bias in that she relied more on right-hemisphere strategies to identify global traits and less on left-hemisphere processes compared with healthy subjects. This case provides novel evidence for a differential contribution of the two hemispheres to face recognition. Hyperfamiliarity for unknown faces might arise from an imbalance between reciprocal hemispheric functions in face recognition, with relative hypoactivation of left hemisphere processes but hyperactivation of right-hemisphere processes for retrieving stored associations about people, linking seen faces to representations of affective and personal relevance. Hence, abnormal bias in attributing some personal meaning to

Temporo-sylvian arachnoidal cyst and an extreme pneumatization of the cranial sinuses: a case report.

Science.gov (United States)

Zara, Gabriella; Ponza, Isabella; Citton, Valentina; Manara, Renzo

2010-11-01

We present a patient who showed MRI evidence of a giant temporo-sylvian arachnoidal cyst of the left hemisphere and an extreme pneumatization of the sphenoid and frontal sinuses. No sign of mass effect or cerebral atrophy was detected. This patient presented a deficit of memory and control functions, but quality of life was not affected. Surgery was not performed. Arachnoidal cyst and anatomic variants of the sinus region have not a common etiology. This is the first report that describes a giant temporo-sylvian arachnoidal cyst with anatomic variants of the paranasal sinuses. Copyright © 2010 Elsevier B.V. All rights reserved.

Avaliação quantitativa da movimentação parietal regional do ventrículo esquerdo na endomiocardiofibrose Quantitative assessment of left ventricular regional wall motion in endomyocardial fibrosis

Directory of Open Access Journals (Sweden)

Charles Mady

2005-03-01

Full Text Available OBJETIVO: Analisar a movimentação parietal regional do ventrículo esquerdo (VE em pacientes com endomiocardiofibrose (EMF. MÉTODOS: Estudados 88 pacientes, 59 do sexo feminino, com idade média de 39±13 anos (variação de 9 a 65 com evidência ecocardiográfica e angiográfica de EMF do VE. A intensidade da deposição de tecido fibroso na cineventriculografia contrastada foi classificada como discreta, moderada ou importante. A fração de ejeção global do ventrículo esquerdo (FEVE foi determinada pelo método área-comprimento por meio da ventriculografia. O movimento foi medido em 100 cordas eqüidistantes e perpendiculares à linha média desenhada no meio dos contornos diastólico e sistólico finais e normalizadas para o tamanho cardíaco. Analisaram-se cinco segmentos do VE: A - apical; AL - ântero-lateral; AB - ântero-basal; IA - ínfero-apical; IB - ínfero-basal. A anormalidade foi expressa em unidades de desvio padrão do movimento médio em uma população de referência normal, composta por 103 pacientes com VE normal, conforme dados de clínica, eletrocardiograma e padrões angiográficos. RESULTADOS: A FEVE média foi de 0,47±0,12. O envolvimento de tecido fibroso do VE foi discreto em 12 pacientes, moderado em 40 e importante em 36. As regiões com pior movimentação parietal foram A (-1,4±1,6 desvio-padrão/cordas e IA (-1,6±1,8 desvio-padrão/cordas comparadas com AB (-0,3±1,9 desvio-padrão /cordas, AL (-0,5±1,8 desvio-padrão/cordas e IB (-0,9±1,3 desvio-padrão/cordas. Não se observou relação entre a intensidade de envolvimento do tecido fibroso e a manutenção parietal regional. CONCLUSÃO : Existe alteração da movimentação parietal regional na EMF e é independente da intensidade de deposição de tecido fibroso avaliada qualitativamente. O envolvimento não uniforme do VE deve ser levado em conta no planejamento cirúrgico dessa doença.OBJECTIVE: To analyze left ventricular (LV regional wall

Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

International Nuclear Information System (INIS)

Maeshima, S.; Matsumoto, T.; Ueyoshi, A.; Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H.; Roger, P.

2002-01-01

We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

Transcortical mixed aphasia due to cerebral infarction in left inferior frontal lobe and temporo-parietal lobe

Energy Technology Data Exchange (ETDEWEB)

Maeshima, S.; Matsumoto, T.; Ueyoshi, A. [Department of Physical Medicine and Rehabilitation, Wakayama Medical University, Wakayama (Japan); Toshiro, H.; Sekiguchi, E.; Okita, R.; Yamaga, H.; Ozaki, F.; Moriwaki, H. [Department of Neurological Surgery, Hidaka General Hospital, Wakayama (Japan); Roger, P. [School of Communication Sciences and Disorders, University of Sydney, Sydney, NSW (Australia)

2002-02-01

We present a case of transcortical mixed aphasia caused by a cerebral embolism. A 77-year-old right-handed man was admitted to our hospital with speech disturbance and a right hemianopia. His spontaneous speech was remarkably reduced, and object naming, word fluency, comprehension, reading and writing were all severely disturbed. However, repetition of phonemes and sentences and reading aloud were fully preserved. Although magnetic resonance imaging (MRI) showed cerebral infarcts in the left frontal and parieto-occipital lobe which included the inferior frontal gyrus and angular gyrus, single photon emission CT revealed a wider area of low perfusion over the entire left hemisphere except for part of the left perisylvian language areas. The amytal (Wada) test, which was performed via the left internal carotid artery, revealed that the left hemisphere was dominant for language. Hence, it appears that transcortical mixed aphasia may be caused by the isolation of perisylvian speech areas, even if there is a lesion in the inferior frontal gyrus, due to disconnection from surrounding areas. (orig.)

Examining the role of the temporo-parietal network in memory, imagery and viewpoint transformations

Directory of Open Access Journals (Sweden)

Kiret eDhindsa

2014-09-01

Full Text Available The traditional view of the medial temporal lobe (MTL focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g. O’Keefe (1976; Ekstrom et al. (2003; King et al. (2002. According to our BBB model (Byrne et al. (2007, these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal ’window’. Such imagery is necessarily egocentric and forms part of visuospatial working memory, where it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al. (2012; Zhang et al. (2012 supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object 1 from visuospatial working memory (we assume working memory due to the order of tasks and the consistency viewpoint, but long-term memory is also possible, 2 after a rotation of viewpoint, or 3 after a rotation and translation (judgement of relative direction. We found performance-related activity in both tasks requiring viewpoint rotation in the core medial temporal to medial parietal. These results are consistent with the BBB model and shed further light on the mechanisms underlying spatial memory, mental imagery and viewpoint

Vulnerability of the frontal and parietal regions in hypertensive patients during working memory task.

Science.gov (United States)

Li, Xin; Wang, Wenxiao; Wang, Ailin; Li, Peng; Zhang, Junying; Tao, Wuhai; Zhang, Zhanjun

2017-05-01

Hypertension is related with cognitive decline in the elderly. The frontal-parietal executive system plays an important role in cognitive aging and is also vulnerable to damage in elderly patients with hypertension. Examination of the brain's functional characteristics in frontal-parietal regions of hypertension is likely to be important for understanding the neural mechanisms of hypertension's effect on cognitive aging. We address this issue by comparing hypertension and control-performers in a functional MRI study. Twenty-eight hypertensive patients and 32 elderly controls were tested with n-back task with two load levels. The hypertensive patients exhibited worse executive and memory abilities than control subjects. The patterns of brain activation changed under different working memory loads in the hypertensive patients, who exhibited reduced activation only in the precentral gyrus under low loads and reduced activation in the middle frontal gyrus, left medial superior frontal gyrus and right precuneus under high loads. Thus, more regions of diminished activation were observed in the frontal and parietal regions with increasing task difficulty. More importantly, we found that lower activation in changed frontal and parietal regions was associated with worse cognitive function in high loads. The results demonstrate the relationship between cognitive function and frontoparietal functional activation in hypertension and their relevance to cognitive aging risk. Our findings provide a better understanding of the mechanism of cognitive decline in hypertension and highlight the importance of brain protection in hypertension.

Examining the role of the temporo-parietal network in memory, imagery, and viewpoint transformations.

Science.gov (United States)

Dhindsa, Kiret; Drobinin, Vladislav; King, John; Hall, Geoffrey B; Burgess, Neil; Becker, Suzanna

2014-01-01

The traditional view of the medial temporal lobe (MTL) focuses on its role in episodic memory. However, some of the underlying functions of the MTL can be ascertained from its wider role in supporting spatial cognition in concert with parietal and prefrontal regions. The MTL is strongly implicated in the formation of enduring allocentric representations (e.g., O'Keefe, 1976; King et al., 2002; Ekstrom et al., 2003). According to our BBB model (Byrne et al., 2007), these representations must interact with head-centered and body-centered representations in posterior parietal cortex via a transformation circuit involving retrosplenial areas. Egocentric sensory representations in parietal areas can then cue the recall of allocentric spatial representations in long-term memory and, conversely, the products of retrieval in MTL can generate mental imagery within a parietal "window." Such imagery is necessarily egocentric and forms part of visuospatial working memory, in which it can be manipulated for the purpose of planning/imagining the future. Recent fMRI evidence (Lambrey et al., 2012; Zhang et al., 2012) supports the BBB model. To further test the model, we had participants learn the locations of objects in a virtual scene and tested their spatial memory under conditions that impose varying demands on the transformation circuit. We analyzed how brain activity correlated with accuracy in judging the direction of an object (1) from visuospatial working memory (we assume transient working memory due to the order of tasks and the absence of change in viewpoint, but long-term memory retrieval is also possible), (2) after a rotation of viewpoint, or (3) after a rotation and translation of viewpoint (judgment of relative direction). We found performance-related activity in both tasks requiring viewpoint rotation (ROT and JRD, i.e., conditions 2 and 3) in the core medial temporal to medial parietal circuit identified by the BBB model. These results are consistent with the

Resting-state functional connectivity of ventral parietal regions associated with attention reorienting and episodic recollection

Directory of Open Access Journals (Sweden)

Sander M Daselaar

2013-02-01

Full Text Available In functional neuroimaging studies, ventral parietal cortex (VPC is recruited by very different cognitive tasks. Explaining the contributions VPC to these tasks has become a topic of intense study and lively debate. Perception studies frequently find VPC activations during tasks involving attention-reorienting, and memory studies frequently find them during tasks involving episodic recollection. According to the Attention to Memory (AtoM model, both phenomena can be explained by the same VPC function: bottom-up attention. Yet, a recent functional MRI (fMRI meta-analysis suggested that attention-reorienting activations are more frequent in anterior VPC, whereas recollection activations are more frequent in posterior VPC. Also, there is evidence that anterior and posterior VPC regions have different functional connectivity patterns. To investigate these issues, we conducted a resting-state functional connectivity analysis using as seeds the center-of-mass of attention-reorienting and recollection activations in the meta-analysis, which were located in the supramarginal gyrus (SMG, around the temporo-parietal junction—TPJ and in the angular gyrus (AG, respectively. The SMG seed showed stronger connectivity with ventrolateral prefrontal cortex (VLPFC and occipito-temporal cortex, whereas the AG seed showed stronger connectivity with the hippocampus and default network regions. To investigate whether these connectivity differences were graded or sharp, VLPFC and hippocampal connectivity was measured in VPC regions traversing through the SMG and AG seeds. The results showed a graded pattern: VLPFC connectivity gradually decreases from SMG to AG, whereas hippocampal connectivity gradually increases from SMG to AG. Importantly, both gradients showed an abrupt break when extended beyond VPC borders. This finding suggests that functional differences between SMG and AG are more subtle than previously thought. These connectivity differences can be

Anatomo-functional study of the temporo-parieto-occipital region: dissection, tractographic and brain mapping evidence from a neurosurgical perspective

Science.gov (United States)

De Benedictis, Alessandro; Duffau, Hugues; Paradiso, Beatrice; Grandi, Enrico; Balbi, Sergio; Granieri, Enrico; Colarusso, Enzo; Chioffi, Franco; Marras, Carlo Efisio; Sarubbo, Silvio

2014-01-01

The temporo-parieto-occipital (TPO) junction is a complex brain territory heavily involved in several high-level neurological functions, such as language, visuo-spatial recognition, writing, reading, symbol processing, calculation, self-processing, working memory, musical memory, and face and object recognition. Recent studies indicate that this area is covered by a thick network of white matter (WM) connections, which provide efficient and multimodal integration of information between both local and distant cortical nodes. It is important for neurosurgeons to have good knowledge of the three-dimensional subcortical organisation of this highly connected region to minimise post-operative permanent deficits. The aim of this dissection study was to highlight the subcortical functional anatomy from a topographical surgical perspective. Eight human hemispheres (four left, four right) obtained from four human cadavers were dissected according to Klingler's technique. Proceeding latero-medially, the authors describe the anatomical courses of and the relationships between the main pathways crossing the TPO. The results obtained from dissection were first integrated with diffusion tensor imaging reconstructions and subsequently with functional data obtained from three surgical cases, all resection of infiltrating glial tumours using direct electrical mapping in awake patients. The subcortical limits for performing safe lesionectomies within the TPO region are as follows: within the parietal region, the anterior horizontal part of the superior longitudinal fasciculus and, more deeply, the arcuate fasciculus; dorsally, the vertical projective thalamo-cortical fibres. For lesions located within the temporal and occipital lobes, the resection should be tailored according to the orientation of the horizontal associative pathways (the inferior fronto-occipital fascicle, inferior longitudinal fascicle and optic radiation). The relationships between the WM tracts and the ventricle

Investigating the Functional Utility of the Left Parietal ERP Old/New Effect: Brain Activity Predicts within But Not between Participant Variance in Episodic Recollection

Directory of Open Access Journals (Sweden)

Catherine A. MacLeod

2017-12-01

Full Text Available A success story within neuroimaging has been the discovery of distinct neural correlates of episodic retrieval, providing insight into the processes that support memory for past life events. Here we focus on one commonly reported neural correlate, the left parietal old/new effect, a positive going modulation seen in event-related potential (ERP data that is widely considered to index episodic recollection. Substantial evidence links changes in the size of the left parietal effect to changes in remembering, but the precise functional utility of the effect remains unclear. Here, using forced choice recognition of verbal stimuli, we present a novel population level test of the hypothesis that the magnitude of the left parietal effect correlates with memory performance. We recorded ERPs during old/new recognition, source accuracy and Remember/Know/Guess tasks in two large samples of healthy young adults, and successfully replicated existing within participant modulations of the magnitude of the left parietal effect with recollection. Critically, however, both datasets also show that across participants the magnitude of the left parietal effect does not correlate with behavioral measures of memory – including both subjective and objective estimates of recollection. We conclude that in these tasks, and across this healthy young adult population, the generators of the left parietal ERP effect do not index performance as expected. Taken together, these novel findings provide important constraints on the functional interpretation of the left parietal effect, suggesting that between group differences in the magnitude of old/new effects cannot always safely be used to infer differences in recollection.

Revealing and Quantifying the Impaired Phonological Analysis Underpinning Impaired Comprehension in Wernicke's Aphasia

Science.gov (United States)

Robson, Holly; Keidel, James L.; Lambon Ralph, Matthew A.; Sage, Karen

2012-01-01

Wernicke's aphasia is a condition which results in severely disrupted language comprehension following a lesion to the left temporo-parietal region. A phonological analysis deficit has traditionally been held to be at the root of the comprehension impairment in Wernicke's aphasia, a view consistent with current functional neuroimaging which finds…

Bilingualism alters brain functional connectivity between "control" regions and "language" regions: Evidence from bimodal bilinguals.

Science.gov (United States)

Li, Le; Abutalebi, Jubin; Zou, Lijuan; Yan, Xin; Liu, Lanfang; Feng, Xiaoxia; Wang, Ruiming; Guo, Taomei; Ding, Guosheng

2015-05-01

Previous neuroimaging studies have revealed that bilingualism induces both structural and functional neuroplasticity in the dorsal anterior cingulate cortex (dACC) and the left caudate nucleus (LCN), both of which are associated with cognitive control. Since these "control" regions should work together with other language regions during language processing, we hypothesized that bilingualism may also alter the functional interaction between the dACC/LCN and language regions. Here we tested this hypothesis by exploring the functional connectivity (FC) in bimodal bilinguals and monolinguals using functional MRI when they either performed a picture naming task with spoken language or were in resting state. We found that for bimodal bilinguals who use spoken and sign languages, the FC of the dACC with regions involved in spoken language (e.g. the left superior temporal gyrus) was stronger in performing the task, but weaker in the resting state as compared to monolinguals. For the LCN, its intrinsic FC with sign language regions including the left inferior temporo-occipital part and right inferior and superior parietal lobules was increased in the bilinguals. These results demonstrate that bilingual experience may alter the brain functional interaction between "control" regions and "language" regions. For different control regions, the FC alters in different ways. The findings also deepen our understanding of the functional roles of the dACC and LCN in language processing. Copyright © 2015 Elsevier Ltd. All rights reserved.

Subtle gray matter changes in temporo-parietal cortex associated with cardiovascular risk factors.

Science.gov (United States)

de Toledo Ferraz Alves, Tânia Corrêa; Scazufca, Márcia; Squarzoni, Paula; de Souza Duran, Fábio Luiz; Tamashiro-Duran, Jaqueline Hatsuko; Vallada, Homero P; Andrei, Anna; Wajngarten, Mauricio; Menezes, Paulo R; Busatto, Geraldo F

2011-01-01

Vascular risk factors may play an important role in the pathophysiology of Alzheimer's disease (AD). While there is consistent evidence of gray matter (GM) abnormalities in earlier stages of AD, the presence of more subtle GM changes associated with vascular risk factors in the absence of clinically significant vascular events has been scarcely investigated. This study aimed to examine GM changes in elderly subjects with cardiovascular risk factors. We predicted that the presence of cardiovascular risk would be associated with GM abnormalities involving the temporal-parietal cortices and limbic structures. We recruited 248 dementia-free subjects, age range 66-75 years, from the population-based "São Paulo Ageing and Health Study", classified in accordance to their Framingham Coronary Heart Disease Risk (FCHDR) score to undergo an MRI scan. We performed an overall analysis of covariance, controlled to total GM and APOE4 status, to investigate the presence of regional GM abnormalities in association with FCHDR subgroups (high-risk, medium-risk, and low-risk), and followed by post hoc t-test. We also applied a co-relational design in order to investigate the presence of linear progression of the GM vulnerability in association with cardiovascular risk factor. Voxel-based morphometry showed that the presence of cardiovascular risk factors were associated with regional GM loss involving the temporal cortices bilaterally. Those results retained statistical significance after including APOE4 as a covariate of interest. We also observed that there was a negative correlation between FCHDR scores and rGM distribution in the parietal cortex. Subclinical cerebrovascular abnormalities involving GM loss may provide an important link between cardiovascular risk factors and AD.

Early Left Parietal Activity Elicited by Direct Gaze: A High-Density EEG Study

Science.gov (United States)

Burra, Nicolas; Kerzel, Dirk; George, Nathalie

2016-01-01

Gaze is one of the most important cues for human communication and social interaction. In particular, gaze contact is the most primary form of social contact and it is thought to capture attention. A very early-differentiated brain response to direct versus averted gaze has been hypothesized. Here, we used high-density electroencephalography to test this hypothesis. Topographical analysis allowed us to uncover a very early topographic modulation (40–80 ms) of event-related responses to faces with direct as compared to averted gaze. This modulation was obtained only in the condition where intact broadband faces–as opposed to high-pass or low-pas filtered faces–were presented. Source estimation indicated that this early modulation involved the posterior parietal region, encompassing the left precuneus and inferior parietal lobule. This supports the idea that it reflected an early orienting response to direct versus averted gaze. Accordingly, in a follow-up behavioural experiment, we found faster response times to the direct gaze than to the averted gaze broadband faces. In addition, classical evoked potential analysis showed that the N170 peak amplitude was larger for averted gaze than for direct gaze. Taken together, these results suggest that direct gaze may be detected at a very early processing stage, involving a parallel route to the ventral occipito-temporal route of face perceptual analysis. PMID:27880776

Combined rTMS treatment targeting the Anterior Cingulate and the Temporal Cortex for the Treatment of Chronic Tinnitus

Science.gov (United States)

Kreuzer, Peter M.; Lehner, Astrid; Schlee, Winfried; Vielsmeier, Veronika; Schecklmann, Martin; Poeppl, Timm B.; Landgrebe, Michael; Rupprecht, Rainer; Langguth, Berthold

2015-01-01

Repetitive transcranial magnetic stimulation (rTMS) has been proposed as a tinnitus treatment option. Promising results have been obtained by consecutive stimulation of lateral frontal and auditory brain regions. We investigated a combined stimulation paradigm targeting the anterior cingulate cortex (ACC) with double cone coil rTMS, followed by stimulation of the temporo-parietal junction area with a figure-of-eight coil. The study was conducted as a randomized, double-blind pilot trial in 40 patients suffering from chronic tinnitus. We compared mediofrontal stimulation with double-cone-coil, (2000 stimuli, 10 Hz) followed by left temporo-parietal stimulation with figure-of-eight-coil (2000 stimuli, 1 Hz) to left dorsolateral-prefrontal-cortex stimulation with figure-of-eight-coil (2000 stimuli, 10 Hz) followed by temporo-parietal stimulation with figure-of-eight-coil (2000 stimuli, 1 Hz). The stimulation was feasible with comparable dropout rates in both study arms; no severe adverse events were registered. Responder rates did not differ in both study arms. There was a significant main effect of time for the change in the TQ score, but no significant time x group interaction. This pilot study demonstrated the feasibility of combined mediofrontal/temporoparietal-rTMS-stimulation with double cone coil in tinnitus patients but failed to show better outcome compared to an actively rTMS treated control group. PMID:26667790

Transient contribution of left posterior parietal cortex to cognitive restructuring.

Science.gov (United States)

Sutoh, Chihiro; Matsuzawa, Daisuke; Hirano, Yoshiyuki; Yamada, Makiko; Nagaoka, Sawako; Chakraborty, Sudesna; Ishii, Daisuke; Matsuda, Shingo; Tomizawa, Haruna; Ito, Hiroshi; Tsuji, Hiroshi; Obata, Takayuki; Shimizu, Eiji

2015-03-17

Cognitive restructuring is a fundamental method within cognitive behavioural therapy of changing dysfunctional beliefs into flexible beliefs and learning to react appropriately to the reality of an anxiety-causing situation. To clarify the neural mechanisms of cognitive restructuring, we designed a unique task that replicated psychotherapy during a brain scan. The brain activities of healthy male participants were analysed using functional magnetic resonance imaging. During the brain scan, participants underwent Socratic questioning aimed at cognitive restructuring regarding the necessity of handwashing after using the restroom. The behavioural result indicated that the Socratic questioning effectively decreased the participants' degree of belief (DOB) that they must wash their hands. Alterations in the DOB showed a positive correlation with activity in the left posterior parietal cortex (PPC) while the subject thought about and rated own belief. The involvement of the left PPC not only in planning and decision-making but also in conceptualization may play a pivotal role in cognitive restructuring.

Effects of low frequency rTMS treatment on brain networks for inner speech in patients with schizophrenia and auditory verbal hallucinations.

Science.gov (United States)

Bais, Leonie; Liemburg, Edith; Vercammen, Ans; Bruggeman, Richard; Knegtering, Henderikus; Aleman, André

2017-08-01

Efficacy of repetitive Transcranial Magnetic Stimulation (rTMS) targeting the temporo-parietal junction (TPJ) for the treatment of auditory verbal hallucinations (AVH) remains under debate. We assessed the influence of a 1Hz rTMS treatment on neural networks involved in a cognitive mechanism proposed to subserve AVH. Patients with schizophrenia (N=24) experiencing medication-resistant AVH completed a 10-day 1Hz rTMS treatment. Participants were randomized to active stimulation of the left or bilateral TPJ, or sham stimulation. The effects of rTMS on neural networks were investigated with an inner speech task during fMRI. Changes within and between neural networks were analyzed using Independent Component Analysis. rTMS of the left and bilateral TPJ areas resulted in a weaker network contribution of the left supramarginal gyrus to the bilateral fronto-temporal network. Left-sided rTMS resulted in stronger network contributions of the right superior temporal gyrus to the auditory-sensorimotor network, right inferior gyrus to the left fronto-parietal network, and left middle frontal gyrus to the default mode network. Bilateral rTMS was associated with a predominant inhibitory effect on network contribution. Sham stimulation showed different patterns of change compared to active rTMS. rTMS of the left temporo-parietal region decreased the contribution of the left supramarginal gyrus to the bilateral fronto-temporal network, which may reduce the likelihood of speech intrusions. On the other hand, left rTMS appeared to increase the contribution of functionally connected regions involved in perception, cognitive control and self-referential processing. These findings hint to potential neural mechanisms underlying rTMS for hallucinations but need corroboration in larger samples. Copyright © 2017 Elsevier Inc. All rights reserved.

Developmental dyscalculia: compensatory mechanisms in left intraparietal regions in response to nonsymbolic magnitudes

Directory of Open Access Journals (Sweden)

Starke Marc

2009-08-01

Full Text Available Abstract Background Functional magnetic resonance imaging (fMRI studies investigating the neural mechanisms underlying developmental dyscalculia are scarce and results are thus far inconclusive. Main aim of the present study is to investigate the neural correlates of nonsymbolic number magnitude processing in children with and without dyscalculia. Methods 18 children (9 with dyscalculia were asked to solve a non-symbolic number magnitude comparison task (finger patterns during brain scanning. For the spatial control task identical stimuli were employed, instructions varying only (judgment of palm rotation. This design enabled us to present identical stimuli with identical visual processing requirements in the experimental and the control task. Moreover, because numerical and spatial processing relies on parietal brain regions, task-specific contrasts are expected to reveal true number-specific activations. Results Behavioral results during scanning reveal that despite comparable (almost at ceiling performance levels, task-specific activations were stronger in dyscalculic children in inferior parietal cortices bilaterally (intraparietal sulcus, supramarginal gyrus, extending to left angular gyrus. Interestingly, fMRI signal strengths reflected a group × task interaction: relative to baseline, controls produced significant deactivations in (intraparietal regions bilaterally in response to number but not spatial processing, while the opposite pattern emerged in dyscalculics. Moreover, beta weights in response to number processing differed significantly between groups in left – but not right – (intraparietal regions (becoming even positive in dyscalculic children. Conclusion Overall, findings are suggestive of (a less consistent neural activity in right (intraparietal regions upon processing nonsymbolic number magnitudes; and (b compensatory neural activity in left (intraparietal regions in developmental dyscalculia.

Theory of Mind Performance in Children Correlates with Functional Specialization of a Brain Region for Thinking about Thoughts

Science.gov (United States)

Gweon, Hyowon; Dodell-Feder, David; Bedny, Marina; Saxe, Rebecca

2012-01-01

Thinking about other people's thoughts recruits a specific group of brain regions, including the temporo-parietal junctions (TPJ), precuneus (PC), and medial prefrontal cortex (MPFC). The same brain regions were recruited when children (N = 20, 5-11 years) and adults (N = 8) listened to descriptions of characters' mental states, compared to…

MRI language dominance assessment in epilepsy patients at 1.0 T: region of interest analysis and comparison with intracarotid amytal testing

International Nuclear Information System (INIS)

Deblaere, K.; Vandemaele, P.; Tieleman, A.; Achten, E.; Boon, P.A.; Vonck, K.; Vingerhoets, G.; Backes, W.; Defreyne, L.

2004-01-01

The primary goal of this study was to test the reliability of presurgical language lateralization in epilepsy patients with functional magnetic resonance imaging (fMRI) with a 1.0-T MR scanner using a simple word generation paradigm and conventional equipment. In addition, hemispherical fMRI language lateralization analysis and region of interest (ROI) analysis in the frontal and temporo-parietal regions were compared with the intracarotid amytal test (IAT). Twenty epilepsy patients under presurgical evaluation were prospectively examined by both fMRI and IAT. The fMRI experiment consisted of a word chain task (WCT) using the conventional headphone set and a sparse sequence. In 17 of the 20 patients, data were available for comparison between the two procedures. Fifteen of these 17 patients were categorized as left hemispheric dominant, and 2 patients demonstrated bilateral language representation by both fMRI and IAT. The highest reliability for lateralization was obtained using frontal ROI analysis. Hemispherical analysis was less powerful and reliable in all cases but one, while temporo-parietal ROI analysis was unreliable as a stand-alone analysis when compared with IAT. The effect of statistical threshold on language lateralization prompted for the use of t-value-dependent lateralization index plots. This study illustrates that fMRI-determined language lateralization can be performed reliably in a clinical MR setting operating at a low field strength of 1 T without expensive stimulus presentation systems. (orig.)

MRI language dominance assessment in epilepsy patients at 1.0 T: region of interest analysis and comparison with intracarotid amytal testing

Energy Technology Data Exchange (ETDEWEB)

Deblaere, K.; Vandemaele, P.; Tieleman, A.; Achten, E. [Department of Neuroradiology, Ghent University Hospital, De Pintelaan 185, 9000, Ghent (Belgium); Boon, P.A.; Vonck, K. [Reference Center for Refractory Epilepsy of the Department of Neurology, Ghent University Hospital, Ghent (Belgium); Vingerhoets, G. [Labaratory for Neuropsychology, Neurology Section of the Department of Internal Medicine, Ghent University, Ghent (Belgium); Backes, W. [Department of Neuroradiology, University Hospital Maastricht, Maastricht (Netherlands); Defreyne, L. [Department of Interventional Radiology, Ghent University Hospital, Ghent (Belgium)

2004-06-01

The primary goal of this study was to test the reliability of presurgical language lateralization in epilepsy patients with functional magnetic resonance imaging (fMRI) with a 1.0-T MR scanner using a simple word generation paradigm and conventional equipment. In addition, hemispherical fMRI language lateralization analysis and region of interest (ROI) analysis in the frontal and temporo-parietal regions were compared with the intracarotid amytal test (IAT). Twenty epilepsy patients under presurgical evaluation were prospectively examined by both fMRI and IAT. The fMRI experiment consisted of a word chain task (WCT) using the conventional headphone set and a sparse sequence. In 17 of the 20 patients, data were available for comparison between the two procedures. Fifteen of these 17 patients were categorized as left hemispheric dominant, and 2 patients demonstrated bilateral language representation by both fMRI and IAT. The highest reliability for lateralization was obtained using frontal ROI analysis. Hemispherical analysis was less powerful and reliable in all cases but one, while temporo-parietal ROI analysis was unreliable as a stand-alone analysis when compared with IAT. The effect of statistical threshold on language lateralization prompted for the use of t-value-dependent lateralization index plots. This study illustrates that fMRI-determined language lateralization can be performed reliably in a clinical MR setting operating at a low field strength of 1 T without expensive stimulus presentation systems. (orig.)

Differentiated parietal connectivity of frontal regions for "what" and "where" memory.

Science.gov (United States)

Rottschy, C; Caspers, S; Roski, C; Reetz, K; Dogan, I; Schulz, J B; Zilles, K; Laird, A R; Fox, P T; Eickhoff, S B

2013-11-01

In a previous meta-analysis across almost 200 neuroimaging experiments, working memory for object location showed significantly stronger convergence on the posterior superior frontal gyrus, whereas working memory for identity showed stronger convergence on the posterior inferior frontal gyrus (dorsal to, but overlapping with Brodmann's area BA 44). As similar locations have been discussed as part of a dorsal frontal-superior parietal reach system and an inferior frontal grasp system, the aim of the present study was to test whether the regions of working-memory related "what" and "where" processing show a similar distinction in parietal connectivity. The regions that were found in the previous meta-analysis were used as seeds for functional connectivity analyses using task-based meta-analytic connectivity modelling and task-independent resting state correlations. While the ventral seed showed significantly stronger connectivity with the bilateral intraparietal sulcus (IPS), the dorsal seed showed stronger connectivity with the bilateral posterior inferior parietal and the medial superior parietal lobule. The observed connections of regions involved in memory for object location and identity thus clearly demonstrate a distinction into separate pathways that resemble the parietal connectivity patterns of the dorsal and ventral premotor cortex in non-human primates and humans. It may hence be speculated that memory for a particular location and reaching towards it as well as object memory and finger positioning for manipulation may rely on shared neural systems. Moreover, the ensuing regions, in turn, featured differential connectivity with the bilateral ventral and dorsal extrastriate cortex, suggesting largely segregated bilateral connectivity pathways from the dorsal visual cortex via the superior and inferior parietal lobules to the dorsal posterior frontal cortex and from the ventral visual cortex via the IPS to the ventral posterior frontal cortex that may

The organization of the posterior parietal cortex devoted to upper limb actions: An fMRI study

Science.gov (United States)

Ferri, Stefania; Rizzolatti, Giacomo

2015-01-01

Abstract The present fMRI study examined whether upper‐limb action classes differing in their motor goal are encoded by different PPC sectors. Action observation was used as a proxy for action execution. Subjects viewed actors performing object‐related (e.g., grasping), skin‐displacing (e.g., rubbing the skin), and interpersonal upper limb actions (e.g., pushing someone). Observation of the three action classes activated a three‐level network including occipito‐temporal, parietal, and premotor cortex. The parietal region common to observing all three action classes was located dorsally to the left intraparietal sulcus (DIPSM/DIPSA border). Regions specific for observing an action class were obtained by combining the interaction between observing action classes and stimulus types with exclusive masking for observing the other classes, while for regions considered preferentially active for a class the interaction was exclusively masked with the regions common to all observed actions. Left putative human anterior intraparietal was specific for observing manipulative actions, and left parietal operculum including putative human SII region, specific for observing skin‐displacing actions. Control experiments demonstrated that this latter activation depended on seeing the skin being moved and not simply on seeing touch. Psychophysiological interactions showed that the two specific parietal regions had similar connectivities. Finally, observing interpersonal actions preferentially activated a dorsal sector of left DIPSA, possibly the homologue of ventral intraparietal coding the impingement of the target person's body into the peripersonal space of the actor. These results support the importance of segregation according to the action class as principle of posterior parietal cortex organization for action observation and by implication for action execution. Hum Brain Mapp 36:3845–3866, 2015. © 2015 The Authors Human Brain Mapping Published by Wiley

Functional network-based statistics in depression: Theory of mind subnetwork and importance of parietal region.

Science.gov (United States)

Lai, Chien-Han; Wu, Yu-Te; Hou, Yuh-Ming

2017-08-01

The functional network analysis of whole brain is an emerging field for research in depression. We initiated this study to investigate which subnetwork is significantly altered within the functional connectome in major depressive disorder (MDD). The study enrolled 52 first-episode medication-naïve patients with MDD and 40 controls for functional network analysis. All participants received the resting-state functional imaging using a 3-Tesla magnetic resonance scanner. After preprocessing, we calculated the connectivity matrix of functional connectivity in whole brain for each subject. The network-based statistics of connectome was used to perform group comparisons between patients and controls. The correlations between functional connectivity and clinical parameters were also performed. MDD patients had significant alterations in the network involving "theory of mind" regions, such as the left precentral gyrus, left angular gyrus, bilateral rolandic operculums and left inferior frontal gyrus. The center node of significant network was the left angular gyrus. No significant correlations of functional connectivity within the subnetwork and clinical parameters were noted. Functional connectivity of "theory of mind" subnetwork may be the core issue for pathophysiology in MDD. In addition, the center role of parietal region should be emphasized in future study. Copyright © 2017. Published by Elsevier B.V.

[Successive subcortical hemorrhages in the superior parietal lobule and postcentral gyrus in a 23-year-old female].

Science.gov (United States)

Sato, K; Yoshikawa, H; Komai, K; Takamori, M

1998-04-01

We report a non-hypertensive 23-year-old female with successive hemorrhages in parietal subcortical regions. She had first experienced a transient pain in the left upper extremity one month before admission. She noticed dysesthesia in the same limb and weakness on her left hand, and, five days after, visited our hospital because of suddenly developed convulsion in the limb and loss of consciousness for a few minutes. Neurological examination revealed distal dominant flaccid paresis, positive pathological reflex and touch and position sense disturbances in the affected limb. Brain CT detected two high-density areas in the parietal lobe. Brain MRI demonstrated an acute phase subcortical hematoma in the left postcentral gyrus and a subacute phase one in the left superior parietal lobule. SPECT indicated hypoperfusion in the left frontal and parietal cortex. Cerebral angiography showed no abnormal findings. Her symptoms gradually improved, but left ulnar-type pseudoradicular sensory impairment remained on discharge. We considered the hemorrhage in this patient have arisen from rupture of cavernous hemangioma, because she was relatively young, the hematomas were oval in shape and successively developed in the left parietal lobe. Our patient suggests that a subcortical hemorrhage in the post-central gyrus causes flaccid paresis and pyramidal tract involvement.

Further Evidence for the Impact of a Genome-Wide-Supported Psychosis Risk Variant in ZNF804A on the Theory of Mind Network

Science.gov (United States)

Mohnke, Sebastian; Erk, Susanne; Schnell, Knut; Schütz, Claudia; Romanczuk-Seiferth, Nina; Grimm, Oliver; Haddad, Leila; Pöhland, Lydia; Garbusow, Maria; Schmitgen, Mike M; Kirsch, Peter; Esslinger, Christine; Rietschel, Marcella; Witt, Stephanie H; Nöthen, Markus M; Cichon, Sven; Mattheisen, Manuel; Mühleisen, Thomas; Jensen, Jimmy; Schott, Björn H; Maier, Wolfgang; Heinz, Andreas; Meyer-Lindenberg, Andreas; Walter, Henrik

2014-01-01

The single-nucleotide polymorphism (SNP) rs1344706 in ZNF804A is one of the best-supported risk variants for psychosis. We hypothesized that this SNP contributes to the development of schizophrenia by affecting the ability to understand other people's mental states. This skill, commonly referred to as Theory of Mind (ToM), has consistently been found to be impaired in schizophrenia. Using functional magnetic resonance imaging, we previously showed that in healthy individuals rs1344706 impacted on activity and connectivity of key areas of the ToM network, including the dorsomedial prefrontal cortex, temporo-parietal junction, and the posterior cingulate cortex, which show aberrant activity in schizophrenia patients, too. We aimed to replicate these results in an independent sample of 188 healthy German volunteers. In order to assess the reliability of brain activity elicited by the ToM task, 25 participants performed the task twice with an interval of 14 days showing excellent accordance in recruitment of key ToM areas. Confirming our previous results, we observed decreasing activity of the left temporo-parietal junction, dorsomedial prefrontal cortex, and the posterior cingulate cortex with increasing number of risk alleles during ToM. Complementing our replication sample with the discovery sample, analyzed in a previous report (total N=297), further revealed negative genotype effects in the left dorsomedial prefrontal cortex as well as in the temporal and parietal regions. In addition, as shown previously, rs1344706 risk allele dose positively predicted increased frontal–temporo-parietal connectivity. These findings confirm the effects of the psychosis risk variant in ZNF804A on the dysfunction of the ToM network. PMID:24247043

Regional Cerebral Blood Flow differences in early and severe Alzheimer Disease as assessed by SPECT and Principal Component Analysis

International Nuclear Information System (INIS)

Pagani, M.M.E.; Sanchez-Creaspo, A.; Jonsson, C.; Engelin, L.; Danielsson, A.M.; Larsson, S.A.; Jacobsson, H.; Waegner, A.; Salmaso, D.

2002-01-01

Aim: In its development into severe Alzheimer's Disease (AD), early Alzheimer Disease (eAD) involves progressively larger regions of the brain. These regions share close anatomo-functional relationships. The aim of this study was to investigate the rCBF changes occurring in eAD and AD as compared to a group of normal individuals by means of SPECT and Principal Component Analysis. Materials and Methods. Thirty eAD, 17 AD and 66 normal controls (CTR) were included in the study. 99m Tc-HMPAO SPECT, using a three-headed gamma camera, was performed at rest and the uptake in 27 functional bilateral sub-volumes of the brain was assessed by a standardised digitalised brain atlas. Data were grouped into anatomo-functionally connected regions by means of PCA analysis performed on all 113 individuals. Analysis of variance (ANOVA) was used to test the significance of the differences in flow in such functional regions and data were co-variated for age differences. Results. In the global analysis, rCBF significantly differed between groups (0.001) with a progressive reduction of flow from CTR to AD. PCA reduced the 54 variables to 11 anatomo-functional regions that interacted with groups (p<0.001) and gender (p<0.001). In the overall analysis the three groups differed significantly in all functional regions except for bilateral occipital cortex, anterior cingulated cortex, thalamus and putamen. In both CTR/eAD and CTR/AD comparisons the largest rCBF reductions were found in functional regions including left (p<0.0001) and right (p<0.0001) temporo-parietal cortex and associative parietal cortex (p<0.0001). When eAD was compared to AD, this latter showed the largest reductions in right temporo-parietal cortex (p<0.0001) and in right prefrontal cortex (p<0.005). Conclusions. In this study the rCBF was investigated in early and severe Alzheimer's Disease taking into account the functional connectivity among brain regions. Our results confirm previous findings on the progression of

Exogenous vs. endogenous attention: Shifting the balance of fronto-parietal activity.

Science.gov (United States)

Meyer, Kristin N; Du, Feng; Parks, Emily; Hopfinger, Joseph B

2018-03-01

Despite behavioral and electrophysiological evidence for dissociations between endogenous (voluntary) and exogenous (reflexive) attention, fMRI results have yet to consistently and clearly differentiate neural activation patterns between these two types of attention. This study specifically aimed to determine whether activity in the dorsal fronto-parietal network differed between endogenous and exogenous conditions. Participants performed a visual discrimination task in endogenous and exogenous attention conditions while undergoing fMRI scanning. Analyses revealed robust and bilateral activation throughout the dorsal fronto-parietal network for each condition, in line with many previous results. In order to investigate possible differences in the balance of neural activity within this network with greater sensitivity, a priori regions of interest (ROIs) were selected for analysis, centered on the frontal eye fields (FEF) and intraparietal sulcus (IPS) regions identified in previous studies. The results revealed a significant interaction between region, condition, and hemisphere. Specifically, in the left hemisphere, frontal areas were more active than parietal areas, but only during endogenous attention. Activity in the right hemisphere, in contrast, remained relatively consistent for these regions across conditions. Analysis of this activity over time indicates that this left-hemispheric regional imbalance is present within the FEF early, at 3-6.5 s post-stimulus presentation, whereas a regional imbalance in the exogenous condition is not evident until 6.5-8 s post-stimulus presentation. Overall, our results provide new evidence that although the dorsal fronto-parietal network is indeed associated with both types of attentional orienting, regions of the network are differentially engaged over time and across hemispheres depending on the type of attention. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Temporo-mandibular joint. Morpho-functional considerations].

Science.gov (United States)

Scutariu, M D; Indrei, Anca

2004-01-01

The temporo-mandibular joint is distinguished from most other synovial joints of the body by two features: 1. the two jointed components carry teeth whose position and occlusion introduce a very strong influence on the movements of the temporo-mandibular joint and 2. its articular surfaces are not covered by hyaline cartilage, but by a dense, fibrous tissue. This paper describes the parts of the temporo-mandibular joint: the articular surfaces (the condylar process of the mandible and the glenoid part of the temporal bone), the fibrocartilaginous disc which is interposed between the mandibular and the temporal surface, the fibrous capsule of the temporo-mandibular joint and the ligaments of this joint. All these parts present a very strong adaptation at the important functions of the temporo-mandibular joint.

Hemispheric involvement in the processing of Chinese idioms: An fMRI study.

Science.gov (United States)

Yang, Jie; Li, Ping; Fang, Xiaoping; Shu, Hua; Liu, Youyi; Chen, Lang

2016-07-01

Although the left hemisphere is believed to handle major language functions, the role of the right hemisphere in language comprehension remains controversial. Recently researchers have investigated hemispheric language processing with figurative language materials (e.g., metaphors, jokes, and idioms). The current study capitalizes on the pervasiveness and distinct features of Chinese idioms to examine the brain mechanism of figurative language processing. Native Chinese speakers performed a non-semantic task while reading opaque idioms, transparent idioms, and non-idiomatic literal phrases. Whole-brain analyses indicated strong activations for all three conditions in an overlapping brain network that includes the bilateral inferior/middle frontal gyrus and the temporo-parietal and occipital-temporal regions. The two idiom conditions elicited additional activations in the right superior parietal lobule and right precuneus. Item-based modulation analyses further demonstrated that activation amplitudes in the right angular gyrus, right superior parietal lobule and right precuneus, as well as left inferior temporo-occipital cortex, are negatively correlated with the semantic transparency of the idioms. These results suggest that both hemispheres are involved in idiom processing but they play different roles. Implications of the findings are discussed in light of theories of figurative language processing and hemispheric functions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Xenomelia: a new right parietal lobe syndrome.

Science.gov (United States)

McGeoch, Paul D; Brang, David; Song, Tao; Lee, Roland R; Huang, Mingxiong; Ramachandran, V S

2011-12-01

Damage to the right parietal lobe has long been associated with various disorders of body image. The authors have recently suggested that an unusual behavioural condition in which otherwise rational individuals desire the amputation of a healthy limb might also arise from right parietal dysfunction. Four subjects who desired the amputation of healthy legs (two right, one left and one, at first, bilateral and then left only) were recruited and underwent magnetoencephalography (MEG) scans during tactile stimulation of sites above and below the desired amputation line. Regions of interest (ROIs) in each hemisphere (superior parietal lobule (SPL), inferior parietal lobule, S1, M1, insula, premotor cortex and precuneus) were defined using FreeSurfer software. Analysis of average MEG activity across the 40-140 ms post-stimulation timeframe was carried out using an unpaired t test. This revealed significantly reduced activation only in the right SPL ROI for the subjects' affected legs when compared with both subjects' unaffected legs and that of controls. The right SPL is a cortical area that appears ideally placed to unify disparate sensory inputs to create a coherent sense of having a body. The authors propose that inadequate activation of the right SPL leads to the unnatural situation in which the sufferers can feel the limb in question being touched without it actually incorporating into their body image, with a resulting desire for amputation. The authors introduce the term 'xenomelia' as a more appropriate name than apotemnophilia or body integrity identity disorder, for what appears to be an unrecognised right parietal lobe syndrome.

Brain activity dynamics in human parietal regions during spontaneous switches in bistable perception.

Science.gov (United States)

Megumi, Fukuda; Bahrami, Bahador; Kanai, Ryota; Rees, Geraint

2015-02-15

The neural mechanisms underlying conscious visual perception have been extensively investigated using bistable perception paradigms. Previous functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) studies suggest that the right anterior superior parietal (r-aSPL) and the right posterior superior parietal lobule (r-pSPL) have opposite roles in triggering perceptual reversals. It has been proposed that these two areas are part of a hierarchical network whose dynamics determine perceptual switches. However, how these two parietal regions interact with each other and with the rest of the brain during bistable perception is not known. Here, we investigated such a model by recording brain activity using fMRI while participants viewed a bistable structure-from-motion stimulus. Using dynamic causal modeling (DCM), we found that resolving such perceptual ambiguity was specifically associated with reciprocal interactions between these parietal regions and V5/MT. Strikingly, the strength of bottom-up coupling between V5/MT to r-pSPL and from r-pSPL to r-aSPL predicted individual mean dominance duration. Our findings are consistent with a hierarchical predictive coding model of parietal involvement in bistable perception and suggest that visual information processing underlying spontaneous perceptual switches can be described as changes in connectivity strength between parietal and visual cortical regions. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of age and gender on neural networks of motor response inhibition: from adolescence to mid-adulthood.

Science.gov (United States)

Rubia, Katya; Lim, Lena; Ecker, Christine; Halari, Rozmin; Giampietro, Vincent; Simmons, Andrew; Brammer, Michael; Smith, Anna

2013-12-01

Functional inhibitory neural networks mature progressively with age. However, nothing is known about the impact of gender on their development. This study employed functional magnetic resonance imaging (fMRI) to investigate the effects of age, sex, and sex by age interactions on the brain activation of 63 healthy males and females, between 13 and 38 years, performing a Stop task. Increasing age was associated with progressively increased activation in typical response inhibition areas of right inferior and dorsolateral prefrontal and temporo-parietal regions. Females showed significantly enhanced activation in left inferior and superior frontal and striatal regions relative to males, while males showed increased activation relative to females in right inferior and superior parietal areas. Importantly, left frontal and striatal areas that showed increased activation in females, also showed significantly increased functional maturation in females relative to males, while the right inferior parietal activation that was increased in males showed significantly increased functional maturation relative to females. The findings demonstrate for the first time that sex-dimorphic activation patterns of enhanced left fronto-striatal activation in females and enhanced right parietal activation in males during motor inhibition appear to be the result of underlying gender differences in the functional maturation of these brain regions. © 2013. Published by Elsevier Inc. All rights reserved.

Case report

African Journals Online (AJOL)

ebutamanya

2016-03-24

Mar 24, 2016 ... Wernicke aphasia without other deficiencies. A contrast-enhanced computed tomography scan of the brain showed a left temporo- parietal venous infarct with incomplete enhancement of left transverse sinus. A cerebral angio-magnetic resonance imaging confirmed the venous infarct and revealed an ...

Spinal and temporo-mandibular disorders in male workers of the State Police.

Science.gov (United States)

Sancini, Angela; Tomei, Francesco; Tomei, Gianfranco; Caciari, Tiziana; Capozzella, Assunta; Di Famiani, Manuela; Samperi, Ilaria; Scala, Barbara; Fiaschetti, Maria; Cetica, Carlotta; Ciarrocca, Manuela

2013-01-01

The aims of this study are to evaluate the prevalence of disorders of the lumbar region and the temporo-mandibular district co-morbidity in drivers and workers of the State Police employed for different office activities. The study population included 103 drivers as cases and 100 police officers as controls. The study was carried out through questionnaire and clinical evaluation of the spine and temporo-mandibular region. At clinical examination, the drivers were found to have a higher prevalence (p temporo-mandibular joint (TMJ), when compared with the controls. The results also showed a higher prevalence (p < 0.05) of co-morbidity in the two districts among the drivers, when compared with the controls. These results confirm that morbidity related to back and TMJ and increase in co-morbidity between the two districts are higher in professional drivers.

Regional intercostal bulging of the parietal pleura

International Nuclear Information System (INIS)

Jantsch, H.; Greene, R.; Lechner, G.; Mavritz, W.; Pichler, W.; Winkler, M.; Zadrobilek, E.

1989-01-01

This paper describes bedside radiographs with localized intercostal bulging as the sole indication of tension pneumothorax in six patients with acute deterioration in gas exchange. Relief of the pneumothorax was followed by a rush of gas from the tension space and a prompt improvement in gas exchange. The authors concluded the regional intercostal bulging of the parietal pleura may be the sole indicator of life-threatening tension pneumothorax in patients on mechanical ventilation

The left visual-field advantage in rapid visual presentation is amplified rather than reduced by posterior-parietal rTMS

DEFF Research Database (Denmark)

Verleger, Rolf; Möller, Friderike; Kuniecki, Michal

2010-01-01

) either as effective or as sham stimulation. In two experiments, either one of these two factors, hemisphere and effectiveness of rTMS, was varied within or between participants. Again, T2 was much better identified in the left than in the right visual field. This advantage of the left visual field......In the present task, series of visual stimuli are rapidly presented left and right, containing two target stimuli, T1 and T2. In previous studies, T2 was better identified in the left than in the right visual field. This advantage of the left visual field might reflect dominance exerted...... by the right over the left hemisphere. If so, then repetitive transcranial magnetic stimulation (rTMS) to the right parietal cortex might release the left hemisphere from right-hemispheric control, thereby improving T2 identification in the right visual field. Alternatively or additionally, the asymmetry in T2...

Body-centred map in parietal eye fields - functional MRI study

International Nuclear Information System (INIS)

Brotchie, P.; Chen, D.Y.; Bradley, W.G.

2002-01-01

Full text: In order for us to interact with our environment we need to know where objects are around us, relative to our body. In monkeys, a body-centred map of visual space is known to exist within the parietal eye fields. This map is formed by the modulation of neuronal activity by eye and head position (Brotchie et al, Nature 1995; Synder et al, Nature 1998). In humans no map of body centred space has been demonstrated. By using functional MRI we have localised a region along the intraparietal sulcus which has properties similar to the parietal eye fields of monkeys (Brotchie et al, ISMRM, 2000). The aim of this study was to determine if activity in this region is modulated by head position, consistent with a body centered representation of visual space. Functional MRI was performed on 6 subjects performing simple visually guided saccades using a 1.5 Tesla GE Echospeed scanner. 10 scans were performed on the 6 subjects at left and right body orientations. Regions of interest were selected around the intraparietal sulcus proper (IPSP) of both hemispheres and voxels with BOLD signal which correlated with the paradigm (r>0.35) were selected for further analysis. Comparisons of percentage signal change were made between the left and right IPSP using Student t test. Of the 10 MRI examinations, 6 demonstrated statistically significant differences in the amount of signal change between left and right IPSP. In each of these 6 cases, the signal change was greater within the IPSP contralateral to the direction of head position relative to the body. This indicates a modulation of activity within the IPSP related to head position, most likely reflecting modulation of the underlying neuronal activity and suggests the existence of a body-centred encoding of space within the parietal eye fields of humans. Copyright (2002) Blackwell Science Pty Ltd

Cerebral circulation and metabolism with recovery of chronic poststroke aphasia

International Nuclear Information System (INIS)

Yamada, Tomoyuki; Kabasawa, Hidehiro; Matsubara, Michitaka; Hibino, Hiroaki; Kamimoto, Kaoru; Fukagawa, Kazutoshi

2004-01-01

The recruitment of cerebral circulation and oxygen metabolism in the particular brain areas responsible for poststroke aphasia are necessary for recovery. This study was undertaken to investigate changes in cerebral circulation and oxygen metabolism corresponding to improvement of aphasia. Twenty-nine right-handed chronic aphasic patients with left hemispheric stroke were studied. Aphasia was evaluated as the score of fluency, comprehension, repetition and naming by the Western Aphasia Battery (Japanese version). Concurrent with the evaluation of aphasia, positron emission tomography (PET) scans were performed. After several months of speech therapy, PET scans and evaluation of aphasia were reperformed. Both regional cerebral blood flow and the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, and in the left upper inferior frontal gyrus in the fair recovery group for comprehension, repetition and naming. In the fair recovery group for fluency, the cerebral metabolic rate for oxygen significantly increased in the left upper superior and middle temporal gyri, but regional cerebral blood flow increased insignificantly in these areas. In the lower white matter of the right parietal lobe, both the regional cerebral blood flow and the cerebral metabolic rate for oxygen were significantly increased in the fair recovery group for all aphasic features. The recruitment of cerebral circulation and oxygen metabolism in the left temporo-parietal area, in the left inferior frontal area, and in the right deep parietal area are essentially responsible for the recovery of aphasia. (author)

Severe traumatic brain injury managed with decompressive ...

African Journals Online (AJOL)

2012-05-29

May 29, 2012 ... Patients with severe taumatic brain injury may develop intractable raised ICP resulting in high mortality ... Glasgow coma score was 8/15 (E1V3M4) and he had left ... An emergency right fronto-temporo-parietal decompressive.

Dissociated repetition deficits in aphasia can reflect flexible interactions between left dorsal and ventral streams and gender-dimorphic architecture of the right dorsal stream.

Science.gov (United States)

Berthier, Marcelo L; Froudist Walsh, Seán; Dávila, Guadalupe; Nabrozidis, Alejandro; Juárez Y Ruiz de Mier, Rocío; Gutiérrez, Antonio; De-Torres, Irene; Ruiz-Cruces, Rafael; Alfaro, Francisco; García-Casares, Natalia

2013-01-01

Assessment of brain-damaged subjects presenting with dissociated repetition deficits after selective injury to either the left dorsal or ventral auditory pathways can provide further insight on their respective roles in verbal repetition. We evaluated repetition performance and its neural correlates using multimodal imaging (anatomical MRI, DTI, fMRI, and(18)FDG-PET) in a female patient with transcortical motor aphasia (TCMA) and in a male patient with conduction aphasia (CA) who had small contiguous but non-overlapping left perisylvian infarctions. Repetition in the TCMA patient was fully preserved except for a mild impairment in nonwords and digits, whereas the CA patient had impaired repetition of nonwords, digits and word triplet lists. Sentence repetition was impaired, but he repeated novel sentences significantly better than clichés. The TCMA patient had tissue damage and reduced metabolism in the left sensorimotor cortex and insula. DTI showed damage to the left temporo-frontal and parieto-frontal segments of the arcuate fasciculus (AF) and part of the left ventral stream together with well-developed right dorsal and ventral streams, as has been reported in more than one-third of females. The CA patient had tissue damage and reduced metabolic activity in the left temporoparietal cortex with additional metabolic decrements in the left frontal lobe. DTI showed damage to the left temporo-parietal and temporo-frontal segments of the AF, but the ventral stream was spared. The direct segment of the AF in the right hemisphere was also absent with only vestigial remains of the other dorsal subcomponents present, as is often found in males. fMRI during word and nonword repetition revealed bilateral perisylvian activation in the TCMA patient suggesting recruitment of spared segments of the left dorsal stream and right dorsal stream with propagation of signals to temporal lobe structures suggesting a compensatory reallocation of resources via the ventral streams. The

Reduced parietal activation in cervical dystonia after parietal TMS interleaved with fMRI

NARCIS (Netherlands)

de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Hinson, Vanessa K.; George, Mark S.; Leenders, Klaus L.

Objective: Clinically normal hand movement with altered cerebral activation patterns in cervical dystonia (CD) may imply cerebral adaptation. Since impaired sensorimotor integration appears to play a role in dystonia, left superior parietal cortex modulation with repetitive transcranial magnetic

Voxel-based lesion analysis of brain regions underlying reading and writing.

Science.gov (United States)

Baldo, Juliana V; Kacinik, Natalie; Ludy, Carl; Paulraj, Selvi; Moncrief, Amber; Piai, Vitória; Curran, Brian; Turken, And; Herron, Tim; Dronkers, Nina F

2018-03-20

The neural basis of reading and writing has been a source of inquiry as well as controversy in the neuroscience literature. Reading has been associated with both left posterior ventral temporal zones (termed the "visual word form area") as well as more dorsal zones, primarily in left parietal cortex. Writing has also been associated with left parietal cortex, as well as left sensorimotor cortex and prefrontal regions. Typically, the neural basis of reading and writing are examined in separate studies and/or rely on single case studies exhibiting specific deficits. Functional neuroimaging studies of reading and writing typically identify a large number of activated regions but do not necessarily identify the core, critical hubs. Last, due to constraints on the functional imaging environment, many previous studies have been limited to measuring the brain activity associated with single-word reading and writing, rather than sentence-level processing. In the current study, the brain correlates of reading and writing at both the single- and sentence-level were studied in a large sample of 111 individuals with a history of chronic stroke using voxel-based lesion symptom mapping (VLSM). VLSM provides a whole-brain, voxel-by-voxel statistical analysis of the role of distinct regions in a particular behavior by comparing performance of individuals with and without a lesion at every voxel. Rather than comparing individual cases or small groups with particular behavioral dissociations in reading and writing, VLSM allowed us to analyze data from a large, well-characterized sample of stroke patients exhibiting a wide range of reading and writing impairments. The VLSM analyses revealed that reading was associated with a critical left inferior temporo-occipital focus, while writing was primarily associated with the left supramarginal gyrus. Separate VLSM analyses of single-word versus sentence-level reading showed that sentence-level reading was uniquely associated with anterior

Modification of EEG power spectra and EEG connectivity in autobiographical memory: a sLORETA study.

Science.gov (United States)

Imperatori, Claudio; Brunetti, Riccardo; Farina, Benedetto; Speranza, Anna Maria; Losurdo, Anna; Testani, Elisa; Contardi, Anna; Della Marca, Giacomo

2014-08-01

The aim of the present study was to explore the modifications of scalp EEG power spectra and EEG connectivity during the autobiographical memory test (AM-T) and during the retrieval of an autobiographical event (the high school final examination, Task 2). Seventeen healthy volunteers were enrolled (9 women and 8 men, mean age 23.4 ± 2.8 years, range 19-30). EEG was recorded at baseline and while performing the autobiographical memory (AM) tasks, by means of 19 surface electrodes and a nasopharyngeal electrode. EEG analysis was conducted by means of the standardized LOw Resolution Electric Tomography (sLORETA) software. Power spectra and lagged EEG coherence were compared between EEG acquired during the memory tasks and baseline recording. The frequency bands considered were as follows: delta (0.5-4 Hz); theta (4.5-7.5 Hz); alpha (8-12.5 Hz); beta1 (13-17.5 Hz); beta2 (18-30 Hz); gamma (30.5-60 Hz). During AM-T, we observed a significant delta power increase in left frontal and midline cortices (T = 3.554; p < 0.05) and increased EEG connectivity in delta band in prefrontal, temporal, parietal, and occipital areas, and for gamma bands in the left temporo-parietal regions (T = 4.154; p < 0.05). In Task 2, we measured an increased power in the gamma band located in the left posterior midline areas (T = 3.960; p < 0.05) and a significant increase in delta band connectivity in the prefrontal, temporal, parietal, and occipital areas, and in the gamma band involving right temporo-parietal areas (T = 4.579; p < 0.05). These results indicate that AM retrieval engages in a complex network which is mediated by both low- (delta) and high-frequency (gamma) EEG bands.

Automatic and Intentional Number Processing Both Rely on Intact Right Parietal Cortex: A Combined fMRI and Neuronavigated TMS Study

Science.gov (United States)

Cohen Kadosh, Roi; Bien, Nina; Sack, Alexander T.

2012-01-01

Practice and training usually lead to performance increase in a given task. In addition, a shift from intentional toward more automatic processing mechanisms is often observed. It is currently debated whether automatic and intentional processing is subserved by the same or by different mechanism(s), and whether the same or different regions in the brain are recruited. Previous correlational evidence provided by behavioral, neuroimaging, modeling, and neuropsychological studies addressing this question yielded conflicting results. Here we used transcranial magnetic stimulation (TMS) to compare the causal influence of disrupting either left or right parietal cortex during automatic and intentional numerical processing, as reflected by the size congruity effect and the numerical distance effect, respectively. We found a functional hemispheric asymmetry within parietal cortex with only the TMS-induced right parietal disruption impairing both automatic and intentional numerical processing. In contrast, disrupting the left parietal lobe with TMS, or applying sham stimulation, did not affect performance during automatic or intentional numerical processing. The current results provide causal evidence for the functional relevance of right, but not left, parietal cortex for intentional, and automatic numerical processing, implying that at least within the parietal cortices, automatic, and intentional numerical processing rely on the same underlying hemispheric lateralization. PMID:22347175

The differential effects of acute right- vs. left-sided vestibular failure on brain metabolism.

Science.gov (United States)

Becker-Bense, Sandra; Dieterich, Marianne; Buchholz, Hans-Georg; Bartenstein, Peter; Schreckenberger, Mathias; Brandt, Thomas

2014-07-01

The human vestibular system is represented in the brain bilaterally, but it has functional asymmetries, i.e., a dominance of ipsilateral pathways and of the right hemisphere in right-handers. To determine if acute right- or left-sided unilateral vestibular neuritis (VN) is associated with differential patterns of brain metabolism in areas representing the vestibular network and the visual-vestibular interaction, patients with acute VN (right n = 9; left n = 13) underwent resting state (18)F-FDG PET once in the acute phase and once 3 months later after central vestibular compensation. The contrast acute vs. chronic phase showed signal differences in contralateral vestibular areas and the inverse contrast in visual cortex areas, both more pronounced in VN right. In VN left additional regions were found in the cerebellar hemispheres and vermis bilaterally, accentuated in severe cases. In general, signal changes appeared more pronounced in patients with more severe vestibular deficits. Acute phase PET data of patients compared to that of age-matched healthy controls disclosed similarities to these patterns, thus permitting the interpretation that the signal changes in vestibular temporo-parietal areas reflect signal increases, and in visual areas, signal decreases. These data imply that brain activity in the acute phase of right- and left-sided VN exhibits different compensatory patterns, i.e., the dominant ascending input is shifted from the ipsilateral to the contralateral pathways, presumably due to the missing ipsilateral vestibular input. The visual-vestibular interaction patterns were preserved, but were of different prominence in each hemisphere and more pronounced in patients with right-sided failure and more severe vestibular deficits.

Altered functional connectivity differs in stroke survivors with impaired touch sensation following left and right hemisphere lesions.

Science.gov (United States)

Goodin, Peter; Lamp, Gemma; Vidyasagar, Rishma; McArdle, David; Seitz, Rüdiger J; Carey, Leeanne M

2018-01-01

One in two survivors experience impairment in touch sensation after stroke. The nature of this impairment is likely associated with changes associated with the functional somatosensory network of the brain; however few studies have examined this. In particular, the impact of lesioned hemisphere has not been investigated. We examined resting state functional connectivity in 28 stroke survivors, 14 with left hemisphere and 14 with right hemisphere lesion, and 14 healthy controls. Contra-lesional hands showed significantly decreased touch discrimination. Whole brain functional connectivity (FC) data was extracted from four seed regions, i.e. primary (S1) and secondary (S2) somatosensory cortices in both hemispheres. Whole brain FC maps and Laterality Indices (LI) were calculated for subgroups. Inter-hemispheric FC was greater in healthy controls compared to the combined stroke cohort from the left S1 seed and bilateral S2 seeds. The left lesion subgroup showed decreased FC, relative to controls, from left ipsi-lesional S1 to contra-lesional S1 and to distributed temporal, occipital and parietal regions. In comparison, the right lesion group showed decreased connectivity from contra-lesional left S1 and bilateral S2 to ipsi-lesional parietal operculum (S2), and to occipital and temporal regions. The right lesion group also showed increased intra-hemispheric FC from ipsi-lesional right S1 to inferior parietal regions compared to controls. In comparison to the left lesion group, those with right lesion showed greater intra-hemispheric connectivity from left S1 to left parietal and occipital regions and from right S1 to right angular and parietal regions. Laterality Indices were significantly greater for stroke subgroups relative to matched controls for contra-lesional S1 (left lesion group) and contra-lesional S2 (both groups). We provide evidence of altered functional connectivity within the somatosensory network, across both hemispheres, and to other networks in stroke

Altered functional connectivity differs in stroke survivors with impaired touch sensation following left and right hemisphere lesions

Directory of Open Access Journals (Sweden)

Peter Goodin

Full Text Available One in two survivors experience impairment in touch sensation after stroke. The nature of this impairment is likely associated with changes associated with the functional somatosensory network of the brain; however few studies have examined this. In particular, the impact of lesioned hemisphere has not been investigated. We examined resting state functional connectivity in 28 stroke survivors, 14 with left hemisphere and 14 with right hemisphere lesion, and 14 healthy controls. Contra-lesional hands showed significantly decreased touch discrimination. Whole brain functional connectivity (FC data was extracted from four seed regions, i.e. primary (S1 and secondary (S2 somatosensory cortices in both hemispheres. Whole brain FC maps and Laterality Indices (LI were calculated for subgroups. Inter-hemispheric FC was greater in healthy controls compared to the combined stroke cohort from the left S1 seed and bilateral S2 seeds. The left lesion subgroup showed decreased FC, relative to controls, from left ipsi-lesional S1 to contra-lesional S1 and to distributed temporal, occipital and parietal regions. In comparison, the right lesion group showed decreased connectivity from contra-lesional left S1 and bilateral S2 to ipsi-lesional parietal operculum (S2, and to occipital and temporal regions. The right lesion group also showed increased intra-hemispheric FC from ipsi-lesional right S1 to inferior parietal regions compared to controls. In comparison to the left lesion group, those with right lesion showed greater intra-hemispheric connectivity from left S1 to left parietal and occipital regions and from right S1 to right angular and parietal regions. Laterality Indices were significantly greater for stroke subgroups relative to matched controls for contra-lesional S1 (left lesion group and contra-lesional S2 (both groups. We provide evidence of altered functional connectivity within the somatosensory network, across both hemispheres, and to other

Bone structure of the temporo-mandibular joint in the individuals aged 18-25.

Science.gov (United States)

Parafiniuk, M; Gutsch-Trepka, A; Trepka, S; Sycz, K; Wolski, S; Parafiniuk, W

1998-01-01

Osteohistometric studies were performed in 15 female and 15 male cadavers aged 18-25. Condyloid process and right and left acetabulum of the temporo-mandibular joint have been studied. Density has been investigated using monitor screen linked with microscope (magnification 80x). Density in the spongy part of the condyloid process was 26.67-26.77%; in the subchondrial layer--72.13-72.72%, and in the acetabular wall 75.03-75.91%. Microscopic structure of the bones of the temporo-mandibular joint revealed no differences when compared with images of compact and cancellous bone shown in the histology textbooks. Sex and the side of the body had no influence on microscopic image and proportional bone density. Isles of chondrocytes in the trabeculae of the spongy structure of the condyloid process were found in 4 cases and isles of the condensed bone resembling the compact pattern in 7 cases.

Aphasia following left thalamic hemorrhage

International Nuclear Information System (INIS)

Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro.

1984-01-01

We reported 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months), and described language disorders examined by Western Aphasia Battery (WAB) and measured cerebral blood flow by single photon emission CT. Examination of language by WAB revealed 4 aphasics out of 7 cases, and 3 patients had no language deficit. The patient with Wernicke's aphasia showed low density area only in the left posterior thalamus in X-ray CT, and revealed severe low blood flow area extending to left temporal lobe in emission CT. In the case with transcortical sensory aphasia, although X-ray CT showed no obvious low density area, emission CT revealed moderate low flow area in watershed area that involved the territory between posterior cerebral and middle cerebral arteries in the left temporooccipital region in addition to low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, whose score of repetition (8.4) was higher than that of comprehension (7.4), emission CT showed slight low flow area at the temporo-occipital region similarly as the case with transcortical sensory aphasia. In another case with anomic aphasia, scored 9 on both fluensy and comprehension subtests and 10 on repetition, there was wide low density area all over the left thalamus and midline shift to the right in X-ray CT, and emission CT showed severe low blood flow in the same region spreading widely toward the cerebral surface. On the other hand, in all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus. (J.P.N.)

The role of human parietal area 7A as a link between sequencing in hand actions and in overt speech production

Directory of Open Access Journals (Sweden)

Stefan eHeim

2012-12-01

Full Text Available Research on the evolutionary basis of the human language faculty has proposed the mirror neuron system as a link between motor processing and speech development. Consequently, most work has focussed on the left inferior frontal cortex, in particular Broca's region, and the left inferior parietal cortex. However, the direct link between planning of hand motor and speech actions remains to be elucidated. Thus, the present study investigated whether sequencing of hand motor actions vs. speech motor actions has a common neural denominator. For the hand motor task, 25 subjects performed single, repeated, or sequenced button presses with either the left or right hand. The speech task was in analogy; the same subjects produced the syllable "po" once or repeatedly, or a sequence of different syllables (po-pi-po. Speech motor vs. hand motor effectors resulted in increased perisylvian activation including Broca's region (left area 44 and areas medially adjacent to left area 45. In contrast, common activation for sequenced vs. repeated production of button presses and syllables revealed the effector-independent involvement of left area 7A in the superior parietal lobule (SPL in sequencing. These data demonstrate that sequencing of vocal gestures, an important precondition for ordered utterances and ultimately human speech, shares area 7A, rather than inferior parietal regions, as a common cortical module with hand motor sequencing. Interestingly, area 7A has previously also been shown to be involved in the observation of hand and non-hand actions. In combination with the literature, the present data thus suggest a distinction between area 44, which is specifically recruited for (cognitive aspects of speech, and SPL area 7A for general aspects of motor sequencing. In sum, the study demonstrates a yet little considered role of the superior parietal lobule in the origins of speech, and may be discussed in the light of embodiment of speech and language in the

Neural correlates of pantomiming familiar and unfamiliar tools: action semantics versus mechanical problem solving?

Science.gov (United States)

Vingerhoets, Guy; Vandekerckhove, Elisabeth; Honoré, Pieterjan; Vandemaele, Pieter; Achten, Eric

2011-06-01

This study aims to reveal the neural correlates of planning and executing tool use pantomimes and explores the brain's response to pantomiming the use of unfamiliar tools. Sixteen right-handed volunteers planned and executed pantomimes of equally graspable familiar and unfamiliar tools while undergoing fMRI. During the planning of these pantomimes, we found bilateral temporo-occipital and predominantly left hemispheric frontal and parietal activation. The execution of the pantomimes produced additional activation in frontal and sensorimotor regions. In the left posterior parietal region both familiar and unfamiliar tool pantomimes elicit peak activity in the anterior portion of the lateral bank of the intraparietal sulcus--A region associated with the representation of action goals. The cerebral activation during these pantomimes is remarkably similar for familiar and unfamiliar tools, and direct comparisons revealed only few differences. First, the left cuneus is significantly active during the planning of pantomimes of unfamiliar tools, reflecting increased visual processing of the novel objects. Second, executing (but not planning) familiar tool pantomimes showed significant activation on the convex portion of the inferior parietal lobule, a region believed to serve as a repository for skilled object-related gestures. Given the striking similarity in brain activation while pantomiming familiar and unfamiliar tools, we argue that normal subjects use both action semantics and function from structure inferences simultaneously and interactively to give rise to flexible object-to-goal directed behavior. Copyright © 2010 Wiley-Liss, Inc.

[Tourette syndrome and reading disorder in a boy with left parietofrontal tract disruption].

Science.gov (United States)

Martín Fernández-Mayoralas, D; Fernández-Jaén, A; Gómez Herrera, J J; Jiménez de la Peña, M

2014-01-01

We present the case of a nine-year-old boy with Tourette syndrome and reading disorder with a history of a severe infectious process in the late neonatal period. Brain MRI showed a left parietal malacotic cavity and diffusion tensor imaging and tractography showed a striking disruption of the white matter bundle that joins the left parietal region with the ipsilateral frontal region with involvement of the left superior longitudinal fasciculus and of the left arcuate fasciculus. Although Tourette syndrome and reading disorder are fundamentally hereditary neuropsychiatric disorders, they can also occur secondary to cerebral alterations like those existing in this boy. The introduction of modern neuroimaging techniques in patients with neuropsychiatric disorders (or the risk of developing them) can be very useful in the diagnosis and prognosis in the future. Copyright © 2011 SERAM. Published by Elsevier Espana. All rights reserved.

Understanding Actions of Others: The Electrodynamics of the Left and Right Hemispheres. A High-Density EEG Neuroimaging Study

Science.gov (United States)

Ortigue, Stephanie; Sinigaglia, Corrado; Rizzolatti, Giacomo; Grafton, Scott T.

2010-01-01

Background When we observe an individual performing a motor act (e.g. grasping a cup) we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping) and the intention underlying it (i.e. grasping for drinking). Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. Methodology/Principal Findings Volunteers were presented with two-frame video-clips. The first frame (T0) showed an object with or without context; the second frame (T1) showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs) were recorded time-locked with the frame showing the hand-object interaction (T1). The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1) bilateral posterior cortical activations; 2) a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3) a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4) a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. Conclusions/Significance We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network mediates the

Seeing is not feeling: posterior parietal but not somatosensory cortex engagement during touch observation.

Science.gov (United States)

Chan, Annie W-Y; Baker, Chris I

2015-01-28

Observing touch has been reported to elicit activation in human primary and secondary somatosensory cortices and is suggested to underlie our ability to interpret other's behavior and potentially empathy. However, despite these reports, there are a large number of inconsistencies in terms of the precise topography of activation, the extent of hemispheric lateralization, and what aspects of the stimulus are necessary to drive responses. To address these issues, we investigated the localization and functional properties of regions responsive to observed touch in a large group of participants (n = 40). Surprisingly, even with a lenient contrast of hand brushing versus brushing alone, we did not find any selective activation for observed touch in the hand regions of somatosensory cortex but rather in superior and inferior portions of neighboring posterior parietal cortex, predominantly in the left hemisphere. These regions in the posterior parietal cortex required the presence of both brush and hand to elicit strong responses and showed some selectivity for the form of the object or agent of touch. Furthermore, the inferior parietal region showed nonspecific tactile and motor responses, suggesting some similarity to area PFG in the monkey. Collectively, our findings challenge the automatic engagement of somatosensory cortex when observing touch, suggest mislocalization in previous studies, and instead highlight the role of posterior parietal cortex. Copyright © 2015 the authors 0270-6474/15/351468-13$15.00/0.

Poor neurological sequelae of herpes simplex virus encephalitis in an infant despite adequate antiviral and adjunct corticosteroid therapy

Directory of Open Access Journals (Sweden)

Ratna B Basak

2011-01-01

Full Text Available A 2-month-old infant presented to our emergency department with fever, altered consciousness, and focal seizures of acute onset. He had vesicular skin lesions over the right preauricular region. CT brain showed a large hypodense lesion involving the left temporo-parietal region, left basal ganglia and left thalamus. MRI brain revealed bilateral multifocal corticomedullary lesions suggestive of encephalitis. CSF-PCR was positive for herpes simplex virus (HSV type I. He was treated with standard dose intravenous acyclovir for 15 days along with a trial of pulse methylprednisolone, but was readmitted within a week with features of an early relapse. The infant survived but developed significant neurological sequelae. Although treatment of HSV is available, the neurological outcome is guarded even with adequate antiviral therapy. Adjunct corticosteroid therapy did not appear to attenuate the neurological sequelae.

Thinking about Seeing: perceptual sources of knowledge are encoded in the theory of mind brain regions of sighted and blind adults

Science.gov (United States)

Koster-Hale, Jorie; Bedny, Marina; Saxe, Rebecca

2014-01-01

Blind people's inferences about how other people see provide a window into fundamental questions about the human capacity to think about one another's thoughts. By working with blind individuals, we can ask both what kinds of representations people form about others’ minds, and how much these representations depend on the observer having had similar mental states themselves. Thinking about others’ mental states depends on a specific group of brain regions, including the right temporo-parietal junction (RTPJ). We investigated the representations of others’ mental states in these brain regions, using multivoxel pattern analyses (MVPA). We found that, first, in the RTPJ of sighted adults, the pattern of neural response distinguished the source of the mental state (did the protagonist see or hear something?) but not the valence (did the protagonist feel good or bad?). Second, these neural representations were preserved in congenitally blind adults. These results suggest that the temporo-parietal junction contains explicit, abstract representations of features of others’ mental states, including the perceptual source. The persistence of these representations in congenitally blind adults, who have no first-person experience with sight, provides evidence that these representations emerge even in the absence of first-person perceptual experiences. PMID:24960530

Thinking about seeing: perceptual sources of knowledge are encoded in the theory of mind brain regions of sighted and blind adults.

Science.gov (United States)

Koster-Hale, Jorie; Bedny, Marina; Saxe, Rebecca

2014-10-01

Blind people's inferences about how other people see provide a window into fundamental questions about the human capacity to think about one another's thoughts. By working with blind individuals, we can ask both what kinds of representations people form about others' minds, and how much these representations depend on the observer having had similar mental states themselves. Thinking about others' mental states depends on a specific group of brain regions, including the right temporo-parietal junction (RTPJ). We investigated the representations of others' mental states in these brain regions, using multivoxel pattern analyses (MVPA). We found that, first, in the RTPJ of sighted adults, the pattern of neural response distinguished the source of the mental state (did the protagonist see or hear something?) but not the valence (did the protagonist feel good or bad?). Second, these neural representations were preserved in congenitally blind adults. These results suggest that the temporo-parietal junction contains explicit, abstract representations of features of others' mental states, including the perceptual source. The persistence of these representations in congenitally blind adults, who have no first-person experience with sight, provides evidence that these representations emerge even in the absence of relevant first-person perceptual experiences. Copyright © 2014 Elsevier B.V. All rights reserved.

[Neuroanatomy of the Parietal Association Areas].

Science.gov (United States)

Kobayashi, Yasushi

2016-11-01

The parietal association cortex comprises the superior and inferior parietal lobules, the precuneus and the cortices in the intraparietal, parietooccipital and lunate sulci. By processing somatic, visual, acoustic and vestibular sensory information, the parietal association cortex plays a pivotal role in spatial cognition and motor control of the eyes and the extremities. Sensory information from the primary and secondary somatosensory areas enters the superior parietal lobule and is transferred to the inferior parietal lobule. Visual information is processed through the dorsal visual pathway and it reaches the inferior parietal lobule, the intraparietal sulcus and the precuneus. Acoustic information is transferred posteriorly from the primary acoustic area, and it reaches the posterior region of the inferior parietal lobule. The areas in the intraparietal sulcus project to the premotor area, the frontal eye fields, and the prefrontal area. These areas are involved in the control of ocular movements, reaching and grasping of the upper extremities, and spatial working memory. The posterior region of the inferior parietal lobule and the precuneus both project either directly, or indirectly via the posterior cingulate gyrus, to the parahippocampal and entorhinal cortices. Both these areas are strongly associated with hippocampal functions for long-term memory formation.

Cognitive neuropsychological and regional cerebral blood flow study of a Japanese-English bilingual girl with specific language impairment (SLI).

Science.gov (United States)

Uno, Akira; Wydell, Taeko N; Kato, Motoichiro; Itoh, Kanae; Yoshino, Fumihiro

2009-02-01

We report here on an investigation into the possible factors which might have contributed to language impairment (LI) in EM, a 14-year-old Japanese-English bilingual girl. EM was born in the UK to Japanese parents with no other siblings, and used English to communicate with all other people except for her parents. A delay in her English language development was identified at primary school in the UK, which was attributed to her bilingualism. The deficiency in her English language skills persisted into her adolescence despite more than adequate educational opportunities (including additional language support). At the start of her secondary education, language ability/literacy attainment tests were conducted in both English and Japanese, and the results suggested specific language impairment (SLI) in both languages. Further, her brain Single Photon Emission Computed Tomography (SPECT) revealed significantly lower Regional Cerebral Blood Flow(rCBF) in the left temporo-parietal area, which is also similar to the area of dysfunction often found among Japanese individuals with SLI.

Sentence processing and verbal working memory in a white-matter-disconnection patient.

Science.gov (United States)

Meyer, Lars; Cunitz, Katrin; Obleser, Jonas; Friederici, Angela D

2014-08-01

The Arcuate Fasciculus/Superior Longitudinal Fasciculus (AF/SLF) is the white-matter bundle that connects posterior superior temporal and inferior frontal cortex. Its causal functional role in sentence processing and verbal working memory is currently under debate. While impairments of sentence processing and verbal working memory often co-occur in patients suffering from AF/SLF damage, it is unclear whether these impairments result from shared white-matter damage to the verbal-working-memory network. The present study sought to specify the behavioral consequences of focal AF/SLF damage for sentence processing and verbal working memory, which were assessed in a single patient suffering from a cleft-like lesion spanning the deep left superior temporal gyrus, sparing most surrounding gray matter. While tractography suggests that the ventral fronto-temporal white-matter bundle is intact in this patient, the AF/SLF was not visible to tractography. In line with the hypothesis that the AF/SLF is causally involved in sentence processing, the patient׳s performance was selectively impaired on sentences that jointly involve both complex word orders and long word-storage intervals. However, the patient was unimpaired on sentences that only involved long word-storage intervals without involving complex word orders. On the contrary, the patient performed generally worse than a control group across standard verbal-working-memory tests. We conclude that the AF/SLF not only plays a causal role in sentence processing, linking regions of the left dorsal inferior frontal gyrus to the temporo-parietal region, but moreover plays a crucial role in verbal working memory, linking regions of the left ventral inferior frontal gyrus to the left temporo-parietal region. Together, the specific sentence-processing impairment and the more general verbal-working-memory impairment may imply that the AF/SLF subserves both sentence processing and verbal working memory, possibly pointing to the AF

Hemispheric lateralization of linguistic prosody recognition in comparison to speech and speaker recognition.

Science.gov (United States)

Kreitewolf, Jens; Friederici, Angela D; von Kriegstein, Katharina

2014-11-15

Hemispheric specialization for linguistic prosody is a controversial issue. While it is commonly assumed that linguistic prosody and emotional prosody are preferentially processed in the right hemisphere, neuropsychological work directly comparing processes of linguistic prosody and emotional prosody suggests a predominant role of the left hemisphere for linguistic prosody processing. Here, we used two functional magnetic resonance imaging (fMRI) experiments to clarify the role of left and right hemispheres in the neural processing of linguistic prosody. In the first experiment, we sought to confirm previous findings showing that linguistic prosody processing compared to other speech-related processes predominantly involves the right hemisphere. Unlike previous studies, we controlled for stimulus influences by employing a prosody and speech task using the same speech material. The second experiment was designed to investigate whether a left-hemispheric involvement in linguistic prosody processing is specific to contrasts between linguistic prosody and emotional prosody or whether it also occurs when linguistic prosody is contrasted against other non-linguistic processes (i.e., speaker recognition). Prosody and speaker tasks were performed on the same stimulus material. In both experiments, linguistic prosody processing was associated with activity in temporal, frontal, parietal and cerebellar regions. Activation in temporo-frontal regions showed differential lateralization depending on whether the control task required recognition of speech or speaker: recognition of linguistic prosody predominantly involved right temporo-frontal areas when it was contrasted against speech recognition; when contrasted against speaker recognition, recognition of linguistic prosody predominantly involved left temporo-frontal areas. The results show that linguistic prosody processing involves functions of both hemispheres and suggest that recognition of linguistic prosody is based on

Application of SPECT to psychiatry

International Nuclear Information System (INIS)

Matsuda, Hiroshi

1999-01-01

Brain perfusion SPECT using 99m Tc-ethyl-cysteinate dimer ( 99m Tc-ECD) was applied to psychiatric diseases with aid of statistical parametric mapping (SPM) for analysis of data. To evaluate influence of aging on brain perfusion, noninvasive measurements of cerebral blood flow using 99m Tc-ECD were performed in 53 normal volunteers, age 18 to 87 years old. Mean cerebral blood flow (mCBF) was 43.9±5.0 ml/100 g/min and showed weak negative correlation with aging (r=0.451). Perisylvian cerebral cortices and medial frontal areas including anterior cingulate gyri showed greater negative correlation than other areas. These findings suggest the necessity of age-matched control regional CBF (rCBF) data to investigate rCBF abnormality in patients. Four drug-naive schizophrenic patients showed flow decrease in bilateral frontal and superior temporal areas and a left infero-posterior temporal area. Haloperidol administration induced flow decrease in bilateral frontal and left parietal areas, while flow increase in bilateral striatal and right hippocampal areas. Ten aged depressive patients showed flow decrease in bilateral frontal and left temporo-parietal areas. Even after remission patients showed flow decrease in the left frontal area as compared with normal subjects. Remission induced flow increase in the right frontal, right parietal, and right orbitofrontal areas compared with depression. These results suggest that CBF measurements using 99m Tc-ECD were useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

Repetitive transcranial magnetic stimulation reveals a role for the left inferior parietal lobule in matching observed kinematics during imitation.

Science.gov (United States)

Reader, Arran T; Royce, Ben P; Marsh, Jade E; Chivers, Katy-Jayne; Holmes, Nicholas P

2018-04-01

Apraxia (a disorder of complex movement) suggests that the left inferior parietal lobule (IPL) plays a role in kinematic or spatial aspects of imitation, which may be particularly important for meaningless (i.e. unfamiliar intransitive) actions. Mirror neuron theories indicate that the IPL is part of a frontoparietal system that can support imitation by linking observed and stored actions through visuomotor matching, and have less to say about different subregions of the left IPL, or how different types of action (i.e. meaningful or meaningless) are processed for imitation. We used repetitive transcranial magnetic stimulation (rTMS) to bridge this gap and better understand the roles of the left supramarginal gyrus (SMG) and left angular gyrus (AG) in imitation. We also examined whether these areas are differentially involved in meaningful and meaningless action imitation. We applied rTMS over the left SMG, over the left AG or during a no-rTMS baseline condition, and then asked participants to imitate a confederate's actions whilst the arm and hand movements of both individuals were motion-tracked. rTMS over both the left SMG and the left AG reduced the velocity of participants' finger movements relative to the actor during imitation of finger gestures, regardless of action meaning. Our results support recent claims in apraxia and confirm a role for the left IPL in kinematic processing during gesture imitation, regardless of action meaning. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Dyscalculia, Dysgraphia, and Left-Right Confusion from a Left Posterior Peri-Insular Infarct

Directory of Open Access Journals (Sweden)

S. Bhattacharyya

2014-01-01

Full Text Available The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

Dyscalculia, dysgraphia, and left-right confusion from a left posterior peri-insular infarct.

Science.gov (United States)

Bhattacharyya, S; Cai, X; Klein, J P

2014-01-01

The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

Changes in cerebral activations during movement execution and imagery after parietal cortex TMS interleaved with 3T MRI

NARCIS (Netherlands)

de Vries, Paulien M.; de Jong, Bauke M.; Bohning, Daryl E.; Walker, John A.; George, Mark S.; Leenders, Klaus L.

2009-01-01

The left parietal cortex contributes to goal-directed hand movement. In this study, we targeted this region with transcranial magnetic stimulation (TMS) to assess the effects on a wider distributed circuitry related to motor control. Ten healthy subjects underwent 3 Tesla functional magnetic

Altered Parietal Activation during Non-symbolic Number Comparison in Children with Prenatal Alcohol Exposure

Directory of Open Access Journals (Sweden)

Keri J. Woods

2018-01-01

Full Text Available Number processing is a cognitive domain particularly sensitive to prenatal alcohol exposure, which relies on intact parietal functioning. Alcohol-related alterations in brain activation have been found in the parietal lobe during symbolic number processing. However, the effects of prenatal alcohol exposure on the neural correlates of non-symbolic number comparison and the numerical distance effect have not been investigated. Using functional magnetic resonance imaging (fMRI, we examined differences in brain activation associated with prenatal alcohol exposure in five parietal regions involved in number processing during a non-symbolic number comparison task with varying degrees of difficulty. fMRI results are presented for 27 Cape Colored children (6 fetal alcohol syndome (FAS/partial FAS, 5 heavily exposed (HE non-sydromal, 16 controls; mean age ± SD = 11.7 ± 1.1 years. Fetal alcohol exposure was assessed by interviewing mothers using a timeline follow-back approach. Separate subject analyses were performed in each of five regions of interest, bilateral horizontal intraparietal sulci (IPS, bilateral posterior superior parietal lobules (PSPL, and left angular gyrus (left AG, using the general linear model with predictors for number comparison and difficulty level. Mean percent signal change for each predictor was extracted for each subject for each region to examine group differences and associations with continuous measures of alcohol exposure. Although groups did not differ in performance, controls activated the right PSPL more during non-symbolic number comparison than exposed children, but this was not significant after controlling for maternal smoking, and the right IPS more than children with fetal alcohol syndrome (FAS or partial FAS. More heavily exposed children recruited the left AG to a greater extent as task difficulty increased, possibly to compensate, in part, for impairments in function in the PSPL and IPS. Notably, in non

Temporo-insular enhancement of EEG low and high frequencies in patients with chronic tinnitus. QEEG study of chronic tinnitus patients

Directory of Open Access Journals (Sweden)

Weisz Nathan

2010-03-01

Full Text Available Abstract Background The physiopathological mechanism underlying the tinnitus phenomenon is still the subject of an ongoing debate. Since oscillatory EEG activity is increasingly recognized as a fundamental hallmark of cortical integrative functions, this study investigates deviations from the norm of different resting EEG parameters in patients suffering from chronic tinnitus. Results Spectral parameters of resting EEG of male tinnitus patients (n = 8, mean age 54 years were compared to those of age-matched healthy males (n = 15, mean age 58.8 years. On average, the patient group exhibited higher spectral power over the frequency range of 2-100 Hz. Using LORETA source analysis, the generators of delta, theta, alpha and beta power increases were localized dominantly to left auditory (Brodmann Areas (BA 41,42, 22, temporo-parietal, insular posterior, cingulate anterior and parahippocampal cortical areas. Conclusions Tinnitus patients show a deviation from the norm of different resting EEG parameters, characterized by an overproduction of resting state delta, theta and beta brain activities, providing further support for the microphysiological and magnetoencephalographic evidence pointing to a thalamocortical dysrhythmic process at the source of tinnitus. These results also provide further confirmation that reciprocal involvements of both auditory and associative/paralimbic areas are essential in the generation of tinnitus.

Modulation of fronto-parietal connections during the rubber hand illusion

DEFF Research Database (Denmark)

Karabanov, Anke Ninija; Ritterband-Rosenbaum, Anina; Christensen, Mark Schram

2017-01-01

Accumulating evidence suggests that parieto-frontal connections play a role in adjusting body ownership during the Rubber Hand Illusion (RHI). Using a motor version of the rubber hand illusion paradigm, we applied single-site and dual-site transcranial magnetic stimulation (TMS) to investigate...... and during three RHI conditions: a) agency and ownership, b) agency but no ownership and c) neither agency nor ownership. Parietal-motor communication differed among experimental conditions. The induction of action ownership was associated with an inhibitory parietal-to-motor connectivity, which...... cortico-spinal and parietal-frontal connectivity during perceived rubber hand ownership. Healthy volunteers received a conditioning TMS pulse over left anterior intraparietal sulcus (aIPS) and a test TMS pulse over left primary motor cortex (M1). Motor Evoked Potentials (MEPs) were recorded at rest...

Neural correlates of hemispheric dominance and ipsilaterality within the vestibular system.

Science.gov (United States)

Janzen, J; Schlindwein, P; Bense, S; Bauermann, T; Vucurevic, G; Stoeter, P; Dieterich, M

2008-10-01

Earlier functional imaging studies on the processing of vestibular information mainly focused on cortical activations due to stimulation of the horizontal semicircular canals in right-handers. Two factors were found to determine its processing in the temporo-parietal cortex: a dominance of the non-dominant hemisphere and an ipsilaterality of the neural pathways. In an investigation of the role of these factors in the vestibular otoliths, we used vestibular evoked myogenic potentials (VEMPs) in a fMRI study of monaural saccular-otolith stimulation. Our aim was to (1) analyze the hemispheric dominance for saccular-otolith information in healthy left-handers, (2) determine if there is a predominance of the ipsilateral saccular-otolith projection, and (3) evaluate the impact of both factors on the temporo-parieto-insular activation pattern. A block design with three stimulation and rest conditions was applied: (1) 102 dB-VEMP stimulation; (2) 65 dB-control-acoustic stimulation, (3) 102 dB-white-noise-control stimulation. After subtraction of acoustic side effects, bilateral activations were found in the posterior insula, the superior/middle/transverse temporal gyri, and the inferior parietal lobule. The distribution of the saccular-otolith activations was influenced by the two factors but with topographic disparity: whereas the inferior parts of the temporo-parietal cortex were mainly influenced by the ipsilaterality of the pathways, the upper parts reflected the dominance of the non-dominant hemisphere. This is in contrast to the processing of acoustic stimulation, which showed a predominance of the contralateral pathways. Our study proves the importance of the hemispheric preponderance also in left-handers, which is of relevance in the superior parts of the insula gyrus V, the inferior parietal lobule, and the superior temporal gyri.

Unleashing creativity: The role of left temporoparietal regions in evaluating and inhibiting the generation of creative ideas.

Science.gov (United States)

Mayseless, Naama; Aharon-Peretz, Judith; Shamay-Tsoory, Simone

2014-11-01

Human creativity is thought to entail two processes. One is idea generation, whereby ideas emerge in an associative manner, and the other is idea evaluation, whereby generated ideas are evaluated and screened. Thus far, neuroimaging studies have identified several brain regions as being involved in creativity, yet only a handful of studies have examined the neural basis underlying these two processes. We found that an individual with left temporoparietal hemorrhage who had no previous experience as an artist developed remarkable artistic creativity, which diminished as the hemorrhage receded. We thus hypothesized that damage to the evaluation network of creativity during the initial hematoma had a releasing effect on creativity by "freeing" the idea generation system. In line with this hypothesis, we conducted a subsequent fMRI study showing that decreased left temporal and parietal activations among healthy individuals as they evaluated creative ideas selectively predicted higher creativity. The current studies provide converging multi-method evidence suggesting that the left temporoparietal area is part of a neural network involved in evaluating creativity, and that as such may act as inhibitors of creativity. We propose an explanatory model of creativity centered upon the key role of the left temporoparietal regions in evaluating and inhibiting creativity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Induction of motor associative plasticity in the posterior parietal cortex-primary motor network

DEFF Research Database (Denmark)

Chao, Chi-Chao; Karabanov, Anke Ninija; Paine, Rainer

2015-01-01

There is anatomical and functional connectivity between the primary motor cortex (M1) and posterior parietal cortex (PPC) that plays a role in sensorimotor integration. In this study, we applied corticocortical paired-associative stimuli to ipsilateral PPC and M1 (parietal ccPAS) in healthy right......-handed subjects to test if this procedure could modulate M1 excitability and PPC–M1 connectivity. One hundred and eighty paired transcranial magnetic stimuli to the PPC and M1 at an interstimulus interval (ISI) of 8 ms were delivered at 0.2 Hz. We found that parietal ccPAS in the left hemisphere increased...... the excitability of conditioned left M1 assessed by motor evoked potentials (MEPs) and the input–output curve. Motor behavior assessed by the Purdue pegboard task was unchanged compared with controls. At baseline, conditioning stimuli over the left PPC potentiated MEPs from left M1 when ISI was 8 ms...

Demonstration of a reduction in muscarinic receptor binding in early Alzheimer's disease using iodine-123 dexetimide single-photon emission tomography

International Nuclear Information System (INIS)

Claus, J.J.; Dubois, E.A.; Booij, J.; Habraken, J.; Munck, J.C. van; Herk, M. van; Verbeeten, B. Jr.; Royen, E.A. van

1997-01-01

Decreased muscarinic receptor binding has been suggested in single-photon emission tomography (SPET) studies of Alzheimer's disease. However, it remains unclear whether these changes are present in mildly demented patients, and the role of cortical atrophy in receptor binding assessment has not been investigated. We studied muscarinic receptor binding normalized to neostriatum with SPET using [ 123 I[4-iododexetimide in five mildly affected patients with probable Alzheimer's disease and in five age-matched control subjects. Region of interest (ROI) analysis was performed in a consensus procedure blind to clinical diagnosis using matched magnetic resonance (MRI) images. Cortical atrophy was assessed by calculating percentages of cerebrospinal fluid in each ROI. An observer study with three observers was conducted to validate this method. Alzheimer patients showed statistically significantly less [ 123 I[4-iododexetimide binding in left temporal and right temporo-parietal cortex compared with controls, independent of age, sex and cortical atrophy. Mean intra-observer variability was 3.6% and inter-observer results showed consistent differences in [ 123 I[4-iododexetimide binding between observers. However, differences between patients and controls were comparable among observers and statistically significant in the same regions as in the consensus procedure. Using an MRI-SPET matching technique, we conclude that [ 123 I[4-iododexetimide binding is reduced in patients with mild probable Alzheimer's disease in areas of temporal and temporo-parietal cortex. (orig.). With 1 fig., 4 tabs

A case of left-sided unilateral spatial neglect owing to the cerebral infarction in the distribution of the right posterior cerebral artery

International Nuclear Information System (INIS)

Odagaki, Yuji; Oka, Iori; Kon, Yutaka; Asano, Yutaka

1985-01-01

We report a case of left-sided unilateral spatial neglect (USN) induced by the cerebral infarction in the distribution of right posterior cerebral artery (PCA). A 69-year-old, right-handed man, who had had a sudden onset of left hemiparesis in August 1983, was admitted to our hospital on January 16, 1984, because of nocturnal delirium. He became alert a few days after admission, but was euphoric and sometimes irritable. Neurologic examination disclosed left homonymous hemianopsia, dysarthria, left central facial weakness, spastic left hemiparesis, hyperactive reflexes on the left with no Babinski sign, left hemisensory loss, and left thalamic pain. On neuropsychologic examination it was revealed that he had a tendency to neglect the left half of his extrapersonal space. When asked to locate cities on a blank map of Japan, he located most of them not only on the right side of the map but also incorrectly. He also had a severe acalculia. There was gradual improvement in these neuropsychologic symptoms. CT demonstrated an area of decreased density in the territory of the right PCA, posterolateral portion of the right thalamus, and the posterior limb of right internal capsule, sparing parietal and temporal lobes. Single-photon emission computed tomography (SPECT) using the Xenon-133 inhalation method showed, however, diminished regional cerebral blood flow (rCBF) in an area larger than the area of infarction demonstrated by CT, including the right parieto-temporo-occipital junctional area, which has been considerd to be responsible for left-sided USN. The authors ascribed the patient's left-sided USN to the lesion of this area that was revealed not morphologically by CT but functionally by SPECT, although the possibility that the lesions of the medial portion of the right occipital lobe and/or subcortical lesions of such areas as the thalamus and the internal capsule more or less influenced the neuropsychologic symptoms could not be excluded. (author)

Regional ejection fraction: a quantitative radionuclide index of regional left ventricular performance

International Nuclear Information System (INIS)

Maddox, D.E.; Wynne, J.; Uren, R.; Parker, J.A.; Idoine, J.; Siegel, L.C.; Neill, J.M.; Cohn, P.F.; Holman, B.L.

1979-01-01

Left ventricular regional ejection fractions were derived from background-corrected, time-activity curves in 43 patients assessed by both gated equilibrium radionuclide angiocardiography and left ventricular contrast angiography. From a single, modified left anterior oblique projection, the regional change in background corrected counts was determined in each of three anatomic regions. The normal range for regional radionuclide ejection fraction was determined in 10 patients with normal contrast ventriculograms and without obstructive coronary artery disease at coronary arteriography. Regional ejection fraction was compared with percent segmental axis shortening and extent of akinetic segments in corresponding regions of the contrast ventriculogram. Radionuclide and roentgenographic methods were in agreement as to the presence or absence of abnormal wall motion in 83 of 99 left ventricular regions (84%) in 33 patients evaluated prospectively. Comparison of regional ejection fraction demonstrated significant differences between regions with roentgenographically determined normokinesis hypokinesis, and akinesis. We conclude that the left ventricular regional ejection fraction provides a reliable quantitative assessment of regional left ventricular performance

Aberrant connectivity of areas for decoding degraded speech in patients with auditory verbal hallucinations.

Science.gov (United States)

Clos, Mareike; Diederen, Kelly M J; Meijering, Anne Lotte; Sommer, Iris E; Eickhoff, Simon B

2014-03-01

Auditory verbal hallucinations (AVH) are a hallmark of psychotic experience. Various mechanisms including misattribution of inner speech and imbalance between bottom-up and top-down factors in auditory perception potentially due to aberrant connectivity between frontal and temporo-parietal areas have been suggested to underlie AVH. Experimental evidence for disturbed connectivity of networks sustaining auditory-verbal processing is, however, sparse. We compared functional resting-state connectivity in 49 psychotic patients with frequent AVH and 49 matched controls. The analysis was seeded from the left middle temporal gyrus (MTG), thalamus, angular gyrus (AG) and inferior frontal gyrus (IFG) as these regions are implicated in extracting meaning from impoverished speech-like sounds. Aberrant connectivity was found for all seeds. Decreased connectivity was observed between the left MTG and its right homotope, between the left AG and the surrounding inferior parietal cortex (IPC) and the left inferior temporal gyrus, between the left thalamus and the right cerebellum, as well as between the left IFG and left IPC, and dorsolateral and ventrolateral prefrontal cortex (DLPFC/VLPFC). Increased connectivity was observed between the left IFG and the supplementary motor area (SMA) and the left insula and between the left thalamus and the left fusiform gyrus/hippocampus. The predisposition to experience AVH might result from decoupling between the speech production system (IFG, insula and SMA) and the self-monitoring system (DLPFC, VLPFC, IPC) leading to misattribution of inner speech. Furthermore, decreased connectivity between nodes involved in speech processing (AG, MTG) and other regions implicated in auditory processing might reflect aberrant top-down influences in AVH.

The Neural Basis of Changing Social Norms through Persuasion.

Science.gov (United States)

Yomogida, Yukihito; Matsumoto, Madoka; Aoki, Ryuta; Sugiura, Ayaka; Phillips, Adam N; Matsumoto, Kenji

2017-11-24

Social norms regulate behavior, and changes in norms have a great impact on society. In most modern societies, norms change through interpersonal communication and persuasive messages found in media. Here, we examined the neural basis of persuasion-induced changes in attitude toward and away from norms using fMRI. We measured brain activity while human participants were exposed to persuasive messages directed toward specific norms. Persuasion directed toward social norms specifically activated a set of brain regions including temporal poles, temporo-parietal junction, and medial prefrontal cortex. Beyond these regions, when successful, persuasion away from an accepted norm specifically recruited the left middle temporal and supramarginal gyri. Furthermore, in combination with data from a separate attitude-rating task, we found that left supramarginal gyrus activity represented participant attitude toward norms and tracked the persuasion-induced attitude changes that were away from agreement.

The impact of top-down spatial attention on laterality and hemispheric asymmetry in the human parietal cortex.

Science.gov (United States)

Jeong, Su Keun; Xu, Yaoda

2016-08-01

The human parietal cortex exhibits a preference to contralaterally presented visual stimuli (i.e., laterality) as well as an asymmetry between the two hemispheres with the left parietal cortex showing greater laterality than the right. Using visual short-term memory and perceptual tasks and varying target location predictability, this study examined whether hemispheric laterality and asymmetry are fixed characteristics of the human parietal cortex or whether they are dynamic and modulated by the deployment of top-down attention to the target present hemifield. Two parietal regions were examined here that have previously been shown to be involved in visual object individuation and identification and are located in the inferior and superior intraparietal sulcus (IPS), respectively. Across three experiments, significant laterality was found in both parietal regions regardless of attentional modulation with laterality being greater in the inferior than superior IPS, consistent with their roles in object individuation and identification, respectively. Although the deployment of top-down attention had no effect on the superior IPS, it significantly increased laterality in the inferior IPS. The deployment of top-down spatial attention can thus amplify the strength of laterality in the inferior IPS. Hemispheric asymmetry, on the other hand, was absent in both brain regions and only emerged in the inferior but not the superior IPS with the deployment of top-down attention. Interestingly, the strength of hemispheric asymmetry significantly correlated with the strength of laterality in the inferior IPS. Hemispheric asymmetry thus seems to only emerge when there is a sufficient amount of laterality present in a brain region.

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

International Nuclear Information System (INIS)

Hirano, Masaharu

1998-01-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Percent wall thickness evaluated by Gd-DTPA enhanced cine MRI as an indicator of local parietal movement in hypertrophic cardiomyopathy

Energy Technology Data Exchange (ETDEWEB)

Hirano, Masaharu [Tokyo Medical Coll. (Japan)

1998-11-01

Hypertrophic cardiomyopathy (HCM) is a cardiac disease, the basic pathology of which consists of a decrease in left ventricular dilation compliance due to uneven hypertrophy of the left ventricular wall. Magnetic resonance imaging (MRI) is useful in monitoring uneven parietal hypertrophy and kinetics in HCM patients. The present study was undertaken in 47 HCM patients who showed asymmetrical septal hypertrophy to determine if percent thickness can be an indicator of left ventricular local movement using cine MRI. Longest and shortest axis images were acquired by the ECG synchronization method using a 1.5 T MR imager. Cardiac function was analyzed based on longest axis cine images, and telediastolic and telesystolic parietal thickness were measured based on shorter axis cine images at the papillary muscle level. Parietal movement index and percent thickness were used as indicators of local parietal movement. The correlation between these indicators and parietal thickness was evaluated. The percent thickness changed at an earlier stage of hypertrophy than the parietal movement index, thus it is thought to be useful in detecting left ventricular parietal movement disorders at an early stage of HCM. (author)

Multimodal FMRI resting-state functional connectivity in granulin mutations: the case of fronto-parietal dementia.

Directory of Open Access Journals (Sweden)

Enrico Premi

Full Text Available BACKGROUND: Monogenic dementias represent a great opportunity to trace disease progression from preclinical to symptomatic stages. Frontotemporal Dementia related to Granulin (GRN mutations presents a specific framework of brain damage, involving fronto-temporal regions and long inter-hemispheric white matter bundles. Multimodal resting-state functional MRI (rs-fMRI is a promising tool to carefully describe disease signature from the earliest disease phase. OBJECTIVE: To define local connectivity alterations in GRN related pathology moving from the presymptomatic (asymptomatic GRN mutation carriers to the clinical phase of the disease (GRN- related Frontotemporal Dementia. METHODS: Thirty-one GRN Thr272fs mutation carriers (14 patients with Frontotemporal Dementia and 17 asymptomatic carriers and 38 healthy controls were recruited. Local connectivity measures (Regional Homogeneity (ReHo, Fractional Amplitude of Low Frequency Fluctuation (fALFF and Degree Centrality (DC were computed, considering age and gender as nuisance variables as well as the influence of voxel-level gray matter atrophy. RESULTS: Asymptomatic GRN carriers had selective reduced ReHo in the left parietal region and increased ReHo in frontal regions compared to healthy controls. Considering Frontotemporal Dementia patients, all measures (ReHo, fALFF and DC were reduced in inferior parietal, frontal lobes and posterior cingulate cortex. Considering GRN mutation carriers, an inverse correlation with age in the posterior cingulate cortex, inferior parietal lobule and orbitofrontal cortex was found. CONCLUSIONS: GRN pathology is characterized by functional brain network alterations even decades before the clinical onset; they involve the parietal region primarily and then spread to the anterior regions of the brain, supporting the concept of molecular nexopathies.

Quantification of cerebral blood flow and its clinical usefulness. Application of SPECT to psychiatry

Energy Technology Data Exchange (ETDEWEB)

Matsuda, Hiroshi; Uema, Takeshi; Kogure, Daisuke; Takano, Harumasa; Terada, Tomo [National Center Hospital for Mental, Nervous and Muscular Disorders, Kodaira, Tokyo (Japan)

1998-10-01

Brain perfusion SPECT using {sup 99m}Tc-ethyl-cysteinate dimer ({sup 99m}Tc-ECD) was applied to psychiatric diseases with aid of statistical parametric mapping (SPM) for analysis of data. To evaluate influence of aging on brain perfusion, noninvasive measurements of cerebral blood flow using {sup 99m}Tc-ECD were performed in 53 normal volunteers, aged 18 to 87 years old. Mean cerebral blood flow (mCBF) was 43.9{+-}5.0 ml/100 g/min and showed weak negative correlation with aging (r=-0.451). Perisylvian cerebral cortices and medial frontal areas including anterior cingulate gyri showed greater negative correlation than other areas. These findings suggest the necessity of age-matched control regional CBF (rCBF) data to investigate rCBF abnormality in patients. Four drug-naive schizophrenic patients showed flow decrease in bilateral frontal and superior temporal areas and a left infero-posterior temporal area. Haloperidol administration induced flow decrease in bilateral frontal and left parietal areas, while flow increase in bilateral striatal and right hippocampal areas. Ten aged depressive patients showed flow decrease in bilateral frontal and left temporo-parietal areas. Even after remission patients showed flow decrease in the left frontal area as compared with normal subjects. Remission induced flow increase in the right frontal, right parietal, and right orbitofrontal areas compared with depression. These results suggest that CBF measurements using {sup 99m}Tc-ECD are useful for objective evaluation of regional abnormality in brain function in psychiatric diseases. (author)

Dissociation of Subtraction and Multiplication in the Right Parietal Cortex: Evidence from Intraoperative Cortical Electrostimulation

Science.gov (United States)

Yu, Xiaodan; Chen, Chuansheng; Pu, Song; Wu, Chenxing; Li, Yongnian; Jiang, Tao; Zhou, Xinlin

2011-01-01

Previous research has consistently shown that the left parietal cortex is critical for numerical processing, but the role of the right parietal lobe has been much less clear. This study used the intraoperative cortical electrical stimulation approach to investigate neural dissociation in the right parietal cortex for subtraction and…

Understanding actions of others: the electrodynamics of the left and right hemispheres. A high-density EEG neuroimaging study.

Directory of Open Access Journals (Sweden)

Stephanie Ortigue

Full Text Available BACKGROUND: When we observe an individual performing a motor act (e.g. grasping a cup we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping and the intention underlying it (i.e. grasping for drinking. Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. METHODOLOGY/PRINCIPAL FINDINGS: Volunteers were presented with two-frame video-clips. The first frame (T0 showed an object with or without context; the second frame (T1 showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs were recorded time-locked with the frame showing the hand-object interaction (T1. The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1 bilateral posterior cortical activations; 2 a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3 a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4 a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. CONCLUSIONS/SIGNIFICANCE: We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network

Preliminary optical coherence tomography investigation of the temporo-mandibular joint disc

Science.gov (United States)

Mărcăuteanu, Corina; Demjan, Enikö; Sinescu, Cosmin; Negrutiu, Meda; Motoc, Adrian; Lighezan, Rodica; Vasile, Liliana; Hughes, Mike; Bradu, Adrian; Dobre, George; Podoleanu, Adrian G.

2010-02-01

Aim and objectives. The morphology and position of the temporo-mandibular disc are key issues in the diagnosis and treatment of arthrogenous temporo-mandibular disorders. Magnetic resonance imaging and arthroscopy are used today to identify: flattening of the pars posterior of the disc, perforation and/or adhesions in the pars intermedia of the disc and disc displacements. The present study proposes the investigation of the temporo-mandibular joint disc by optical coherence tomography (OCT). Material and methods. 8 human temporo-mandibular joint discs were harvested from dead subjects, under 40 year of age, and conserved in formalin. They had a normal morphology, with a thicker pars posterior (2,6 mm on the average) and a thinner pars intermedia (1mm on the average). We investigated the disc samples using two different OCT systems: an en-face OCT (time domain (TD)-OCT) system, working at 1300 nm (C-scan and B-scan mode) and a spectral OCT system (a Fourier domain (FD)-OCT) system , working at 840 nm (B-scan mode). Results. The OCT investigation of the temporo-mandibular joint discs revealed a homogeneous microstructure. The longer wavelength of the TD-OCT offers a higher penetration depth (2,5 mm in air), which is important for the analysis of the pars posterior, while the FD-OCT is much faster. Conclusions: OCT is a promising imaging method for the microstructural characterization of the temporo-mandibular disc.

Clinical use of regional Tc-99m-HMPAO uptake in dementia of the Alzheimer type (DAT)

International Nuclear Information System (INIS)

Gebhardt, U.; Schmauss, F.; Wagner-Manslau, C.; Buttermann, G.; Zimmer, R.

1993-01-01

In 46 patients with dementia of the Alzheimer type (DAT) regional cerebral blood flow (rCBF) was compared with cognitive performance (MMSE, CAMCOG). The cortico-cerebellar ratio (CCR), determined by 99m Tc-HMPAO-SPECT was used as a rCBF-equivalent. In the mild demented group we found a bilateral CCR-reduction parietal posterior, in moderate DAT bilateral temporoparietal and leftsided frontolateral defects were seen. Severe DAT showed an additional perfusion decrease mid frontal. With increasing severity of DAT an asymmetric perfusion occurred in 17/46 patients with accentuated CCR-reduction on the left side (temporal>parietal). High correlations between CCR and MMSE (r≥0.70) existed frontolateral, temporal and parietal in the left hemisphere. Significant associations between CCR and CAMCOG were obtained for language in the left temporal posterior region (r=0.64), for memory task left temporal anterior (r=0.59) and for praxis left parietal posterior (r=0.55). In detecting rCBF abnormalities the sensitivity for all 46 DAT patients was 91% and 70% in the mild cases. (orig.) [de

The role of the left inferior parietal lobule in second language learning: An intensive language training fMRI study.

Science.gov (United States)

Barbeau, Elise B; Chai, Xiaoqian J; Chen, Jen-Kai; Soles, Jennika; Berken, Jonathan; Baum, Shari; Watkins, Kate E; Klein, Denise

2017-04-01

Research to date suggests that second language acquisition results in functional and structural changes in the bilingual brain, however, in what way and how quickly these changes occur remains unclear. To address these questions, we studied fourteen English-speaking monolingual adults enrolled in a 12-week intensive French language-training program in Montreal. Using functional MRI, we investigated the neural changes associated with new language acquisition. The participants were scanned before the start of the immersion program and at the end of the 12 weeks. The fMRI scan aimed to investigate the brain regions recruited in a sentence reading task both in English, their first language (L1), and in French, their second language (L2). For the L1, fMRI patterns did not change from Time 1 to Time 2, while for the L2, the brain response changed between Time 1 and Time 2 in language-related areas. Of note, for the L2, there was higher activation at Time 2 compared to Time 1 in the left inferior parietal lobule (IPL) including the supramarginal gyrus. At Time 2 this higher activation in the IPL correlated with faster L2 reading speed. Moreover, higher activation in the left IPL at Time 1 predicted improvement in L2 reading speed from Time 1 to Time 2. Our results suggest that learning-induced plasticity occurred as early as 12 weeks into immersive second-language training, and that the IPL appears to play a special role in language learning. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of erythropoietin on memory-relevant neurocircuitry activity and recall in mood disorders

DEFF Research Database (Denmark)

Miskowiak, K W; Macoveanu, J; Vinberg, M

2016-01-01

MRI at 3T, mood ratings, and blood tests at baseline and week 14. During fMRI, participants performed a picture encoding task followed by postscan recall. RESULTS: Sixty-two patients had complete data (EPO: N = 32, saline: N = 30). EPO improved picture recall and increased encoding-related activity......OBJECTIVE: Erythropoietin (EPO) improves verbal memory and reverses subfield hippocampal volume loss across depression and bipolar disorder (BD). This study aimed to investigate with functional magnetic resonance imaging (fMRI) whether these effects were accompanied by functional changes in memory...... in dorsolateral prefrontal cortex (dlPFC) and temporo-parietal regions, but not in hippocampus. Recall correlated with activity in the identified dlPFC and temporo-parietal regions at baseline, and change in recall correlated with activity change in these regions from baseline to follow-up across the entire...

Effects of CPAP-therapy on brain electrical activity in obstructive sleep apneic patients: a combined EEG study using LORETA and Omega complexity : reversible alterations of brain activity in OSAS.

Science.gov (United States)

Toth, Marton; Faludi, Bela; Kondakor, Istvan

2012-10-01

Effects of initiation of continuous positive airway pressure (CPAP) therapy on EEG background activity were investigated in patients with obstructive sleep apnea syndrome (OSAS, N = 25) to test possible reversibility of alterations of brain electrical activity caused by chronic hypoxia. Normal control group (N = 14) was also examined. Two EEG examinations were done in each groups: at night and in the next morning. Global and regional (left vs. right, anterior vs. posterior) measures of spatial complexity (Omega complexity) were used to characterize the degree of spatial synchrony of EEG. Low resolution electromagnetic tomography (LORETA) was used to localize generators of EEG activity in separate frequency bands. Before CPAP-treatment, a significantly lower Omega complexity was found globally and over the right hemisphere. Due to CPAP-treatment, these significant differences vanished. Significantly decreased Omega complexity was found in the anterior region after treatment. LORETA showed a decreased activity in all of the beta bands after therapy in the right hippocampus, premotor and temporo-parietal cortex, and bilaterally in the precuneus, paracentral and posterior cingulate cortex. No significant changes were seen in control group. Comparing controls and patients before sleep, an increased alpha2 band activity was seen bilaterally in the precuneus, paracentral and posterior cingulate cortex, while in the morning an increased beta3 band activity in the left precentral and bilateral premotor cortex and a decreased delta band activity in the right temporo-parietal cortex and insula were observed. These findings indicate that effect of sleep on EEG background activity is different in OSAS patients and normal controls. In OSAS patients, significant changes lead to a more normal EEG after a night under CPAP-treatment. Compensatory alterations of brain electrical activity in regions associated with influencing sympathetic outflow, visuospatial abilities, long

Neural correlates of lexicon and grammar: evidence from the production, reading, and judgment of inflection in aphasia.

Science.gov (United States)

Ullman, Michael T; Pancheva, Roumyana; Love, Tracy; Yee, Eiling; Swinney, David; Hickok, Gregory

2005-05-01

Are the linguistic forms that are memorized in the mental lexicon and those that are specified by the rules of grammar subserved by distinct neurocognitive systems or by a single computational system with relatively broad anatomic distribution? On a dual-system view, the productive -ed-suffixation of English regular past tense forms (e.g., look-looked) depends upon the mental grammar, whereas irregular forms (e.g., dig-dug) are retrieved from lexical memory. On a single-mechanism view, the computation of both past tense types depends on associative memory. Neurological double dissociations between regulars and irregulars strengthen the dual-system view. The computation of real and novel, regular and irregular past tense forms was investigated in 20 aphasic subjects. Aphasics with non-fluent agrammatic speech and left frontal lesions were consistently more impaired at the production, reading, and judgment of regular than irregular past tenses. Aphasics with fluent speech and word-finding difficulties, and with left temporal/temporo-parietal lesions, showed the opposite pattern. These patterns held even when measures of frequency, phonological complexity, articulatory difficulty, and other factors were held constant. The data support the view that the memorized words of the mental lexicon are subserved by a brain system involving left temporal/temporo-parietal structures, whereas aspects of the mental grammar, in particular the computation of regular morphological forms, are subserved by a distinct system involving left frontal structures.

Visuo-spatial construction in patients with frontal and parietal lobe lesions

Directory of Open Access Journals (Sweden)

Himani Kashyap

2011-04-01

Full Text Available Visuospatial construction, traditionally viewed as a putative parietal function, also requires sustained attention, planning, organization strategies and error correction, and hence frontal lobe mediation. The relative contributions of the frontal and parietal lobes are poorly understood. To examine the contributions of parietal, frontal lobes, as well as right and left cerebral hemispheres to visuospatial construction. The Stick Construction Test for two-dimensional construction and the Block Construction Test for three-dimensional construction were administered pre-surgically to patients with lesions in the parietal lobe (n =9 and the frontal lobe (n=11, along with normal control subjects (n =20 matched to the patients on age (+/- 3 years, gender, education (+/- 3 years and handedness. The patients were significantly slower than the controls on both two-dimensional and three-dimensional tests. Patients with parietal lesions were slower than those with frontal lesions on the test of three-dimensional construction. Within each lobe patients with right and left sided lesions did not differ significantly. It appears that tests of three-dimensional construction might be most sensitive to visuospatial construction deficits. Visuospatial construction involves the mediation of both frontal and parietal lobes. The function does not appear to be lateralized. The networks arising from the parieto-occipital areas and projecting to the frontal cortices (e.g., occipito-frontal fasciculus may be the basis of the mediation of both lobes in visuospatial construction. The present findings need replication from studies with larger sample sizes.

Inactivation of Parietal Reach Region Affects Reaching But Not Saccade Choices in Internally Guided Decisions.

Science.gov (United States)

Christopoulos, Vassilios N; Bonaiuto, James; Kagan, Igor; Andersen, Richard A

2015-08-19

The posterior parietal cortex (PPC) has traditionally been considered important for awareness, spatial perception, and attention. However, recent findings provide evidence that the PPC also encodes information important for making decisions. These findings have initiated a running argument of whether the PPC is critically involved in decision making. To examine this issue, we reversibly inactivated the parietal reach region (PRR), the area of the PPC that is specialized for reaching movements, while two monkeys performed a memory-guided reaching or saccade task. The task included choices between two equally rewarded targets presented simultaneously in opposite visual fields. Free-choice trials were interleaved with instructed trials, in which a single cue presented in the peripheral visual field defined the reach and saccade target unequivocally. We found that PRR inactivation led to a strong reduction of contralesional choices, but only for reaches. On the other hand, saccade choices were not affected by PRR inactivation. Importantly, reaching and saccade movements to single instructed targets remained largely intact. These results cannot be explained as an effector-nonspecific deficit in spatial attention or awareness, since the temporary "lesion" had an impact only on reach choices. Hence, the PPR is a part of a network for reach decisions and not just reach planning. There has been an ongoing debate on whether the posterior parietal cortex (PPC) represents only spatial awareness, perception, and attention or whether it is also involved in decision making for actions. In this study we explore whether the parietal reach region (PRR), the region of the PPC that is specialized for reaches, is involved in the decision process. We inactivated the PRR while two monkeys performed reach and saccade choices between two targets presented simultaneously in both hemifields. We found that inactivation affected only the reach choices, while leaving saccade choices intact

Frontal and parietal theta burst TMS impairs working memory for visual-spatial conjunctions.

Science.gov (United States)

Morgan, Helen M; Jackson, Margaret C; van Koningsbruggen, Martijn G; Shapiro, Kimron L; Linden, David E J

2013-03-01

In tasks that selectively probe visual or spatial working memory (WM) frontal and posterior cortical areas show a segregation, with dorsal areas preferentially involved in spatial (e.g. location) WM and ventral areas in visual (e.g. object identity) WM. In a previous fMRI study [1], we showed that right parietal cortex (PC) was more active during WM for orientation, whereas left inferior frontal gyrus (IFG) was more active during colour WM. During WM for colour-orientation conjunctions, activity in these areas was intermediate to the level of activity for the single task preferred and non-preferred information. To examine whether these specialised areas play a critical role in coordinating visual and spatial WM to perform a conjunction task, we used theta burst transcranial magnetic stimulation (TMS) to induce a functional deficit. Compared to sham stimulation, TMS to right PC or left IFG selectively impaired WM for conjunctions but not single features. This is consistent with findings from visual search paradigms, in which frontal and parietal TMS selectively affects search for conjunctions compared to single features, and with combined TMS and functional imaging work suggesting that parietal and frontal regions are functionally coupled in tasks requiring integration of visual and spatial information. Our results thus elucidate mechanisms by which the brain coordinates spatially segregated processing streams and have implications beyond the field of working memory. Copyright © 2013 Elsevier Inc. All rights reserved.

Controversies over the mechanisms underlying the crucial role of the left fronto-parietal areas in the representation of tools

Directory of Open Access Journals (Sweden)

Guido eGainotti

2013-10-01

Full Text Available Anatomo-clinical and neuroimaging data show that the left fronto-parietal areas play an important role in representing tools. As manipulation is an important source of knowledge about tools, it has been assumed that motor activity explains the link between tool knowledge and the left fronto-parietal areas. However, controversies exist over the exact mechanisms underlying this relationship. According to a strong version of the ‘embodied cognition theory’, activation of a tool concept necessarily involves re-enactment of the corresponding kind of action. Impairment of the ability to use tools should, therefore, lead to impairment of tool knowledge. Both the ‘domains of knowledge hypothesis’ and the ‘sensory-motor model of conceptual knowledge’ refute the strong version of the ‘embodied cognition hypothesis’ but acknowledge that manipulation and other action schemata play an important role in our knowledge of tools. The basic difference between these two models is that the former is based on an innatist model and the latter holds that the brain’s organization of categories is experience dependent. Data supporting and arguing against each of these models are briefly reviewed. In particular, the following lines of research, which argue against the innate nature of the brain’s categorical organization, are discussed: (1 the observation that in patients with category-specific disorders the semantic impairment does not respect the boundaries between biological entities and artefact items; (2 data showing that experience-driven neuroplasticity in musicians is not confined to alterations of perceptual and motor maps but also leads to the establishment of higher-level semantic representations for musical instruments; (3 results of experiments using previously unfamiliar materials showing that the history of our sensory-motor experience with an object significantly affects its neural representation.

Distinct contribution of the parietal and temporal cortex to hand configuration and contextual judgements about tools.

Science.gov (United States)

Andres, Michael; Pelgrims, Barbara; Olivier, Etienne

2013-09-01

Neuropsychological studies showed that manipulatory and semantic knowledge can be independently impaired in patients with upper-limb apraxia, leading to different tool use disorders. The present study aimed to dissociate the brain regions involved in judging the hand configuration or the context associated to tool use. We focussed on the left supramarginalis gyrus (SMG) and left middle temporal gyrus (MTG), whose activation, as evidenced by functional magnetic resonance imaging (fMRI) studies, suggests that they may play a critical role in tool use. The distinctive location of SMG in the dorsal visual stream led us to postulate that this parietal region could play a role in processing incoming information about tools to shape hand posture. In contrast, we hypothesized that MTG, because of its interconnections with several cortical areas involved in semantic memory, could contribute to retrieving semantic information necessary to create a contextual representation of tool use. To test these hypotheses, we used neuronavigated transcranial magnetic stimulation (TMS) to interfere transiently with the function of either left SMG or left MTG in healthy participants performing judgement tasks about either hand configuration or context of tool use. We found that SMG virtual lesions impaired hand configuration but not contextual judgements, whereas MTG lesions selectively interfered with judgements about the context of tool use while leaving hand configuration judgements unaffected. This double dissociation demonstrates that the ability to infer a context of use or a hand posture from tool perception relies on distinct processes, performed in the temporal and parietal regions. The present findings suggest that tool use disorders caused by SMG lesions will be characterized by difficulties in selecting the appropriate hand posture for tool use, whereas MTG lesions will yield difficulties in using tools in the appropriate context. Copyright © 2012. Published by Elsevier Ltd.

[Diagnosis and treatment of temporo-mandibular disorders in orthodontics].

Science.gov (United States)

Bocquet, Emmanuelle; Moreau, Alexis; Danguy, Michel; Danguy, Chantal

2010-03-01

Orthodontists are fully prepared to treat the problems of occlusion that they are called upon to deal with every day. On the other hand temporo-mandibular joint disorders present more obscure difficulties from the point of view of detection and diagnosis as well the management of their treatment. That is why a profound understanding of the anatomical and physiological functioning of the temporo-mandibular joint has become indispensable for today's orthodontists who are now asked to detect and diagnose an assortment of TMJ disturbances whose etiology may vary greatly. By performing a rigorous diagnostic procedure, based on a thorough clinical examination supported by careful axiographic and radiological studies, of temporo-mandibular malfunctioning and its underlying etiological causes, which are primarily dento-alveolar and occlusal in nature, orthodontists will be able to adopt an appropriate therapeutic approach that might be purely orthodontic or multi-disciplinary and carried out with the collaboration of specialists in occlusion, oral surgery, and even osteopathy. EDP Sciences, SFODF, 2010.

Effects of erythropoietin on memory-relevant neurocircuitry activity and recall in mood disorders.

Science.gov (United States)

Miskowiak, K W; Macoveanu, J; Vinberg, M; Assentoft, E; Randers, L; Harmer, C J; Ehrenreich, H; Paulson, O B; Knudsen, G M; Siebner, H R; Kessing, L V

2016-09-01

Erythropoietin (EPO) improves verbal memory and reverses subfield hippocampal volume loss across depression and bipolar disorder (BD). This study aimed to investigate with functional magnetic resonance imaging (fMRI) whether these effects were accompanied by functional changes in memory-relevant neuro-circuits in this cohort. Eighty-four patients with treatment-resistant unipolar depression who were moderately depressed or BD in remission were randomized to eight weekly EPO (40 000 IU) or saline infusions in a double-blind, parallel-group design. Participants underwent whole-brain fMRI at 3T, mood ratings, and blood tests at baseline and week 14. During fMRI, participants performed a picture encoding task followed by postscan recall. Sixty-two patients had complete data (EPO: N = 32, saline: N = 30). EPO improved picture recall and increased encoding-related activity in dorsolateral prefrontal cortex (dlPFC) and temporo-parietal regions, but not in hippocampus. Recall correlated with activity in the identified dlPFC and temporo-parietal regions at baseline, and change in recall correlated with activity change in these regions from baseline to follow-up across the entire cohort. The effects of EPO were not correlated with change in mood, red blood cells, blood pressure, or medication. The findings highlight enhanced encoding-related dlPFC and temporo-parietal activity as key neuronal underpinnings of EPO-associated memory improvement. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Lateralization of Egocentric and Allocentric Spatial Processing after Parietal Brain Lesions

Science.gov (United States)

Iachini, Tina; Ruggiero, Gennaro; Conson, Massimiliano; Trojano, Luigi

2009-01-01

The purpose of this paper was to verify whether left and right parietal brain lesions may selectively impair egocentric and allocentric processing of spatial information in near/far spaces. Two Right-Brain-Damaged (RBD), 2 Left-Brain-Damaged (LBD) patients (not affected by neglect or language disturbances) and eight normal controls were submitted…

[The temporo-mandibular articulation].

Science.gov (United States)

Dargaud, J; Vinkka-Puhakka, H

2004-04-01

The standing posture of humans has created both morphological and functional adaptations in the temporo-mandibular joint and the masticatory function. This biped state is the one of the most important characteristic of human evolution. It is furthermore the agent determining most of the functional changes in the whole body. This survey will be carried out in several levels including, a descriptive anatomy, biomechanics, radiological imaging, functioning in the articulation of TMJ. The descriptive anatomic picture will be obtained by the traditional dissection techniques. 20 TMJ joints are dissected from 10 cadavers: 7 cadavers, 65-75 year old, 3 cadavers, 60-65 year old. The x-rays are lateral view and the subjects of the radiological imaging are young's, adults and olds: 1, 3 y-old Male; 1, 7 y-old Female; 1, 14 y-old Female; 10, 19-23 y-old Male; 1, 26 y-old Female; 1, 34 y-old Male; 1, 75 y-old Female. The anatomic elements in the TMJ well resembled the ones described in the literature of the capsule, the ligament, the masticator muscles (masseter, temporal, medial and lateral pterygoids). The temporo-mandibular ligament proved to be difficult to separate from the capsule in some of the specimens. Sometimes it was not always found after a dissection.

Contrasting effects of vocabulary knowledge on temporal and parietal brain structure across lifespan.

Science.gov (United States)

Richardson, Fiona M; Thomas, Michael S C; Filippi, Roberto; Harth, Helen; Price, Cathy J

2010-05-01

Using behavioral, structural, and functional imaging techniques, we demonstrate contrasting effects of vocabulary knowledge on temporal and parietal brain structure in 47 healthy volunteers who ranged in age from 7 to 73 years. In the left posterior supramarginal gyrus, vocabulary knowledge was positively correlated with gray matter density in teenagers but not adults. This region was not activated during auditory or visual sentence processing, and activation was unrelated to vocabulary skills. Its gray matter density may reflect the use of an explicit learning strategy that links new words to lexical or conceptual equivalents, as used in formal education and second language acquisition. By contrast, in left posterior temporal regions, gray matter as well as auditory and visual sentence activation correlated with vocabulary knowledge throughout lifespan. We propose that these effects reflect the acquisition of vocabulary through context, when new words are learnt within the context of semantically and syntactically related words.

Dominant lymph drainage patterns in the occipital and parietal regions: evaluation of lymph nodes in patients with skin cancer of the head.

Science.gov (United States)

Maeda, Taku; Yamamoto, Yuhei; Furukawa, Hiroshi; Oyama, Akihiko; Funayama, Emi; Murao, Naoki; Hayashi, Toshihiko

2017-08-01

The purpose of this study was to evaluate the superficial lymph drainage patterns of primary skin cancers of the head arising from the occipital or parietal region. The dominant patterns of lymph drainage were retrospectively reviewed in eight patients aged 36-85 years with skin cancers in the occipital or parietal region in whom sentinel lymph node biopsy or lymph node dissection had been performed at Hokkaido University Hospital between January 1981 and December 2015. Lymph drainage was mainly to the occipital (6/8, 75%), level II (5/8, 63%), and level V lymph nodes (5/8, 63%). Of the six patients with drainage to the occipital lymph nodes, four (67%) also had drainage to level V nodes. The dominant lymph drainage pattern in patients with skin cancer arising from the occipital or parietal region was to the occipital, level II, and level V lymph nodes. Further, lymph tended to drain directly from the occipital region to the level V lymph nodes.

The role of prefrontal and parietal cortices in esthetic appreciation of representational and abstract art: a TMS study.

Science.gov (United States)

Cattaneo, Zaira; Lega, Carlotta; Gardelli, Chiara; Merabet, Lotfi B; Cela-Conde, Camilo J; Nadal, Marcos

2014-10-01

To explain the biological foundations of art appreciation is to explain one of our species' distinctive traits. Previous neuroimaging and electrophysiological studies have pointed to the prefrontal and the parietal cortex as two critical regions mediating esthetic appreciation of visual art. In this study, we applied transcranial magnetic stimulation (TMS) over the left prefrontal cortex and the right posterior parietal cortex while participants were evaluating whether they liked, and by how much, a particular painting. By depolarizing cell membranes in the targeted regions, TMS transiently interferes with the activity of specific cortical areas, which allows clarifying their role in a given task. Our results show that both regions play a fundamental role in mediating esthetic appreciation. Critically though, the effects of TMS varied depending on the type of art considered (i.e. representational vs. abstract) and on participants' a-priori inclination toward one or the other. Copyright © 2014 Elsevier Inc. All rights reserved.

SYNOVIAL CHONDROMATOSIS OF THE TEMPORO-MANDIBULAR JOINT. A CASE REPORT

Directory of Open Access Journals (Sweden)

V. MALANCHUK

2015-09-01

Full Text Available The study describes a rare clinical case of synovial chondromatosis of the temporo-mandibular joint, in a 53 year-old patient. In the prehospital stage, the patient was examined by additional diagnostic methods – 3D CT and subsequent computer simulation, in view of subsequent surgery. In January 2015, partial synovektomy of the right temporo-mandibular joint with removal of cartilaginous impurities was performed under general anesthesia. After histopathological confirmation of the clinical diagnosis, the patient was discharged in satisfactory condition, with recommendations for further examination and radiological control. Synovial chondromatosis of the temporo-mandibular joint is a disease characterized by impaired formation of cartilage or of intraarticular, cartilaginous, and relatively rare bone impurities. An important role in the diagnosis of joints’ synovial chondromatosis is played by the instrumental research methods, especially X-ray. Surgical treatment is recommended as a function of the prevalence of lesions.

Gyri of the human parietal lobe: Volumes, spatial extents, automatic labelling, and probabilistic atlases.

Directory of Open Access Journals (Sweden)

Heather M Wild

Full Text Available Accurately describing the anatomy of individual brains enables interlaboratory communication of functional and developmental studies and is crucial for possible surgical interventions. The human parietal lobe participates in multimodal sensory integration including language processing and also contains the primary somatosensory area. We describe detailed protocols to subdivide the parietal lobe, analyze morphological and volumetric characteristics, and create probabilistic atlases in MNI152 stereotaxic space. The parietal lobe was manually delineated on 3D T1 MR images of 30 healthy subjects and divided into four regions: supramarginal gyrus (SMG, angular gyrus (AG, superior parietal lobe (supPL and postcentral gyrus (postCG. There was the expected correlation of male gender with larger brain and intracranial volume. We examined a wide range of anatomical features of the gyri and the sulci separating them. At least a rudimentary primary intermediate sulcus of Jensen (PISJ separating SMG and AG was identified in nearly all (59/60 hemispheres. Presence of additional gyri in SMG and AG was related to sulcal features and volumetric characteristics. The parietal lobe was slightly (2% larger on the left, driven by leftward asymmetries of the postCG and SMG. Intersubject variability was highest for SMG and AG, and lowest for postCG. Overall the morphological characteristics tended to be symmetrical, and volumes also tended to covary between hemispheres. This may reflect developmental as well as maturation factors. To assess the accuracy with which the labels can be used to segment newly acquired (unlabelled T1-weighted brain images, we applied multi-atlas label propagation software (MAPER in a leave-one-out experiment and compared the resulting automatic labels with the manually prepared ones. The results showed strong agreement (mean Jaccard index 0.69, corresponding to a mean Dice index of 0.82, average mean volume error of 0.6%. Stereotaxic

Kernohan-Woltman notch phenomenon and intention tremors in case of chronic subdural hematoma

Directory of Open Access Journals (Sweden)

Sasikala P.

2014-03-01

Full Text Available Movement disorders are atypical and rare presentation of chronic subdural hematomas. We report a case of 60 year man who presented with intention tremors and altered sensorium. The patient had Kernohan-Woltman notch phenomenon on clinical examination. CT scan brain showed a large left fronto-temporo-parietal chronic subdural hematoma with significant mass effect and midline shift. His symptoms relieved completely after surgical evacuation of the hematoma.

Clinical evidence of parietal cortex dysfunction and correlation with extent of allodynia in CRPS type 1.

Science.gov (United States)

Cohen, H; McCabe, C; Harris, N; Hall, J; Lewis, J; Blake, D R

2013-04-01

Unusual symptoms such as digit misidentification and neglect-like phenomena have been reported in complex regional pain syndrome (CRPS), which we hypothesized could be explained by parietal lobe dysfunction. Twenty-two patients with chronic CRPS attending an in-patient rehabilitation programme underwent standard neurological examination followed by clinical assessment of parietal lobe function and detailed sensory testing. Fifteen (68%) patients had evidence of parietal lobe dysfunction. Six (27%) subjects failed six or more test categories and demonstrated new clinical signs consistent with their parietal testing impairments, which were impacting significantly on activities of daily living. A higher incidence was noted in subjects with >1 limb involvement, CRPS affecting the dominant side and in left-handed subjects. Eighteen patients (82%) had mechanical allodynia covering 3-57.5% of the body surface area. Allochiria (unilateral tactile stimulation perceived only in the analogous location on the opposite limb), sensory extinction (concurrent bilateral tactile stimulation perceived only in one limb), referred sensations (unilateral tactile stimulation perceived concurrently in another discrete body area) and dysynchiria (unilateral non-noxious tactile stimulation perceived bilaterally as noxious) were present in some patients. Greater extent of body surface allodynia was correlated with worse parietal function (Spearman's rho = -0.674, p = 0.001). In patients with chronic CRPS, detailed clinical examination may reveal parietal dysfunction, with severity relating to the extent of allodynia. © 2012 European Federation of International Association for the Study of Pain Chapters.

Dissociable parietal regions facilitate successful retrieval of recently learned and personally familiar information.

Science.gov (United States)

Elman, Jeremy A; Cohn-Sheehy, Brendan I; Shimamura, Arthur P

2013-03-01

In fMRI analyses, the posterior parietal cortex (PPC) is particularly active during the successful retrieval of episodic memory. To delineate the neural correlates of episodic retrieval more succinctly, we compared retrieval of recently learned spatial locations (photographs of buildings) with retrieval of previously familiar locations (photographs of familiar campus buildings). Episodic retrieval of recently learned locations activated a circumscribed region within the ventral PPC (anterior angular gyrus and adjacent regions in the supramarginal gyrus) as well as medial PPC regions (posterior cingulated gyrus and posterior precuneus). Retrieval of familiar locations activated more posterior regions in the ventral PPC (posterior angular gyrus, LOC) and more anterior regions in the medial PPC (anterior precuneus and retrosplenial cortex). These dissociable effects define more precisely PPC regions involved in the retrieval of recent, contextually bound information as opposed to regions involved in other processes, such as visual imagery, scene reconstruction, and self-referential processing. Copyright © 2012 Elsevier Ltd. All rights reserved.

Aphasia following left thalamic hemorrhage. A study by Western Aphasia Battery and single photon emission CT

Energy Technology Data Exchange (ETDEWEB)

Makishita, Hideo; Miyasaka, Motomaro; Tanizaki, Yoshio; Yanagisawa, Nobuo; Sugishita, Morihiro

1984-07-01

A report is given of 7 patients with left thalamic hemorrhage in the chronic stage (from 1.5 months to 4.5 months) in which language disorders were examined by Western Aphasia Battery (WAB) and cerebral blood flow was measured by single photon emission CT. Examination of language by WAB revealed 4 aphasics out of 7 cases, and 3 patients had no language deficit. The patient with Wernicke's aphasia showed low density area only in the left posterior thalamus in X-ray CT, and revealed severe low blood flow area extending to left temporal lobe in emission CT. In the case with transcortical sensory aphasia, although X-ray CT showed no obvious low density area, emission CT revealed moderate low flow area in the left temporooccipital region and low blood flow at the left thalamus. In one of the two patients classified as anomic aphasia, emission CT showed slight low flow area at the temporo-occipital region similar to the case with transcortical sensory aphasia. In another case with anomic aphasia there was a wide low density area all over the left thalamus and midline shift to the right in X-ray CT, and emission CT showed severe low blood flow in the same region spreading widely toward the cerebral surface. In all of the 3 patients without aphasia, emission CT showed low flow region restricted to the left thalamus.

Evaluation of aural manifestations in temporo-mandibular joint dysfunction.

Science.gov (United States)

Sobhy, O A; Koutb, A R; Abdel-Baki, F A; Ali, T M; El Raffa, I Z; Khater, A H

2004-08-01

Thirty patients with temporo-mandibular joint dysfunction were selected to investigate the changes in otoacoustic emissions before and after conservative treatment of their temporo-mandibular joints. Pure tone audiometry, transient-evoked otoacoustic emissions (TEOAE), distortion-product otoacoustic emissions (DPOAE) as well as a tinnitus questionnaire were administered to all patients before and after therapy. Therapy was conservative in the form of counselling, physiotherapy, anti-inflammatory agents, muscle relaxants, and occlusal splints. Results indicated insignificant changes in the TEOAEs, whereas there were significant increases in distortion product levels at most of the frequency bands. These results were paralleled to subjective improvement of tinnitus.

Temporo-mandibular joint condylectomy and its effect over occlusion in cats: cadaveric study.

Science.gov (United States)

El-Warrak, A O; Ferrer, G A; Lanthier, T; Loureiro Silva, B; El-Warrak, L O

2011-03-01

To determine the effect of unilateral condylectomy on dental occlusion in cats. Twelve feline cadaver heads were randomly submitted to either a right or left unilateral condylectomy of the temporo-mandibular joint. The distance between the mandibular and maxillary canine tooth was measured before (B0) and after the unilateral condylectomy (P0). A right or left latero--lateral standardised force (4 N) was applied to the mandibular mentus area before and after the surgical procedure. These measurements were analysed with a linear model for repeated measures. The comparative analysis between pre- and postsurgical values indicated no significant variation in teeth displacement following condylectomy between B0 and P0 measurements. Statistically significant differences were detected after either left or right condylectomy with respect to all measurements after application of the standardised forces. Occlusion changes are significant when comparing bites before and after surgery. Unilateral condylectomy causes a significant increase in latero-lateral amplitude of jaw movement which might clinically affect feline dental occlusion. Clinical studies are required to determine the effect of unilateral condylectomies on mastication and dental occlusion in feline patients. © 2011 British Small Animal Veterinary Association.

Anatomical and spatial matching in imitation: Evidence from left and right brain-damaged patients.

Science.gov (United States)

Mengotti, Paola; Ripamonti, Enrico; Pesavento, Valentina; Rumiati, Raffaella Ida

2015-12-01

Imitation is a sensorimotor process whereby the visual information present in the model's movement has to be coupled with the activation of the motor system in the observer. This also implies that greater the similarity between the seen and the produced movement, the easier it will be to execute the movement, a process also known as ideomotor compatibility. Two components can influence the degree of similarity between two movements: the anatomical and the spatial component. The anatomical component is present when the model and imitator move the same body part (e.g., the right hand) while the spatial component is present when the movement of the model and that of the imitator occur at the same spatial position. Imitation can be achieved by relying on both components, but typically the model's and imitator's movements are matched either anatomically or spatially. The aim of this study was to ascertain the contribution of the left and right hemisphere to the imitation accomplished either with anatomical or spatial matching (or with both). Patients with unilateral left and right brain damage performed an ideomotor task and a gesture imitation task. Lesions in the left and right hemispheres gave rise to different performance deficits. Patients with lesions in the left hemisphere showed impaired imitation when anatomical matching was required, and patients with lesions in the right hemisphere showed impaired imitation when spatial matching was required. Lesion analysis further revealed a differential involvement of left and right hemispheric regions, such as the parietal opercula, in supporting imitation in the ideomotor task. Similarly, gesture imitation seemed to rely on different regions in the left and right hemisphere, such as parietal regions in the left hemisphere and premotor, somatosensory and subcortical regions in the right hemisphere. Copyright © 2015 Elsevier Ltd. All rights reserved.

Electroencephalographic abnormalities in antisocial personality disorder.

Science.gov (United States)

Calzada-Reyes, Ana; Alvarez-Amador, Alfredo; Galán-García, Lídice; Valdés-Sosa, Mitchell

2012-01-01

The presence of brain dysfunction in violent offenders has been frequently examined with inconsistent results. The aim of the study was to assess the EEG of 84 violent offenders by visual inspection and frequency-domain quantitative analysis in 84 violent prisoners. Low-resolution electromagnetic tomography (LORETA) was also employed for theta band of the EEG spectra. Antisocial personality disorder (ASPD) was present in 50 of the offenders and it was absent in the remaining 34. The prevalence of EEG abnormalities, by visual inspection, was similar for both the ASPD group (82%) and non-ASPD group (79%). The brain topography of these anomalies also did not differ between groups, in contrast to results of the EEG quantitative analysis (QEEG) and LORETA that showed remarkable regional differences between both groups. QEEG analysis showed a pattern of excess of theta-delta activities and decrease of alpha band on the right fronto-temporal and left temporo-parietal regions in the ASPD group. LORETA signified an increase of theta activity (5.08 Hz) in ASPD group relative to non-ASPD group within left temporal and parietal regions. Findings indicate that QEEG analysis and techniques of source localization may reveal differences in brain electrical activity among offenders with ASPD, which was not obvious to visual inspection. Copyright © 2011 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Neural correlates supporting sensory discrimination after left hemisphere stroke

Science.gov (United States)

Borstad, Alexandra; Schmalbrock, Petra; Choi, Seongjin; Nichols-Larsen, Deborah S.

2012-01-01

Background Nearly half of stroke patients have impaired sensory discrimination, however, the neural structures that support post-stroke sensory function have not been described. Objectives 1) To evaluate the role of the primary somatosensory (S1) cortex in post-stroke sensory discrimination and 2) To determine the relationship between post-stroke sensory discrimination and structural integrity of the sensory component of the superior thalamic radiation (sSTR). Methods 10 healthy adults and 10 individuals with left hemisphere stroke participated. Stroke participants completed sensory discrimination testing. An fMRI was conducted during right, impaired hand sensory discrimination. Fractional anisotropy and volume of the sSTR were quantified using diffusion tensor tractography. Results Sensory discrimination was impaired in 60% of participants with left stroke. Peak activation in the left (S1) did not correlate with sensory discrimination ability, rather a more distributed pattern of activation was evident in post-stroke subjects with a positive correlation between peak activation in the parietal cortex and discrimination ability (r=.70, p=.023). The only brain region in which stroke participants had significantly different cortical activation than control participants was the precuneus. Region of interest analysis of the precuneus across stroke participants revealed a positive correlation between peak activation and sensory discrimination ability (r=.77, p=.008). The L/R ratio of sSTR fractional anisotropy also correlated with right hand sensory discrimination (r=.69, p=.027). Conclusions Precuneus cortex, distributed parietal lobe activity, and microstructure of the sSTR support sensory discrimination after left hemisphere stroke. PMID:22592076

Parietal cortex and representation of the mental Self

DEFF Research Database (Denmark)

Lou, Hans C; Luber, Bruce; Crupain, Michael

2004-01-01

For a coherent and meaningful life, conscious self-representation is mandatory. Such explicit "autonoetic consciousness" is thought to emerge by retrieval of memory of personally experienced events ("episodic memory"). During episodic retrieval, functional imaging studies consistently show....... The medial parietal region may, then, be conceived of as a nodal structure in self-representation, functionally connected to both the right parietal and the medial prefrontal cortices. To determine whether medial parietal cortex in this network is essential for episodic memory retrieval with self...

Bayesian network analysis reveals alterations to default mode network connectivity in individuals at risk for Alzheimer's disease.

Science.gov (United States)

Li, Rui; Yu, Jing; Zhang, Shouzi; Bao, Feng; Wang, Pengyun; Huang, Xin; Li, Juan

2013-01-01

Alzheimer's disease (AD) is associated with abnormal functioning of the default mode network (DMN). Functional connectivity (FC) changes to the DMN have been found in patients with amnestic mild cognitive impairment (aMCI), which is the prodromal stage of AD. However, whether or not aMCI also alters the effective connectivity (EC) of the DMN remains unknown. We employed a combined group independent component analysis (ICA) and Bayesian network (BN) learning approach to resting-state functional MRI (fMRI) data from 17 aMCI patients and 17 controls, in order to establish the EC pattern of DMN, and to evaluate changes occurring in aMCI. BN analysis demonstrated heterogeneous regional convergence degree across DMN regions, which were organized into two closely interacting subsystems. Compared to controls, the aMCI group showed altered directed connectivity weights between DMN regions in the fronto-parietal, temporo-frontal, and temporo-parietal pathways. The aMCI group also exhibited altered regional convergence degree in the right inferior parietal lobule. Moreover, we found EC changes in DMN regions in aMCI were correlated with regional FC levels, and the connectivity metrics were associated with patients' cognitive performance. This study provides novel sights into our understanding of the functional architecture of the DMN and adds to a growing body of work demonstrating the importance of the DMN as a mechanism of aMCI.

Functional and structural brain correlates of theory of mind and empathy deficits in schizophrenia.

Science.gov (United States)

Benedetti, Francesco; Bernasconi, Alessandro; Bosia, Marta; Cavallaro, Roberto; Dallaspezia, Sara; Falini, Andrea; Poletti, Sara; Radaelli, Daniele; Riccaboni, Roberta; Scotti, Giuseppe; Smeraldi, Enrico

2009-10-01

Patients affected by schizophrenia show deficits in social cognition, with abnormal performance on tasks targeting theory of mind (ToM) and empathy (Emp). Brain imaging studies suggested that ToM and Emp depend on the activation of brain networks mainly localized at the superior temporal lobe and temporo-parietal junction. Participants included 24 schizophrenia patients and 20 control subjects. We used brain blood oxygen level dependent fMRI to study the neural responses to tasks targeting ToM and Emp. We then studied voxel-based morphometry of grey matter in areas where diagnosis influenced functional activation to both tasks. Outcomes were analyzed in the context of the general linear model, with global grey matter volume as nuisance covariate for structural MRI. Patients showed worse performance on both tasks. We found significant effects of diagnosis on neural responses to the tasks in a wide cluster in right posterior superior temporal lobe (encompassing BA 22-42), in smaller clusters in left temporo-parietal junction and temporal pole (BA 38 and 39), and in a white matter region adjacent to medial prefrontal cortex (BA 10). A pattern of double dissociation of the effects of diagnosis and task on neural responses emerged. Among these areas, grey matter volume was found to be reduced in right superior temporal lobe regions of patients. Functional and structural abnormalities were observed in areas affected by the schizophrenic process early in the illness course, and known to be crucial for social cognition, suggesting a biological basis for social cognition deficits in schizophrenia.

Intrinsic connections and architectonics of posterior parietal cortex in the rhesus monkey

International Nuclear Information System (INIS)

Pandya, D.N.; Seltzer, B.

1982-01-01

By means of autoradiographic and ablation-degeneration techniques, the intrinsic cortical connections of the posterior parietal cortex in the rhesus monkey were traced and correlated with a reappraisal of cerebral architectonics. Two major rostral-to-caudal connectional sequences exist. One begins in the dorsal postcentral gyrus (area 2) and proceeds, through architectonic divisions of the superior parietal lobule (areas PE and PEc), to a cortical region on the medial surface of the parietal lobe (area PGm). This area has architectonic features similar to those of the caudal inferior parietal lobule (area PG). The second sequence begins in the ventral post/central gyrus (area 2) and passes through the rostral inferior parietal lobule (areas PG and PFG) to reach the caudal inferior parietal lobule (area PG). Both the superior parietal lobule and the rostral inferior parietal lobule also send projections to various other zones located in the parietal opercular region, the intraparietal sulcus, and the caudalmost portion of the cingulate sulcus. Areas PGm and PG, on the other hand, project to each other, to the cingulate region, to the caudalmost portion of the superior temporal gyrus, and to the upper bank of the superior temporal sulcus. Finally, a reciprocal sequence of connections, directed from caudal to rostral, links together many of the above-mentioned parietal zones. With regard to the laminar pattern of termination, the rostral-to-caudal connections are primarily distributed in the form of cortical ''columns'' while the caudal-to-rostral connections are found mainly over the first cortical cell layer

Cortical thickness in de novo patients with Parkinson disease and mild cognitive impairment with consideration of clinical phenotype and motor laterality.

Science.gov (United States)

Danti, S; Toschi, N; Diciotti, S; Tessa, C; Poletti, M; Del Dotto, P; Lucetti, C

2015-12-01

Parkinson's disease (PD) is a progressive neurodegenerative disorder with motor and non-motor symptoms, including cognitive deficits. Several magnetic resonance imaging approaches have been applied to investigate brain atrophy in PD. The aim of this study was to detect early structural cortical and subcortical changes in de novo PD whilst distinguishing cognitive status, clinical phenotype and motor laterality. Eighteen de novo PD with mild cognitive impairment (PD-MCI), 18 de novo PD without MCI (PD-NC) and 18 healthy control subjects were evaluated. In the PD-MCI group, nine were tremor dominant and nine were postural instability gait disorder (PIGD) phenotype; 11 had right-sided symptom dominance and seven had left-sided symptom dominance. FreeSurfer was used to measure cortical thickness/folding, subcortical structures and to study group differences as well as the association with clinical and neuropsychological data. Parkinson's disease with MCI showed regional thinning in the right frontal, right middle temporal areas and left insula compared to PD-NC. A reduction of the volume of the left and right thalamus and left hippocampus was found in PD-MCI compared to PD-NC. PD-MCI PIGD showed regional thinning in the right inferior parietal area compared to healthy controls. A decreased volume of the left thalamus was reported in PD-MCI with right-sided symptom dominance compared to PD-NC and PD-MCI with left-sided symptom dominance. When MCI was present, PD patients showed a fronto-temporo-parietal pattern of cortical thinning. This cortical pattern does not appear to be influenced by motor laterality, although one-sided symptom dominance may contribute to volumetric reduction of specific subcortical structures. © 2015 EAN.

The Neuroanatomical Basis for Posterior Superior Parietal Lobule Control Lateralization of visuospatial Attention

Directory of Open Access Journals (Sweden)

Yan eWu

2016-03-01

Full Text Available The right hemispheric dominance in visuospatial attention in human brain has been well established. Converging evidence has documented that ventral posterior parietal cortex (PPC plays an important role in visuospatial attention. The role of dorsal PPC subregions, especially the superior parietal lobule (SPL in visuospatial attention is still controversial. In the current study, we used repetitive transcranial magnetic stimulation (rTMS and diffusion magnetic resonance imaging (MRI techniques to test the role of posterior SPL in visuospatial attention and to investigate the potential neuroanatomical basis for right hemisphere dominance in visuospatial function. TMS results unraveled that the right SPL predominantly mediated visuospatial attention compared to left SPL. Anatomical connections analyses between the posterior SPL and the intrahemispheric frontal subregions and the contralateral PPC revealed that right posterior SPL has stronger anatomical connections with the ipsilateral middle frontal gyrus, with the ipsilateral inferior frontal gyrus, and with contralateral PPC than that of the left posterior SPL. Furthermore, these asymmetric anatomical connections were closely related to behavioral performances. Our findings indicate that SPL plays a crucial role in regulating visuospatial attention, and dominance of visuospatial attention results from unbalanced interactions between the bilateral fronto-parietal networks and the interhemispheric parietal network.

Regional cerebral blood flow patterns in extremely elderly patients with Alzheimer's disease

International Nuclear Information System (INIS)

Hirao, Kentaro; Hanyu, Haruo; Kanetaka, Hidekazu; Shimizu, Soichiro; Sato, Tomohiko; Iwamoto, Toshihiko

2008-01-01

Clinical and pathologic features in Alzheimer's disease (AD) patients differ depending on the age of onset. The aim of our study was to compare the regional cerebral blood flow (rCBF) patterns of younger, elderly, and extremely elderly patients with AD with that of controls to characterize the rCBF patterns in extremely elderly patients with AD. Single photon emission CT (SPECT) was performed in 113 patients with probable AD, including 34 younger (<70 years), 41 elderly (70-84 years), and 38 extremely elderly (≥85 years) patients divided according to age at examination. The SPECT data were analyzed using three-dimensional stereotactic surface projection (3D-SSP). No significant differences regarding gender, duration of disease, education, and Mini-Mental State Examination score were found among the groups. As compared with controls, younger and elderly AD demonstrated significant reduction of rCBF in the temporo-parietal areas, posterior cingulate cortices and precunei, which is considered to be a characteristic rCBF pattern in AD. On the other hand, the extremely elderly AD group demonstrated significant reduction of rCBF in the frontal and medial temporal areas, in addition to the temporo-parietal areas, posterior cingulate cortices and precunei, but the reductions were milder than in those in younger and elderly AD groups. The extremely elderly patients with AD showed atypical rCBF patterns in AD compared to younger and elderly patients with AD. Our data suggest that pathological features in extremely elderly AD may be different from those in younger and elderly AD and that diseases different from AD, such as senile dementia of the neurofibrillary tangle type may be clinically diagnosed as extremely elderly AD. (author)

Right parietal cortex mediates recognition memory for melodies.

Science.gov (United States)

Schaal, Nora K; Javadi, Amir-Homayoun; Halpern, Andrea R; Pollok, Bettina; Banissy, Michael J

2015-07-01

Functional brain imaging studies have highlighted the significance of right-lateralized temporal, frontal and parietal brain areas for memory for melodies. The present study investigated the involvement of bilateral posterior parietal cortices (PPCs) for the recognition memory of melodies using transcranial direct current stimulation (tDCS). Participants performed a recognition task before and after tDCS. The task included an encoding phase (12 melodies), a retention period, as well as a recognition phase (24 melodies). Experiment 1 revealed that anodal tDCS over the right PPC led to a deterioration of overall memory performance compared with sham. Experiment 2 confirmed the results of Experiment 1 and further showed that anodal tDCS over the left PPC did not show a modulatory effect on memory task performance, indicating a right lateralization for musical memory. Furthermore, both experiments revealed that the decline in memory for melodies can be traced back to an interference of anodal stimulation on the recollection process (remember judgements) rather than to familiarity judgements. Taken together, this study revealed a causal involvement of the right PPC for memory for melodies and demonstrated a key role for this brain region in the recollection process of the memory task. © 2015 The Authors. European Journal of Neuroscience published by Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Patients' Priorities and Attitudes Towards Their Temporo-Mandibular Disorders.

Science.gov (United States)

Kelleher, Martin; Ray-Chaudhuri, Arijit; Khawaja, Noman

2015-08-01

The diagnosis and appropriate management of temporo-mandibular disorders (TMDs) remains controversial. Current scientific evidence highlights the importance of psychosocial factors in sufferers and the reducing emphasis on occlusal or dental/prosthetic factors. This paper describes the findings of a survey of 211 patients reporting pain from their temporo-mandibular joint area and associated structures. This article offers busy primary dental care practitioners a cost effective questionnaire for obtaining relevant information from patients about the history of their condition and highlights what patients hope to achieve through the management of their disorder. It also emphasises the importance of communicating effectively with patients and offers practical tips for the management of TMDs in primary care.

Exploratory study of once-daily transcranial direct current stimulation (tDCS) as a treatment for auditory hallucinations in schizophrenia.

Science.gov (United States)

Fröhlich, F; Burrello, T N; Mellin, J M; Cordle, A L; Lustenberger, C M; Gilmore, J H; Jarskog, L F

2016-03-01

Auditory hallucinations are resistant to pharmacotherapy in about 25% of adults with schizophrenia. Treatment with noninvasive brain stimulation would provide a welcomed additional tool for the clinical management of auditory hallucinations. A recent study found a significant reduction in auditory hallucinations in people with schizophrenia after five days of twice-daily transcranial direct current stimulation (tDCS) that simultaneously targeted left dorsolateral prefrontal cortex and left temporo-parietal cortex. We hypothesized that once-daily tDCS with stimulation electrodes over left frontal and temporo-parietal areas reduces auditory hallucinations in patients with schizophrenia. We performed a randomized, double-blind, sham-controlled study that evaluated five days of daily tDCS of the same cortical targets in 26 outpatients with schizophrenia and schizoaffective disorder with auditory hallucinations. We found a significant reduction in auditory hallucinations measured by the Auditory Hallucination Rating Scale (F2,50=12.22, PtDCS for treatment of auditory hallucinations and the pronounced response in the sham-treated group in this study contrasts with the previous finding and demonstrates the need for further optimization and evaluation of noninvasive brain stimulation strategies. In particular, higher cumulative doses and higher treatment frequencies of tDCS together with strategies to reduce placebo responses should be investigated. Additionally, consideration of more targeted stimulation to engage specific deficits in temporal organization of brain activity in patients with auditory hallucinations may be warranted. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Dislocation of temporo-mandibular joint - an uncommon circumstance of occurrence: vaginal delivery.

Science.gov (United States)

El Bouazzaoui, Abderrahim; Labib, Smael; Derkaoui, Ali; Adnane Berdai, Mohammed; Bendadi, Azzeddine; Harandou, Mustapha

2010-06-25

Dislocation of temporo-mandibular joint (TMJ) is an infrequent disease but still spectacular. This disease consists of a permanent, to some extent complete disruption of the temporo-mandibular joint. These dislocations often occur in a context of yawning, and less frequently after a burst of laughing or relatively mild facial trauma (slap, punch on the chin). We report a case of TMJ occurring in an uncommon circumstance: vaginal delivery. A woman aged 24-years with no special past medical history; primipara was admitted in the Department of Maternity of the University Hospital Hassan II of Fez for an imminent delivery of a twin pregnancy. Ten minutes after admission, the patient delivered vaginally with episiotomy. She gave birth to twins weighing 2800 g and 2400 g. During labour, and due to efforts of crying, the patient developed a sudden and immediate loss of function of the temporo-mandibular joint, with difficulty of speaking, the mouth permanently opened and with the chin lowered and thrown forward. The examination found an empty glenoid fossa of the temporo-mandibular joint in both sides. The diagnosis of dislocation of the TMJ was established. A CT scan of facial bones was done, objectifying a bilateral dislocation of TMJ. The reduction of this dislocation was performed in the operating room under sedation.

Bilateral, posterior parietal polymicrogyria as part of speech therapy ...

African Journals Online (AJOL)

SA Journal of Radiology ... Magnetic resonance imaging (MRI) has been associated with either diffuse polymicrogyria around the entire extent of the sylvian fissure or in the posterior aspects of the parietal regions, in which case it is called posterior parietal ... This article discusses the possible embryological origin of these

Bilateral septic arthritis of the temporo mandibular joint: case report.

Science.gov (United States)

Ayachi, Samia; Mziou, Zouha; Moatemri, Ramzi; Khochtali, Habib

2016-01-01

Septic arthritis of the temporo-mandibular joint (TMJ) is a rare disease that has been reported infrequently. To the best of the authors' knowledge, only one case of bilateral TMJ septic arthritis has been reported. The contamination may result from direct extension of adjacent infection (dental or ENT), from hematogenous spread of blood-borne organisms or from direct inoculation. The most common presenting are trismus and pain, although swelling, tenderness and erythema have also been described. In addition, patients may develop fever, regional lymphadenopathy and malocclusion. Through a successively bilateral case of TMJ arthritis, without obvious portal of entry of the bacteria, we will analyze characteristics and treatment of this disease.

Fronto-Parietal Network Reconfiguration Supports the Development of Reasoning Ability.

Science.gov (United States)

Wendelken, Carter; Ferrer, Emilio; Whitaker, Kirstie J; Bunge, Silvia A

2016-05-01

The goal of this fMRI study was to examine how well developmental improvements in reasoning ability can be explained by changes in functional connectivity between specific nodes in prefrontal and parietal cortices. To this end, we examined connectivity within the lateral fronto-parietal network (LFPN) and its relation to reasoning ability in 132 children and adolescents aged 6-18 years, 56 of whom were scanned twice over the course of 1.5 years. Developmental changes in strength of connections within the LFPN were most prominent in late childhood and early adolescence. Reasoning ability was related to functional connectivity between left rostrolateral prefrontal cortex (RLPFC) and inferior parietal lobule (IPL), but only among 12-18-year olds. For 9-11-year olds, reasoning ability was most strongly related to connectivity between left and right RLPFC; this relationship was mediated by working memory. For 6-8-year olds, significant relationships between connectivity and performance were not observed; in this group, processing speed was the primary mediator of improvement in reasoning ability. We conclude that different connections best support reasoning at different points in development and that RLPFC-IPL connectivity becomes an important predictor of reasoning during adolescence. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Clinical use of regional Tc-99m-HMPAO uptake in dementia of the Alzheimer type (DAT). Klinische Wertigkeit des regionalen [sup 99m]Tc-HMPAO Uptake bei der Demenz vom Alzheimer-Typ (DAT)

Energy Technology Data Exchange (ETDEWEB)

Gebhardt, U [Nuklearmedizinische Klinik und Poliklinik, TU Muenchen (Germany); Schmauss, F [Nuklearmedizinische Klinik und Poliklinik, TU Muenchen (Germany); Wagner-Manslau, C [Nuklearmedizinische Klinik und Poliklinik, TU Muenchen (Germany); Buttermann, G [Nuklearmedizinische Klinik und Poliklinik, TU Muenchen (Germany); Zimmer, R [Psychiatrische Klinik, TU Muenchen (Germany)

1993-12-01

In 46 patients with dementia of the Alzheimer type (DAT) regional cerebral blood flow (rCBF) was compared with cognitive performance (MMSE, CAMCOG). The cortico-cerebellar ratio (CCR), determined by [sup 99m]Tc-HMPAO-SPECT was used as a rCBF-equivalent. In the mild demented group we found a bilateral CCR-reduction parietal posterior, in moderate DAT bilateral temporoparietal and leftsided frontolateral defects were seen. Severe DAT showed an additional perfusion decrease mid frontal. With increasing severity of DAT an asymmetric perfusion occurred in 17/46 patients with accentuated CCR-reduction on the left side (temporal>parietal). High correlations between CCR and MMSE (r[>=]0.70) existed frontolateral, temporal and parietal in the left hemisphere. Significant associations between CCR and CAMCOG were obtained for language in the left temporal posterior region (r=0.64), for memory task left temporal anterior (r=0.59) and for praxis left parietal posterior (r=0.55). In detecting rCBF abnormalities the sensitivity for all 46 DAT patients was 91% and 70% in the mild cases. (orig.)

Human left ventral premotor cortex mediates matching of hand posture to object use.

Directory of Open Access Journals (Sweden)

Guy Vingerhoets

Full Text Available Visuomotor transformations for grasping have been associated with a fronto-parietal network in the monkey brain. The human homologue of the parietal monkey region (AIP has been identified as the anterior part of the intraparietal sulcus (aIPS, whereas the putative human equivalent of the monkey frontal region (F5 is located in the ventral part of the premotor cortex (vPMC. Results from animal studies suggest that monkey F5 is involved in the selection of appropriate hand postures relative to the constraints of the task. In humans, the functional roles of aIPS and vPMC appear to be more complex and the relative contribution of each region to grasp selection remains uncertain. The present study aimed to identify modulation in brain areas sensitive to the difficulty level of tool object - hand posture matching. Seventeen healthy right handed participants underwent fMRI while observing pictures of familiar tool objects followed by pictures of hand postures. The task was to decide whether the hand posture matched the functional use of the previously shown object. Conditions were manipulated for level of difficulty. Compared to a picture matching control task, the tool object - hand posture matching conditions conjointly showed increased modulation in several left hemispheric regions of the superior and inferior parietal lobules (including aIPS, the middle occipital gyrus, and the inferior temporal gyrus. Comparison of hard versus easy conditions selectively modulated the left inferior frontal gyrus with peak activity located in its opercular part (Brodmann area (BA 44. We suggest that in the human brain, vPMC/BA44 is involved in the matching of hand posture configurations in accordance with visual and functional demands.

[Inferior hemiarthroplasty of the temporo-mandibular joint with articulated condylar prosthesis type Stryker].

Science.gov (United States)

Bucur, A; Dincă, O; Totan, C; Ghită, V

2007-01-01

The optimal reconstruction of the mandible and of the temporo-mandibular joint after mandibular hemi-resection with disarticulation is still controversial in literature. This paperwork presents our experience on four cases in the reconstruction of the mandible together with the inferior arthroplasty of the temporo-mandibular joint, after the resection of extended benign tumors of the mandible, based on fibular free vascularized grafts having attached a Stryker titanium condylar prosthesis reconstructing the inferior segment of the temporo-mandibular joint. Our results for the this technique were excellent, with a functional rehabilitation very close to normal. After reviewing the various techniques and their arguments in literature, with accent on the TMJ reconstruction, we consider this method to be optimal for the reconstruction of mandibular defects in patients with neoplastic conditions.

Dysplasia of the temporo-maxillary joint of mouse embryos due to x-ray irradiation

International Nuclear Information System (INIS)

Shibata, Shigeo

1974-01-01

On the 9-13 pregnant days of ddN mice 200-300 R of X-ray was daily irradiated, and observations were made on the formation of micro-mandible and changes in the temporo-maxillary joint in the embryos on the 18th pregnant day using skeletal and H-E stain specimens. Gross observation revealed the emergence of observable micro-mandible in groups exposed to 200 R on the 10th and 11th pregnant days and in groups exposed to 300 R on the 11th and 12th pregnant days. By skeletal specimens also, micro-mandible was observed in groups exposed on and after the 10th pregnant day, and anomaly of the malar arch was frequently associated with anomaly of the mandibular branches and growth inhibition of the anterior region of the mandible. Histologically, there were observed embryos totally lacking the temporo-maxillary joint composing elements, resulting in fusion with the temporal bone, or embryos lacking the elements partially or complicated by anomaly of cartilagious tissue of the mandibular head. (Mukohata, S.)

Pure alexia after right temporo-occipital hemorrhage in a right-handed female

Directory of Open Access Journals (Sweden)

Buse Rahime Hasırcı

2016-12-01

Full Text Available Alexia without agraphia is a rare clinical disorder which is characterized by impairment of reading in spite of protection of writing ability. It usually results from infarction within the vascular territory of the posterior cerebral artery. The lesions of left occipital lobe or splenium of corpus callosum can cause alexia without agraphia by the deterioration of connection between the right occipital lobe and left parietal lobe. We describe the case of a 70-year-old right-handed woman who was presented with moderate headache and blurred vision and affected by alexia without agraphia and aphasia. Our case indicates that pure alexia may arise as a consequence of damage to the right hemisphere in right-handed patients and may lead to a severe reading disorder, as in individuals with left-hemisphere dominance for language.

[Bruxism, temporo-mandibular dysfunction and botulinum toxin].

Science.gov (United States)

Chikhani, L; Dichamp, J

2003-07-01

Tooth grinding and tooth clenching are unvoluntary mainly nocturnal habits that result in an hypertrophy of masseter and temporalis muscles with an unbalance between opening and closing muscles of the jaw and lead to an alteration of mandibular condyles movements and to hyper pressure in the temporo-mandibular joints (TMJ) which can generate severe pain. Intra muscular injections of botulinum toxin permit to restablish the balance between closing and opening muscles, to relieve pain, to treat masseteric hypertrophy with improvement of face outline and to recover a normal cinetic of temporo-mandibular joints. Moreover, botulinum toxin injections permit to quit habits of tooth grinding and clenching and one single session of injections is curative for 2/3 of the patients. There are no side effects apart from slight diffusion to superficial muscles of the face resulting in a "fixed" smile for about 6 to 8 weeks. So injections of botulinum toxin in masseter and temporalis muscles are an efficient treatment of bruxism and TMJ dysfunction, cheap with no lasting side effect.

Development of parietal bone surrogates for parietal graft lift training

Directory of Open Access Journals (Sweden)

Hollensteiner Marianne

2016-09-01

Full Text Available Currently the surgical training of parietal bone graft techniques is performed on patients or specimens. Commercially available bone models do not deliver realistic haptic feedback. Thus customized parietal skull surrogates were developed for surgical training purposes. Two human parietal bones were used as reference. Based on the measurement of insertion forces of drilling, milling and saw procedures suitable material compositions for molding cortical and cancellous calvarial layers were found. Artificial skull caps were manufactured and tested. Additionally microtomograpy images of human and artificial parietal bones were performed to analyze outer table and diploe thicknesses. Significant differences between human and artificial skulls were not detected with the mechanical procedures tested. Highly significant differences were found for the diploe thickness values. In conclusion, an artificial bone has been created, mimicking the properties of human parietal bone thus being suitable for tabula externa graft lift training.

Empathy and aversion: the neural signature of mentalizing in Tourette syndrome.

Science.gov (United States)

Eddy, C M; Cavanna, A E; Hansen, P C

2017-02-01

Previous studies suggest that adults with Tourette syndrome (TS) can respond unconventionally on tasks involving social cognition. We therefore hypothesized that these patients would exhibit different neural responses to healthy controls in response to emotionally salient expressions of human eyes. Twenty-five adults with TS and 25 matched healthy controls were scanned using fMRI during the standard version of the Reading the Mind in the Eyes Task which requires mental state judgements, and a novel comparison version requiring judgements about age. During prompted mental state recognition, greater activity was apparent in TS within left orbitofrontal cortex, posterior cingulate, right amygdala and right temporo-parietal junction (TPJ), while reduced activity was apparent in regions including left inferior parietal cortex. Age judgement elicited greater activity in TS within precuneus, medial prefrontal and temporal regions involved in mentalizing. The interaction between group and task revealed differential activity in areas including right inferior frontal gyrus. Task-related activity in the TPJ covaried with global ratings of the urge to tic. While recognizing mental states, adults with TS exhibit greater activity than controls in brain areas involved in the processing of negative emotion, in addition to reduced activity in regions associated with the attribution of agency. In addition, increased recruitment of areas involved in mental state reasoning is apparent in these patients when mentalizing is not a task requirement. Our findings highlight differential neural reactivity in response to emotive social cues in TS, which may interact with tic expression.

Technetium-99m HM-PAO-SPECT study of regional cerebral perfusion in early Alzheimer's disease

International Nuclear Information System (INIS)

Perani, D.; Di Piero, V.; Vallar, G.

1988-01-01

Regional cerebral perfusion was evaluated by single photon emission computed tomography (SPECT) using technetium-99m hexamethylpropyleneamine oxime ([/sup 99m/Tc]HM-PAO) in sixteen patients with Alzheimer's disease (AD) in early clinical phase and in 16 healthy elderly controls. In all patients transmission computed tomography (TCT) and/or magnetic resonance imaging (MRI) did not show focal brain abnormalities. Relative to normal subjects, AD patients showed significant reductions in cortical/cerebellar activity ratio: cortical perfusion was globally depressed with the largest reductions in frontal and posterior temporo-parietal cortices. Asymmetries of relative perfusion between cerebral hemispheres were also demonstrated when language was affected or visuospatial functions were unevenly impaired. In patients with early AD, SPECT provides functional information to be compared with clinical and psychometric data

Anatomical Modularity of Verbal Working Memory? Functional Anatomical Evidence from a Famous Patient with Short-Term Memory Deficits.

Science.gov (United States)

Paulesu, Eraldo; Shallice, Tim; Danelli, Laura; Sberna, Maurizio; Frackowiak, Richard S J; Frith, Chris D

2017-01-01

Cognitive skills are the emergent property of distributed neural networks. The distributed nature of these networks does not necessarily imply a lack of specialization of the individual brain structures involved. However, it remains questionable whether discrete aspects of high-level behavior might be the result of localized brain activity of individual nodes within such networks. The phonological loop of working memory, with its simplicity, seems ideally suited for testing this possibility. Central to the development of the phonological loop model has been the description of patients with focal lesions and specific deficits. As much as the detailed description of their behavior has served to refine the phonological loop model, a classical anatomoclinical correlation approach with such cases falls short in telling whether the observed behavior is based on the functions of a neural system resembling that seen in normal subjects challenged with phonological loop tasks or whether different systems have taken over. This is a crucial issue for the cross correlation of normal cognition, normal physiology, and cognitive neuropsychology. Here we describe the functional anatomical patterns of JB, a historical patient originally described by Warrington et al. (1971), a patient with a left temporo-parietal lesion and selective short phonological store deficit. JB was studied with the H 2 15 O PET activation technique during a rhyming task, which primarily depends on the rehearsal system of the phonological loop. No residual function was observed in the left temporo-parietal junction, a region previously associated with the phonological buffer of working memory. However, Broca's area, the major counterpart of the rehearsal system, was the major site of activation during the rhyming task. Specific and autonomous activation of Broca's area in the absence of afferent inputs from the other major anatomical component of the phonological loop shows that a certain degree of

Visual Short-Term Memory Activity in Parietal Lobe Reflects Cognitive Processes beyond Attentional Selection.

Science.gov (United States)

Sheremata, Summer L; Somers, David C; Shomstein, Sarah

2018-02-07

Visual short-term memory (VSTM) and attention are distinct yet interrelated processes. While both require selection of information across the visual field, memory additionally requires the maintenance of information across time and distraction. VSTM recruits areas within human (male and female) dorsal and ventral parietal cortex that are also implicated in spatial selection; therefore, it is important to determine whether overlapping activation might reflect shared attentional demands. Here, identical stimuli and controlled sustained attention across both tasks were used to ask whether fMRI signal amplitude, functional connectivity, and contralateral visual field bias reflect memory-specific task demands. While attention and VSTM activated similar cortical areas, BOLD amplitude and functional connectivity in parietal cortex differentiated the two tasks. Relative to attention, VSTM increased BOLD amplitude in dorsal parietal cortex and decreased BOLD amplitude in the angular gyrus. Additionally, the tasks differentially modulated parietal functional connectivity. Contrasting VSTM and attention, intraparietal sulcus (IPS) 1-2 were more strongly connected with anterior frontoparietal areas and more weakly connected with posterior regions. This divergence between tasks demonstrates that parietal activation reflects memory-specific functions and consequently modulates functional connectivity across the cortex. In contrast, both tasks demonstrated hemispheric asymmetries for spatial processing, exhibiting a stronger contralateral visual field bias in the left versus the right hemisphere across tasks, suggesting that asymmetries are characteristic of a shared selection process in IPS. These results demonstrate that parietal activity and patterns of functional connectivity distinguish VSTM from more general attention processes, establishing a central role of the parietal cortex in maintaining visual information. SIGNIFICANCE STATEMENT Visual short-term memory (VSTM) and

Acute parietal lobe infarction presenting as Gerstmann’s syndrome and cognitive decline mimicking senile dementia

Directory of Open Access Journals (Sweden)

Chen TY

2013-07-01

Full Text Available Tien-Yu Chen,1 Chun-Yen Chen,1,3 Che-Hung Yen,2,3 Shin-Chang Kuo,1,3 Yi-Wei Yeh,1,3 Serena Chang,1 San-Yuan Huang1,31Department of Psychiatry, 2Department of Neurology, Tri-Service General Hospital, School of Medicine, National Defense Medical Center, 3Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of ChinaAbstract: Gerstmann’s syndrome encompasses the tetrad of finger agnosia, agraphia, acalculia, and right-left confusion. An elderly man with a history of several cardiovascular diseases was initially brought to the psychiatric outpatient department by his family because of worsening of recent memory, executive function, and mixed anxious-depressive mood. Gerstmann’s syndrome without obvious motor function impairment and dementia-like features could be observed at first. Emergent brain computed tomography scan revealed new left-middle cerebral artery infarction over the left posterior parietal lobe. This case reminds us that acute cerebral infarction involving the parietal lobe may present as Gerstmann’s syndrome accompanied by cognitive decline mimicking dementia. As a result, emergent organic workups should be arranged, especially for elderly patients at high risk for cerebral vascular accident.Keywords: Gerstmann’s syndrome, dementia, parietal lobe infarction

Convergent Findings of Altered Functional and Structural Brain Connectivity in Individuals with High Functioning Autism: A Multimodal MRI Study.

Directory of Open Access Journals (Sweden)

Sophia Mueller

Full Text Available Brain tissue changes in autism spectrum disorders seem to be rather subtle and widespread than anatomically distinct. Therefore a multimodal, whole brain imaging technique appears to be an appropriate approach to investigate whether alterations in white and gray matter integrity relate to consistent changes in functional resting state connectivity in individuals with high functioning autism (HFA. We applied diffusion tensor imaging (DTI, voxel-based morphometry (VBM and resting state functional connectivity magnetic resonance imaging (fcMRI to assess differences in brain structure and function between 12 individuals with HFA (mean age 35.5, SD 11.4, 9 male and 12 healthy controls (mean age 33.3, SD 9.0, 8 male. Psychological measures of empathy and emotionality were obtained and correlated with the most significant DTI, VBM and fcMRI findings. We found three regions of convergent structural and functional differences between HFA participants and controls. The right temporo-parietal junction area and the left frontal lobe showed decreased fractional anisotropy (FA values along with decreased functional connectivity and a trend towards decreased gray matter volume. The bilateral superior temporal gyrus displayed significantly decreased functional connectivity that was accompanied by the strongest trend of gray matter volume decrease in the temporal lobe of HFA individuals. FA decrease in the right temporo-parietal region was correlated with psychological measurements of decreased emotionality. In conclusion, our results indicate common sites of structural and functional alterations in higher order association cortex areas and may therefore provide multimodal imaging support to the long-standing hypothesis of autism as a disorder of impaired higher-order multisensory integration.

Dissociable Changes of Frontal and Parietal Cortices in Inherent Functional Flexibility across the Human Life Span.

Science.gov (United States)

Yin, Dazhi; Liu, Wenjing; Zeljic, Kristina; Wang, Zhiwei; Lv, Qian; Fan, Mingxia; Cheng, Wenhong; Wang, Zheng

2016-09-28

Extensive evidence suggests that frontoparietal regions can dynamically update their pattern of functional connectivity, supporting cognitive control and adaptive implementation of task demands. However, it is largely unknown whether this flexibly functional reconfiguration is intrinsic and occurs even in the absence of overt tasks. Based on recent advances in dynamics of resting-state functional resonance imaging (fMRI), we propose a probabilistic framework in which dynamic reconfiguration of intrinsic functional connectivity between each brain region and others can be represented as a probability distribution. A complexity measurement (i.e., entropy) was used to quantify functional flexibility, which characterizes heterogeneous connectivity between a particular region and others over time. Following this framework, we identified both functionally flexible and specialized regions over the human life span (112 healthy subjects from 13 to 76 years old). Across brainwide regions, we found regions showing high flexibility mainly in the higher-order association cortex, such as the lateral prefrontal cortex (LPFC), lateral parietal cortex, and lateral temporal lobules. In contrast, visual, auditory, and sensory areas exhibited low flexibility. Furthermore, we observed that flexibility of the right LPFC improved during maturation and reduced due to normal aging, with the opposite occurring for the left lateral parietal cortex. Our findings reveal dissociable changes of frontal and parietal cortices over the life span in terms of inherent functional flexibility. This study not only provides a new framework to quantify the spatiotemporal behavior of spontaneous brain activity, but also sheds light on the organizational principle behind changes in brain function across the human life span. Recent neuroscientific research has demonstrated that the human capability of adaptive task control is primarily the result of the flexible operation of frontal brain networks. However

Attenuating illusory binding with TMS of the right parietal cortex

OpenAIRE

Esterman, Michael; Verstynen, Timothy; Robertson, Lynn C.

2007-01-01

A number of neuroimaging and neuropsychology studies have implicated various regions of parietal cortex as playing a critical role in the binding of color and form into conjunctions. The current study investigates the role of two such regions by examining how parietal transcranial magnetic stimulation (TMS) influences binding errors known as ‘illusory conjunctions.’ Participants made fewer binding errors after 1 Hz rTMS of the right intraparietal sulcus (IPS), while basic perception of featur...

Differential Effect of Left vs. Right White Matter Hyperintensity Burden on Functional Decline: The Northern Manhattan Study.

Science.gov (United States)

Dhamoon, Mandip S; Cheung, Ying-Kuen; Bagci, Ahmet; Alperin, Noam; Sacco, Ralph L; Elkind, Mitchell S V; Wright, Clinton B

2017-01-01

Asymmetry of brain dysfunction may disrupt brain network efficiency. We hypothesized that greater left-right white matter hyperintensity volume (WMHV) asymmetry was associated with functional trajectories. Methods: In the Northern Manhattan Study, participants underwent brain MRI with axial T1, T2, and fluid attenuated inversion recovery sequences, with baseline interview and examination. Volumetric WMHV distribution across 14 brain regions was determined separately by combining bimodal image intensity distribution and atlas based methods. Participants had annual functional assessments with the Barthel index (BI, range 0-100) over a mean of 7.3 years. Generalized estimating equations (GEE) models estimated associations of regional WMHV and regional left-right asymmetry with baseline BI and change over time, adjusted for baseline medical risk factors, sociodemographics, and cognition, and stroke and myocardial infarction during follow-up. Results: Among 1,195 participants, greater WMHV asymmetry in the parietal lobes (-8.46 BI points per unit greater WMHV on the right compared to left, 95% CI -3.07, -13.86) and temporal lobes (-2.48 BI points, 95% CI -1.04, -3.93) was associated with lower overall function. Greater WMHV asymmetry in the parietal lobes (-1.09 additional BI points per year per unit greater WMHV on the left compared to right, 95% CI -1.89, -0.28) was independently associated with accelerated functional decline. Conclusions: In this large population-based study with long-term repeated measures of function, greater regional WMHV asymmetry was associated with lower function and functional decline. In addition to global WMHV, WHMV asymmetry may be an important predictor of long-term functional status.

Results of MRI of the temporo-mandibular joint using optimised surface coils

Energy Technology Data Exchange (ETDEWEB)

Vogl, T.; Kellermann, O.; Randzio, J.; Kniha, H.; Requardt, H.; Tiling, R.; Lissner, J.

1988-11-01

One hundred temporo-mandibular joints were examined with a super-conducting nuclear resonance tomograph (1.0 Tesla) using various high resolution surface coils. The optimal method proved to be a spin echo sequence with a repetition time of 1,000 msec and an echo period of 28 msec with a 4 mm slice width. There were significant advantages from the non-invasive MRT diagnosis of the temporo-mandibular joints when compared with CT and with arthrography in recognising abnormal discs, changes in the tissues and for post-operative control.

Exploration of Functional Connectivity During Preferred Music Stimulation in Patients with Disorders of Consciousness.

Science.gov (United States)

Heine, Lizette; Castro, Maïté; Martial, Charlotte; Tillmann, Barbara; Laureys, Steven; Perrin, Fabien

2015-01-01

Preferred music is a highly emotional and salient stimulus, which has previously been shown to increase the probability of auditory cognitive event-related responses in patients with disorders of consciousness (DOC). To further investigate whether and how music modifies the functional connectivity of the brain in DOC, five patients were assessed with both a classical functional connectivity scan (control condition), and a scan while they were exposed to their preferred music (music condition). Seed-based functional connectivity (left or right primary auditory cortex), and mean network connectivity of three networks linked to conscious sound perception were assessed. The auditory network showed stronger functional connectivity with the left precentral gyrus and the left dorsolateral prefrontal cortex during music as compared to the control condition. Furthermore, functional connectivity of the external network was enhanced during the music condition in the temporo-parietal junction. Although caution should be taken due to small sample size, these results suggest that preferred music exposure might have effects on patients auditory network (implied in rhythm and music perception) and on cerebral regions linked to autobiographical memory.

Exploration of functional connectivity during preferred music stimulation in patients with disorders of consciousness

Directory of Open Access Journals (Sweden)

Lizette eHeine

2015-11-01

Full Text Available Preferred music is a highly emotional and salient stimulus, which has previously been shown to increase the probability of auditory cognitive event-related responses in patients with disorders of consciousness (DOC. To further investigate whether and how music modifies the functional connectivity of the brain in DOC, five patients were assessed with both a classical functional connectivity scan (control condition, and a scan while they were exposed to their preferred music (music condition. Seed-based functional connectivity (left or right primary auditory cortex, and mean network connectivity of three networks linked to conscious sound perception were assessed. The auditory network showed stronger functional connectivity with the left precentral gyrus and the left dorsolateral prefrontal cortex during music as compared to the control condition. Furthermore, functional connectivity of the external network was enhanced during the music condition in the temporo-parietal junction. Although caution should be taken due to small sample size, these results suggest that preferred music exposure might have effects on patients auditory network (implied in rhythm and music perception and on cerebral regions linked to autobiographical memory.

[Visual Texture Agnosia in Humans].

Science.gov (United States)

Suzuki, Kyoko

2015-06-01

Visual object recognition requires the processing of both geometric and surface properties. Patients with occipital lesions may have visual agnosia, which is impairment in the recognition and identification of visually presented objects primarily through their geometric features. An analogous condition involving the failure to recognize an object by its texture may exist, which can be called visual texture agnosia. Here we present two cases with visual texture agnosia. Case 1 had left homonymous hemianopia and right upper quadrantanopia, along with achromatopsia, prosopagnosia, and texture agnosia, because of damage to his left ventromedial occipitotemporal cortex and right lateral occipito-temporo-parietal cortex due to multiple cerebral embolisms. Although he showed difficulty matching and naming textures of real materials, he could readily name visually presented objects by their contours. Case 2 had right lower quadrantanopia, along with impairment in stereopsis and recognition of texture in 2D images, because of subcortical hemorrhage in the left occipitotemporal region. He failed to recognize shapes based on texture information, whereas shape recognition based on contours was well preserved. Our findings, along with those of three reported cases with texture agnosia, indicate that there are separate channels for processing texture, color, and geometric features, and that the regions around the left collateral sulcus are crucial for texture processing.

Assessment of demented patients by dynamic SPECT of inhaled xenon-133

International Nuclear Information System (INIS)

Komatani, A.; Yamaguchi, K.; Sugai, Y.; Takanashi, T.; Kera, M.; Shinohara, M.; Kawakatsu, S.

1988-01-01

We studied the potential for using dynamic single photon emission computed tomography of inhaled xenon-133 ( 133 Xe) gas in the assessment of demented patients. An advanced ring-type single photon emission computed tomography (SPECT) HEADTOME with improved spatial resolution [15 mm in full width at half maximum (FWHM)] was used for tomographic measurement of regional cerebral blood flow (rCBF). All 34 patients underwent a detailed psychiatric examination and x-ray computed tomography scan, and matched research criteria for Alzheimer's disease (n = 13), senile dementia of the Alzheimer type (n = 9), or multi-infarct dementia (n = 12). In comparison with a senile control group (n = 7), mean CBF of both the whole brain and the temporo-parietal region was significantly less in the Alzheimer's disease and senile dementia Alzheimer type groups, but no significant difference was seen between the senile control group and multi-infarct dementia group. The correlation was 0.72 (p less than 0.004) between the mean CBF of the whole brain and the score of Hasegawa's Dementia Scale, and 0.94 (p less than 0.0001) between rCBF of the temporo-parietal region and the scale in Alzheimer's disease. In the senile dementia Alzheimer type group, the correlations were 0.77 (p less than 0.01) and 0.83 (p less than 0.004) respectively. No significant correlations were found in the multi-infarct dementia group. A temporo-parietal reduction in the distribution of the rCBF characteristic in the Alzheimer's disease group and a patchy whole brain reduction characteristic in the multi-infarct dementia group was detected. The ability of our improved SPECT to provide both quantitative measurement of rCBF and characteristic rCBF distribution patterns, makes it a promising tool for research or routine examination of demented patients

Visual gravitational motion and the vestibular system in humans

Directory of Open Access Journals (Sweden)

Francesco eLacquaniti

2013-12-01

Full Text Available The visual system is poorly sensitive to arbitrary accelerations, but accurately detects the effects of gravity on a target motion. Here we review behavioral and neuroimaging data about the neural mechanisms for dealing with object motion and egomotion under gravity. The results from several experiments show that the visual estimates of a target motion under gravity depend on the combination of a prior of gravity effects with on-line visual signals on target position and velocity. These estimates are affected by vestibular inputs, and are encoded in a visual-vestibular network whose core regions lie within or around the Sylvian fissure, and are represented by the posterior insula/retroinsula/temporo-parietal junction. This network responds both to target motions coherent with gravity and to vestibular caloric stimulation in human fMRI studies. Transient inactivation of the temporo-parietal junction selectively disrupts the interception of targets accelerated by gravity.

Visual gravitational motion and the vestibular system in humans.

Science.gov (United States)

Lacquaniti, Francesco; Bosco, Gianfranco; Indovina, Iole; La Scaleia, Barbara; Maffei, Vincenzo; Moscatelli, Alessandro; Zago, Myrka

2013-12-26

The visual system is poorly sensitive to arbitrary accelerations, but accurately detects the effects of gravity on a target motion. Here we review behavioral and neuroimaging data about the neural mechanisms for dealing with object motion and egomotion under gravity. The results from several experiments show that the visual estimates of a target motion under gravity depend on the combination of a prior of gravity effects with on-line visual signals on target position and velocity. These estimates are affected by vestibular inputs, and are encoded in a visual-vestibular network whose core regions lie within or around the Sylvian fissure, and are represented by the posterior insula/retroinsula/temporo-parietal junction. This network responds both to target motions coherent with gravity and to vestibular caloric stimulation in human fMRI studies. Transient inactivation of the temporo-parietal junction selectively disrupts the interception of targets accelerated by gravity.

Sylvian Fissure and Parietal Anatomy in Children with Autism Spectrum Disorder

Directory of Open Access Journals (Sweden)

Tracey A. Knaus

2012-01-01

Full Text Available Autism spectrum disorder (ASD is characterized by deficits in social functioning and language and communication, with restricted interests or stereotyped behaviors. Anatomical differences have been found in the parietal cortex in children with ASD, but parietal subregions and associations between Sylvian fissure (SF and parietal anatomy have not been explored. In this study, SF length and anterior and posterior parietal volumes were measured on MRI in 30 right-handed boys with ASD and 30 right-handed typically developing boys (7–14 years, matched on age and non-verbal IQ. There was leftward SF and anterior parietal asymmetry, and rightward posterior parietal asymmetry, across groups. There were associations between SF and parietal asymmetries, with slight group differences. Typical SF asymmetry was associated with typical anterior and posterior parietal asymmetry, in both groups. In the atypical SF asymmetry group, controls had atypical parietal asymmetry, whereas in ASD there were more equal numbers of individuals with typical as atypical anterior parietal asymmetry. We did not find significant anatomical-behavioral associations. Our findings of more individuals in the ASD group having a dissociation between cortical asymmetries warrants further investigation of these subgroups and emphasizes the importance of investigating anatomical relationships in addition to group differences in individual regions.

Dislocation of temporo-mandibular joint - an uncommon circumstance of occurrence: vaginal delivery

Directory of Open Access Journals (Sweden)

Abderrahim El Bouazzaoui

2010-06-01

Full Text Available Dislocation of temporo-mandibular joint (TMJ is an infrequent disease but still almost spectacular. This disease consists of a permanent, to some extent complete disruption of the temporo-mandibular joint. These dislocations often occurs in a context of yawning, and less frequently after a burst of laughing or relatively mild facial trauma (slap, punch on the chin.We report a case of TMJ occurring in an uncommon circumstance : vaginal delivery. A young woman aged 24-years with no special past medical history; primipara was admitted in the Department of Maternity of the University Hospital Hassan II of Fez for an imminent delivery of a twin pregnancy. Obstetrical analgesia was not possible so the parturient cried in a strong manner during labour. Ten minutes after admission, the patient delivered vaginally with episiotomy. She gave birth to twins weighing 2800g and 2400g. During labour, and effort of crying, the patient presented a sudden and immediate loss of function of the temporo-mandibular joint, with difficulty of speaking, the mouth permanently opened, with the chin lowered and thrown forward. The examination found an emptiness of the glenoid fossa of the temporo-mandibular joint in both sides. The diagnosis of dislocation of the TMJ has established. Performance of special radiologic screening to study the TM was technically not possible. A CT scan of facial bones has been achieved so objectifying a bilateral dislocation of TMJ. The reduction of this dislocation was performed in the operating room under sedation

Functional development of fronto-striato-parietal networks associated with time perception

Directory of Open Access Journals (Sweden)

Anna eSmith

2011-11-01

Full Text Available Compared to our understanding of the functional maturation of executive functions, little is known about the neurofunctional development of perceptive functions. Time perception develops during late adolescence, underpinning many functions including motor and verbal processing, as well as late maturing higher order cognitive skills such as forward planning and future-related decision-making. Nothing, however, is known about the neurofunctional changes associated with time perception from childhood to adulthood. Using functional magnetic resonance imaging we explored the effects of age on the brain activation and functional connectivity of 32 male participants from 10 to 53 years of age during a time discrimination task that required the discrimination of temporal intervals of seconds differing by several hundred milliseconds. Increasing development was associated with progressive activation increases within left lateralised dorsolateral and inferior fronto-parieto-striato-thalamic brain regions. Furthermore, despite comparable task performance, adults showed increased functional connectivity between inferior/dorsolateral interhemispheric fronto-frontal activation as well as between inferior fronto-parietal regions compared with adolescents. Activation in caudate, specifically, was associated with both increasing age and better temporal discrimination. Progressive decreases in activation with age were observed in ventromedial prefrontal cortex, limbic regions and cerebellum. The findings demonstrate age-dependent developmentally dissociated neural networks for time discrimination. With increasing age there is progressive recruitment of later maturing left hemispheric and lateralised fronto-parieto-striato-thalamic networks, known to mediate time discrimination in adults, while earlier developing brain regions such as ventromedial prefrontal cortex, limbic and paralimbic areas and cerebellum subserve fine-temporal processing functions in children

Schizotypal perceptual aberrations of time: correlation between score, behavior and brain activity.

Directory of Open Access Journals (Sweden)

Shahar Arzy

Full Text Available A fundamental trait of the human self is its continuum experience of space and time. Perceptual aberrations of this spatial and temporal continuity is a major characteristic of schizophrenia spectrum disturbances--including schizophrenia, schizotypal personality disorder and schizotypy. We have previously found the classical Perceptual Aberration Scale (PAS scores, related to body and space, to be positively correlated with both behavior and temporo-parietal activation in healthy participants performing a task involving self-projection in space. However, not much is known about the relationship between temporal perceptual aberration, behavior and brain activity. To this aim, we composed a temporal Perceptual Aberration Scale (tPAS similar to the traditional PAS. Testing on 170 participants suggested similar performance for PAS and tPAS. We then correlated tPAS and PAS scores to participants' performance and neural activity in a task of self-projection in time. tPAS scores correlated positively with reaction times across task conditions, as did PAS scores. Evoked potential mapping and electrical neuroimaging showed self-projection in time to recruit a network of brain regions at the left anterior temporal cortex, right temporo-parietal junction, and occipito-temporal cortex, and duration of activation in this network positively correlated with tPAS and PAS scores. These data demonstrate that schizotypal perceptual aberrations of both time and space, as reflected by tPAS and PAS scores, are positively correlated with performance and brain activation during self-projection in time in healthy individuals along the schizophrenia spectrum.

Widespread temporo-occipital lobe dysfunction in amyotrophic lateral sclerosis.

Science.gov (United States)

Loewe, Kristian; Machts, Judith; Kaufmann, Jörn; Petri, Susanne; Heinze, Hans-Jochen; Borgelt, Christian; Harris, Joseph Allen; Vielhaber, Stefan; Schoenfeld, Mircea Ariel

2017-01-09

Recent studies suggest that amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) lie on a single clinical continuum. However, previous neuroimaging studies have found only limited involvement of temporal lobe regions in ALS. To better delineate possible temporal lobe involvement in ALS, the present study aimed to examine changes in functional connectivity across the whole brain, particularly with regard to extra-motor regions, in a group of 64 non-demented ALS patients and 38 healthy controls. To assess between-group differences in connectivity, we computed edge-level statistics across subject-specific graphs derived from resting-state functional MRI data. In addition to expected ALS-related decreases in functional connectivity in motor-related areas, we observed extensive changes in connectivity across the temporo-occipital cortex. Although ALS patients with comorbid FTD were deliberately excluded from this study, the pattern of connectivity alterations closely resembles patterns of cerebral degeneration typically seen in FTD. This evidence for subclinical temporal dysfunction supports the idea of a common pathology in ALS and FTD.

Phosphene-guided transcranial magnetic stimulation of occipital but not parietal cortex suppresses stimulus visibility

Science.gov (United States)

Tapia, Evelina; Mazzi, Chiara; Savazzi, Silvia; Beck, Diane M.

2014-01-01

Transcranial magnetic stimulation (TMS) applied over the occipital lobe approximately 100 ms after the onset of a stimulus decreases its visibility if it appears in the location of the phosphene. Because phosphenes can also be elicited by stimulation of the parietal regions, we asked if the same procedure that is used to reduce visibility of stimuli with occipital TMS will lead to decreased stimulus visibility when TMS is applied to parietal regions. TMS was randomly applied at 0 to 130 ms after the onset of the stimulus (SOA) in steps of 10 ms in occipital and parietal regions. Participants responded to the orientation of the line stimulus and rated its visibility. We replicate previous reports of phosphenes from both occipital and parietal TMS. As previously reported, we also observed visual suppression around the classical 100 ms window both in the objective line orientation and subjective visibility responses with occipital TMS. Parietal stimulation, on the other hand, did not consistently reduce stimulus visibility in any time window. PMID:24584900

Evolution of posterior parietal cortex and parietal-frontal networks for specific actions in primates.

Science.gov (United States)

Kaas, Jon H; Stepniewska, Iwona

2016-02-15

Posterior parietal cortex (PPC) is an extensive region of the human brain that develops relatively late and is proportionally large compared with that of monkeys and prosimian primates. Our ongoing comparative studies have led to several conclusions about the evolution of this posterior parietal region. In early placental mammals, PPC likely was a small multisensory region much like PPC of extant rodents and tree shrews. In early primates, PPC likely resembled that of prosimian galagos, in which caudal PPC (PPCc) is visual and rostral PPC (PPCr) has eight or more multisensory domains where electrical stimulation evokes different complex motor behaviors, including reaching, hand-to-mouth, looking, protecting the face or body, and grasping. These evoked behaviors depend on connections with functionally matched domains in premotor cortex (PMC) and motor cortex (M1). Domains in each region compete with each other, and a serial arrangement of domains allows different factors to influence motor outcomes successively. Similar arrangements of domains have been retained in New and Old World monkeys, and humans appear to have at least some of these domains. The great expansion and prolonged development of PPC in humans suggest the addition of functionally distinct territories. We propose that, across primates, PMC and M1 domains are second and third levels in a number of parallel, interacting networks for mediating and selecting one type of action over others. © 2015 Wiley Periodicals, Inc.

Differential Effect of Left vs. Right White Matter Hyperintensity Burden on Functional Decline: The Northern Manhattan Study

Directory of Open Access Journals (Sweden)

Mandip S. Dhamoon

2017-09-01

Full Text Available Asymmetry of brain dysfunction may disrupt brain network efficiency. We hypothesized that greater left-right white matter hyperintensity volume (WMHV asymmetry was associated with functional trajectories.Methods: In the Northern Manhattan Study, participants underwent brain MRI with axial T1, T2, and fluid attenuated inversion recovery sequences, with baseline interview and examination. Volumetric WMHV distribution across 14 brain regions was determined separately by combining bimodal image intensity distribution and atlas based methods. Participants had annual functional assessments with the Barthel index (BI, range 0–100 over a mean of 7.3 years. Generalized estimating equations (GEE models estimated associations of regional WMHV and regional left-right asymmetry with baseline BI and change over time, adjusted for baseline medical risk factors, sociodemographics, and cognition, and stroke and myocardial infarction during follow-up.Results: Among 1,195 participants, greater WMHV asymmetry in the parietal lobes (−8.46 BI points per unit greater WMHV on the right compared to left, 95% CI −3.07, −13.86 and temporal lobes (−2.48 BI points, 95% CI −1.04, −3.93 was associated with lower overall function. Greater WMHV asymmetry in the parietal lobes (−1.09 additional BI points per year per unit greater WMHV on the left compared to right, 95% CI −1.89, −0.28 was independently associated with accelerated functional decline.Conclusions: In this large population-based study with long-term repeated measures of function, greater regional WMHV asymmetry was associated with lower function and functional decline. In addition to global WMHV, WHMV asymmetry may be an important predictor of long-term functional status.

LANGUAGE REPETITION AND SHORT-TERM MEMORY: AN INTEGRATIVE FRAMEWORK

Directory of Open Access Journals (Sweden)

Steve eMajerus

2013-07-01

Full Text Available Short-term maintenance of verbal information is a core factor of language repetition, especially when reproducing multiple or unfamiliar stimuli. Many models of language processing locate the verbal short-term maintenance function in the left posterior superior temporo-parietal area and its connections with the inferior frontal gyrus. However, research in the field of short-term memory has implicated bilateral fronto-parietal networks, involved in attention and serial order processing, as being critical for the maintenance and reproduction of verbal sequences. We present here an integrative framework aimed at bridging research in the language processing and short-term memory fields. This framework considers verbal short-term maintenance as an emergent function resulting from synchronized and integrated activation in dorsal and ventral language processing networks as well as fronto-parietal attention and serial order processing networks. To-be-maintained item representations are temporarily activated in the dorsal and ventral language processing networks, novel phoneme and word serial order information is proposed to be maintained via a right fronto-parietal serial order processing network, and activation in these different networks is proposed to be coordinated and maintained via a left fronto-parietal attention processing network. This framework provides new perspectives for our understanding of information maintenance at the nonword-, word- and sentence-level as well as of verbal maintenance deficits in case of brain injury.

Language repetition and short-term memory: an integrative framework.

Science.gov (United States)

Majerus, Steve

2013-01-01

Short-term maintenance of verbal information is a core factor of language repetition, especially when reproducing multiple or unfamiliar stimuli. Many models of language processing locate the verbal short-term maintenance function in the left posterior superior temporo-parietal area and its connections with the inferior frontal gyrus. However, research in the field of short-term memory has implicated bilateral fronto-parietal networks, involved in attention and serial order processing, as being critical for the maintenance and reproduction of verbal sequences. We present here an integrative framework aimed at bridging research in the language processing and short-term memory fields. This framework considers verbal short-term maintenance as an emergent function resulting from synchronized and integrated activation in dorsal and ventral language processing networks as well as fronto-parietal attention and serial order processing networks. To-be-maintained item representations are temporarily activated in the dorsal and ventral language processing networks, novel phoneme and word serial order information is proposed to be maintained via a right fronto-parietal serial order processing network, and activation in these different networks is proposed to be coordinated and maintained via a left fronto-parietal attention processing network. This framework provides new perspectives for our understanding of information maintenance at the non-word-, word- and sentence-level as well as of verbal maintenance deficits in case of brain injury.

Alterations in regional homogeneity of resting-state brain activity in internet gaming addicts

Directory of Open Access Journals (Sweden)

Dong Guangheng

2012-08-01

Full Text Available Abstract Backgrounds Internet gaming addiction (IGA, as a subtype of internet addiction disorder, is rapidly becoming a prevalent mental health concern around the world. The neurobiological underpinnings of IGA should be studied to unravel the potential heterogeneity of IGA. This study investigated the brain functions in IGA patients with resting-state fMRI. Methods Fifteen IGA subjects and fourteen healthy controls participated in this study. Regional homogeneity (ReHo measures were used to detect the abnormal functional integrations. Results Comparing to the healthy controls, IGA subjects show enhanced ReHo in brainstem, inferior parietal lobule, left posterior cerebellum, and left middle frontal gyrus. All of these regions are thought related with sensory-motor coordination. In addition, IGA subjects show decreased ReHo in temporal, occipital and parietal brain regions. These regions are thought responsible for visual and auditory functions. Conclusions Our results suggest that long-time online game playing enhanced the brain synchronization in sensory-motor coordination related brain regions and decreased the excitability in visual and auditory related brain regions.

Motor role of parietal cortex in a monkey model of hemispatial neglect.

Science.gov (United States)

Kubanek, Jan; Li, Jingfeng M; Snyder, Lawrence H

2015-04-21

Parietal cortex is central to spatial cognition. Lesions of parietal cortex often lead to hemispatial neglect, an impairment of choices of targets in space. It has been unclear whether parietal cortex implements target choice at the general cognitive level, or whether parietal cortex subserves the choice of targets of particular actions. To address this question, monkeys engaged in choice tasks in two distinct action contexts--eye movements and arm movements. We placed focused reversible lesions into specific parietal circuits using the GABAA receptor agonist muscimol and validated the lesion placement using MRI. We found that lesions on the lateral bank of the intraparietal sulcus [lateral intraparietal area (LIP)] specifically biased choices made using eye movements, whereas lesions on the medial bank of the intraparietal sulcus [parietal reach region (PRR)] specifically biased choices made using arm movements. This double dissociation suggests that target choice is implemented in dedicated parietal circuits in the context of specific actions. This finding emphasizes a motor role of parietal cortex in spatial choice making and contributes to our understanding of hemispatial neglect.

Overlapping Parietal Activity in Memory and Perception: Evidence for the Attention to Memory Model

Science.gov (United States)

Cabeza, Roberto; Mazuz, Yonatan S.; Stokes, Jared; Kragel, James E.; Woldorff, Marty G.; Ciaramelli, Elisa; Olson, Ingrid R.; Moscovitch, Morris

2011-01-01

The specific role of different parietal regions to episodic retrieval is a topic of intense debate. According to the Attention to Memory (AtoM) model, dorsal parietal cortex (DPC) mediates top-down attention processes guided by retrieval goals, whereas ventral parietal cortex (VPC) mediates bottom-up attention processes captured by the retrieval…

Low regional cerebral blood flow in burning mouth syndrome patients with depression.

Science.gov (United States)

Liu, B-L; Yao, H; Zheng, X-J; Du, G-H; Shen, X-M; Zhou, Y-M; Tang, G-Y

2015-07-01

The main aims of this study were to (i) investigate the emotional disorder status of patients with burning mouth syndrome (BMS) and (ii) detect regional cerebral blood flow in BMS patients with the application of combined single-photon emission computed tomography and computed tomography (SPECT/CT). The degree of pain was measured using the visual analysis scale, and emotional disorder with the self-rating anxiety scale, self-rating depression scale, and Hamilton depression rating scale in 29 patients with BMS and 10 healthy controls. SPECT/CT was performed in 29 patients with BMS and 10 healthy controls, and statistical parametric mapping method was used for between-group analyses. The incidence rate of depression in patients with BMS was 31.0%. Compared to the control group, patients with BMS displayed significantly different depression and anxiety scales (P < 0.05). Significantly lower regional cerebral blood flow in the left parietal and left temporal lobes was recorded for BMS patients with depression (P < 0.05). Patients with BMS experience more depression and anxious emotion. Moreover, depression in patients with BMS may be associated with lower regional cerebral blood flow in the left temporal and left parietal lobes. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory.

Science.gov (United States)

Greene, Ciara M; Flannery, Oliver; Soto, David

2014-12-01

The two dimensions of emotion, mood valence and arousal, have independent effects on recognition memory. At present, however, it is not clear how those effects are reflected in the human brain. Previous research in this area has generally dealt with memory for emotionally valenced or arousing stimuli, but the manner in which interacting mood and arousal states modulate responses in memory substrates remains poorly understood. We investigated memory for emotionally neutral items while independently manipulating mood valence and arousal state by means of music exposure. Four emotional conditions were created: positive mood/high arousal, positive mood/low arousal, negative mood/high arousal, and negative mood/low arousal. We observed distinct effects of mood valence and arousal in parietal substrates of recognition memory. Positive mood increased activity in ventral posterior parietal cortex (PPC) and orbitofrontal cortex, whereas arousal condition modulated activity in dorsal PPC and the posterior cingulate. An interaction between valence and arousal was observed in left ventral PPC, notably in a parietal area distinct from the those identified for the main effects, with a stronger effect of mood on recognition memory responses here under conditions of relative high versus low arousal. We interpreted the PPC activations in terms of the attention-to-memory hypothesis: Increased arousal may lead to increased top-down control of memory, and hence dorsal PPC activation, whereas positive mood valence may result in increased activity in ventral PPC regions associated with bottom-up attention to memory. These findings indicate that distinct parietal sites mediate the influences of mood, arousal, and their interplay during recognition memory.

The contribution of the human posterior parietal cortex to episodic memory.

Science.gov (United States)

Sestieri, Carlo; Shulman, Gordon L; Corbetta, Maurizio

2017-02-17

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional-anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push-pull relationship, potentially mediated by prefrontal regions. Moreover, different PPC regions carry out specific functions during retrieval - for example, representing retrieved information, recoding this information based on task demands, or accumulating evidence for memory decisions.

Activation of right parietal cortex during memory retrieval of nonlinguistic auditory stimuli.

Science.gov (United States)

Klostermann, Ellen C; Loui, Psyche; Shimamura, Arthur P

2009-09-01

In neuroimaging studies, the left ventral posterior parietal cortex (PPC) is particularly active during memory retrieval. However, most studies have used verbal or verbalizable stimuli. We investigated neural activations associated with the retrieval of short, agrammatical music stimuli (Blackwood, 2004), which have been largely associated with right hemisphere processing. At study, participants listened to music stimuli and rated them on pleasantness. At test, participants made old/new recognition judgments with high/low confidence ratings. Right, but not left, ventral PPC activity was observed during the retrieval of these music stimuli. Thus, rather than indicating a special status of left PPC in retrieval, both right and left ventral PPC participate in memory retrieval, depending on the type of information that is to be remembered.

The neural correlates of theory of mind and their role during empathy and the game of chess: A functional magnetic resonance imaging study.

Science.gov (United States)

Powell, Joanne L; Grossi, Davide; Corcoran, Rhiannon; Gobet, Fernand; García-Fiñana, Marta

2017-07-04

Chess involves the capacity to reason iteratively about potential intentional choices of an opponent and therefore involves high levels of explicit theory of mind [ToM] (i.e. ability to infer mental states of others) alongside clear, strategic rule-based decision-making. Functional magnetic resonance imaging was used on 12 healthy male novice chess players to identify cortical regions associated with chess, ToM and empathizing. The blood-oxygenation-level-dependent (BOLD) response for chess and empathizing tasks was extracted from each ToM region. Results showed neural overlap between ToM, chess and empathizing tasks in right-hemisphere temporo-parietal junction (TPJ) [BA40], left-hemisphere superior temporal gyrus [BA22] and posterior cingulate gyrus [BA23/31]. TPJ is suggested to underlie the capacity to reason iteratively about another's internal state in a range of tasks. Areas activated by ToM and empathy included right-hemisphere orbitofrontal cortex and bilateral middle temporal gyrus: areas that become active when there is need to inhibit one's own experience when considering the internal state of another and for visual evaluation of action rationality. Results support previous findings, that ToM recruits a neural network with each region sub-serving a supporting role depending on the nature of the task itself. In contrast, a network of cortical regions primarily located within right- and left-hemisphere medial-frontal and parietal cortex, outside the internal representational network, was selectively recruited during the chess task. We hypothesize that in our cohort of novice chess players the strategy was to employ an iterative thinking pattern which in part involved mentalizing processes and recruited core ToM-related regions. Copyright © 2017. Published by Elsevier Ltd.

Specific marker of feigned memory impairment: The activation of left superior frontal gyrus.

Science.gov (United States)

Chen, Zi-Xiang; Xue, Li; Liang, Chun-Yu; Wang, Li-Li; Mei, Wei; Zhang, Qiang; Zhao, Hu

2015-11-01

Faking memory impairment means normal people complain lots of memory problems without organic damage in forensic assessments. Using alternative forced-choice paradigm, containing digital or autobiographical information, previous neuroimaging studies have indicated that faking memory impairment could cause the activation in the prefrontal and parietal regions, and might involve a fronto-parietal-subcortical circuit. However, it is still unclear whether different memory types have influence on faking or not. Since different memory types, such as long-term memory (LTM) and short-term memory (STM), were found supported by different brain areas, we hypothesized that feigned STM or LTM impairment had distinct neural activation mapping. Besides that, some common neural correlates may act as the general characteristic of feigned memory impairment. To verify this hypothesis, the functional magnetic resonance imaging (fMRI) combined with an alternative word forced-choice paradigm were used in this study. A total of 10 right-handed participants, in this study, had to perform both STW and LTM tasks respectively under answering correctly, answering randomly and feigned memory impairment conditions. Our results indicated that the activation of the left superior frontal gyrus and the left medial frontal gyrus was associated with feigned LTM impairment, whereas the left superior frontal gyrus, the left precuneus and the right anterior cingulate cortex (ACC) were highly activated while feigning STM impairment. Furthermore, an overlapping was found in the left superior frontal gyrus, and it suggested that the activity of the left superior frontal gyrus might be acting as a specific marker of feigned memory impairment. Copyright © 2015. Published by Elsevier Ltd.

The rehabilitative effects on written language of a combined language and parietal dual-tDCS treatment in a stroke case.

Science.gov (United States)

De Tommaso, Barbara; Piedimonte, Alessandro; Caglio, Marcella M; D'Agata, Federico; Campagnoli, Marcello; Orsi, Laura; Raimondo, Simona; Vighetti, Sergio; Mortara, Paolo; Massazza, Giuseppe; Pinessi, Lorenzo

2017-09-01

In this paper we report the effect of a combined transcranial direct current stimulation (tDCS) and speech language therapy on linguistic deficits following left brain damage in a stroke case. We show that simultaneous electrical excitatory stimulation to the left and inhibitory stimulation to the right parietal regions (dual-tDCS) affected writing and reading rehabilitation, enhancing speech therapy outcomes. The results of a comparison with healthy controls showed that application of dual-tDCS could improve, in particular, sub-lexical transcoding and, specifically, the reading of non-words with increasing length and complexity. Positive repercussions on patient's quality of functional communication were also ascertained. Significant changes were also found in other language and cognitive tasks not directly treated (comprehension and constructive apraxia).

Disrupting the brain to validate hypotheses on the neurobiology of language

Directory of Open Access Journals (Sweden)

Liuba ePapeo

2013-04-01

Full Text Available Comprehension of words is an important part of the language faculty, involving the joint activity of frontal and temporo-parietal brain regions. Transcranial Magnetic Stimulation (TMS enables the controlled perturbation of brain activity, and thus offers a unique tool to test specific predictions about the causal relationship between brain regions and language understanding. This potential has been exploited to better define the role of regions that are classically accepted as part of the language-semantic network. For instance, TMS has contributed to establish the semantic relevance of the left anterior temporal lobe, or to solve the ambiguity between the semantic versus phonological function assigned to the left inferior frontal gyrus. We consider, more closely, the results from studies where the same technique, similar paradigms (lexical-semantic tasks and materials (words have been used to assess the relevance of regions outside the classically-defined language-semantic network – i.e., precentral motor regions – for the semantic analysis of words. This research shows that different aspects of the left precentral gyrus (primary motor and premotor sites are sensitive to the action-non action distinction of words’ meanings. However, the behavioral changes due to TMS over these sites are incongruent with what is expected after perturbation of a task-relevant brain region. Thus, the relationship between motor activity and language-semantic behavior remains far from clear. A better understanding of this issue could be guaranteed by investigating functional interactions between motor sites and semantically-relevant regions.

Functional Clustering of the Human Inferior Parietal Lobule by Whole-Brain Connectivity Mapping of Resting-State Functional Magnetic Resonance Imaging Signals

Science.gov (United States)

Li, Chiang-Shan R.

2014-01-01

Abstract The human inferior parietal lobule (IPL) comprised the lateral bank of the intraparietal sulcus, angular gyrus, and supramarginal gyrus, defined on the basis of anatomical landmarks and cytoarchitectural organization of neurons. However, it is not clear as to whether the three areas represent functional subregions within the IPL. For instance, imaging studies frequently identified clusters of activities that cut across areal boundaries. Here, we used resting-state functional magnetic resonance imaging (fMRI) data to examine how individual voxels within the IPL are best clustered according to their connectivity to the whole brain. The results identified a best estimate of seven clusters that are hierarchically arranged as the anterior, middle, and posterior subregions. The anterior, middle, and posterior IPL are each significantly connected to the somatomotor areas, superior/middle/inferior frontal gyri, and regions of the default mode network. This functional segregation is supported by recent cytoarchitechtonics and tractography studies. IPL showed hemispheric differences in connectivity that accord with a predominantly left parietal role in tool use and language processing and a right parietal role in spatial attention and mathematical cognition. The functional clusters may also provide a more parsimonious and perhaps even accurate account of regional activations of the IPL during a variety of cognitive challenges, as reported in earlier fMRI studies. PMID:24308753

Vascular risk factors, atherosclerosis, cerebral white matter lesions and cerebral perfusion in a population-based study

International Nuclear Information System (INIS)

Claus, J.J.; Breteler, M.M.B.; Hasan, D.; Krenning, E.P.; Bots, M.L.; Grobbee, D.E.; Swieten, J.C. van; Harskamp, F. van; Hofman, A.

1996-01-01

We studied risk factors for cerebral vascular disease (blood pressure and hypertension, factor VIIc, factor VIIIc, fibrinogen), indicators of atherosclerosis (intima-media thickness and plaques in the carotid artery) and cerebral white matter lesions in relation to regional cerebral blood flow (rCBF) in 60 persons (aged 65-85 years) recruited from a population-based study. rCBF was assessed with single-photon emission tomography using technetium-99m d,l-hexamethylpropylene amine oxime ( 99m Tc-HMPAO). Statistical analysis was performed with multiple linear regression with adjustment for age, sex and ventricle-to-brain ratio. A significant positive association was found between systolic and diastolic blood pressure and temporo-parietal rCBF. In analysis with quartiles of the distribution, we found a threshold effect for the relation of low diastolic blood pressure (≤60 mmHg) and low temporo-parietal rCBF. Levels of plasma fibrinogen were inversely related to parietal rCBF, with a threshold effect of high fibrinogen levels (>3.2 g/l) and low rCBF. Increased atherosclerosis was related to low rCBF in all cortical regions, but these associations were not significant. No consistent relation was observed between severity of cerebral white matter lesions and rCBF. Our results may have implications for blood pressure control in the elderly population. (orig.)

The preliminary study of 18F-FDG PET in diagnosis of Alzheimer's disease

International Nuclear Information System (INIS)

Ma, Y.; Zhang, X.; Le, D.

2000-01-01

To investigate the imaging characteristic and diagnostic criteria of 18F-FDG brain PET in detecting Alzheimer's disease (AD). The study included in 12 normal subject, 12 patients with AD, 6 patients with vascular dementia, 3 patients with Lewy body disease (LBD) and 2 patients with mixed dementia. The dementia severity was measured by ESD and MMSE. 12 cases had mild, 7 moderate and 4 severe dementia. 23 patients and 6 normal subjects underwent MR imaging of the brain. All participants fasted for at least 6 hours. 40 minutes after intravenous administration of 185-370 MBq 18F-FDG, 2D brain scan in 25 cases and 3D scan in 10 cases were performed using SIEMENS ECAT 47 scanner. The transaxial, coronal and sagittal images were then reconstructed by computer. At the same time, semiquantitative analysis was also applied to help evaluation using the ratio of mean radioactivity between cerebral lobe to cerebellum (Rcl/cb). In normal subjects PET scan showed clear images of cerebral cortex, basal ganglia, thalamus and cerebellum with symmetrical distribution of radioactivity. 22 of 23 patients were found to have decreased uptake of FDG in the brain. 20 patients had cerebral atrophy and it also appeared in 6 normal elder people. PET images for Alzheimer's disease were classified in 6 normal elder people. PET image for Alzheimer's 3 patterns: bilateral parietal hypo metabolism in 5 cases, bilateral temporo-parietal hypo metabolism in 4 cases and unilateral temporo-parietal hypo metabolism in 3 cases. The Rcl/cb of AD patents in parietal and temporal was significantly decreased than normal subjects (p<0.05). PET images for non-AD dementia were also classified 3 patterns: multiple and asymmetrical patch foci with decreased radioactivity in 8 cases, bilateral temporo-parietal with diffuse cortical hypo metabolism in 2 cases, and normal imaging in 1 case. The hypo metabolic involvement was accorded with severity of dementia. The more dementia had, the bigger hypometabloic region

Connectivity of the hippocampus and Broca's area during acquisition of a novel grammar.

Science.gov (United States)

Kepinska, Olga; de Rover, Mischa; Caspers, Johanneke; Schiller, Niels O

2018-01-15

Following Opitz and Friederici (2003) suggesting interactions of the hippocampal system and the prefrontal cortex as the neural mechanism underlying novel grammar learning, the present fMRI study investigated functional connectivity of bilateral BA 44/45 and the hippocampus during an artificial grammar learning (AGL) task. Our results, contrary to the previously reported interactions, demonstrated parallel (but separate) contributions of both regions, each with their own interactions, to the process of novel grammar acquisition. The functional connectivity pattern of Broca's area pointed to the importance of coherent activity of left frontal areas around the core language processing region for successful grammar learning. Furthermore, connectivity patterns of left and right hippocampi (predominantly with occipital areas) were found to be a strong predictor of high performance on the task. Finally, increasing functional connectivity over time of both left and right BA 44/45 with the right posterior cingulate cortex and the right temporo-parietal areas points to the importance of multimodal and attentional processes supporting novel grammar acquisition. Moreover, it highlights the right-hemispheric involvement in initial stages of L2 learning. These latter interactions were found to operate irrespective of the task performance, making them an obligatory mechanism accompanying novel grammar learning. Copyright © 2017 Elsevier Inc. All rights reserved.

Functional segregation and integration within fronto-parietal networks.

Science.gov (United States)

Parlatini, Valeria; Radua, Joaquim; Dell'Acqua, Flavio; Leslie, Anoushka; Simmons, Andy; Murphy, Declan G; Catani, Marco; Thiebaut de Schotten, Michel

2017-02-01

Experimental data on monkeys and functional studies in humans support the existence of a complex fronto-parietal system activating for cognitive and motor tasks, which may be anatomically supported by the superior longitudinal fasciculus (SLF). Advanced tractography methods have recently allowed the separation of the three branches of the SLF but are not suitable for their functional investigation. In order to gather comprehensive information about the functional organisation of these fronto-parietal connections, we used an innovative method, which combined tractography of the SLF in the largest dataset so far (129 participants) with 14 meta-analyses of functional magnetic resonance imaging (fMRI) studies. We found that frontal and parietal functions can be clustered into a dorsal spatial/motor network associated with the SLF I, and a ventral non-spatial/motor network associated with the SLF III. Further, all the investigated functions activated a middle network mostly associated with the SLF II. Our findings suggest that dorsal and ventral fronto-parietal networks are segregated but also share regions of activation, which may support flexible response properties or conscious processing. In sum, our novel combined approach provided novel findings on the functional organisation of fronto-parietal networks, and may be successfully applied to other brain connections. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Functional connectivity of parietal cortex during temporal selective attention.

Science.gov (United States)

Tyler, Sarah C; Dasgupta, Samhita; Agosta, Sara; Battelli, Lorella; Grossman, Emily D

2015-04-01

Perception of natural experiences requires allocation of attention towards features, objects, and events that are moving and changing over time. This allocation of attention is controlled by large-scale brain networks that, when damaged, cause widespread cognitive deficits. In particular, damage to ventral parietal cortex (right lateralized TPJ, STS, supramarginal and angular gyri) is associated with failures to selectively attend to and isolate features embedded within rapidly changing visual sequences (Battelli, Pascual-Leone, & Cavanagh, 2007; Husain, Shapiro, Martin, & Kennard, 1997). In this study, we used fMRI to investigate the neural activity and functional connectivity of intact parietal cortex while typical subjects judged the relative onsets and offsets of rapidly flickering tokens (a phase discrimination task in which right parietal patients are impaired). We found two regions in parietal cortex correlated with task performance: a bilateral posterior TPJ (pTPJ) and an anterior right-lateralized TPJ (R aTPJ). Both regions were deactivated when subjects engaged in the task but showed different patterns of functional connectivity. The bilateral pTPJ was strongly connected to nodes within the default mode network (DMN) and the R aTPJ was connected to the attention network. Accurate phase discriminations were associated with increased functional correlations between sensory cortex (hMT+) and the bilateral pTPJ, whereas accuracy on a control task was associated with yoked activity in the hMT+ and the R aTPJ. We conclude that temporal selective attention is particularly sensitive for revealing information pathways between sensory and core cognitive control networks that, when damaged, can lead to nonspatial attention impairments in right parietal stroke patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

Thalamic and parietal brain morphology predicts auditory category learning.

Science.gov (United States)

Scharinger, Mathias; Henry, Molly J; Erb, Julia; Meyer, Lars; Obleser, Jonas

2014-01-01

Auditory categorization is a vital skill involving the attribution of meaning to acoustic events, engaging domain-specific (i.e., auditory) as well as domain-general (e.g., executive) brain networks. A listener's ability to categorize novel acoustic stimuli should therefore depend on both, with the domain-general network being particularly relevant for adaptively changing listening strategies and directing attention to relevant acoustic cues. Here we assessed adaptive listening behavior, using complex acoustic stimuli with an initially salient (but later degraded) spectral cue and a secondary, duration cue that remained nondegraded. We employed voxel-based morphometry (VBM) to identify cortical and subcortical brain structures whose individual neuroanatomy predicted task performance and the ability to optimally switch to making use of temporal cues after spectral degradation. Behavioral listening strategies were assessed by logistic regression and revealed mainly strategy switches in the expected direction, with considerable individual differences. Gray-matter probability in the left inferior parietal lobule (BA 40) and left precentral gyrus was predictive of "optimal" strategy switch, while gray-matter probability in thalamic areas, comprising the medial geniculate body, co-varied with overall performance. Taken together, our findings suggest that successful auditory categorization relies on domain-specific neural circuits in the ascending auditory pathway, while adaptive listening behavior depends more on brain structure in parietal cortex, enabling the (re)direction of attention to salient stimulus properties. © 2013 Published by Elsevier Ltd.

Functional asymmetries in early learning during right, left, and bimanual performance in right-handed subjects.

Science.gov (United States)

Aznárez-Sanado, Maite; Fernández-Seara, Maria A; Loayza, Francis R; Pastor, Maria A

2013-03-01

To elucidate differences in activity and connectivity during early learning due to the performing hand. Twenty right-handed subjects were recruited. The neural correlates of explicit visuospatial learning executed with the right, the left hand, and bimanually were investigated using functional magnetic resonance imaging. Connectivity analyses were carried out using the psychophysiological interactions model, considering right and left anterior putamen as index regions. A common neural network was found for the three tasks during learning. Main activity increases were located in posterior cingulate cortex, supplementary motor area, parietal cortex, anterior putamen, and cerebellum (IV-V), whereas activity decrements were observed in prefrontal regions. However, the left hand task showed a greater recruitment of left hippocampal areas when compared with the other tasks. In addition, enhanced connectivity between the right anterior putamen and motor cortical and cerebellar regions was found for the left hand when compared with the right hand task. An additional recruitment of brain regions and increased striato-cortical and striato-cerebellar functional connections is needed when early learning is performed with the nondominant hand. In addition, access to brain resources during learning may be directed by the dominant hand in the bimanual task. Copyright © 2012 Wiley Periodicals, Inc.

Abnormal parietal function in conversion paresis.

Directory of Open Access Journals (Sweden)

Marije van Beilen

Full Text Available The etiology of medically unexplained symptoms such as conversion disorder is poorly understood. This is partly because the interpretation of neuroimaging results in conversion paresis has been complicated by the use of different control groups, tasks and statistical comparisons. The present study includes these different aspects in a single data set. In our study we included both normal controls and feigners to control for conversion paresis. We studied both movement execution and imagery, and we contrasted both within-group and between-group activation. Moreover, to reveal hemisphere-specific effects that have not been reported before, we performed these analyses using both flipped and unflipped data. This approach resulted in the identification of abnormal parietal activation which was specific for conversion paresis patients. Patients also showed reduced activity in the prefrontal cortex, supramarginal gyrus and precuneus, including hemisphere-specific activation that is lateralized in the same hemisphere, regardless of right- or left-sided paresis. We propose that these regions are candidates for an interface between psychological mechanisms and disturbed higher-order motor control. Our study presents an integrative neurophysiological view of the mechanisms that contribute to the etiology of this puzzling psychological disorder, which can be further investigated with other types of conversion symptoms.

Self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal superior longitudinal fasciculus III network.

Science.gov (United States)

Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru; Naito, Eiichi

2017-04-21

Proprioception is somatic sensation that allows us to sense and recognize position, posture, and their changes in our body parts. It pertains directly to oneself and may contribute to bodily awareness. Likewise, one's face is a symbol of oneself, so that visual self-face recognition directly contributes to the awareness of self as distinct from others. Recently, we showed that right-hemispheric dominant activity in the inferior fronto-parietal cortices, which are connected by the inferior branch of the superior longitudinal fasciculus (SLF III), is associated with proprioceptive illusion (awareness), in concert with sensorimotor activity. Herein, we tested the hypothesis that visual self-face recognition shares brain regions active during proprioceptive illusion in the right inferior fronto-parietal SLF III network. We scanned brain activity using functional magnetic resonance imaging while twenty-two right-handed healthy adults performed two tasks. One was a proprioceptive illusion task, where blindfolded participants experienced a proprioceptive illusion of right hand movement. The other was a visual self-face recognition task, where the participants judged whether an observed face was their own. We examined whether the self-face recognition and the proprioceptive illusion commonly activated the inferior fronto-parietal cortices connected by the SLF III in a right-hemispheric dominant manner. Despite the difference in sensory modality and in the body parts involved in the two tasks, both tasks activated the right inferior fronto-parietal cortices, which are likely connected by the SLF III, in a right-side dominant manner. Here we discuss possible roles for right inferior fronto-parietal activity in bodily awareness and self-awareness. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

[The para-clinic investigation of temporo-mandibular joint changes in patients with acromegaly].

Science.gov (United States)

Morăraşu, C; Burlui, V; Olaru, C; Boza, C; Bortă, C; Morăraşu, G; Brînză, M

2001-01-01

The Acromegaly is an endocrinological disease determined by the hypersecretion of STH in a certain period of the body evolution and it causes the hypertrophy of bones in general and of mandible and cranio-facial bones, determining a disorder due to this development of bones, associated with troubles in the activity of muscles and of the phospho-calcium metabolism. This study was made on a group of 33 acromegaly patients. Their temporo-mandibular joint was investigated by ortopantomography, tomography, computer tomography and scintigraphy. All of these exams shows the changes in temporo-mandibular joint due to the cells hyperactivity determined by the hypersecretion of STH.

[Temporo-mandibular joints and orthognathic surgery].

Science.gov (United States)

Bouletreau, P

2016-09-01

Temporo-Mandibular Joints (TMJ) and orthognathic surgery are closely linked. In the past, some authors have even described (with mixed results) the correction of some dysmorphosis through direct procedures on the TMJs. Nowadays, performing orthognathic surgery involves the TMJ in three different occasions: (1) TMJ disorders potentially responsible for dento-maxillary dysmorphosis, (2) effects of orthognathic surgery on TMJs, and (3) condylar positioning methods in orthognathic surgery. These three chapters are developed in order to focus on the close relationships between TMJ and orthognathic surgery. Some perspectives close this article. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Simple index of functional connectivity at rest in Multiple Sclerosis fatigue.

Science.gov (United States)

Buyukturkoglu, Korhan; Porcaro, Camillo; Cottone, Carlo; Cancelli, Andrea; Inglese, Matilde; Tecchio, Franca

2017-05-01

To investigate the EEG-derived functional connectivity at rest (FCR) patterns of fatigued Multiple Sclerosis (MS) patients in order to find good parameters for a future EEG-Neurofeedback intervention to reduce their fatigue symptoms. We evaluated FCR between hemispheric homologous areas, via spectral coherence between pairs of corresponding left and right bipolar derivations, in the Theta, Alpha and Beta bands. We estimated FCR in 18MS patients with different levels of fatigue and minimal clinical severity and in 11 age and gender matched healthy controls. We used correlation analysis to assess the relationship between the fatigue scores and the FCR values differing between fatigued MS patients and controls. Among FCR values differing between fatigued MS patients and controls, fatigue symptoms increased with higher Beta temporo-parietal FCR (p=0.00004). Also, positive correlations were found between the fatigue levels and the fronto-frontal FCR in Beta and Theta bands (p=0.0002 and p=0.001 respectively). We propose that a future EEG-Neurofeedback system against MS fatigue would train patients to decrease voluntarily the beta coherence between the homologous temporo-parietal areas. We extracted a feature for building an EEG-Neurofeedback system against fatigue in MS. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

ESTRÉS COMO FACTOR ETIOLÓGICO O PERPETUANTE DE DISFUNCION DE ARTICULACION TEMPORO MANDIBULAR

OpenAIRE

López Aguilar, Abigail

2012-01-01

El propósito del presente trabajo fué valorar la prevalencia de pacientes con síntomas o signos de disfunción de la articulación Temporo mandibular y si existe relación entre esos síntomas o signos de DTM con el estrés. La muestra seleccionada estuvo integrada por pacientes que reunieron los criterios de selección. Se realizó la Historia clínica de Articulación Temporo Mandibular del Diplomado en prótesis fija, removible y oclusión de la Universidad Michoacana de San Nicolás...

Central and peripheral components of writing critically depend on a defined area of the dominant superior parietal gyrus.

Science.gov (United States)

Magrassi, Lorenzo; Bongetta, Daniele; Bianchini, Simonetta; Berardesca, Marta; Arienta, Cesare

2010-07-30

Classical neuropsychological models of writing separate central (linguistic) processes common to oral spelling, writing and typing from peripheral (motor) processes that are modality specific. Damage to the left superior parietal gyrus, an area of the cortex involved in peripheral processes specific to handwriting, should generate distorted graphemes but not misspelled words, while damage to other areas of the cortex like the frontal lobe should produce alterations in written and oral spelling without distorted graphemes. We describe the clinical and neuropsychological features of a patient with combined agraphia for handwriting and typewriting bearing a small glioblastoma in the left parietal lobe. His agraphia resolved after antiedema therapy and we tested by bipolar cortical stimulation his handwriting abilities during an awake neurosurgical procedure. We found that we could reversibly re-induce the same defects of writing by stimulating during surgery a limited area of the superior parietal gyrus in the same patient and in an independent patient that was never agraphic before the operation. In those patients stimulation caused spelling errors, poorly formed letters and in some cases a complete cessation of writing with minimal or no effects on oral spelling. Our results suggest that stimulating a specific area in the superior parietal gyrus we can generate different patterns of agraphia. Moreover, our findings also suggest that some of the central processes specific for typing and handwriting converge with motor processes at least in the limited portion of the superior parietal gyrus we mapped in our patients. Copyright 2010 Elsevier B.V. All rights reserved.

Parietal lesion effects on cued recall following pair associate learning.

Science.gov (United States)

Ben-Zvi, Shir; Soroker, Nachum; Levy, Daniel A

2015-07-01

We investigated the involvement of the posterior parietal cortex in episodic memory in a lesion-effects study of cued recall following pair-associate learning. Groups of patients who had experienced first-incident stroke, generally in middle cerebral artery territory, and exhibited damage that included lateral posterior parietal regions, were tested within an early post-stroke time window. In three experiments, patients and matched healthy comparison groups executed repeated study and cued recall test blocks of pairs of words (Experiment 1), pairs of object pictures (Experiment 2), or pairs of object pictures and environmental sounds (Experiment 3). Patients' brain CT scans were subjected to quantitative analysis of lesion volumes. Behavioral and lesion data were used to compute correlations between area lesion extent and memory deficits, and to conduct voxel-based lesion-symptom mapping. These analyses implicated lateral ventral parietal cortex, especially the angular gyrus, in cued recall deficits, most pronouncedly in the cross-modal picture-sound pairs task, though significant parietal lesion effects were also found in the unimodal word pairs and picture pairs tasks. In contrast to an earlier study in which comparable parietal lesions did not cause deficits in item recognition, these results indicate that lateral posterior parietal areas make a substantive contribution to demanding forms of recollective retrieval as represented by cued recall, especially for complex associative representations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transcranial direct current stimulation of the posterior parietal cortex modulates arithmetic learning.

Science.gov (United States)

Grabner, Roland H; Rütsche, Bruno; Ruff, Christian C; Hauser, Tobias U

2015-07-01

The successful acquisition of arithmetic skills is an essential step in the development of mathematical competencies and has been associated with neural activity in the left posterior parietal cortex (PPC). It is unclear, however, whether this brain region plays a causal role in arithmetic skill acquisition and whether arithmetic learning can be modulated by means of non-invasive brain stimulation of this key region. In the present study we addressed these questions by applying transcranial direct current stimulation (tDCS) over the left PPC during a short-term training that simulates the typical path of arithmetic skill acquisition (specifically the transition from effortful procedural to memory-based problem-solving strategies). Sixty participants received either anodal, cathodal or sham tDCS while practising complex multiplication and subtraction problems. The stability of the stimulation-induced learning effects was assessed in a follow-up test 24 h after the training. Learning progress was modulated by tDCS. Cathodal tDCS (compared with sham) decreased learning rates during training and resulted in poorer performance which lasted over 24 h after stimulation. Anodal tDCS showed an operation-specific improvement for subtraction learning. Our findings extend previous studies by demonstrating that the left PPC is causally involved in arithmetic learning (and not only in arithmetic performance) and that even a short-term tDCS application can modulate the success of arithmetic knowledge acquisition. Moreover, our finding of operation-specific anodal stimulation effects suggests that the enhancing effects of tDCS on learning can selectively affect just one of several cognitive processes mediated by the stimulated area. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

The contribution of the human posterior parietal cortex to episodic memory

OpenAIRE

Sestieri, Carlo; Shulman, Gordon L.; Corbetta, Maurizio

2017-01-01

The posterior parietal cortex (PPC) is traditionally associated with attention, perceptual decision making and sensorimotor transformations, but more recent human neuroimaging studies support an additional role in episodic memory retrieval. In this Opinion article, we present a functional–anatomical model of the involvement of the PPC in memory retrieval. Parietal regions involved in perceptual attention and episodic memory are largely segregated and often show a push–pull relationship, poten...

Positron emission tomographic localization of left-sided unilateral spatial agnosia

International Nuclear Information System (INIS)

Tagawa, Koichi; Nagata, Ken; Shishido, Fumio; Uemura, Kazuo

1986-01-01

Positron emission tomography (PET) was used to clarify the localization and the underlying mechanisms of left-sided unilateral spatial agnosia (LUSA). Eleven right-handed patients with cerebral infarction in the territory of the right middle cerebral artery who had LUSA were included in this study. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO 2 ) were measured with PET using 15 O steady state method. Sixteen right-handed patients with cerebral infarction who did not exhibit LUSA served as a control group. The mean local values of CBF and CMRO 2 in the control group were 37.4 ml/100 ml tissue/min and 2.66 ml/100 ml tissue/min, respectively. By contrast, those values of CBF and CMRO 2 in the patients with LUSA were 21.7 ml/100 ml tissue/min and 1.43 ml/100 ml tissue/min, respectively. Both CBF and CMRO 2 in the right posterior parietal region were significantly lower in the patients with LUSA as compared with the control group (p 2 between 1.8 and 2.2 ml/100 ml tissue/min. These ranges of CBF and CMRO 2 in the right parietal region were considered to include the threshold level producing LUSA. The CMRO 2 values were more stabilized in the course of cerebral infarction as compared with the CBF values which may be variable on account of luxury perfusion syndrome. The right posterior parietal CMRO 2 values less than 2.0 ml/100 ml tissue/min was considered to be critical in causing LUSA. The above results may suggest that severe damages of CBF and metabolism in the posterior part of the right parietal lobe play an important role in the occurrence of LUSA. (J.P.N.)

Anatomical Modularity of Verbal Working Memory? Functional Anatomical Evidence from a Famous Patient with Short-Term Memory Deficits

Directory of Open Access Journals (Sweden)

Eraldo Paulesu

2017-05-01

Full Text Available Cognitive skills are the emergent property of distributed neural networks. The distributed nature of these networks does not necessarily imply a lack of specialization of the individual brain structures involved. However, it remains questionable whether discrete aspects of high-level behavior might be the result of localized brain activity of individual nodes within such networks. The phonological loop of working memory, with its simplicity, seems ideally suited for testing this possibility. Central to the development of the phonological loop model has been the description of patients with focal lesions and specific deficits. As much as the detailed description of their behavior has served to refine the phonological loop model, a classical anatomoclinical correlation approach with such cases falls short in telling whether the observed behavior is based on the functions of a neural system resembling that seen in normal subjects challenged with phonological loop tasks or whether different systems have taken over. This is a crucial issue for the cross correlation of normal cognition, normal physiology, and cognitive neuropsychology. Here we describe the functional anatomical patterns of JB, a historical patient originally described by Warrington et al. (1971, a patient with a left temporo-parietal lesion and selective short phonological store deficit. JB was studied with the H215O PET activation technique during a rhyming task, which primarily depends on the rehearsal system of the phonological loop. No residual function was observed in the left temporo-parietal junction, a region previously associated with the phonological buffer of working memory. However, Broca's area, the major counterpart of the rehearsal system, was the major site of activation during the rhyming task. Specific and autonomous activation of Broca's area in the absence of afferent inputs from the other major anatomical component of the phonological loop shows that a certain

The self-liking brain: a VBM study on the structural substrate of self-esteem.

Science.gov (United States)

Agroskin, Dmitrij; Klackl, Johannes; Jonas, Eva

2014-01-01

Abundant evidence suggests that self-esteem is an important personality resource for emotion regulation in response to stressful experiences. It was thus hypothesized that the relative grey matter volume of brain regions involved in responding to and coping with stress is related to individual differences in trait self-esteem. Using structural magnetic resonance imaging of 48 healthy adults in conjunction with voxel-based morphometry and diffeomorphic anatomical registration using exponentiated lie algebra (VBM-DARTEL), positive associations between self-esteem and regional grey matter volume were indeed found in the anterior cingulate cortex (ACC), right lateral prefrontal cortex (LPFC), right hippocampus, and left hypothalamus. In addition, self-esteem positively covaried with grey matter volume in the right temporo-parietal junction (TPJ), which has been implicated in pride and theory of mind. The results suggest that persons with low self-esteem have reduced grey matter volume in brain regions that contribute to emotion/stress regulation, pride, and theory of mind. The findings provide novel neuroanatomical evidence for the view that self-esteem constitutes a vital coping resource.

Cultural influences on neural basis of intergroup empathy.

Science.gov (United States)

Cheon, Bobby K; Im, Dong-Mi; Harada, Tokiko; Kim, Ji-Sook; Mathur, Vani A; Scimeca, Jason M; Parrish, Todd B; Park, Hyun Wook; Chiao, Joan Y

2011-07-15

Cultures vary in the extent to which people prefer social hierarchical or egalitarian relations between individuals and groups. Here we examined the effect of cultural variation in preference for social hierarchy on the neural basis of intergroup empathy. Using cross-cultural neuroimaging, we measured neural responses while Korean and American participants observed scenes of racial ingroup and outgroup members in emotional pain. Compared to Caucasian-American participants, Korean participants reported experiencing greater empathy and elicited stronger activity in the left temporo-parietal junction (L-TPJ), a region previously associated with mental state inference, for ingroup compared to outgroup members. Furthermore, preferential reactivity within this region to the pain of ingroup relative to outgroup members was associated with greater preference for social hierarchy and ingroup biases in empathy. Together, these results suggest that cultural variation in preference for social hierarchy leads to cultural variation in ingroup-preferences in empathy, due to increased engagement of brain regions associated with representing and inferring the mental states of others. Copyright © 2011 Elsevier Inc. All rights reserved.

The Self-Liking Brain: A VBM Study on the Structural Substrate of Self-Esteem

Science.gov (United States)

Agroskin, Dmitrij; Klackl, Johannes; Jonas, Eva

2014-01-01

Abundant evidence suggests that self-esteem is an important personality resource for emotion regulation in response to stressful experiences. It was thus hypothesized that the relative grey matter volume of brain regions involved in responding to and coping with stress is related to individual differences in trait self-esteem. Using structural magnetic resonance imaging of 48 healthy adults in conjunction with voxel-based morphometry and diffeomorphic anatomical registration using exponentiated lie algebra (VBM-DARTEL), positive associations between self-esteem and regional grey matter volume were indeed found in the anterior cingulate cortex (ACC), right lateral prefrontal cortex (LPFC), right hippocampus, and left hypothalamus. In addition, self-esteem positively covaried with grey matter volume in the right temporo-parietal junction (TPJ), which has been implicated in pride and theory of mind. The results suggest that persons with low self-esteem have reduced grey matter volume in brain regions that contribute to emotion/stress regulation, pride, and theory of mind. The findings provide novel neuroanatomical evidence for the view that self-esteem constitutes a vital coping resource. PMID:24489727

The self-liking brain: a VBM study on the structural substrate of self-esteem.

Directory of Open Access Journals (Sweden)

Dmitrij Agroskin

Full Text Available Abundant evidence suggests that self-esteem is an important personality resource for emotion regulation in response to stressful experiences. It was thus hypothesized that the relative grey matter volume of brain regions involved in responding to and coping with stress is related to individual differences in trait self-esteem. Using structural magnetic resonance imaging of 48 healthy adults in conjunction with voxel-based morphometry and diffeomorphic anatomical registration using exponentiated lie algebra (VBM-DARTEL, positive associations between self-esteem and regional grey matter volume were indeed found in the anterior cingulate cortex (ACC, right lateral prefrontal cortex (LPFC, right hippocampus, and left hypothalamus. In addition, self-esteem positively covaried with grey matter volume in the right temporo-parietal junction (TPJ, which has been implicated in pride and theory of mind. The results suggest that persons with low self-esteem have reduced grey matter volume in brain regions that contribute to emotion/stress regulation, pride, and theory of mind. The findings provide novel neuroanatomical evidence for the view that self-esteem constitutes a vital coping resource.

[The transverse movement of the temporo-mandibular joint (translation movement) of the dog, also with reference to dysplasia of this joint in the dachshund].

Science.gov (United States)

Vollmerhaus, B; Roos, H

1996-09-01

Contrary to the accepted opinion, transverse movement is possible in the temporo-mandibular joint of the dog. This movement is arched and is important for mastication. Analysis of transverse movement of the temporo-mandibular joint was done in 20 dog breeds. Accidentally dysplasia of the temporo-mandibular joint was found in the dachshund, a phenomenon which has not been described before.

Faciobrachial dystonic seizures result from fronto-temporo-basalganglial network involvement.

Science.gov (United States)

Iyer, Rajesh Shankar; Ramakrishnan, T C R; Karunakaran; Shinto, Ajit; Kamaleshwaran, Koramadai Karuppuswamy

2017-01-01

•Faciobrachial dystonic seizures (FBDS) are caused by autoantibodies to leucine-rich glioma-inactivated1 proteins, a component of the voltage-gated potassium channel complex (VGKC-complex) and precede the clinical presentation of limbic encephalitis.•The exact pathophysiology of FBDS is not known and whether they are seizures or movement disorder is still debated.•We suggest the fronto-temporo-basal ganglia network involving the medial frontal and temporal regions along with the corpus striatum and substantia nigra being responsible for the clinical phenomenon of FBDS.•The varied clinical, electrical and imaging features of FBDS in our cases and in the literature are best explained by involvement of this network.•Entrainment from any part of this network will result in similar clinical expression of FBDS, whereas other electro-clinical associations and duration depends on the extent of involvement of the network.

Distinct Oscillatory Frequencies Underlie Excitability of Human Occipital and Parietal Cortex.

Science.gov (United States)

Samaha, Jason; Gosseries, Olivia; Postle, Bradley R

2017-03-15

Transcranial magnetic stimulation (TMS) of human occipital and posterior parietal cortex can give rise to visual sensations called phosphenes. We used near-threshold TMS with concurrent EEG recordings to measure how oscillatory brain dynamics covary, on single trials, with the perception of phosphenes after occipital and parietal TMS. Prestimulus power and phase, predominantly in the alpha band (8-13 Hz), predicted occipital TMS phosphenes, whereas higher-frequency beta-band (13-20 Hz) power (but not phase) predicted parietal TMS phosphenes. TMS-evoked responses related to phosphene perception were similar across stimulation sites and were characterized by an early (200 ms) posterior negativity and a later (>300 ms) parietal positivity in the time domain and an increase in low-frequency (∼5-7 Hz) power followed by a broadband decrease in alpha/beta power in the time-frequency domain. These correlates of phosphene perception closely resemble known electrophysiological correlates of conscious perception of near-threshold visual stimuli. The regionally differential pattern of prestimulus predictors of phosphene perception suggests that distinct frequencies may reflect cortical excitability in occipital versus posterior parietal cortex, calling into question the broader assumption that the alpha rhythm may serve as a general index of cortical excitability. SIGNIFICANCE STATEMENT Alpha-band oscillations are thought to reflect cortical excitability and are therefore ascribed an important role in gating information transmission across cortex. We probed cortical excitability directly in human occipital and parietal cortex and observed that, whereas alpha-band dynamics indeed reflect excitability of occipital areas, beta-band activity was most predictive of parietal cortex excitability. Differences in the state of cortical excitability predicted perceptual outcomes (phosphenes), which were manifest in both early and late patterns of evoked activity, revealing the time

Utility of the cerebral SPECT in schizophrenia

International Nuclear Information System (INIS)

Heuguerot, C.H.; Lopez-Lerena, J.J.; Quagliata, A.; Hermida, J.C.; Oliveira, M.C.; Anastasia, H.

2002-01-01

Objective: To compare cortical and subcortical cerebral perfusion in schizophrenics patients with normal controls, and analyze the relation to clinical patterns and neuroleptic treatment. Method: 18 patients meeting DSM-IV criteria for schizophrenia under neuroleptic treatment (except 3 cases), evaluated with clinical scales (BPRS and PANSS). The control group included 5 subjects in good health. All subjects were studied with single photon emission computed tomography (SPECT) using technetium-99 etilencisteinato (99mTc-ECD) as a tracer. Region of interest (ROI) were defined in cerebral cortex and thalamus-basal ganglia areas. The cortical cerebral blood flow was measured with a quantitative analysis, expressed as a ratio of regional tracer uptake to occipital cortex uptake. In basal ganglia and thalamus, regional blood flow was evaluated with a semiquantitative methodology, defining categories. Results: Schizophrenics patients showed a significant reduction of perfusion on a left anterior frontal cortex ('hipofrontality') and global decrease of perfusion on left hemisphere. The interhemispheric (left/right) ratio of perfusion was incremented respect control group. In thalamic-basal ganglia complex, a significant hypoperfusion was found in neuroleptic-free patients and control group. On the other hand, neuroleptic-treated patients revealed normal or increased regional blood flow in thalamus and basal ganglia. Only the clinical item 'thought disorder' had significant high correlation with perfusion on left structures (left anterior frontal, left lateral frontal, left temporo-parietal); the other items correlated with right structures. Conclusions: The findings suggest a pattern o left cerebral hypoperfusion in patients with an incremented interhemispheric ratio of cerebral blood flow. The pivotal role of thalamic and basal ganglia areas in the pathophysiology of schizophrenia and neuroleptic action was reaffirmed; apparently, perfusion in thalamic-basal ganglia

Separating recognition processes of declarative memory via anodal tDCS: boosting old item recognition by temporal and new item detection by parietal stimulation.

Science.gov (United States)

Pisoni, Alberto; Turi, Zsolt; Raithel, Almuth; Ambrus, Géza Gergely; Alekseichuk, Ivan; Schacht, Annekathrin; Paulus, Walter; Antal, Andrea

2015-01-01

There is emerging evidence from imaging studies that parietal and temporal cortices act together to achieve successful recognition of declarative information; nevertheless, the precise role of these regions remains elusive. To evaluate the role of these brain areas in declarative memory retrieval, we applied bilateral tDCS, with anode over the left and cathode over the right parietal or temporal cortices separately, during the recognition phase of a verbal learning paradigm using a balanced old-new decision task. In a parallel group design, we tested three different groups of healthy adults, matched for demographic and neurocognitive status: two groups received bilateral active stimulation of either the parietal or the temporal cortex, while a third group received sham stimulation. Accuracy, discriminability index (d') and reaction times of recognition memory performance were measurements of interest. The d' sensitivity index and accuracy percentage improved in both active stimulation groups, as compared with the sham one, while reaction times remained unaffected. Moreover, the analysis of accuracy revealed a different effect of tDCS for old and new item recognition. While the temporal group showed enhanced performance for old item recognition, the parietal group was better at correctly recognising new ones. Our results support an active role of both of these areas in memory retrieval, possibly underpinning different stages of the recognition process.

The preliminary study of 18F-FDG brain PET in diagnosis of alzheimer's disease

International Nuclear Information System (INIS)

Ma Yunchuan; Zhang Xinqing; Li Depeng; Shang Jianwen; Su Yusheng; Zhang Linying; Peng Cheng; Pan Zhongyun

2000-01-01

Objective: To investigate the imaging characteristics and diagnostic criteria of 18 F-FDG brain PET in diagnosis of Alzheimer's disease (AD). Methods: The sutdy included 12 normal subjects, 12 patients with AD and 11 patients with non-AD dementia. 40 min after intravenous administration of 18 F-FDG, brain scan was performed using Siemens ECAT47 scanner. The transaxial, coronal and sagittal images were then reconstructed by computer. At the same time, semiquantitative analysis was also applied to help evaluation using the ratio of mean radioactivity of cerebral lobe to cerebellum (R cl/cb ). Results: In normal subjects PET scan showed clear images of cerebral cortex, basal ganglia, thalamus and cerebellum with symmetrical distribution of radioactivity. PET images from Alzheimer's disease patients were classified into 3 patterns: bilateral parietal hypometabolism in 5 cases, bilateral temporo-parietal hypometabolism in 4 cases and unilateral temporo-parietal hypometabolism in 3 cases. The R cl/cb of AD patients in parietal and temporal lobe was significantly decreased than normal subjects (P cl/cb was also reflecting thedementia degree. Compared with MRI imaging , 12 patients with AD had cerebral hypometabolism but only 10 had hippocampus atrophy. 10 patients with non-AD dementia had local structural foci seen in MRI, including old hemorrhage, infarction and encephalomalacia, but these lesions were not found in AD. Conclusions: Based on excluding cerebral structural lesions which are better detected by MRI, bilateral or unilateral parietal or temporo-parietal hypometabolism found in FDG PET can be considered indicative of Alzheimer's disease. Semiquantitative analysis of the images yielded can help to evaluate the dementia degree

Specialization in the default mode: Task-induced brain deactivations dissociate between visual working memory and attention.

Science.gov (United States)

Mayer, Jutta S; Roebroeck, Alard; Maurer, Konrad; Linden, David E J

2010-01-01

The idea of an organized mode of brain function that is present as default state and suspended during goal-directed behaviors has recently gained much interest in the study of human brain function. The default mode hypothesis is based on the repeated observation that certain brain areas show task-induced deactivations across a wide range of cognitive tasks. In this event-related functional resonance imaging study we tested the default mode hypothesis by comparing common and selective patterns of BOLD deactivation in response to the demands on visual attention and working memory (WM) that were independently modulated within one task. The results revealed task-induced deactivations within regions of the default mode network (DMN) with a segregation of areas that were additively deactivated by an increase in the demands on both attention and WM, and areas that were selectively deactivated by either high attentional demand or WM load. Attention-selective deactivations appeared in the left ventrolateral and medial prefrontal cortex and the left lateral temporal cortex. Conversely, WM-selective deactivations were found predominantly in the right hemisphere including the medial-parietal, the lateral temporo-parietal, and the medial prefrontal cortex. Moreover, during WM encoding deactivated regions showed task-specific functional connectivity. These findings demonstrate that task-induced deactivations within parts of the DMN depend on the specific characteristics of the attention and WM components of the task. The DMN can thus be subdivided into a set of brain regions that deactivate indiscriminately in response to cognitive demand ("the core DMN") and a part whose deactivation depends on the specific task. 2009 Wiley-Liss, Inc.

Correlation of neuropsychological and metabolic changes after epilepsy surgery in patients with left mesial temporal lobe epilepsy with hippocampal sclerosis.

Science.gov (United States)

Güvenç, Canan; Dupont, Patrick; Van den Stock, Jan; Seynaeve, Laura; Porke, Kathleen; Dries, Eva; Van Bouwel, Karen; van Loon, Johannes; Theys, Tom; Goffin, Karolien E; Van Paesschen, Wim

2018-04-12

Epilepsy surgery often causes changes in cognition and cerebral glucose metabolism. Our aim was to explore relationships between pre- and postoperative cerebral metabolism as measured with 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) and neuropsychological test scores in patients with left mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), who were rendered seizure-free after epilepsy surgery. Thirteen patients were included. All had neuropsychological testing and an interictal FDG-PET scan of the brain pre- and postoperative. Correlations between changes in neuropsychological test scores and metabolism were examined using statistical parametric mapping (SPM). There were no significant changes in the neuropsychological test scores pre- and postoperatively at the group level. Decreased metabolism was observed in the left mesial temporal regions and occipital lobe. Increased metabolism was observed in the bi-frontal and right parietal lobes, temporal lobes, occipital lobes, thalamus, cerebellum, and vermis. In these regions, we did not find a correlation between changes in metabolism and neuropsychological test scores. A significant negative correlation, however, was found between metabolic changes in the precuneus and Boston Naming Test (BNT) scores. There are significant metabolic decreases in the left mesial temporal regions and increases in the bi-frontal lobes; right parietal, temporal, and occipital lobes; right thalamus; cerebellum; and vermis in patients with left MTLE-HS who were rendered seizure-free after epilepsy surgery. We could not confirm that these changes translate into significant cognitive changes. A significant negative correlation was found between changes in confrontation naming and changes in metabolism in the precuneus. We speculate that the precuneus may play a compensatory role in patients with postoperative naming difficulties after left TLE surgery. Understanding of these neural mechanisms may aid in

[Benign tumors and pseudotumors of temporo-mandibular joint: radiologic aspects].

Science.gov (United States)

Izzo, L; Caputo, M; Buffone, A; Casullo, A; Perrone, A; Sassi, S; Impara, L; Luppi, G; Mazza, D; Marini, Marina

2005-01-01

Benign tumors and tumor-like lesions that involve temporo mandibular joint are very rare. Those more frequent are osteochondroma, chondroma, osteoma, pigmented villonodular synovitis and synovial chondromatosis. The Authors report six cases of patients affected by these pathologies in which imaging, such as TC, MRI and/or ortopantomography have been useful to have a diagnosis.

Parietal and premotor cortices: activation reflects imitation accuracy during observation, delayed imitation and concurrent imitation.

Science.gov (United States)

Krüger, Britta; Bischoff, Matthias; Blecker, Carlo; Langhanns, Christine; Kindermann, Stefan; Sauerbier, Isabell; Reiser, Mathias; Stark, Rudolf; Munzert, Jörn; Pilgramm, Sebastian

2014-10-15

This study investigated whether activation within areas belonging to the action observation and imitation network reveals a linear relation to the subsequent accuracy of imitating a bimanual rhythmic movement measured via a motion capturing system. 20 participants were scanned with functional magnetic resonance imaging (fMRI) when asked to imitate observed bimanual movements either concurrently versus with a delay (2s) or simply to observe the movements without imitation. Results showed that action observation relates to activation within classic mirror-related areas. Activation patterns were more widespread when participants were asked to imitate the movement. During observation with concurrent imitation, activation in the left inferior parietal lobe (IPL) was associated negatively with imitation accuracy. During observation in the delayed imitation condition, higher subsequent imitation accuracy was coupled with higher activation in the right superior parietal lobe (SPL) and the left parietal operculum (POp). During the delayed imitation itself, a negative association between imitation accuracy and brain activation was revealed in the right ventral premotor cortex (vPMC). We conclude that the IPL is involved in online comparison and visuospatial attention processes during imitation, the SPL provides a kinesthetic blueprint during movement observation, the POp preserves body identity, and the vPMC recruits motor representations--especially when no concurrent visual guidance is possible. Copyright © 2014 Elsevier Inc. All rights reserved.

Parietal podocytes in normal human glomeruli.

Science.gov (United States)

Bariety, Jean; Mandet, Chantal; Hill, Gary S; Bruneval, Patrick

2006-10-01

Although parietal podocytes along the Bowman's capsule have been described by electron microscopy in the normal human kidney, their molecular composition remains unknown. Ten human normal kidneys that were removed for cancer were assessed for the presence and the extent of parietal podocytes along the Bowman's capsule. The expression of podocyte-specific proteins (podocalyxin, glomerular epithelial protein-1, podocin, nephrin, synaptopodin, and alpha-actinin-4), podocyte synthesized proteins (vascular endothelial growth factor and novH), transcription factors (WT1 and PAX2), cyclin-dependent kinase inhibitor p57, and intermediate filaments (cytokeratins and vimentin) was tested. In addition, six normal fetal kidneys were studied to track the ontogeny of parietal podocytes. The podocyte protein labeling detected parietal podocytes in all of the kidneys, was found in 76.6% on average of Bowman's capsule sections, and was prominent at the vascular pole. WT1 and p57 were expressed in some parietal cells, whereas PAX2 was present in all or most of them, so some parietal cells coexpressed WT1 and PAX2. Furthermore, parietal podocytes coexpressed WT1 and podocyte proteins. Cytokeratin-positive cells covered a variable part of the capsule and did not express podocyte proteins. Tuft-capsular podocyte bridges were present in 15.5 +/- 3.7% of the glomerular sections. Parietal podocytes often covered the juxtaglomerular arterioles and were present within the extraglomerular mesangium. Parietal podocytes were present in fetal kidneys. Parietal podocytes that express the same epitopes as visceral podocytes do exist along Bowman's capsule in the normal adult kidney. They are a constitutive cell type of the Bowman's capsule. Therefore, their role in physiology and pathology should be investigated.

Investigating the effects of nitrous oxide sedation on frontal-parietal interactions.

Science.gov (United States)

Ryu, Ji-Ho; Kim, Pil-Jong; Kim, Hong-Gee; Koo, Yong-Seo; Shin, Teo Jeon

2017-06-09

Although functional connectivity has received considerable attention in the study of consciousness, few studies have investigated functional connectivity limited to the sedated state where consciousness is maintained but impaired. The aim of the present study was to investigate changes in functional connectivity of the parietal-frontal network resulting from nitrous oxide-induced sedation, and to determine the neural correlates of cognitive impairment during consciousness transition states. Electroencephalography was acquired from healthy adult patients who underwent nitrous oxide inhalation to induce cognitive impairment, and was analyzed using Granger causality (GC). Periods of awake, sedation and recovery for GC between frontal and parietal areas in the delta, theta, alpha, beta, gamma and total frequency bands were obtained. The Friedman test with post-hoc analysis was conducted for GC values of each period for comparison. As a sedated state was induced by nitrous oxide inhalation, power in the low frequency band showed increased activity in frontal regions that was reversed with discontinuation of nitrous oxide. Feedback and feedforward connections analyzed in spectral GC were changed differently in accordance with EEG frequency bands in the sedated state by nitrous oxide administration. Calculated spectral GC of the theta, alpha, and beta frequency regions in the parietal-to-frontal direction was significantly decreased in the sedated state while spectral GC in the reverse direction did not show significant change. Frontal-parietal functional connectivity is significantly affected by nitrous oxide inhalation. Significantly decreased parietal-to-frontal interaction may induce a sedated state. Copyright © 2017 Elsevier B.V. All rights reserved.

Short parietal lobe connections of the human and monkey brain

DEFF Research Database (Denmark)

Catani, Marco; Robertsson, Naianna; Beyh, Ahmad

2017-01-01

projections were reconstructed for both species and results compared to identify similarities or differences in tract anatomy (i.e., trajectories and cortical projections). In addition, post-mortem dissections were performed in a human brain. The largest tract identified in both human and monkey brains...... and angular gyri of the inferior parietal lobule in humans but only to the supramarginal gyrus in the monkey brain. The third tract connects the postcentral gyrus to the anterior region of the superior parietal lobule and is more prominent in monkeys compared to humans. Finally, short U-shaped fibres...... and monkeys with some differences for those areas that have cytoarchitectonically distinct features in humans. The overall pattern of intraparietal connectivity supports the special role of the inferior parietal lobule in cognitive functions characteristic of humans....

The inferior parietal lobule and recognition memory : expectancy violation or successful retrieval?

OpenAIRE

O'Connor, Akira R.; Han, Sanghoon; Dobbins, Ian G.

2010-01-01

Functional neuroimaging studies of episodic recognition demonstrate an increased lateral parietal response for studied versus new materials, often termed a retrieval success effect. Using a novel memory analog of attentional cueing, we manipulated the correspondence between anticipated and actual recognition evidence by presenting valid or invalid anticipatory cues (e. g., "likely old") before recognition judgments. Although a superior parietal region demonstrated the retrieval success patter...

The preliminary study of {sup 18}F-FDG PET in diagnosis of Alzheimer's disease

Energy Technology Data Exchange (ETDEWEB)

Ma, Y.; Zhang, X.; Le, D. [Capital Univ. of Medical Sciences, Beijing (Switzerland)] [and others

2000-07-01

hypometabloic region was. The Rcl/cb can also be indicated the dementia degree. Compared with MR imaging, 12 patients with AD had cerebral hypo metabolism but only 10 had hippocampus atrophy. 10 patients with non-AD dementia had local structural foci which were seen in MR, including old hemorrhage infarction and encephalomalacia, but these lesions were not found in AD. 1 patient with mild LBD was both negative PET and MR. Based on excluding cerebral structural lesions which are better detected by MR, bilateral or unilateral parietal or temporo-parietal hypo metabolism found in FDG PET are considered as indicative of Alxhemer's disease. Semiquantitative analysis can help to evaluate dementia degree.

Bilateral parietal extradural metastatic ewing's sarcoma simulating acute epidural hematoma

International Nuclear Information System (INIS)

Aslam, E.; Imran, M.; Faridi, N.M.

2006-01-01

Sarcomas usually metastasize to lugs. The following case report describes an unusual metastasis of Ewing's sarcoma to extradural parietal region bilaterally. The primary was found at lower end of ulna. (author)

Visual Categorization and the Parietal Cortex

Directory of Open Access Journals (Sweden)

Jamie K Fitzgerald

2012-05-01

Full Text Available The primate brain is adept at rapidly grouping items and events into functional classes, or categories, in order to recognize the significance of stimuli and guide behavior. Higher cognitive functions have traditionally been considered the domain of frontal areas. However, increasing evidence suggests that parietal cortex is also involved in categorical and associative processes. Previous work showed that the parietal cortex is highly involved in spatial processing, attention and saccadic eye movement planning, and more recent studies have found decision-making signals in LIP. We recently found that a subdivision of parietal cortex, the lateral intraparietal area (LIP, reflects learned categories for multiple types of visual stimuli. Additionally, a comparison of categorization signals in parietal and frontal areas found stronger and earlier categorization signals in parietal cortex, arguing that parietal abstract association or category signals are unlikely to arise via feedback from prefrontal cortex (PFC.

Increased gray matter density in the parietal cortex of mathematicians: a voxel-based morphometry study.

Science.gov (United States)

Aydin, K; Ucar, A; Oguz, K K; Okur, O O; Agayev, A; Unal, Z; Yilmaz, S; Ozturk, C

2007-01-01

The training to acquire or practicing to perform a skill, which may lead to structural changes in the brain, is called experience-dependent structural plasticity. The main purpose of this cross-sectional study was to investigate the presence of experience-dependent structural plasticity in mathematicians' brains, which may develop after long-term practice of mathematic thinking. Twenty-six volunteer mathematicians, who have been working as academicians, were enrolled in the study. We applied an optimized method of voxel-based morphometry in the mathematicians and the age- and sex-matched control subjects. We assessed the gray and white matter density differences in mathematicians and the control subjects. Moreover, the correlation between the cortical density and the time spent as an academician was investigated. We found that cortical gray matter density in the left inferior frontal and bilateral inferior parietal lobules of the mathematicians were significantly increased compared with the control subjects. Furthermore, increase in gray matter density in the right inferior parietal lobule of the mathematicians was strongly correlated with the time spent as an academician (r = 0.84; P mathematicians' brains revealed increased gray matter density in the cortical regions related to mathematic thinking. The correlation between cortical density increase and the time spent as an academician suggests experience-dependent structural plasticity in mathematicians' brains.

Resting-state, functional MRI on regional homogeneity changes of brain in the heavy smokers

International Nuclear Information System (INIS)

Yang Shiqi; Wu Guangyao; Lin Fuchun; Kong Xiangquan; Zhou Guofeng; Pang Haopeng; Zhu Ling; Liu Guobing; Lei Hao

2012-01-01

Objective: To explore the mechanism of self-awareness in the heavy smokers (HS) by using regional homogeneity (ReHo) combined with resting-state functional MRI (fMRI). Methods: Thirty HS and 31 healthy non-smokers (NS) matched for age and sex underwent a 3.0 T resting-state fMRI. The data were post-processed by SPM 5 and then the ReHo values were calculated by REST software. The ReHo values between the two groups were compared by two-sample t-test. The brain map with significant difference of ReHo value was obtained. Results: Compared with that in NS group, the regions with decreased ReHo value included the bilateral precuneus, superior frontal gyrus,medial prefrontal cortex, right angular gyrus, inferior frontal gyrus, inferior occipital gyrus, cerebellum, and left middle frontal gyrus in HS group. The regions of increased ReHo value included the bilateral insula, parahippocampal gyrus, white matter of parietal lobe, pons, left inferior parietal lobule, lingual gyrus, thalamus, inferior orbital gyrus, white matter of temporal-frontal lobe, and cerebellum. The difference was more obvious in the left hemisphere. Conclusions: In HS, abnormal ReHo on a resting state which reflects network of smoking addiction. This method may be helpful in understanding the mechanism of self-awareness in HS. (authors)

Differential Recruitment of Parietal Cortex during Spatial and Non-spatial Reach Planning

Directory of Open Access Journals (Sweden)

Pierre-Michel Bernier

2017-05-01

Full Text Available The planning of goal-directed arm reaching movements is associated with activity in the dorsal parieto-frontal cortex, within which multiple regions subserve the integration of arm- and target-related sensory signals to encode a motor goal. Surprisingly, many of these regions show sustained activity during reach preparation even when target location is not specified, i.e., when a motor goal cannot be unambiguously formed. The functional role of these non-spatial preparatory signals remains unresolved. Here this process was investigated in humans by comparing reach preparatory activity in the presence or absence of information regarding upcoming target location. In order to isolate the processes specific to reaching and to control for visuospatial attentional factors, the reaching task was contrasted to a finger movement task. Functional MRI and electroencephalography (EEG were used to characterize the spatio-temporal pattern of reach-related activity in the parieto-frontal cortex. Reach planning with advance knowledge of target location induced robust blood oxygenated level dependent and EEG responses across parietal and premotor regions contralateral to the reaching arm. In contrast, reach preparation without knowledge of target location was associated with a significant BOLD response bilaterally in the parietal cortex. Furthermore, EEG alpha- and beta-band activity was restricted to parietal scalp sites, the magnitude of the latter being correlated with reach reaction times. These results suggest an intermediate stage of sensorimotor transformations in bilateral parietal cortex when target location is not specified.

Temporo-mandibular joint disease in ankylosing spondylitis.

Science.gov (United States)

Davidson, C; Wojtulewski, J A; Bacon, P A; Winstock, D

1975-01-01

The occurrence of temporo-mandibular joint (TMJ) disease in ankylosing spondylitis is not widely recognized and its incidence is disputed. Seventy-nine patients attending two routine rheumatology clinics were therefore examined by dental surgeon and nine (11-5 per cent) were considered to have specific TMJ involvement. These patients were older than the remainder, and had more extensive spinal and peripheral joint disease. Symptoms were mild and the predominant clinical feature was restricted mouth opening, which could present considerable difficulties during emergency anaesthesia. Bilateral condylectomy was undertaken in one patient with some benefit. Images PMID:1124959

Temporo-mandibular joint kinetics and chewing cycles in children. A 3-year follow-up.

Science.gov (United States)

Bodin, C; Lodetti, G; Marinone, M G

2002-01-01

To report the temporo-mandibular joint (TMJ) kinetics and masticatory function in healthy children. Temporo-mandibular joint palpation and electrognathographic registrations of chewing cycles were repeated for 3 years in order to evaluate changes. Healthy children without systemic pathologies, decayed cavities and previous dental treatment. Electrognathographic (EGN) registration of masticatory cycles and TMJ palpation were carried out on 52 patients (mean age: 5 years 8 months, range: 5 years 1 month, 6 years 8 months), by two university researchers, once a year for 3 consecutive years. TMJ palpation, differentiated TMJ synchronism (simultaneous bilateral opening movement) and TMJ asynchronism (not simultaneous bilateral opening movement), TMJ subluxation and click were observed. Electrognathographic registrations differentiated normal and abnormal jaw chewing cycles, and narrow and large cycles. Temporo-mandibular joint asynchronism was evident in 34 of 52 patients in the primary dentition, in 42 of 52 patients after the eruption of the first permanent molar, and in 31 of 52 patients after the eruption of the permanent incisors. TMJ subluxation increased during the full period of observation. Three temporomandibular clicks appeared after the eruption of the permanent incisors. Altered mastication was not always associated with TMJ disorders. In children, normal chewing cycles can coexist with occlusal discrepancies, cranio-facial growth and TMJ alterations.

Independent component processes underlying emotions during natural music listening.

Science.gov (United States)

Rogenmoser, Lars; Zollinger, Nina; Elmer, Stefan; Jäncke, Lutz

2016-09-01

The aim of this study was to investigate the brain processes underlying emotions during natural music listening. To address this, we recorded high-density electroencephalography (EEG) from 22 subjects while presenting a set of individually matched whole musical excerpts varying in valence and arousal. Independent component analysis was applied to decompose the EEG data into functionally distinct brain processes. A k-means cluster analysis calculated on the basis of a combination of spatial (scalp topography and dipole location mapped onto the Montreal Neurological Institute brain template) and functional (spectra) characteristics revealed 10 clusters referring to brain areas typically involved in music and emotion processing, namely in the proximity of thalamic-limbic and orbitofrontal regions as well as at frontal, fronto-parietal, parietal, parieto-occipital, temporo-occipital and occipital areas. This analysis revealed that arousal was associated with a suppression of power in the alpha frequency range. On the other hand, valence was associated with an increase in theta frequency power in response to excerpts inducing happiness compared to sadness. These findings are partly compatible with the model proposed by Heller, arguing that the frontal lobe is involved in modulating valenced experiences (the left frontal hemisphere for positive emotions) whereas the right parieto-temporal region contributes to the emotional arousal. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

Characterization of visual percepts evoked by noninvasive stimulation of the human posterior parietal cortex.

Directory of Open Access Journals (Sweden)

Peter J Fried

Full Text Available Phosphenes are commonly evoked by transcranial magnetic stimulation (TMS to study the functional organization, connectivity, and excitability of the human visual brain. For years, phosphenes have been documented only from stimulating early visual areas (V1-V3 and a handful of specialized visual regions (V4, V5/MT+ in occipital cortex. Recently, phosphenes were reported after applying TMS to a region of posterior parietal cortex involved in the top-down modulation of visuo-spatial processing. In the present study, we systematically characterized parietal phosphenes to determine if they are generated directly by local mechanisms or emerge through indirect activation of other visual areas. Using technology developed in-house to record the subjective features of phosphenes, we found no systematic differences in the size, shape, location, or frame-of-reference of parietal phosphenes when compared to their occipital counterparts. In a second experiment, discrete deactivation by 1 Hz repetitive TMS yielded a double dissociation: phosphene thresholds increased at the deactivated site without producing a corresponding change at the non-deactivated location. Overall, the commonalities of parietal and occipital phosphenes, and our ability to independently modulate their excitability thresholds, lead us to conclude that they share a common neural basis that is separate from either of the stimulated regions.

Object integration requires attention: Visual search for Kanizsa figures in parietal extinction.

Science.gov (United States)

Gögler, Nadine; Finke, Kathrin; Keller, Ingo; Müller, Hermann J; Conci, Markus

2016-11-01

The contribution of selective attention to object integration is a topic of debate: integration of parts into coherent wholes, such as in Kanizsa figures, is thought to arise either from pre-attentive, automatic coding processes or from higher-order processes involving selective attention. Previous studies have attempted to examine the role of selective attention in object integration either by employing visual search paradigms or by studying patients with unilateral deficits in selective attention. Here, we combined these two approaches to investigate object integration in visual search in a group of five patients with left-sided parietal extinction. Our search paradigm was designed to assess the effect of left- and right-grouped nontargets on detecting a Kanizsa target square. The results revealed comparable reaction time (RT) performance in patients and controls when they were presented with displays consisting of a single to-be-grouped item that had to be classified as target vs. nontarget. However, when display size increased to two items, patients showed an extinction-specific pattern of enhanced RT costs for nontargets that induced a partial shape grouping on the right, i.e., in the attended hemifield (relative to the ungrouped baseline). Together, these findings demonstrate a competitive advantage for right-grouped objects, which in turn indicates that in parietal extinction, attentional competition between objects particularly limits integration processes in the contralesional, i.e., left hemifield. These findings imply a crucial contribution of selective attentional resources to visual object integration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Spatial imagery relies on a sensory independent, though sensory sensitive, functional organization within the parietal cortex: a fMRI study of angle discrimination in sighted and congenitally blind individuals.

Science.gov (United States)

Bonino, Daniela; Ricciardi, Emiliano; Bernardi, Giulio; Sani, Lorenzo; Gentili, Claudio; Vecchi, Tomaso; Pietrini, Pietro

2015-02-01

Although vision offers distinctive information to space representation, individuals who lack vision since birth often show perceptual and representational skills comparable to those found in sighted individuals. However, congenitally blind individuals may result in impaired spatial analysis, when engaging in 'visual' spatial features (e.g., perspective or angle representation) or complex spatial mental abilities. In the present study, we measured behavioral and brain responses using functional magnetic resonance imaging in sighted and congenitally blind individuals during spatial imagery based on a modified version of the mental clock task (e.g., angle discrimination) and a simple recognition control condition, as conveyed across distinct sensory modalities: visual (sighted individuals only), tactile and auditory. Blind individuals were significantly less accurate during the auditory task, but comparable-to-sighted during the tactile task. As expected, both groups showed common neural activations in intraparietal and superior parietal regions across visual and non-visual spatial perception and imagery conditions, indicating the more abstract, sensory independent functional organization of these cortical areas, a property that we named supramodality. At the same time, however, comparisons in brain responses and functional connectivity patterns across experimental conditions demonstrated also a functional lateralization, in a way that correlated with the distinct behavioral performance in blind and sighted individuals. Specifically, blind individuals relied more on right parietal regions, mainly in the tactile and less in the auditory spatial processing. In sighted, spatial representation across modalities relied more on left parietal regions. In conclusions, intraparietal and superior parietal regions subserve supramodal spatial representations in sighted and congenitally blind individuals. Differences in their recruitment across non-visual spatial processing in

Quantitative description of the regional mechanics of the left atria by electroanatomical mapping

International Nuclear Information System (INIS)

Kuklik, Pawel; Molaee, Payman; Brooks, Anthony G; John, Bobby; Worthley, Stephen G; Sanders, Prashanthan

2010-01-01

The left atrium is a complex chamber, which plays an integral role in the maintenance of physiologic hemodynamic and electrical stability of the heart and is involved in many disease states, most commonly atrial fibrillation. Preserving regions of the left atrium that contribute the greatest to atrial mechanical function during curative strategies for atrial fibrillation are important. We present here a new application of the CARTO electroanatomical mapping system in the assessment of the left atria mechanical function. Electroanatomical data were collected in course of the electrophysiological procedure in 11 control patients and 12 patients with paroxysmal atrial fibrillation. The three-dimensional geometry of the left atria was reconstructed in 10 ms intervals and segmented into distinct regions. For each segment, a regional ejection fraction was calculated. We found that anterior, septal and lateral segments have significantly greater regional ejection fraction than atria roof, inferior and posterior segments. Therefore, we hypothesize that in order to minimize the impact on atrial mechanical function, an important determinant of thromboembolic risk, damage should be minimized to these atrial regions

Left-right cortical asymmetries of regional cerebral blood flow during listening to words

DEFF Research Database (Denmark)

Nishizawa, Y; Olsen, T S; Larsen, B

1982-01-01

1. Regional cerebral blood flow (rCBF) was measured during rest and during listening to simple words. The xenon-133 intracarotid technique was used and results were obtained from 254 regions of seven right hemispheres and seven left hemispheres. The measurements were performed just after carotid...... of the entire hemisphere. The focal rCBF increases were localized to the superior part of the temporal regions, the prefrontal regions, the frontal eye fields, and the orbitofrontal regions. Significant asymmetries were found in particular in the superior temporal region with the left side showing a more...

The Oft-Neglected Role of Parietal EEG Asymmetry and Risk for Major Depressive Disorder

Science.gov (United States)

Stewart, Jennifer L.; Towers, David N.; Coan, James A.; Allen, John J.B.

2010-01-01

Relatively less right parietal activity may reflect reduced arousal and signify risk for major depressive disorder (MDD). Inconsistent findings with parietal electroencephalographic (EEG) asymmetry, however, suggest issues such as anxiety comorbidity and sex differences have yet to be resolved. Resting parietal EEG asymmetry was assessed in 306 individuals (31% male) with (n = 143) and without (n = 163) a DSM-IV diagnosis of lifetime MDD and no comorbid anxiety disorders. Past MDD+ women displayed relatively less right parietal activity than current MDD+ and MDD- women, replicating prior work. Recent caffeine intake, an index of arousal, moderated the relationship between depression and EEG asymmetry for women and men. Findings suggest that sex differences and arousal should be examined in studies of depression and regional brain activity. PMID:20525011

Regional cerebral blood flow in childhood autism: a SPET study with SPM evaluation.

Science.gov (United States)

Burroni, Luca; Orsi, Alessandra; Monti, Lucia; Hayek, Youssef; Rocchi, Raffaele; Vattimo, Angelo G

2008-02-01

To establish a link between rCBF assessed with Tc-ECD SPET and the clinical manifestation of the disease. We performed the study on 11 patients (five girls and six boys; mean age 11.2 years) displaying autistic behaviour and we compared their data with that of an age-matched reference group of eight normal children. A quantitative analysis of rCBF was performed calculating a perfusion index (PI) and an asymmetry index (AI) in each lobe. Images were analysed with statistical parametric mapping software, following the spatial normalization of SPET images for a standard brain. A statistically significant (P=0.003) global reduction of CBF was found in the group of autistic children (PI=1.07+/-0.07) when compared with the reference group (PI=1.25+/-0.12). Moreover, a significant difference was also observed for the right-to-left asymmetry of hemispheric perfusion between the control group and autistic patients (P=0.0085) with a right prevalence greater in autistic (2.90+/-1.68) with respect to normal children (1.12+/-0.49). Our data show a significant decrease of global cerebral perfusion in autistic children in comparison with their normal counterparts and the existence of left-hemispheric dysfunction, especially in the temporo-parietal areas devoted to language and the comprehension of music and sounds. We suggest that these abnormal areas are related to the cognitive impairment observed in autistic children, such as language deficits, impairment of cognitive development and object representation, and abnormal perception and responses to sensory stimuli. Tc-ECD SPET seems to be sensitive in revealing brain blood flow alterations and left-to-right asymmetries, when neuroradiological patterns are normal.

[Comparative evolution surgical accesses to temporo-mandibular joint].

Science.gov (United States)

Sysoliatin, P G; Novikov, A I; Sysoliatin, S P; Bobylev, N G; Brega, I N

2007-01-01

In experiment on 30 corpses of adult people criteria of an operational wound (depth of a wound, a corner of operational action, an axis of operational action, a corner of an inclination of operational action) were studied at preauricularis, intrauricularis, intrauriculo-temporalis and posterior mandibullaris access to temporo-mandibular joint (TMJ). New surgical intrauriculo-temporalis access to the joint is substantrated. On the basis of the analysis of 289 operations at 268 patients the indications to a choice of surgical access were developed at various diseases and damages of TMJ.

[Formed visual hallucination after excision of the right temporo parietal cystic meningioma--a case report].

Science.gov (United States)

Yoshimura, Masaki; Uchiyama, Yoshinori; Kaneko, Akira; Hayashi, Noriko; Yamanaka, Kazuhiro; Iwai, Yoshiyasu

2010-08-01

We report the case of a 64-year-old woman with cystic meningioma; this patients was otherwise healthy and experienced formed visual hallucinations after excision of the tumor. She experienced diplopia associated with metamorphopsia, which had persisted for 5 years only when she laid down and turned on her left side. After the excision of the convexity meningioma located in the right temporoparietal lobe, she experienced several types of formed visual hallucinations such as closet-like pictures, flowers sketched on stones, falling maple-like leaves, and moving or wriggling dwarves. She was alert and her visual field was normal; further, she did not experience delirium or seizures. She experienced these hallucinations only when she closed her eyes; these hallucinations persisted for 3 days after the operation. The patient illustrated her observations with beautiful sketches, and the mechanism of visual hallucinations was studied.

In-vivo measurements of regional acetylcholine esterase activity in degenerative dementia: comparison with blood flow and glucose metabolism.

Science.gov (United States)

Herholz, K; Bauer, B; Wienhard, K; Kracht, L; Mielke, R; Lenz, M O; Strotmann, T; Heiss, W D

2000-01-01

Memory and attention are cognitive functions that depend heavily on the cholinergic system. Local activity of acetylcholine esterase (AChE) is an indicator of its integrity. Using a recently developed tracer for positron emission tomography (PET), C-11-labeled N-methyl-4-piperidyl-acetate (C11-MP4A), we measured regional AChE activity in 4 non-demented subjects, 4 patients with dementia of Alzheimer type (DAT) and 1 patient with senile dementia of Lewy body type (SDLT), and compared the findings with measurements of blood flow (CBF) and glucose metabolism (CMRGlc). Initial tracer extraction was closely related to CBF. AChE activity was reduced significantly in all brain regions in demented subjects, whereas reduction of CMRGlc and CBF was more limited to temporo-parietal association areas. AChE activity in SDLT was in the lower range of values in DAT. Our results indicate that, compared to non-demented controls, there is a global reduction of cortical AChE activity in dementia. Dementia, cholinergic system, acetylcholine esterase, positron emission tomography, cerebral blood flow, cerebral glucose metabolism.

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject.

Science.gov (United States)

Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe; Saridis, George A; Gjedde, Albert; Ptito, Maurice; Kupers, Ron

2013-01-01

Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA) 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong, and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI) revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Resting-state network disruption and APOE genotype in Alzheimer's disease: a lagged functional connectivity study.

Directory of Open Access Journals (Sweden)

Leonides Canuet

Full Text Available BACKGROUND: The apolipoprotein E epsilon 4 (APOE-4 is associated with a genetic vulnerability to Alzheimer's disease (AD and with AD-related abnormalities in cortical rhythms. However, it is unclear whether APOE-4 is linked to a specific pattern of intrinsic functional disintegration of the brain after the development of the disease or during its different stages. This study aimed at identifying spatial patterns and effects of APOE genotype on resting-state oscillations and functional connectivity in patients with AD, using a physiological connectivity index called "lagged phase synchronization". METHODOLOGY/PRINCIPAL FINDINGS: Resting EEG was recorded during awake, eyes-closed state in 125 patients with AD and 60 elderly controls. Source current density and functional connectivity were determined using eLORETA. Patients with AD exhibited reduced parieto-occipital alpha oscillations compared with controls, and those carrying the APOE-4 allele had reduced alpha activity in the left inferior parietal and temporo-occipital cortex relative to noncarriers. There was a decreased alpha2 connectivity pattern in AD, involving the left temporal and bilateral parietal cortex. Several brain regions exhibited increased lagged phase synchronization in low frequencies, specifically in the theta band, across and within hemispheres, where temporal lobe connections were particularly compromised. Areas with abnormal theta connectivity correlated with cognitive scores. In patients with early AD, we found an APOE-4-related decrease in interhemispheric alpha connectivity in frontal and parieto-temporal regions. CONCLUSIONS/SIGNIFICANCE: In addition to regional cortical dysfunction, as indicated by abnormal alpha oscillations, there are patterns of functional network disruption affecting theta and alpha bands in AD that associate with the level of cognitive disturbance or with the APOE genotype. These functional patterns of nonlinear connectivity may potentially

Neural sources of visual working memory maintenance in human parietal and ventral extrastriate visual cortex.

Science.gov (United States)

Becke, Andreas; Müller, Notger; Vellage, Anne; Schoenfeld, Mircea Ariel; Hopf, Jens-Max

2015-04-15

Maintaining information in visual working memory is reliably indexed by the contralateral delay activity (CDA) - a sustained modulation of the event-related potential (ERP) with a topographical maximum over posterior scalp regions contralateral to the memorized input. Based on scalp topography, it is hypothesized that the CDA reflects neural activity in the parietal cortex, but the precise cortical origin of underlying electric activity was never determined. Here we combine ERP recordings with magnetoencephalography based source localization to characterize the cortical current sources generating the CDA. Observers performed a cued delayed match to sample task where either the color or the relative position of colored dots had to be maintained in memory. A detailed source-localization analysis of the magnetic activity in the retention interval revealed that the magnetic analog of the CDA (mCDA) is generated by current sources in the parietal cortex. Importantly, we find that the mCDA also receives contribution from current sources in the ventral extrastriate cortex that display a time-course similar to the parietal sources. On the basis of the magnetic responses, forward modeling of ERP data reveals that the ventral sources have non-optimal projections and that these sources are therefore concealed in the ERP by overlapping fields with parietal projections. The present observations indicate that visual working memory maintenance, as indexed by the CDA, involves the parietal cortical regions as well as the ventral extrastriate regions, which code the sensory representation of the memorized content. Copyright © 2015 Elsevier Inc. All rights reserved.

Excitatory stimulation of the right inferior parietal cortex lessens implicit religiousness/spirituality.

Science.gov (United States)

Crescentini, Cristiano; Di Bucchianico, Marilena; Fabbro, Franco; Urgesi, Cosimo

2015-04-01

Although religiousness and spirituality (RS) are considered two fundamental constituents of human life, neuroscientific investigation has long avoided the study of their neurocognitive basis. Nevertheless, recent investigations with brain imaging and brain damaged patients, and more recently with brain stimulation methods, have documented important associations between RS beliefs and experiences and frontoparietal neural activity. In this study, we further investigated how individuals' implicit RS self-representations can be modulated by changes in right inferior parietal lobe (IPL) excitability, a key region associated to RS. To this end, we combined continuous theta burst stimulation (cTBS), intermittent TBS (iTBS), and sham TBS with RS-related, Implicit Association Test (IAT) and with a control self-esteem (SE) IAT in a group of fourteen healthy adult individuals. A specific decrease of implicit RS, as measured with the IAT effect, was induced by increasing IPL excitability with iTBS; conversely cTBS, which is supposedly inhibitory, left participants' implicit RS unchanged. The performance in the control SE-IAT was left unchanged by any TBS stimulation. These data showed the causative role of right IPL functional state in mediating plastic changes of implicit RS. Implications of these results are also discussed in the light of the variability of behavioral effects associated with TBS. Copyright © 2015 Elsevier Ltd. All rights reserved.

Boosting Memory by tDCS to Frontal or Parietal Brain Regions? A Study of the Enactment Effect Shows No Effects for Immediate and Delayed Recognition

Directory of Open Access Journals (Sweden)

Beat Meier

2018-06-01

Full Text Available Boosting memory with transcranial direct current stimulation (tDCS seems to be an elegant way to optimize learning. Here we tested whether tDCS to the left dorsolateral prefrontal cortex or to the left posterior parietal cortex would boost recognition memory in general and/or particularly for action phrases enacted at study. During study, 48 young adults either read or enacted simple action phrases. Memory for the action phrases was assessed after a retention interval of 45 min and again after 7-days to investigate the long-term consequences of brain stimulation. The results showed a robust enactment effect in both test sessions. Moreover, the decrease in performance was more pronounced for reading than for enacting the phrases at study. However, tDCS did not reveal any effect on subsequent recognition memory performance. We conclude that memory benefits of tDCS are not easily replicated. In contrast, enactment at study reliably boosts subsequent memory.

Meta-analysis: how does posterior parietal cortex contribute to reasoning?

Science.gov (United States)

Wendelken, Carter

2015-01-01

Reasoning depends on the contribution of posterior parietal cortex (PPC). But PPC is involved in many basic operations—including spatial attention, mathematical cognition, working memory, long-term memory, and language—and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: (1) reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing; (2) reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC; and (3) reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest (ROI). Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL). Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific to

Meta-analysis: How does posterior parietal cortex contribute to reasoning?

Directory of Open Access Journals (Sweden)

Carter eWendelken

2015-01-01

Full Text Available Reasoning depends on the contribution of posterior parietal cortex (PPC. But PPC is involved in many basic operations -- including spatial attention, mathematical cognition, working memory, long-term memory, and language -- and the nature of its contribution to reasoning is unclear. Psychological theories of the processes underlying reasoning make divergent claims about the neural systems that are likely to be involved, and better understanding the specific contribution of PPC can help to inform these theories. We set out to address several competing hypotheses, concerning the role of PPC in reasoning: 1 reasoning involves application of formal logic and is dependent on language, with PPC activation for reasoning mainly reflective of linguistic processing, 2 reasoning involves probabilistic computation and is thus dependent on numerical processing mechanisms in PPC, and 3 reasoning is built upon the representation and processing of spatial relations, and PPC activation associated with reasoning reflects spatial processing. We conducted two separate meta-analyses. First, we pooled data from our own studies of reasoning in adults, and examined activation in PPC regions of interest. Second, we conducted an automated meta-analysis using Neurosynth, in which we examined overlap between activation maps associated with reasoning and maps associated with other key functions of PPC. In both analyses, we observed reasoning-related activation concentrated in the left Inferior Parietal Lobe (IPL. Reasoning maps demonstrated the greatest overlap with mathematical cognition. Maintenance, visuospatial, and phonological processing also demonstrated some overlap with reasoning, but a large portion of the reasoning map did not overlap with the map for any other function. This evidence suggests that the PPC’s contribution to reasoning may be most closely related to its role in mathematical cognition, but that a core component of this contribution may be specific

The role of simultaneous gap arthroplasty and distraction osteogenesis in the management of temporo-mandibular joint ankylosis with mandibular deformity in children.

Science.gov (United States)

Rao, Krishna; Kumar, Sudhir; Kumar, Vijay; Singh, Arun Kumar; Bhatnagar, Sudhir Kumar

2004-02-01

Temporo-mandibular joint ankylosis is a common cause of acquired deformity in children. Surgical correction of the ankylosis only leaves the patient with an uncorrected mandibular deformity. This study was to evaluate the use of distraction osteogenesis for simultaneous correction of the mandibular deformity. This study was done on six children with temporo-mandibular joint ankylosis and mandibular deformity. Uniaxial double pin distractors with Schanz pins were used in this study. The patients underwent simultaneous gap arthroplasty and mandibular osteotomy (retromolar) with distractor insertion. Distraction was started on the fifth post-operative day. The patients were put on dynamic temporo-mandibular joint exercises on the first post-operative day. All patients had a satisfactory mouth opening on follow-up. Satisfactory cosmetic correction of the mandibular deformity was also achieved in all these patients. Some degree of malocclusion resulted from treatment due to which the patients were placed on orthodontic treatment. Distraction osteogenesis can be used simultaneously with gap arthroplasty in patients with temporo-mandibular ankylosis, for the correction of the mandibular deformity.

Involvement of the Left Supramarginal Gyrus in Manipulation Judgment Tasks: Contributions to Theories of Tool Use.

Science.gov (United States)

Lesourd, Mathieu; Osiurak, François; Navarro, Jordan; Reynaud, Emanuelle

2017-09-01

Two theories of tool use, namely the gesture engram and the technical reasoning theories, make distinct predictions about the involvement of the left inferior parietal lobe (IPL) in manipulation judgement tasks. The objective here is to test these alternative predictions based on previous studies on manipulation judgment tasks using transcranial magnetic stimulations (TMS) targeting the left supramarginal gyrus (SMG). We review recent TMS studies on manipulation judgement tasks and confront these data with predictions made by both tool use theories. The left SMG is a highly intertwined region, organized following several functionally distinct areas and TMS may have disrupted a cortical network involved in the ability to use tools rather than only one functional area supporting manipulation knowledge. Moreover, manipulation judgement tasks may be impaired following virtual lesions outside the IPL. These data are more in line with the technical reasoning hypothesis, which assumes that the left IPL does not store manipulation knowledge per se. (JINS, 2017, 23, 685-691).

Neural correlates of the numerical distance effect in children

Directory of Open Access Journals (Sweden)

Christophe eMussolin

2013-10-01

Full Text Available In number comparison tasks, the performance is better when the distance between the two numbers to compare increases. During development this so-called numerical distance effect decreases with age and the neuroanatomical correlates of these age-related changes are poorly known. Using functional magnetic resonance imaging, we recorded the brain activity changes in children aged from 8 to 14 years while they performed a number comparison task on pairs of Arabic digits and a control colour comparison task on non-numerical symbols. On the one hand, we observed developmental changes in the recruitment of frontal regions and the left intraparietal sulcus, with lower activation as the age increased. On the other hand, we found that a behavioural index of selective sensitivity to the numerical distance effect was positively correlated with higher brain activity in a right lateralized occipito-temporo-parietal network including the intraparietal sulcus. This leads us to propose that the left intraparietal sulcus would be engaged in the refinement of cognitive processes involved in number comparison during development, while the right intraparietal sulcus would underlie the semantic representation of numbers and its activation would be mainly affected by the numerical proximity between them.

Artrosis en la articulación temporo-mandibular

OpenAIRE

Muñoz, Pablo Nicolás

2017-01-01

Se presenta un caso clínico de una paciente de 70 años que acusa dolor orofacialsimétrico y dolor local a nivel de la articulación temporo-mandibular (ATM) derecha. La exploración clínica muestra disminución del rango de movimiento articular, crepitación a la auscultación, y puntos gatillos miofascialesa nivel de la musculatura masticatoria. El estudio radiológico confirma artrosis en la ATM y se termina concluyendo que la sintomatología es provocada, principalmente, por el síndrome de dolor ...

Mentalizing regions represent distributed, continuous, and abstract dimensions of others' beliefs.

Science.gov (United States)

Koster-Hale, Jorie; Richardson, Hilary; Velez, Natalia; Asaba, Mika; Young, Liane; Saxe, Rebecca

2017-11-01

The human capacity to reason about others' minds includes making causal inferences about intentions, beliefs, values, and goals. Previous fMRI research has suggested that a network of brain regions, including bilateral temporo-parietal junction (TPJ), superior temporal sulcus (STS), and medial prefrontal-cortex (MPFC), are reliably recruited for mental state reasoning. Here, in two fMRI experiments, we investigate the representational content of these regions. Building on existing computational and neural evidence, we hypothesized that social brain regions contain at least two functionally and spatially distinct components: one that represents information related to others' motivations and values, and another that represents information about others' beliefs and knowledge. Using multi-voxel pattern analysis, we find evidence that motivational versus epistemic features are independently represented by theory of mind (ToM) regions: RTPJ contains information about the justification of the belief, bilateral TPJ represents the modality of the source of knowledge, and VMPFC represents the valence of the resulting emotion. These representations are found only in regions implicated in social cognition and predict behavioral responses at the level of single items. We argue that cortical regions implicated in mental state inference contain complementary, but distinct, representations of epistemic and motivational features of others' beliefs, and that, mirroring the processes observed in sensory systems, social stimuli are represented in distinct and distributed formats across the human brain. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Research on spontaneous activity in adult anisometropic amblyopia with regional homogeneity

Science.gov (United States)

Huang, Yufeng; Zhou, Yifeng

2017-06-01

Amblyopia usually occurs in early childhood and results in monocular visual impairment. The functional magnetic resonance imaging (fMRI) studies have reflected functional anomaly in amblyopia. In resting-state fMRI study, spontaneous activity changes abnormally in anisometropic amblyopia could be revealed by the regional homogeneity (ReHo). Twenty two adult anisometropic amblyopes and Twenty one normal controls participated in this fMRI study. Two sample T test was carried out to analysis ReHo within the whole brain for the inter groups. Compare with normal group, our study found that the amblyopia’s ReHo mainly increased in the left frontal lobe, while decreased in the left cerebellum, the temporal lobe (left and right), and the left parietal lobe. And the ReHo values in middle and inferior temporal lobe, the prefrontal lobe, frontal lobe (positive) and parietal lobe and medial frontal gyrus (negative) could be correlated with the acuity deficit of amblyopia. The results increased in ReHo may indicate compensatory plasticity in higher vision information process, while the decreased in ReHo may reflect decreased ability in eye movement, spatial sense and visuo-motor coordination. The correlation revealed that the vision deficit may correspond to the spontaneous in certain brain area.

fMRI characterization of visual working memory recognition.

Science.gov (United States)

Rahm, Benjamin; Kaiser, Jochen; Unterrainer, Josef M; Simon, Juliane; Bledowski, Christoph

2014-04-15

Encoding and maintenance of information in visual working memory have been extensively studied, highlighting the crucial and capacity-limiting role of fronto-parietal regions. In contrast, the neural basis of recognition in visual working memory has remained largely unspecified. Cognitive models suggest that recognition relies on a matching process that compares sensory information with the mental representations held in memory. To characterize the neural basis of recognition we varied both the need for recognition and the degree of similarity between the probe item and the memory contents, while independently manipulating memory load to produce load-related fronto-parietal activations. fMRI revealed a fractionation of working memory functions across four distributed networks. First, fronto-parietal regions were activated independent of the need for recognition. Second, anterior parts of load-related parietal regions contributed to recognition but their activations were independent of the difficulty of matching in terms of sample-probe similarity. These results argue against a key role of the fronto-parietal attention network in recognition. Rather the third group of regions including bilateral temporo-parietal junction, posterior cingulate cortex and superior frontal sulcus reflected demands on matching both in terms of sample-probe-similarity and the number of items to be compared. Also, fourth, bilateral motor regions and right superior parietal cortex showed higher activation when matching provided clear evidence for a decision. Together, the segregation between the well-known fronto-parietal activations attributed to attentional operations in working memory from those regions involved in matching supports the theoretical view of separable attentional and mnemonic contributions to working memory. Yet, the close theoretical and empirical correspondence to perceptual decision making may call for an explicit consideration of decision making mechanisms in

Encefalomenigocele atrésico parietal Parietal atresic encephalomeningocele

Directory of Open Access Journals (Sweden)

Liliana Rivera Oliva

2011-09-01

Full Text Available El encefalocele es una anomalía congénita rara, en la que una porción del encéfalo protruye a través de un orificio craneal (evaginación, generalmente situado en la línea media. Clínicamente se caracteriza por una masa epicraneal, de consistencia blanda, muchas veces acompañada de trastornos psicomotores, convulsiones y trastornos de la visión. Se presenta el caso de un recién nacido con diagnóstico de encefalomeningocele atrésico parietal, intervenido quirúrgicamente y con evolución satisfactoria.The encephalocele is a uncommon congenital anomaly where a portion of encephalon protrudes through a cranial orifice (evagination, generally located in the middle line. Clinically, it is characterized by a soft epicranial mass often accompanied or psychomotor disorders, convulsions and vision disorders. This is the case of a newborn diagnosed with parietal atresic encephalomeningocele operated on with a satisfactory evolution.

CNS activation and regional connectivity during pantomime observation: no engagement of the mirror neuron system for deaf signers.

Science.gov (United States)

Emmorey, Karen; Xu, Jiang; Gannon, Patrick; Goldin-Meadow, Susan; Braun, Allen

2010-01-01

Deaf signers have extensive experience using their hands to communicate. Using fMRI, we examined the neural systems engaged during the perception of manual communication in 14 deaf signers and 14 hearing non-signers. Participants passively viewed blocked video clips of pantomimes (e.g., peeling an imaginary banana) and action verbs in American Sign Language (ASL) that were rated as meaningless by non-signers (e.g., TO-DANCE). In contrast to visual fixation, pantomimes strongly activated fronto-parietal regions (the mirror neuron system, MNS) in hearing non-signers, but only bilateral middle temporal regions in deaf signers. When contrasted with ASL verbs, pantomimes selectively engaged inferior and superior parietal regions in hearing non-signers, but right superior temporal cortex in deaf signers. The perception of ASL verbs recruited similar regions as pantomimes for deaf signers, with some evidence of greater involvement of left inferior frontal gyrus for ASL verbs. Functional connectivity analyses with left hemisphere seed voxels (ventral premotor, inferior parietal lobule, fusiform gyrus) revealed robust connectivity with the MNS for the hearing non-signers. Deaf signers exhibited functional connectivity with the right hemisphere that was not observed for the hearing group for the fusiform gyrus seed voxel. We suggest that life-long experience with manual communication, and/or auditory deprivation, may alter regional connectivity and brain activation when viewing pantomimes. We conclude that the lack of activation within the MNS for deaf signers does not support an account of human communication that depends upon automatic sensorimotor resonance between perception and action.

Right Fronto-Parietal Dysfunction in Children with ADHD and Developmental Dyslexia as Determined by Line Bisection Judgements

Science.gov (United States)

Waldie, Karen E.; Hausmann, Markus

2010-01-01

Visual line bisection is a reliable and valid laterality task that is typically used with patients with acquired brain damage to assess right hemisphere functioning. Neurologically normal individuals tend to bisect lines to the left of the objective midline whereas those with right parietal damage bisect lines to the right. In this study children…

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

DEFF Research Database (Denmark)

Ioannides, Andreas A; Liu, Lichan; Poghosyan, Vahe

2013-01-01

magnetoencephalography (MEG) data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified...... reproducible brain responses in the primary somatosensory (S1) and motor (M1) cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45-70 Hz activity at latencies of 20-50 ms in S1 and M1, and posterior parietal cortex Brodmann...... of information through this pathway occurred in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first...

Visual processing of multiple elements in the dyslexic brain: evidence for a superior parietal dysfunction

Directory of Open Access Journals (Sweden)

Muriel Anne Lobier

2014-07-01

Full Text Available The visual attention (VA span deficit hypothesis of developmental dyslexia posits that impaired multiple element processing can be responsible for poor reading outcomes. In VA span impaired dyslexic children, poor performance on letter report tasks is associated with reduced parietal activations for multiple letter processing. While this hints towards a non-specific, attention-based dysfunction, it is still unclear whether reduced parietal activity generalizes to other types of stimuli. Furthermore, putative links between reduced parietal activity and reduced ventral occipito-temporal (vOT in dyslexia have yet to be explored. Using fMRI, we measured brain activity in 12 VA span impaired dyslexic adults and 12 adult skilled readers while they carried out a categorization task on single or multiple alphanumeric or non-alphanumeric characters. While healthy readers activated parietal areas more strongly for multiple than single element processing (right-sided for alphanumeric and bilateral for non-alphanumeric, similar stronger multiple element right parietal activations were absent for dyslexic participants. Contrasts between skilled and dyslexic readers revealed significantly reduced right superior parietal lobule (SPL activity for dyslexic readers regardless of stimuli type. Using a priori anatomically defined ROI, we showed that neural activity was reduced for dyslexic participants in both SPL and vOT bilaterally. Finally, we used multiple regressions to test whether SPL activity could predict vOT activity in each group. In the left hemisphere, SPL activity modulated vOT activity for both normal and dyslexic readers. In contrast, in the right hemisphere, SPL activity modulated vOT activity only for dyslexic readers. These results bring critical support to the visual attention interpretation of the VA Span deficit. In addition, they offer a new insight on how deficits in automatic vOT based word recognition could arise in developmental dyslexia.

Evaluation of global and regional left ventricular function obtained by quantitative gated SPECT using {sup 99m}Tc-tetrofosmin for left ventricular dysfunction

Energy Technology Data Exchange (ETDEWEB)

Ban, Kazunobu; Nakajima, Tohru; Iseki, Harukazu; Abe, Sumihisa; Handa, Shunnosuke; Suzuki, Yutaka [Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine

2000-08-01

The quantitative gated SPECT (QGS) software is able to calculate LV volumes and visualize LV wall motion and perfusion throughout the cardiac cycle using an automatic edge detection algorithm of the left ventricle. We evaluated the reliability of global and regional LV function assessment derived from QGS by comparing it with the results from left ventriculo-cineangiography (LVG). In 20 patients with left ventricular dysfunction who underwent ECG gated {sup 99m}Tc-tetrofosmin SPECT, the end-diastolic volume (EDV), end-systolic volume (ESV) and ejection fraction (LVEF) were calculated. The QGS-assessed regional wall motion was determined using the cinematic display. QGS-derived EDV, ESV and LVEF correlated well with those by LVG (p<0.001 for each). There was a good correlation between wall motion score (WMS) derived from the QGS and the LVG (r=0.40, p<0.05). In some patients with extensive myocardial infarction, there was a discrepancy in the regional wall motion results between QGS and LVG. The ECG-gated SPECT using QGS is useful to evaluate global and regional LV functions in left ventricular dysfunction. (author)

Enhanced Working Memory Binding by Direct Electrical Stimulation of the Parietal Cortex

Directory of Open Access Journals (Sweden)

Agustina Birba

2017-06-01

Full Text Available Recent works evince the critical role of visual short-term memory (STM binding deficits as a clinical and preclinical marker of Alzheimer’s disease (AD. These studies suggest a potential role of posterior brain regions in both the neurocognitive deficits of Alzheimer’s patients and STM binding in general. Thereupon, we surmised that stimulation of the posterior parietal cortex (PPC might be a successful approach to tackle working memory deficits in this condition, especially at early stages. To date, no causal evidence exists of the role of the parietal cortex in STM binding. A unique approach to assess this issue is afforded by single-subject direct intracranial electrical stimulation of specific brain regions during a relevant cognitive task. Electrical stimulation has been used both for clinical purposes and to causally probe brain mechanisms. Previous evidence of electrical currents spreading through white matter along well defined functional circuits indicates that visual working memory mechanisms are subserved by a specific widely distributed network. Here, we stimulated the parietal cortex of a subject with intracranial electrodes as he performed the visual STM task. We compared the ensuing results to those from a non-stimulated condition and to the performance of a matched control group. In brief, direct stimulation of the parietal cortex induced a selective improvement in STM. These results, together with previous studies, provide very preliminary but promising ground to examine behavioral changes upon parietal stimulation in AD. We discuss our results regarding: (a the usefulness of the task to target prodromal stages of AD; (b the role of a posterior network in STM binding and in AD; and (c the potential opportunity to improve STM binding through brain stimulation.

Q-Ball of Inferior Fronto-Occipital Fasciculus and Beyond

Science.gov (United States)

Amirbekian, Bagrat; Berger, Mitchel S.; Henry, Roland G.

2014-01-01

The inferior fronto-occipital fasciculus (IFOF) is historically described as the longest associative bundle in the human brain and it connects various parts of the occipital cortex, temporo-basal area and the superior parietal lobule to the frontal lobe through the external/extreme capsule complex. The exact functional role and the detailed anatomical definition of the IFOF are still under debate within the scientific community. In this study we present a fiber tracking dissection of the right and left IFOF by using a q-ball residual-bootstrap reconstruction of High-Angular Resolution Diffusion Imaging (HARDI) data sets in 20 healthy subjects. By defining a single seed region of interest on the coronal fractional anisotropy (FA) color map of each subject, we investigated all the pathways connecting the parietal, occipital and posterior temporal cortices to the frontal lobe through the external/extreme capsule. In line with recent post-mortem dissection studies we found more extended anterior-posterior association connections than the “classical” fronto-occipital representation of the IFOF. In particular the pathways we evidenced showed: a) diffuse projections in the frontal lobe, b) fronto-parietal lobes connections trough the external capsule in almost all the subjects and c) widespread connections in the posterior regions. Our study represents the first consistent in vivo demonstration across a large group of individuals of these novel anterior and posterior terminations of the IFOF detailed described only by post-mortem anatomical dissection. Furthermore our work establishes the feasibility of consistent in vivo mapping of this architecture with independent in vivo methodologies. In conclusion q-ball tractography dissection supports a more complex definition of IFOF, which includes several subcomponents likely underlying specific function. PMID:24945305

Q-ball of inferior fronto-occipital fasciculus and beyond.

Directory of Open Access Journals (Sweden)

Eduardo Caverzasi

Full Text Available The inferior fronto-occipital fasciculus (IFOF is historically described as the longest associative bundle in the human brain and it connects various parts of the occipital cortex, temporo-basal area and the superior parietal lobule to the frontal lobe through the external/extreme capsule complex. The exact functional role and the detailed anatomical definition of the IFOF are still under debate within the scientific community. In this study we present a fiber tracking dissection of the right and left IFOF by using a q-ball residual-bootstrap reconstruction of High-Angular Resolution Diffusion Imaging (HARDI data sets in 20 healthy subjects. By defining a single seed region of interest on the coronal fractional anisotropy (FA color map of each subject, we investigated all the pathways connecting the parietal, occipital and posterior temporal cortices to the frontal lobe through the external/extreme capsule. In line with recent post-mortem dissection studies we found more extended anterior-posterior association connections than the "classical" fronto-occipital representation of the IFOF. In particular the pathways we evidenced showed: a diffuse projections in the frontal lobe, b fronto-parietal lobes connections trough the external capsule in almost all the subjects and c widespread connections in the posterior regions. Our study represents the first consistent in vivo demonstration across a large group of individuals of these novel anterior and posterior terminations of the IFOF detailed described only by post-mortem anatomical dissection. Furthermore our work establishes the feasibility of consistent in vivo mapping of this architecture with independent in vivo methodologies. In conclusion q-ball tractography dissection supports a more complex definition of IFOF, which includes several subcomponents likely underlying specific function.

Measurement of global and regional left ventricular performance with isotope technique in coronary heart disease

International Nuclear Information System (INIS)

Bostroem, P.-A.; Svensson, M.; Lilja, B.

1988-01-01

To evaluate left ventricular function in coronary artery disease, radionuclide measurements of global and regional ejection fraction (EF), regional wall motion and phase analyses of left ventricular contraction were performed by equilibrium technique, using sup(99m)Tc. One group of patients with angina pectoris and one group with myocardial infarction were compared with a control group. All above-mentioned parameters significantly separated the infarction group from the reference group both at rest and during work, while the group of patients with angina pectoris showed disturbances mainly during work, such as impaired ability to increase global and regional ejection fraction and regional wall motion. Adding regional analysis and phase analysis to the global EF determination increases the possibility of studying the left ventricular function. However, this addition has a limited value in detecting impaired left ventricular function compared to the determination of just global EF in patients with angina pectoris and in patients with myocardial infarction. (author)

Paradox image: a noninvasive index of regional left-ventricular dyskinesis

International Nuclear Information System (INIS)

Holman, B.L.; Wynne, J.; Idoine, J.; Zielonka, J.; Neill, J.

1979-01-01

The paradox image, a functional image of regional dyskinesis derived from the equilibrium (gated) radionuclide ventriculogram, was constructed by subtracting the background-corrected end-diastolic frame from the background-corrected end-systolic frame. In 11 patients showing dyskinesis by contrast ventriculography, the percentage of left-ventricular picture elements containing paradox ranged from 3.6 to 55.6% (21.44% +- 4.45 s.e.m.). In 11 patients with normokinesis and in eight patients with hypookinesis by contrast ventriculography, the left-ventricular picture elements demonstrating paradox were less than 1.1% in all cases. In nine patients with akinesis, the percentage of left-ventricular picture elements containing paradox was 2.05% +- 0.96 s.e.m. and was less than 2% in seven patients. There was also an excellent agreement between the location of dyskinesis on the paradox image and that by contrast ventriculography. The paradox image is a sensitive indicator of left-ventricular dyskinesis and should be useful in the evaluation of patients with suspected left-ventricular asynergy

Frontal and parietal cortical interactions with distributed visual representations during selective attention and action selection.

Science.gov (United States)

Nelissen, Natalie; Stokes, Mark; Nobre, Anna C; Rushworth, Matthew F S

2013-10-16

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity.

Frontal and Parietal Cortical Interactions with Distributed Visual Representations during Selective Attention and Action Selection

Science.gov (United States)

Stokes, Mark; Nobre, Anna C.; Rushworth, Matthew F. S.

2013-01-01

Using multivoxel pattern analysis (MVPA), we studied how distributed visual representations in human occipitotemporal cortex are modulated by attention and link their modulation to concurrent activity in frontal and parietal cortex. We detected similar occipitotemporal patterns during a simple visuoperceptual task and an attention-to-working-memory task in which one or two stimuli were cued before being presented among other pictures. Pattern strength varied from highest to lowest when the stimulus was the exclusive focus of attention, a conjoint focus, and when it was potentially distracting. Although qualitatively similar effects were seen inside regions relatively specialized for the stimulus category and outside, the former were quantitatively stronger. By regressing occipitotemporal pattern strength against activity elsewhere in the brain, we identified frontal and parietal areas exerting top-down control over, or reading information out from, distributed patterns in occipitotemporal cortex. Their interactions with patterns inside regions relatively specialized for that stimulus category were higher than those with patterns outside those regions and varied in strength as a function of the attentional condition. One area, the frontal operculum, was distinguished by selectively interacting with occipitotemporal patterns only when they were the focus of attention. There was no evidence that any frontal or parietal area actively inhibited occipitotemporal representations even when they should be ignored and were suppressed. Using MVPA to decode information within these frontal and parietal areas showed that they contained information about attentional context and/or readout information from occipitotemporal cortex to guide behavior but that frontal regions lacked information about category identity. PMID:24133250

Observational learning of new movement sequences is reflected in fronto-parietal coherence.

Directory of Open Access Journals (Sweden)

Jurjen van der Helden

Full Text Available Mankind is unique in her ability for observational learning, i.e. the transmission of acquired knowledge and behavioral repertoire through observation of others' actions. In the present study we used electrophysiological measures to investigate brain mechanisms of observational learning. Analysis investigated the possible functional coupling between occipital (alpha and motor (mu rhythms operating in the 10 Hz frequency range for translating "seeing" into "doing". Subjects observed movement sequences consisting of six consecutive left or right hand button presses directed at one of two target-buttons for subsequent imitation. Each movement sequence was presented four times, intervened by short pause intervals for sequence rehearsal. During a control task subjects observed the same movement sequences without a requirement for subsequent reproduction. Although both alpha and mu rhythms desynchronized during the imitation task relative to the control task, modulations in alpha and mu power were found to be largely independent from each other over time, arguing against a functional coupling of alpha and mu generators during observational learning. This independence was furthermore reflected in the absence of coherence between occipital and motor electrodes overlaying alpha and mu generators. Instead, coherence analysis revealed a pair of symmetric fronto-parietal networks, one over the left and one over the right hemisphere, reflecting stronger coherence during observation of movements than during pauses. Individual differences in fronto-parietal coherence were furthermore found to predict imitation accuracy. The properties of these networks, i.e. their fronto-parietal distribution, their ipsilateral organization and their sensitivity to the observation of movements, match closely with the known properties of the mirror neuron system (MNS as studied in the macaque brain. These results indicate a functional dissociation between higher order areas for

Differentiating between self and others: an ALE meta-analysis of fMRI studies of self-recognition and theory of mind.

Science.gov (United States)

van Veluw, Susanne J; Chance, Steven A

2014-03-01

The perception of self and others is a key aspect of social cognition. In order to investigate the neurobiological basis of this distinction we reviewed two classes of task that study self-awareness and awareness of others (theory of mind, ToM). A reliable task to measure self-awareness is the recognition of one's own face in contrast to the recognition of others' faces. False-belief tasks are widely used to identify neural correlates of ToM as a measure of awareness of others. We performed an activation likelihood estimation meta-analysis, using the fMRI literature on self-face recognition and false-belief tasks. The brain areas involved in performing false-belief tasks were the medial prefrontal cortex (MPFC), bilateral temporo-parietal junction, precuneus, and the bilateral middle temporal gyrus. Distinct self-face recognition regions were the right superior temporal gyrus, the right parahippocampal gyrus, the right inferior frontal gyrus/anterior cingulate cortex, and the left inferior parietal lobe. Overlapping brain areas were the superior temporal gyrus, and the more ventral parts of the MPFC. We confirmed that self-recognition in contrast to recognition of others' faces, and awareness of others involves a network that consists of separate, distinct neural pathways, but also includes overlapping regions of higher order prefrontal cortex where these processes may be combined. Insights derived from the neurobiology of disorders such as autism and schizophrenia are consistent with this notion.

Temporo-mandibular joint dislocation: an unusual complication of transoesophageal echocardiography.

Science.gov (United States)

Anantharam, Brijesh; Chahal, Navtej; Stephens, Nigel; Senior, Roxy

2010-03-01

Temporo-mandibular joint (TMJ) dislocation is an unusual complication of transoesophageal echocardiography (TEE). We report a rare case of bilateral TMJ dislocation in an 84-year-old man prior to DC cardioversion (DCCV) for atrial flutter. Shortly after TEE and DCCV, the patient complained of bilateral facial pain. An orthopantomogram revealed bilateral TMJ dislocation. A closed reduction was performed by maxillo-facial surgeons under intravenous anaesthesia. Although very uncommon, the physician should be aware of the complication and its management.

[Brodmann Areas 39 and 40: Human Parietal Association Area and Higher Cortical Function].

Science.gov (United States)

Sakurai, Yasuhisa

2017-04-01

The anatomy and function of the angular gyrus (Brodmann Area 39) and supramarginal gyrus (Brodmann Area 40) are described here. Both gyri constitute the inferior part of the parietal lobe. Association fibers from the angular gyrus project to the dorsolateral prefrontal cortex via the superior longitudinal fasciculus (SLF) II/arcuate fasciculus (AF), whereas those from the supramarginal gyrus project to the ventrolateral prefrontal cortex via SLF III/AF. Damage to the left angular gyrus causes kanji agraphia (lexical agraphia) and mild anomia, whereas damage to the left supramarginal gyrus causes kana alexia (phonological dyslexia) and kana agraphia (phonological agraphia). Damage to either gyrus causes Gerstmann's syndrome (finger agnosia, left-right disorientation, agraphia and acalculia) and verbal short-term memory impairment. "Angular alexia with agraphia" results from damage to the middle occipital gyrus posterior to the angular gyrus. Alexia and agraphia, with lesions in the angular or supramarginal gyrus, are characterized by kana transposition errors in reading words, which suggests the impairment of sequential phonological processing.

Diffusion-weighted MRI in shaken baby syndrome

International Nuclear Information System (INIS)

Chan, Yu-Leung; Chu, Winnie C.W.; Wong, Gary W.K.; Yeung, David K.W.

2003-01-01

We present the characteristic CT and MRI findings of a 2-month-old girl with shaken baby syndrome. Diffusion-weighted MR imaging performed 8 days after the insult established the presence of injury to the white matter in the corpus callosum and subcortical white matter in the temporo-occipito-parietal region. Diffusion-weighted MR imaging is valuable in the diagnostic work-up of suspected shaken baby syndrome, as injury to the white matter can be demonstrated days after the injury. (orig.)

Quantitation of global and regional left ventricular function by MRI

NARCIS (Netherlands)

van der Geest, RJ; Reiber, JHC; Reiber, JHC; VanDerWall, EE

1998-01-01

Magnetic resonance imaging (MRI) provides several imaging strategies for assessing left ventricular function. As a three-dimensional imaging technique, all measurements can be performed without relying on geometrical assumptions. Global and regional function parameters can be derived from

Spontaneous subgaleal aerocele

African Journals Online (AJOL)

2013-06-16

Jun 16, 2013 ... She had a 10‑ month old gradually enlarging soft mass, about. 19‑22 cm wide on the occipital region, about 7 cm on the right temporo‑parietal region, extending from the right temporal region backwards, involving the right parietal and occipital regions, into the left occipito‑parietal region [Figures 1 and 2].

A shared neural substrate for mentalizing and the affective component of sentence comprehension.

Directory of Open Access Journals (Sweden)

Pierre-Yves Hervé

Full Text Available Using event-related fMRI in a sample of 42 healthy participants, we compared the cerebral activity maps obtained when classifying spoken sentences based on the mental content of the main character (belief, deception or empathy or on the emotional tonality of the sentence (happiness, anger or sadness. To control for the effects of different syntactic constructions (such as embedded clauses in belief sentences, we subtracted from each map the BOLD activations obtained during plausibility judgments on structurally matching sentences, devoid of emotions or ToM. The obtained theory of mind (ToM and emotional speech comprehension networks overlapped in the bilateral temporo-parietal junction, posterior cingulate cortex, right anterior temporal lobe, dorsomedial prefrontal cortex and in the left inferior frontal sulcus. These regions form a ToM network, which contributes to the emotional component of spoken sentence comprehension. Compared with the ToM task, in which the sentences were enounced on a neutral tone, the emotional sentence classification task, in which the sentences were play-acted, was associated with a greater activity in the bilateral superior temporal sulcus, in line with the presence of emotional prosody. Besides, the ventromedial prefrontal cortex was more active during emotional than ToM sentence processing. This region may link mental state representations with verbal and prosodic emotional cues. Compared with emotional sentence classification, ToM was associated with greater activity in the caudate nucleus, paracingulate cortex, and superior frontal and parietal regions, in line with behavioral data showing that ToM sentence comprehension was a more demanding task.

Development of Right-hemispheric Dominance of Inferior Parietal Lobule in Proprioceptive Illusion Task

Science.gov (United States)

Naito, Eiichi; Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru

2017-01-01

Abstract Functional lateralization can be an indicator of brain maturation. We have consistently shown that, in the adult brain, proprioceptive processing of muscle spindle afferents generating illusory movement of the right hand activates inferior frontoparietal cortical regions in a right-side dominant manner in addition to the cerebrocerebellar motor network. Here we provide novel evidence regarding the development of the right-dominant use of the inferior frontoparietal cortical regions in humans using this task. We studied brain activity using functional magnetic resonance imaging while 60 right-handed blindfolded healthy children (8–11 years), adolescents (12–15 years), and young adults (18–23 years) (20 per group) experienced the illusion. Adult-like right-dominant use of the inferior parietal lobule (IPL) was observed in adolescents, while children used the IPL bilaterally. In contrast, adult-like lateralized cerebrocerebellar motor activation patterns were already observable in children. The right-side dominance progresses during adolescence along with the suppression of the left-sided IPL activity that emerges during childhood. Therefore, the neuronal processing implemented in the adult's right IPL during the proprioceptive illusion task is likely mediated bilaterally during childhood, and then becomes right-lateralized during adolescence at a substantially later time than the lateralized use of the cerebrocerebellar motor system for kinesthetic processing. PMID:28968653

The contribution of single photon emission computed tomography in the clinical assessment of Alzheimer type dementia

International Nuclear Information System (INIS)

Boudousq, V.; Collombier, L.; Kotzki, P.O.

1999-01-01

Interest of brain single-photon emission computed tomography to support clinical diagnosis of Alzheimer-type dementia is now established. Numerous studies have reported a decreased perfusion in the association cortex of the parietal lobe and the posterior temporal regions. In patients with mild cognitive complaints, the presence of focal hypoperfusion may increase substantially the probability of the disease. In addition, emission tomography emerges as a helpful tool in situation in which there is diagnostic doubt. In this case, the presence of temporo-parietal perfusion deficit associated with hippocampal atrophy on MRI or X-ray computed tomography contributes to diagnostic accuracy. However, some studies suggest that emission tomography may be useful for preclinical prediction of Alzheimer's disease and to predict cognitive decline. (author)

Culture modulates brain activity during empathy with anger.

Science.gov (United States)

de Greck, Moritz; Shi, Zhenhao; Wang, Gang; Zuo, Xiangyu; Yang, Xuedong; Wang, Xiaoying; Northoff, Georg; Han, Shihui

2012-02-01

Interdependent cultures (such as the Chinese) and independent cultures (such as the German) differ in their attitude towards harmony that is more valued in interdependent cultures. Interdependent and independent cultures also differ in their appreciation of anger--an emotion that implies the disruption of harmony. The present study investigated if interdependent and independent cultures foster distinct brain activity associated with empathic processing of familiar angry, familiar neutral, and unfamiliar neutral faces. Using functional MRI, we scanned Chinese and German healthy subjects during an intentional empathy task, a control task (the evaluation of skin color), and a baseline condition. The subject groups were matched with regard to age, gender, and education. Behaviorally, Chinese subjects described themselves as significantly more interdependent compared to German subjects. The contrast 'intentional empathy for familiar angry'>'baseline' revealed several regions, including the left inferior frontal cortex, the left supplementary motor area, and the left insula, that showed comparable hemodynamic responses in both groups. However, the left dorsolateral prefrontal cortex had stronger hemodynamic responses in Chinese subjects in the contrast 'intentional empathy for familiar angry'>'baseline'. Germans, in contrast, showed stronger hemodynamic responses in the right temporo-parietal junction, right inferior and superior temporal gyrus, and left middle insula for the same contrast. Hemodynamic responses in the latter three brain regions correlated with interdependences scores over all subjects. Our results suggest that enhanced emotion regulation during empathy with anger in the interdependent lifestyle is mediated by the left dorsolateral prefrontal cortex. Increased tolerance towards the expression of anger in the independent lifestyle, in contrast, is associated with increased activity of the right inferior and superior temporal gyrus and the left middle

Statistical parametric mapping for analyzing interictal magnetoencephalography in patients with left frontal lobe epilepsy.

Science.gov (United States)

Zhu, Haitao; Zhu, Jinlong; Bao, Forrest Sheng; Liu, Hongyi; Zhu, Xuchuang; Wu, Ting; Yang, Lu; Zou, Yuanjie; Zhang, Rui; Zheng, Gang

2016-01-01

Frontal lobe epilepsy is a common epileptic disorder and is characterized by recurring seizures that arise in the frontal lobes. The purpose of this study is to identify the epileptogenic regions and other abnormal regions in patients with left frontal lobe epilepsy (LFLE) based on the magnetoencephalogram (MEG), and to understand the effects of clinical variables on brain activities in patients with LFLE. Fifteen patients with LFLE (23.20 ± 8.68 years, 6 female and 9 male) and 16 healthy controls (23.13 ± 7.66 years, 6 female and 10 male) were included in resting-stage MEG examinations. Epileptogenic regions of LFLE patients were confirmed by surgery. Regional brain activations were quantified using statistical parametric mapping (SPM). The correlation between the activations of the abnormal brain regions and the clinical seizure parameters were computed for LFLE patients. Brain activations of LFLE patients were significantly elevated in left superior/middle/inferior frontal gyri, postcentral gyrus, inferior temporal gyrus, insula, parahippocampal gyrus and amygdala, including the epileptogenic regions. Remarkable decreased activations were found mainly in the left parietal gyrus and precuneus. There is a positive correlation between the duration of the epilepsy (in month) and activations of the abnormal regions, while no relation was found between age of seizure onset (year), seizure frequency and the regions of the abnormal activity of the epileptic patients. Our findings suggest that the aberrant brain activities of LFLE patients were not restricted to the epileptogenic zones. Long duration of epilepsy might induce further functional damage in patients with LFLE. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Development of rostral inferior parietal lobule area functional connectivity from late childhood to early adulthood.

Science.gov (United States)

Wang, Mengxing; Zhang, Jilei; Dong, Guangheng; Zhang, Hui; Lu, Haifeng; Du, Xiaoxia

2017-06-01

Although the mirror neuron system (MNS) has been extensively studied in monkeys and adult humans, very little is known about its development. Previous studies suggest that the MNS is present by infancy and that the brain and MNS-related cognitive abilities (such as language, empathy, and imitation learning) continue to develop after childhood. In humans, the PFt area of the inferior parietal lobule (IPL) seems to particularly correlate with the functional properties of the PF area in primates, which contains mirror neurons. However, little is known about the functional connectivity (FC) of the PFt area with other brain areas and whether these networks change over time. Here, we investigated the FC development of the PFt area-based network in 59 healthy subjects aged 7-26 years at resting-state to study brain development from late childhood through adolescence to early adulthood. The bilateral PFt showed similar core FC networks, which included the frontal lobe, the cingulate gyri, the insula, the somatosensory cortex, the precuneus, the superior and inferior parietal lobules, the temporal lobe, and the cerebellum posterior lobes. Furthermore, the FC between the left PFt and the left IPL exhibited a significantly positive correlation with age, and the FC between the left PFt and the right postcentral gyrus exhibited a significantly negative correlation with age. In addition, the FC between the right PFt and the right putamen exhibited a significantly negative correlation with age. Our findings suggest that the PFt area-based network develops and is reorganized with age. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

Fronto-parietal contributions to phonological processes in successful artificial grammar learning

Directory of Open Access Journals (Sweden)

Dariya Goranskaya

2016-11-01

Full Text Available Sensitivity to regularities plays a crucial role in the acquisition of various linguistic features from spoken language input. Artificial grammar (AG learning paradigms explore pattern recognition abilities in a set of structured sequences (i.e. of syllables or letters. In the present study, we investigated the functional underpinnings of learning phonological regularities in auditorily presented syllable sequences. While previous neuroimaging studies either focused on functional differences between the processing of correct vs. incorrect sequences or between different levels of sequence complexity, here the focus is on the neural foundation of the actual learning success. During functional magnetic resonance imaging (fMRI, participants were exposed to a set of syllable sequences with an underlying phonological rule system, known to ensure performance differences between participants. We expected that successful learning and rule application would require phonological segmentation and phoneme comparison. As an outcome of four alternating learning and test fMRI sessions, participants split into successful learners and non-learners. Relative to non-learners, successful learners showed increased task-related activity in a fronto-parietal network of brain areas encompassing the left lateral premotor cortex as well as bilateral superior and inferior parietal cortices during both learning and rule application. These areas were previously associated with phonological segmentation, phoneme comparison and verbal working memory. Based on these activity patterns and the phonological strategies for rule acquisition and application, we argue that successful learning and processing of complex phonological rules in our paradigm is mediated via a fronto-parietal network for phonological processes.

HEMOSTATIC SYSTEM CONDITION AND HEART REMODELING IN PATIENTS WITH Q-WAVE MYOCARDIAL INFARCTION WITH ACUTE ANEURYSMS AND LEFT VENTRICLE THROMBUS

Directory of Open Access Journals (Sweden)

V. D. Syvolap

2014-02-01

Full Text Available Introduction. Worldwide myocardial infarction (MI is one of the main causes of morbidity and mortality. Thanks to advances in modern cardiology we achieved a significant reduction in mortality and the incidence of fatal complications of acute Q-wave MI. However, keeping in mind the pathogenetic features of myocardial defeat of the left ventricle (LV cavity dilation and thinning at the focus of myocardial infarction, which increase the risk of left ventricular aneurysm development and parietal thrombus formation, it is impossible to reduce significantly the risk of these serious complications development. Post-infarction left ventricular aneurysm, extremely unfavorable prognostic factor complicates the course of Q-wave myocardial infarction in 30% of cases. The likelihood of parietal clot development in the anterior apical localization of aneurysms is 32%. The reasons of parietal clot formation are varied and are not fully disclosed, that is responsible for the relevance of this study. Aim: to investigate the serum level of protein C, von Willebrand factor, the expression of vascular adhesion molecules sVCAM-1, platelet aggregation properties and to evaluate their relationship with the structural and functional performance of the heart in patients with acute Q-wave myocardial infarction with aneurysm and parietal thrombus of LV. Methods. 110 patients (67 men and 43 women, mean age - 63,2 ± 5,7 years, with a diagnosis of acute Q-wave myocardial infarction were involved into the study. The first group included 72 patients with postinfarction left ventricular aneurysm, the second - 38 patients with postinfarction aneurysm and parietal thrombus of LV. Serum levels of protein C, von Willebrand factor, the expression of vascular adhesion molecules sVCAM-1, platelet aggregation properties were studied and their relationship with the structural and functional performance of the heart were evaluated. Results. There were revealed high activity of the key

Airway Management in a Mental Retardation Patient with Temporo-mandibular Joint Ankylosis

Directory of Open Access Journals (Sweden)

Rauf GÜL

2012-01-01

Full Text Available Temporo-mandibular joint (TMJ ankylosis makes it impossible orotracheal intubation for general anesthesia because of limited mouth opening. We applied a nasotracheal intubation via fiberoptic bronchoscopy (FOB guidance on a 36 years old mental retarded (MR patient with bilateral TMJ, having extremely limited mouth opening. As a result, nasotracheal intubation via FOB is reliable technique on even mental retarded patients with extremely limited opening.

Single-photon tomographic determination of regional cerebral blood flow in psychiatric disorders

International Nuclear Information System (INIS)

Devous, M.D. Sr.; Rush, A.J.; Schlesser, M.A.; Debus, J.; Raese, J.D.; Chehabi, H.H.; Bonte, F.J.

1984-01-01

Regional cerebral blood flow (rCBF) was measured by single-photon emission computed tomography (SPECT) of 133-Xe washout in 29 normal volunteers, 22 unipolar endogenous depressives (UPE), 9 unipolar nonendogenous depressives (UPNE), 13 bipolar depressed patients (BPD), and 14 schizophrenic patients (SCHZ). RCBF was measured 2 and 6 cm above and parallel to the cantho-meatal line and quantitated in 14 gray matter regions. Most subjects were drug-free for 4-14 days. Diagnoses were made by experienced clinicians employing the Research Diagnostic Criteria, the Hamilton Rating Scale, and the dexamethasone suppression test. SCHZ were rated with the Brief Psychiatric Rating Scale. UPE had reduced flow compared to normals in the right parietal and temporal lobes and a nonsignificant trend toward left temporal flow reductions. UPNE were not different from normal or other patient groups. BPD had significant flow elevations in the left hemisphere relative to normal, and in both hemispheres relative to UPE. SCHZ were not significantly different from normal or other patient groups. Anterior-posterior flow shifts were evaluated by subtracting parietal or temporal flows from frontal flows. SCHZ demonstrated a greater posterior shift (lower relative frontal lobe flow) in comparison to both UPE and UPNE. The most significant regional flow abnormalities were observed as frontal flow reductions in individual SCHZ, although these were not significant in the whole group in comparison to normal

Regional cerebral blood flow during comprehension and speech (in cerebrally healthy subjects)

International Nuclear Information System (INIS)

Lechevalier, B.; Petit, M.C.; Eustache, F.; Lambert, J.; Chapon, F.; Viader, F.

1989-01-01

Regional cerebral blood flow (rCBF) was measured by the xenon-133 inhalation method in 10 cerebrally healthy subjects at rest and during linguistic activation tests. These consisted of a comprehension test (binaural listening to a narrative text) and a speech test (making sentences from a list of words presented orally at 30-s intervals). The comprehension task induced a moderate increase in the mean right CBF and in both inferior parietal areas, whereas the speech test resulted in a diffuse increase in the mean CBF of both hemispheres, predominating regionally in both inferior parietal, left operculary, and right upper motor and premotor areas. It is proposed that the activation pattern induced by linguistic stimulation depends on not only specific factors, such as syntactic and semantic aspects of language, but also the contents of the material proposed and the attention required by the test situation

Fractionation of parietal function in bistable perception probed with concurrent TMS-EEG.

Science.gov (United States)

Schauer, Georg; Chang, Acer; Schwartzman, David; Rae, Charlotte L; Iriye, Heather; Seth, Anil K; Kanai, Ryota

2016-08-16

When visual input has conflicting interpretations, conscious perception can alternate spontaneously between these possible interpretations. This is called bistable perception. Previous neuroimaging studies have indicated the involvement of two right parietal areas in resolving perceptual ambiguity (ant-SPLr and post-SPLr). Transcranial magnetic stimulation (TMS) studies that selectively interfered with the normal function of these regions suggest that they play opposing roles in this type of perceptual switch. In the present study, we investigated this fractionation of parietal function by use of combined TMS with electroencephalography (EEG). Specifically, while participants viewed either a bistable stimulus, a replay stimulus, or resting-state fixation, we applied single pulse TMS to either location independently while simultaneously recording EEG. Combined with participant's individual structural magnetic resonance imaging (MRI) scans, this dataset allows for complex analyses of the effect of TMS on neural time series data, which may further elucidate the causal role of the parietal cortex in ambiguous perception.

Application of argon-helium cryoablation in resection of intracranial tumors

Directory of Open Access Journals (Sweden)

Yu-hao ZHOU

2017-07-01

Full Text Available Objective To summarize the curative effect of argon-helium cryoablation in resection of intracranial tumors.  Methods and Results A total of 11 patients with primary intracranial tumors, including 7 cases of glioma and 4 cases of meningioma, were enrolled in this study. The tumor was located in left frontal lobe in 4 cases, left fronto-parietal lobe in 2 cases, left temporal lobe in 2 cases and right temporo-parietal lobe in 3 cases. Argon-helium cryoablation was used to assist intracranial tumor resection. Among 7 cases of glioma, 4 cases were totally removed and 3 cases were partially resected. Four cases of meningioma were totally removed. The average intraoperative blood loss was 80 ml, and average operation time was 80 min. Postoperative clinical symptoms were improved, and head CT or MRI showed no rebleeding. Patients were followed up for an average of 4 years, and none of them suffered from operation-related or postoperative complications such as intracranial infection, or tumor recurrence.  Conclusions Argon - helium cryoablation is suitable for intracranial tumors with different diameters and in different locations. It is safe and effective, with few operation-related or postoperative complications, less rebleeding and low risk of recurrence, which is a highly efficient and relatively low?cost assistant surgical method. DOI: 10.3969/j.issn.1672-6731.2017.06.011

MEG reveals a fast pathway from somatosensory cortex to occipital areas via posterior parietal cortex in a blind subject

Directory of Open Access Journals (Sweden)

Andreas A Ioannides

2013-08-01

Full Text Available Cross-modal activity in visual cortex of blind subjects has been reported during performance of variety of non-visual tasks. A key unanswered question is through which pathways non-visual inputs are funneled to the visual cortex. Here we used tomographic analysis of single trial magnetoencephalography (MEG data recorded from one congenitally blind and two sighted subjects after stimulation of the left and right median nerves at three intensities: below sensory threshold, above sensory threshold and above motor threshold; the last sufficient to produce thumb twitching. We identified reproducible brain responses in the primary somatosensory (S1 and motor (M1 cortices at around 20 ms post-stimulus, which were very similar in sighted and blind subjects. Time-frequency analysis revealed strong 45 to 70 Hz activity at latencies of 20 to 50 ms in S1 and M1, and posterior parietal cortex Brodmann areas (BA 7 and 40, which compared to lower frequencies, were substantially more pronounced in the blind than the sighted subjects. Critically, at frequencies from α-band up to 100 Hz we found clear, strong and widespread responses in the visual cortex of the blind subject, which increased with the intensity of the somatosensory stimuli. Time-delayed mutual information (MI revealed that in blind subject the stimulus information is funneled from the early somatosensory to visual cortex through posterior parietal BA 7 and 40, projecting first to visual areas V5 and V3, and eventually V1. The flow of information through this pathway occured in stages characterized by convergence of activations into specific cortical regions. In sighted subjects, no linked activity was found that led from the somatosensory to the visual cortex through any of the studied brain regions. These results provide the first evidence from MEG that in blind subjects, tactile information is routed from primary somatosensory to occipital cortex via the posterior parietal cortex.

Effects of childhood trauma on left inferior frontal gyrus function during response inhibition across psychotic disorders.

Science.gov (United States)

Quidé, Y; O'Reilly, N; Watkeys, O J; Carr, V J; Green, M J

2018-07-01

Childhood trauma is a risk factor for psychosis. Deficits in response inhibition are common to psychosis and trauma-exposed populations, and associated brain functions may be affected by trauma exposure in psychotic disorders. We aimed to identify the influence of trauma-exposure on brain activation and functional connectivity during a response inhibition task. We used functional magnetic resonance imaging to examine brain function within regions-of-interest [left and right inferior frontal gyrus (IFG), right dorsolateral prefrontal cortex, right supplementary motor area, right inferior parietal lobule and dorsal anterior cingulate cortex], during the performance of a Go/No-Go Flanker task, in 112 clinical cases with psychotic disorders and 53 healthy controls (HCs). Among the participants, 71 clinical cases and 21 HCs reported significant levels of childhood trauma exposure, while 41 clinical cases and 32 HCs did not. In the absence of effects on response inhibition performance, childhood trauma exposure was associated with increased activation in the left IFG, and increased connectivity between the left IFG seed region and the cerebellum and calcarine sulcus, in both cases and healthy individuals. There was no main effect of psychosis, and no trauma-by-psychosis interaction for any other region-of-interest. Within the clinical sample, the effects of trauma-exposure on the left IFG activation were mediated by symptom severity. Trauma-related increases in activation of the left IFG were not associated with performance differences, or dependent on clinical diagnostic status; increased IFG functionality may represent a compensatory (overactivation) mechanism required to exert adequate inhibitory control of the motor response.

Shared neuroanatomical substrates of impaired phonological working memory across reading disability and autism.

Science.gov (United States)

Lu, Chunming; Qi, Zhenghan; Harris, Adrianne; Weil, Lisa Wisman; Han, Michelle; Halverson, Kelly; Perrachione, Tyler K; Kjelgaard, Margaret; Wexler, Kenneth; Tager-Flusberg, Helen; Gabrieli, John D E

2016-03-01

Individuals with reading disability or individuals with autism spectrum disorder (ASD) are characterized, respectively, by their difficulties in reading or social communication, but both groups often have impaired phonological working memory (PWM). It is not known whether the impaired PWM reflects distinct or shared neuroanatomical abnormalities in these two diagnostic groups. White-matter structural connectivity via diffusion weighted imaging was examined in sixty-four children, ages 5-17 years, with reading disability, ASD, or typical development (TD), who were matched in age, gender, intelligence, and diffusion data quality. Children with reading disability and children with ASD exhibited reduced PWM compared to children with TD. The two diagnostic groups showed altered white-matter microstructure in the temporo-parietal portion of the left arcuate fasciculus (AF) and in the temporo-occipital portion of the right inferior longitudinal fasciculus (ILF), as indexed by reduced fractional anisotropy and increased radial diffusivity. Moreover, the structural integrity of the right ILF was positively correlated with PWM ability in the two diagnostic groups, but not in the TD group. These findings suggest that impaired PWM is transdiagnostically associated with shared neuroanatomical abnormalities in ASD and reading disability. Microstructural characteristics in left AF and right ILF may play important roles in the development of PWM. The right ILF may support a compensatory mechanism for children with impaired PWM.

A method to quantitate regional wall motion in left ventriculography using Hildreth algorithm

Energy Technology Data Exchange (ETDEWEB)

Terashima, Mikio [Hyogo Red Cross Blood Center (Japan); Naito, Hiroaki; Sato, Yoshinobu; Tamura, Shinichi; Kurosawa, Tsutomu

1998-06-01

Quantitative measurement of ventricular wall motion is indispensable for objective evaluation of cardiac function associated with coronary artery disease. We have modified the Hildreth`s algorithm to estimate excursions of the ventricular wall on left ventricular images yielded by various imaging techniques. Tagging cine-MRI was carried out on 7 healthy volunteers. The original Hildreth method, the modified Hildreth method and the centerline method were applied to the outlines of the images obtained, to estimate excursion of the left ventricular wall and regional shortening and to evaluate the accuracy of these methods when measuring these parameters, compared to the values of these parameters measured actually using the attached tags. The accuracy of the original Hildreth method was comparable to that of the centerline method, while the modified Hildreth method was significantly more accurate than the centerline method (P<0.05). Regional shortening as estimated using the modified Hildreth method differed less from the actually measured regional shortening than did the shortening estimated using the centerline method (P<0.05). The modified Hildreth method allowed reasonable estimation of left ventricular wall excursion in all cases where it was applied. These results indicate that when applied to left ventriculograms for ventricular wall motion analysis, the modified Hildreth method is more useful than the original Hildreth method. (author)

The role of parietal cortex in the formation of colour and motion based concepts

Directory of Open Access Journals (Sweden)

Samuel William Cheadle

2014-07-01

Full Text Available Imaging evidence shows that separate subdivisions of parietal cortex, in and around the intraparietal sulcus (IPS, are engaged when stimuli are grouped according to colour and to motion (Zeki and Stutters 2013. Since grouping is an essential step in the formation of concepts, we wanted to learn whether parietal cortex is also engaged in the formation of concepts according to these two attributes. Using functional magnetic resonance imaging (fMRI, and choosing the recognition of concept-based colour or motion stimuli as our paradigm, we found that there was strong concept-related activity in and around the intraparietal sulcus (IPS, a region whose homologue in the macaque monkey is known to receive direct but segregated anatomical inputs from V4 and V5. Parietal activity related to colour concepts was juxtaposed but did not overlap with activity related to motion concepts, thus emphasizing the continuation of the segregation of colour and motion into the conceptual system. Concurrent retinotopic mapping experiments showed that within the parietal cortex, concept-related activity increases within later stage IPS areas.

Neural correlates of visualizations of concrete and abstract words in preschool children: A developmental embodied approach

Directory of Open Access Journals (Sweden)

Amedeo eD'angiulli

2015-06-01

Full Text Available The neural correlates of visualization underlying word comprehension were examined in preschool children. On each trial, a concrete or abstract word was delivered binaurally (part 1: post-auditory visualization, followed by a four-picture array (a target plus three distractors (part 2: matching visualization. Children were to select the picture matching the word they heard in part 1. Event-Related Potentials (ERPs locked to each stimulus presentation and task interval were averaged over sets of trials of increasing word abstractness. ERP time-course during both parts of the task showed that early activity (i.e. < 300 ms was predominant in response to concrete words, while activity in response to abstract words became evident only at intermediate (i.e. 300-699 ms and late (i.e. 700-1000 ms ERP intervals. Specifically, ERP topography showed that while early activity during post-auditory visualization was linked to left temporo-parietal areas for concrete words, early activity during matching visualization occurred mostly in occipito-parietal areas for concrete words, but more anteriorly in centro-parietal areas for abstract words. In intermediate ERPs, post-auditory visualization coincided with parieto-occipital and parieto-frontal activity in response to both concrete and abstract words, while in matching visualization a parieto-central activity was common to both types of words. In the late ERPs for both types of words, the post-auditory visualization involved right-hemispheric activity following a post-anterior pathway sequence: occipital, parietal and temporal areas; conversely, matching visualization involved left-hemispheric activity following an ant-posterior pathway sequence: frontal, temporal, parietal and occipital areas. These results suggest that, similarly for concrete and abstract words, meaning in young children depends on variably complex visualization processes integrating visuo-auditory experiences and supramodal embodying

Gender differences in brain regional homogeneity of healthy subjects after normal sleep and after sleep deprivation: a resting-state fMRI study.

Science.gov (United States)

Dai, Xi-Jian; Gong, Hong-Han; Wang, Yi-Xiang; Zhou, Fu-Qing; Min, You-Jiang; Zhao, Feng; Wang, Si-Yong; Liu, Bi-Xia; Xiao, Xiang-Zuo

2012-06-01

To explore the gender differences of brain regional homogeneity (ReHo) in healthy subjects during the resting-state, after normal sleep, and after sleep deprivation (SD) using functional magnetic resonance imaging (fMRI) and the ReHo method. Sixteen healthy subjects (eight males and eight females) each underwent the resting-state fMRI exams twice, i.e., once after normal sleep and again after 24h's SD. According to the gender and sleep, 16 subjects were all measured twice and divided into four groups: the male control group (MC), female control group (FC), male SD group (MSD), and female SD group (FSD). The ReHo method was used to calculate and analyze the data, SPM5 software was used to perform a two-sample T-test and a two-pair T-test with a P value right paracentral lobule (BA3/6), but in no obviously lower regions. Compared with the FC, the FSD showed significantly higher ReHo in bilateral parietal lobes (BA2/3), bilateral vision-related regions of occipital lobes (BA17/18/19), right frontal lobe (BA4/6), and lower ReHo in the right frontal lobe. Compared with the FC, the MC showed significantly higher ReHo in the left occipital lobe (BA18/19), and left temporal lobe (BA21), left frontal lobe, and lower ReHo in the right insula and in the left parietal lobe. Compared with the FSD, the MSD showed significantly higher ReHo in the left cerebellum posterior lobe (uvula/declive of vermis), left parietal lobe, and bilateral frontal lobes, and lower ReHo in the right occipital lobe (BA17) and right frontal lobe (BA4). The differences of brain activity in the resting state can be widely found not only between the control and SD group in a same gender group, but also between the male group and female group. Thus, we should take the gender differences into consideration in future fMRI studies, especially the treatment of brain-related diseases (e.g., depression). Copyright © 2012 Elsevier B.V. All rights reserved.

Assessment of cardiac performance with quantitative radionuclide angiocardiography: sequential left ventricular ejection fraction, normalized left ventricular ejection rate, and regional wall motion

International Nuclear Information System (INIS)

Marshall, R.C.; Berger, H.J.; Costin, J.C.; Freedman, G.S.; Wolberg, J.; Cohen, L.S.; Gotischalk, A.; Zaret, B.L.

1977-01-01

Sequential quantitative first pass radionuclide angiocardiograms (RA) were used to measure left ventricular ejection fraction (LVEF) and left ventricular ejection rate (LVER), and to assess regional wall motion (RWM) in the anterior (ANT) and left anterior oblique (LAO) positions. Studies were obtained with a computerized multicrystal scintillation camera suitable for acquiring high count-rate data. Background was determined in a new fashion by selecting frames temporally from the left ventricular region of interest time-activity curve. A ''representative'' cardiac cycle was formed by summing together counts over three to six cardiac cycles. From this background corrected, high count-rate ''representative''cardiac cycle, LVEF, LVER, and RWM were determined. In 22 patients with normal sinus rhythm in the absence of significant valvular regurgitation, RA LVEF correlated well with that measured by contrast angiography (r = 0.95). LVER correlated well with LVEF measured at contrast angiography (r = 0.90) and allowed complete separation of those with normal (LVER = 3.4 +- 0.17 sec -1 ) and abnormal (LVER = 1.22 +- 0.11 sec -1 ) (P < 0.001) left ventricular performance. This separation was independent of background. Isoproterenol infusion in five normal subjects caused LVER to increase by 81 +- 17% while LVEF increased by 10 +- 2.0%. RWM was correctly defined in 21/22 patients and 89% of left ventricular segments with abnormal wall motion

Asymmetric multisensory interactions of visual and somatosensory responses in a region of the rat parietal cortex.

Directory of Open Access Journals (Sweden)

Michael T Lippert

Full Text Available Perception greatly benefits from integrating multiple sensory cues into a unified percept. To study the neural mechanisms of sensory integration, model systems are required that allow the simultaneous assessment of activity and the use of techniques to affect individual neural processes in behaving animals. While rodents qualify for these requirements, little is known about multisensory integration and areas involved for this purpose in the rodent. Using optical imaging combined with laminar electrophysiological recordings, the rat parietal cortex was identified as an area where visual and somatosensory inputs converge and interact. Our results reveal similar response patterns to visual and somatosensory stimuli at the level of current source density (CSD responses and multi-unit responses within a strip in parietal cortex. Surprisingly, a selective asymmetry was observed in multisensory interactions: when the somatosensory response preceded the visual response, supra-linear summation of CSD was observed, but the reverse stimulus order resulted in sub-linear effects in the CSD. This asymmetry was not present in multi-unit activity however, which showed consistently sub-linear interactions. These interactions were restricted to a specific temporal window, and pharmacological tests revealed significant local intra-cortical contributions to this phenomenon. Our results highlight the rodent parietal cortex as a system to model the neural underpinnings of multisensory processing in behaving animals and at the cellular level.

Altered spontaneous brain activity in adolescent boys with pure conduct disorder revealed by regional homogeneity analysis.

Science.gov (United States)

Wu, Qiong; Zhang, Xiaocui; Dong, Daifeng; Wang, Xiang; Yao, Shuqiao

2017-07-01

Functional magnetic resonance imaging (fMRI) studies have revealed abnormal neural activity in several brain regions of adolescents with conduct disorder (CD) performing various tasks. However, little is known about the spontaneous neural activity in people with CD in a resting state. The aims of this study were to investigate CD-associated regional activity abnormalities and to explore the relationship between behavioral impulsivity and regional activity abnormalities. Resting-state fMRI (rs-fMRI) scans were administered to 28 adolescents with CD and 28 age-, gender-, and IQ-matched healthy controls (HCs). The rs-fMRI data were subjected to regional homogeneity (ReHo) analysis. ReHo can demonstrate the temporal synchrony of regional blood oxygen level-dependent signals and reflect the coordination of local neuronal activity facilitating similar goals or representations. Compared to HCs, the CD group showed increased ReHo bilaterally in the insula as well as decreased ReHo in the right inferior parietal lobule, right middle temporal gyrus and right fusiform gyrus, left anterior cerebellum anterior, and right posterior cerebellum. In the CD group, mean ReHo values in the left and the right insula correlated positively with Barratt Impulsivity Scale (BIS) total scores. The results suggest that CD is associated with abnormal intrinsic brain activity, mainly in the cerebellum and temporal-parietal-limbic cortices, regions that are related to emotional and cognitive processing. BIS scores in adolescents with CD may reflect severity of abnormal neuronal synchronization in the insula.

Functional MRI approach for assessing hemispheric predominance of regions activated by a phonological and a semantic task

Energy Technology Data Exchange (ETDEWEB)

Cousin, Emilie; Peyrin, Carole; Pichat, Cedric [Laboratoire de Psychologie et Neurocognition, UMR CNRS 5105, Universite Pierre Mendes-France, BP 47, 38040 Grenoble Cedex 09 (France); Lamalle, Laurent; Le Bas, Jean-Francois [Unite IRM, IFR1, CHU Grenoble (France); Baciu, Monica [Laboratoire de Psychologie et Neurocognition, UMR CNRS 5105, Universite Pierre Mendes-France, BP 47, 38040 Grenoble Cedex 09 (France)], E-mail: mbaciu@upmf-grenoble.fr

2007-08-15

This fMRI study performed in healthy subjects aimed at using a statistical approach in order to determine significant functional differences between hemispheres and to assess specialized regions activated during a phonological and during a semantic task. This approach ('flip' method and subsequent statistical analyses of the parameter estimates extracted from regions of interest) allows identifying: (a) hemispheric specialized regions for each language task [semantic (living categorization) and phonological (rhyme detection)] and (b) condition-specific regions with respect to paradigm conditions (task and control). Our results showed that the rhyme-specific task regions were the inferior frontal (sub-region of BA 44, 45) and left inferior parietal (BA 40, 39) lobules. Furthermore, within the inferior parietal lobule, the angular gyrus was specific to target (rhyming) items (related to successfully grapho-phonemic processing). The categorization-specific task regions were the left inferior frontal (sub-region of BA 44, 45) and superior temporal (BA 22) cortices. Furthermore, the superior temporal gyrus was related to non-target (non-living) items (correlated to task difficulty). The relatively new approach used in this study has the advantage of providing: (a) statistical significance of the hemispheric specialized regions for a given language task and (b) supplementary information in terms of paradigm condition-specificity of the activated regions. The results (standard hemispheric specialized regions for a semantic and for a phonological task) obtained in healthy subjects may constitute a basement for mapping language and assessing hemispheric predominance in epileptic patients before surgery and avoiding post-surgical impairments of language.

Functional MRI approach for assessing hemispheric predominance of regions activated by a phonological and a semantic task

International Nuclear Information System (INIS)

Cousin, Emilie; Peyrin, Carole; Pichat, Cedric; Lamalle, Laurent; Le Bas, Jean-Francois; Baciu, Monica

2007-01-01

This fMRI study performed in healthy subjects aimed at using a statistical approach in order to determine significant functional differences between hemispheres and to assess specialized regions activated during a phonological and during a semantic task. This approach ('flip' method and subsequent statistical analyses of the parameter estimates extracted from regions of interest) allows identifying: (a) hemispheric specialized regions for each language task [semantic (living categorization) and phonological (rhyme detection)] and (b) condition-specific regions with respect to paradigm conditions (task and control). Our results showed that the rhyme-specific task regions were the inferior frontal (sub-region of BA 44, 45) and left inferior parietal (BA 40, 39) lobules. Furthermore, within the inferior parietal lobule, the angular gyrus was specific to target (rhyming) items (related to successfully grapho-phonemic processing). The categorization-specific task regions were the left inferior frontal (sub-region of BA 44, 45) and superior temporal (BA 22) cortices. Furthermore, the superior temporal gyrus was related to non-target (non-living) items (correlated to task difficulty). The relatively new approach used in this study has the advantage of providing: (a) statistical significance of the hemispheric specialized regions for a given language task and (b) supplementary information in terms of paradigm condition-specificity of the activated regions. The results (standard hemispheric specialized regions for a semantic and for a phonological task) obtained in healthy subjects may constitute a basement for mapping language and assessing hemispheric predominance in epileptic patients before surgery and avoiding post-surgical impairments of language

Neural representations of social status hierarchy in human inferior parietal cortex.

Science.gov (United States)

Chiao, Joan Y; Harada, Tokiko; Oby, Emily R; Li, Zhang; Parrish, Todd; Bridge, Donna J

2009-01-01

Mental representations of social status hierarchy share properties with that of numbers. Previous neuroimaging studies have shown that the neural representation of numerical magnitude lies within a network of regions within inferior parietal cortex. However the neural basis of social status hierarchy remains unknown. Using fMRI, we studied subjects while they compared social status magnitude of people, objects and symbols, as well as numerical magnitude. Both social status and number comparisons recruited bilateral intraparietal sulci. We also observed a semantic distance effect whereby neural activity within bilateral intraparietal sulci increased for semantically close relative to far numerical and social status comparisons. These results demonstrate that social status and number comparisons recruit distinct and overlapping neuronal representations within human inferior parietal cortex.

Histological study of the human temporo-mandibular joint and its surrounding muscles.

Science.gov (United States)

Bravetti, P; Membre, H; El Haddioui, A; Gérard, H; Fyard, J P; Mahler, P; Gaudy, J F

2004-10-01

This is a histological study of the human temporo-mandibular joint and its surrounding muscles. Using a microscopic study of serial sections from anatomical specimens from six subjects, the detailed anatomy of the joint is presented with particular regard to the histology. This study has allowed, in particular, the description of the ligaments and capsule as well as the insertions of the masticatory muscles (temporalis, masseter, lateral pterygoid) on this joint. These observations are then compared with the anatomical and histological data already reported on this subject. This study shows that the bulk of the muscular fibres of the lateral pterygoid passes under the foot of the disc is attached over the whole height of the condylar, unite and extend as far as the medial pole of the joint under the insertion of the articular disc. An insertion of the temporo-masseter musculo-tendinous complex on the anterior and lateral capsulo-discal structures was observed. The lateral pterygoid is composed of a succession of tendinous and fleshy fibres. This study confirms the thickening of the lateral capsule that corresponds to a lateral collateral ligament, and the absence of a medial collateral ligament. Medial stability is conferred by the lateral ligament of the contralateral joint.

Osteosarcoma of the spheno-temporo-orbital bone: Imaging aspects of such unusual location

Directory of Open Access Journals (Sweden)

ABDEL ILAH RAYAN ALAOUI BOUARRAQUI

2018-05-01

Full Text Available Osteosarcoma of the spheno-temporo-orbital bone is a very rare tumor. Despite the fact that primary osteogenic sarcomas are the most common bone neoplasm, their location in the skull bone is uncommon representing less than 2% of all skull tumors. We report the case of a 41-year-old woman, who has experienced periorbital pain with exophthalmos and left eye vision loss. Neuroimaging analysis including both brain computed tomography (CT-scan and Magnetic resonance imaging (MRI were performed. Although radiographic features of skull bone osteosarcomas are not specific, the combination of several radiographic features could lead to this diagnosis in such rare location. The final diagnosis was established by a trans-temporal biopsy with immunohistochemical study. Neurosurgical resection of the primary tumor was not possible given the important extent of the tumor and the involvement of adjacent structures, so the patient underwent conformational radiotherapy. The evolution was marked by local and metastatic progression. The patient received palliative chemotherapy and died few months later. The purpose of presenting this case is not only to report an uncommon malignancy of the skull bone, but also to provide imaging aspects of this rare location and to raise awareness among radiologists in order to consider this radiological entity as a differential diagnosis when a skull bone process is identified.

Sex differences in the association between gray matter volume and verbal creativity.

Science.gov (United States)

Shi, Baoguo; Xu, Li; Chen, Qunlin; Qiu, Jiang

2017-08-02

The explanation for why significant sex differences are found in creativity has become an increasingly important topic. The current study applied a cognitive neuroscience perspective and voxel-based morphometry to investigate the sex differences for the association between verbal creativity and gray matter volume (GMV) in a large sample of healthy adults from the Chinese Mainland (163 men and 193 women). Furthermore, we sought to determine which brain regions are responsible for these differences. Our behavioral results showed a significant sex difference. Specifically, women scored higher than men on originality. The voxel-based morphometry results indicated that the relationship between originality and GMV differed between men and women in the left temporo-occipital junction. Higher originality scores in women were associated with more GMV. In contrast, higher originality scores in men were related to less GMV. These findings suggest the left temporo-occipital junction GMV plays a unique role in the sex differences in verbal creativity because women usually surpass men in semantic processing, which is the major function of the left temporal region.

Frequency of Maternal Touch Predicts Resting Activity and Connectivity of the Developing Social Brain.

Science.gov (United States)

Brauer, Jens; Xiao, Yaqiong; Poulain, Tanja; Friederici, Angela D; Schirmer, Annett

2016-08-01

Previous behavioral research points to a positive relationship between maternal touch and early social development. Here, we explored the brain correlates of this relationship. The frequency of maternal touch was recorded for 43 five-year-old children during a 10 min standardized play session. Additionally, all children completed a resting-state functional magnetic resonance imaging session. Investigating the default mode network revealed a positive relation between the frequency of maternal touch and activity in the right posterior superior temporal sulcus (pSTS) extending into the temporo-parietal junction. Using this effect as a seed in a functional connectivity analysis identified a network including extended bilateral regions along the temporal lobe, bilateral frontal cortex, and left insula. Compared with children with low maternal touch, children with high maternal touch showed additional connectivity with the right dorso-medial prefrontal cortex. Together these results support the notion that childhood tactile experiences shape the developing "social brain" with a particular emphasis on a network involved in mentalizing. © The Author 2016. Published by Oxford University Press.

Multisensory speech perception without the left superior temporal sulcus.

Science.gov (United States)

Baum, Sarah H; Martin, Randi C; Hamilton, A Cris; Beauchamp, Michael S

2012-09-01

Converging evidence suggests that the left superior temporal sulcus (STS) is a critical site for multisensory integration of auditory and visual information during speech perception. We report a patient, SJ, who suffered a stroke that damaged the left tempo-parietal area, resulting in mild anomic aphasia. Structural MRI showed complete destruction of the left middle and posterior STS, as well as damage to adjacent areas in the temporal and parietal lobes. Surprisingly, SJ demonstrated preserved multisensory integration measured with two independent tests. First, she perceived the McGurk effect, an illusion that requires integration of auditory and visual speech. Second, her perception of morphed audiovisual speech with ambiguous auditory or visual information was significantly influenced by the opposing modality. To understand the neural basis for this preserved multisensory integration, blood-oxygen level dependent functional magnetic resonance imaging (BOLD fMRI) was used to examine brain responses to audiovisual speech in SJ and 23 healthy age-matched controls. In controls, bilateral STS activity was observed. In SJ, no activity was observed in the damaged left STS but in the right STS, more cortex was active in SJ than in any of the normal controls. Further, the amplitude of the BOLD response in right STS response to McGurk stimuli was significantly greater in SJ than in controls. The simplest explanation of these results is a reorganization of SJ's cortical language networks such that the right STS now subserves multisensory integration of speech. Copyright © 2012 Elsevier Inc. All rights reserved.

Magnetic resonance imaging of functional connectivity in Parkinson disease in the resting brain

International Nuclear Information System (INIS)

Liu Xian; Liu Bo; Luo Xiaodong; Li Ningna; Chen Zhiguang; Chen Jun

2009-01-01

Objective: To investigate functional connectivity changes in Parkinson disease in the resting brain using functional magnetic resonance imaging. Methods: Nine patients with Parkinson disease and eight age-matched healthy volunteers were entered into the study. The bilateral globus pallidus were chosen as seed points, the functional MR data acquired in the resting state were processed to investigate functional connectivity in PD patients and the results were compared with those of the controls. Results: In age-matched healthy controls, there are regions which had functional connectivity with bilateral globus pallidus, including bilateral temporal poles, bilateral hippocampus, bilateral thalami, posterior cingulate cortex, right middle occipital gyms and right superior parietal gyms. In PD patients, brain regions including bilateral cerebellum, left hippocampus, bilateral superior temporal gyri, left inferior frontal gyrus, left middle frontal gyrus, left precentral gyrus, left inferior parietal gyrus and left superior parietal gyrus, had functional connectivity with bilateral globus pallidus. Compared to healthy controls, increased functional connectivity in bilateral cerebellum, bilateral temporal lobes, left frontal lobe and left parietal lobe, and decreased functional connectivity in bilateral thalami were observed in PD patients. Conclusion: Abnormal changes of brain functional connectivity exists in Parkinson's disease in the resting state. (authors)

[Autopsy case of Lissauer's general paresis with rapidly progressive left hemiparesis].

Science.gov (United States)

Kato, Hiroko; Yoshida, Mari; Ando, Tetsuo; Sugiura, Makoto; Hashizume, Yoshio

2009-06-01

A 48-years-old man presented with slowly progressive bradykinesia, personality change and rapidly progressive left hemiparesis. On admission, he presented dementia, poor judgment, left hemiparesis. MRI revealed a widespread high intensity area in right hemisphere and MRA was almost normal. Serological tests of serum and CSF demonstrated high titers of antibodies to Treponema pallidum. He was treated for syphilis with daily penicillin injections without improvement. He died of sepsis eight months after admission. At autopsy, the brain weighed 1,100 g and the right cerebral hemisphere was atrophic, especially in frontal base, temporal, parietal, angular, and posterior regions covered by thickened, fibrotic leptomeninges. Microscopically, chronic meningoencephalitis was observed. Severe neuronal loss with gliosis was seen in the right cerebral cortices. Scattered rod-shaped microglia and inflammatory cell infiltration were visible in the cerebral parenchyma. The dorsal column of the spinal cord was not involved and meningovascular syphilis was unclear. The distribution of the encephalitic lesions was well correlated with the clinical and neuroradiological findings. This was a rare autopsy case presenting Lissauer's general paresis, clinically manifesting as rapidly progressive stroke-like episode.

Regional homogeneity and functional connectivity patterns in major depressive disorder, cognitive vulnerability to depression and healthy subjects.

Science.gov (United States)

Sun, Hui; Luo, Lizhu; Yuan, Xinru; Zhang, Lu; He, Yini; Yao, Shuqiao; Wang, Jiaojian; Xiao, Jing

2018-08-01

Cognitive vulnerability to depression (CVD) is a high risk for depressive disorder. Recent studies focus on individuals with CVD to determine the neural basis of major depressive disorder (MDD) neuropathology. However, whether CVD showed specific or similar brain functional activity and connectivity patterns, compared to MDD, remain largely unknown. Here, using resting-state functional magnetic resonance imaging in subjects with CVD, healthy controls (HC) and MDD, regional homogeneity (ReHo) and resting-state functional connectivity (R-FC) analyses were conducted to assess local synchronization and changes in functional connectivity patterns. Significant ReHo differences were found in right posterior lobe of cerebellum (PLC), left lingual gyrus (LG) and precuneus. Compared to HC, CVD subjects showed increased ReHo in the PLC, which was similar to the difference found between MDD and HC. Compared to MDD patients, CVD subjects showed decreased ReHo in PLC, LG, and precuneus. R-FC analyses found increased functional connections between LG and left inferior parietal lobule, posterior cingulate cortex, and dorsolateral prefrontal cortex in CVD compared to both HC and MDD. Moreover, Regional mean ReHo values were positively correlated with Center for Epidemiologic Studies Depression Scale scores. These analyses revealed that PLC and functional connections between LG and left inferior parietal lobule, posterior cingulate cortex, and dorsolateral prefrontal cortex may be a potential marker for CVD. Copyright © 2018 Elsevier B.V. All rights reserved.

Structural brain abnormalities in a single gene disorder associated with epilepsy, language impairment and intellectual disability

Directory of Open Access Journals (Sweden)

Joe Bathelt

2016-01-01

Full Text Available Childhood speech and language deficits are highly prevalent and are a common feature of neurodevelopmental disorders. However, it is difficult to investigate the underlying causal pathways because many diagnostic groups have a heterogeneous aetiology. Studying disorders with a shared genetic cause and shared cognitive deficits can provide crucial insight into the cellular mechanisms and neural systems that give rise to those impairments. The current study investigated structural brain differences of individuals with mutations in ZDHHC9, which is associated with a specific neurodevelopmental phenotype including prominent speech and language impairments and intellectual disability. We used multiple structural neuroimaging methods to characterise neuroanatomy in this group, and observed bilateral reductions in cortical thickness in areas surrounding the temporo-parietal junction, parietal lobule, and inferior frontal lobe, and decreased microstructural integrity of cortical, subcortical-cortical, and interhemispheric white matter projections. These findings are compared to reports for other genetic groups and genetically heterogeneous disorders with a similar presentation. Overlap in the neuroanatomical phenotype suggests a common pathway that particularly affects the development of temporo-parietal and inferior frontal areas, and their connections.

Representation of Semantic Similarity in the Left Intraparietal Sulcus: Functional Magnetic Resonance Imaging Evidence

Directory of Open Access Journals (Sweden)

Veerle Neyens

2017-08-01

Full Text Available According to a recent study, semantic similarity between concrete entities correlates with the similarity of activity patterns in left middle IPS during category naming. We examined the replicability of this effect under passive viewing conditions, the potential role of visuoperceptual similarity, where the effect is situated compared to regions that have been previously implicated in visuospatial attention, and how it compares to effects of object identity and location. Forty-six subjects participated. Subjects passively viewed pictures from two categories, musical instruments and vehicles. Semantic similarity between entities was estimated based on a concept-feature matrix obtained in more than 1,000 subjects. Visuoperceptual similarity was modeled based on the HMAX model, the AlexNet deep convolutional learning model, and thirdly, based on subjective visuoperceptual similarity ratings. Among the IPS regions examined, only left middle IPS showed a semantic similarity effect. The effect was significant in hIP1, hIP2, and hIP3. Visuoperceptual similarity did not correlate with similarity of activity patterns in left middle IPS. The semantic similarity effect in left middle IPS was significantly stronger than in the right middle IPS and also stronger than in the left or right posterior IPS. The semantic similarity effect was similar to that seen in the angular gyrus. Object identity effects were much more widespread across nearly all parietal areas examined. Location effects were relatively specific for posterior IPS and area 7 bilaterally. To conclude, the current findings replicate the semantic similarity effect in left middle IPS under passive viewing conditions, and demonstrate its anatomical specificity within a cytoarchitectonic reference frame. We propose that the semantic similarity effect in left middle IPS reflects the transient uploading of semantic representations in working memory.

Neuropsychiatric symptoms and PET imaging characteristics in patients with Parkinson-plus syndromes

Directory of Open Access Journals (Sweden)

Miao ZHANG

2017-01-01

Full Text Available Objective To explore the neuropsychiatric symptoms and 18F-fluoro-2-deoxy-D-glucose (18F-FDG PET imaging features of Parkinson-plus syndromes. Methods There were 8 patients with probable Parkinson-plus syndromes, including one case of multiple system atrophy-cerebellar predominant (MSA-C, 4 cases of progressive supranuclear palsy (PSP, one case of corticobasal ganglionic degeneration (CBD and 2 cases of dementia with Lewy bodies (DLB. Mini-Mental State Examination (MMSE and Montreal Cognitive Assessment (MoCA were used to evaluate cognitive function, Neuropsychiatric Inventory (NPI was used to evaluate neuropsychiatric behaviors, and Hamilton Depression Rating Scale-21 Items (HAMD-21 was used to evaluate the emotional state of patients. Results One MSA-C patient showed only anxiety. Four PSP patients showed different degrees of cognitive disorders, of whom 3 cases also presented obvious depression, anxiety, irritability and sleep disorders. One case of CBD showed dysfunction in executive function, visual spatial ability, verbal function, attention and orientation, as well as depression, anxiety, irritability and sleep disorders. Two cases of DLB were found unable to copy pentagon in MMSE chart or draw a circle in Clock Drawing Test (CDT, and they also presented hallucination, depression and indifference. As for the result of 18F-FDG PET, one MSA-C patient showed cerebellarglucose hypometabolism; 4 PSP patients showed hypometabolism in bilateral symmetrical frontal lobes, anterior cingulate gyrus and parietal lobe, especially in thalamus, basal ganglia region and brain stem; one case of CBD showed hypometabolism in right lateral fronto-temporo-parieto-occipital lobes, left lateral parietal lobe, bilateral cingulate gyri and precuneus; 2 cases of DLB showed hypometabolism in bilateral temporo-occipital lobes. Conclusions Patients with early Parkinson-plus syndromes are easily misdiagnosed as mental illness and delayed treatment, in addition, their

Development of Right-hemispheric Dominance of Inferior Parietal Lobule in Proprioceptive Illusion Task.

Science.gov (United States)

Naito, Eiichi; Morita, Tomoyo; Saito, Daisuke N; Ban, Midori; Shimada, Koji; Okamoto, Yuko; Kosaka, Hirotaka; Okazawa, Hidehiko; Asada, Minoru

2017-11-01

Functional lateralization can be an indicator of brain maturation. We have consistently shown that, in the adult brain, proprioceptive processing of muscle spindle afferents generating illusory movement of the right hand activates inferior frontoparietal cortical regions in a right-side dominant manner in addition to the cerebrocerebellar motor network. Here we provide novel evidence regarding the development of the right-dominant use of the inferior frontoparietal cortical regions in humans using this task. We studied brain activity using functional magnetic resonance imaging while 60 right-handed blindfolded healthy children (8-11 years), adolescents (12-15 years), and young adults (18-23 years) (20 per group) experienced the illusion. Adult-like right-dominant use of the inferior parietal lobule (IPL) was observed in adolescents, while children used the IPL bilaterally. In contrast, adult-like lateralized cerebrocerebellar motor activation patterns were already observable in children. The right-side dominance progresses during adolescence along with the suppression of the left-sided IPL activity that emerges during childhood. Therefore, the neuronal processing implemented in the adult's right IPL during the proprioceptive illusion task is likely mediated bilaterally during childhood, and then becomes right-lateralized during adolescence at a substantially later time than the lateralized use of the cerebrocerebellar motor system for kinesthetic processing. © The Author 2017. Published by Oxford University Press.

Phonological memory in sign language relies on the visuomotor neural system outside the left hemisphere language network.

Science.gov (United States)

Kanazawa, Yuji; Nakamura, Kimihiro; Ishii, Toru; Aso, Toshihiko; Yamazaki, Hiroshi; Omori, Koichi

2017-01-01

Sign language is an essential medium for everyday social interaction for deaf people and plays a critical role in verbal learning. In particular, language development in those people should heavily rely on the verbal short-term memory (STM) via sign language. Most previous studies compared neural activations during signed language processing in deaf signers and those during spoken language processing in hearing speakers. For sign language users, it thus remains unclear how visuospatial inputs are converted into the verbal STM operating in the left-hemisphere language network. Using functional magnetic resonance imaging, the present study investigated neural activation while bilinguals of spoken and signed language were engaged in a sequence memory span task. On each trial, participants viewed a nonsense syllable sequence presented either as written letters or as fingerspelling (4-7 syllables in length) and then held the syllable sequence for 12 s. Behavioral analysis revealed that participants relied on phonological memory while holding verbal information regardless of the type of input modality. At the neural level, this maintenance stage broadly activated the left-hemisphere language network, including the inferior frontal gyrus, supplementary motor area, superior temporal gyrus and inferior parietal lobule, for both letter and fingerspelling conditions. Interestingly, while most participants reported that they relied on phonological memory during maintenance, direct comparisons between letters and fingers revealed strikingly different patterns of neural activation during the same period. Namely, the effortful maintenance of fingerspelling inputs relative to letter inputs activated the left superior parietal lobule and dorsal premotor area, i.e., brain regions known to play a role in visuomotor analysis of hand/arm movements. These findings suggest that the dorsal visuomotor neural system subserves verbal learning via sign language by relaying gestural inputs to

[An attempt to use ultrasonic technique for confirming the diagnosis, planning and observation of long-term treatment results of painful temporo-mandibular joint dysfunction].

Science.gov (United States)

Ey-Chmielewska, H

1998-01-01

The author presents an attempt of using ultrasonographic technique in diagnosis, planning and observation of treatment results of temporo-mandibular joint pain dysfunctions. Temporo-mandibular joint pain dysfunctions are interchangeably also called temporo-mandibular joint functional disorders. The assessment of pain symptoms in temporo-mandibular joint dysfunctions pain symptoms is principally based on a subjective estimation by the examining practitioner. There is no univocal definition of the disease or a simple index evidencing important symptoms in decision making. Additionally X-ray technique examinations, being hitherto used, in early stages of the disorder do not allow to diagnose it, and are also burdensome to a patient. The aim of this study was to confirm visibility of anatomical elements of the temporo-mandibular joint in an ultrasound examination, assess the mobility of the articular disc before, during and after prosthetic treatment with and without the use of ultrasound technique, and to determine the period of time necessary to obtain a therapeutic effect. The study material consisted of 180 patients, 128 women and 52 men, aged 20 to 60 years, treated by applying prostheses because of temporo-mandibular joint pain dysfunction, in the Department of Prosthetic Dentistry of the Pomeranian Medical Academy. The patients were divided into 2 groups, control and study group. The control group consisted of 90 patients, 63 women and 27 men. In this group prosthetic treatment planning and observation of results was based on a subjective estimation of the practitioner. The study group here comprised 90 patients, 65 women and 25 men, aged 26 to 60 years. In this group prosthetic treatment planning and observation of treatment results were carried on with the use of ultrasound technique. Data from both groups concerning history, results of examinations carried out by ultrasound technique, and the assessment of ultrasound examination were noted on standard

Use of explicit memory cues following parietal lobe lesions.

Science.gov (United States)

Dobbins, Ian G; Jaeger, Antonio; Studer, Bettina; Simons, Jon S

2012-11-01

The putative role of the lateral parietal lobe in episodic memory has recently become a topic of considerable debate, owing primarily to its consistent activation for studied materials during functional magnetic resonance imaging studies of recognition. Here we examined the performance of patients with parietal lobe lesions using an explicit memory cueing task in which probabilistic cues ("Likely Old" or "Likely New"; 75% validity) preceded the majority of verbal recognition memory probes. Without cues, patients and control participants did not differ in accuracy. However, group differences emerged during the "Likely New" cue condition with controls responding more accurately than parietal patients when these cues were valid (preceding new materials) and trending towards less accuracy when these cues were invalid (preceding old materials). Both effects suggest insufficient integration of external cues into memory judgments on the part of the parietal patients whose cued performance largely resembled performance in the complete absence of cues. Comparison of the parietal patients to a patient group with frontal lobe lesions suggested the pattern was specific to parietal and adjacent area lesions. Overall, the data indicate that parietal lobe patients fail to appropriately incorporate external cues of novelty into recognition attributions. This finding supports a role for the lateral parietal lobe in the adaptive biasing of memory judgments through the integration of external cues and internal memory evidence. We outline the importance of such adaptive biasing through consideration of basic signal detection predictions regarding maximum possible accuracy with and without informative environmental cues. Copyright © 2012 Elsevier Ltd. All rights reserved.

Regional differences in right versus left congenital heart disease diagnoses in neonates in the United States.

Science.gov (United States)

Nelson, Jennifer S; Strassle, Paula D

2018-03-01

Differences in the prevalence of left and right congenital heart defects (CHD) across the United States are unclear. This study evaluated the overall prevalence and the distribution of right versus left CHD across US regions and divisions in neonates. Newborns born from 2000 to 2014 diagnosed with CHD were identified using the National Inpatient Sample. Heart defects were stratified into right, left, and "neither" subtypes. The risk of right and left heart diagnoses between US Census regions and divisions was compared using multivariable binomial regression, adjusting for infant, and hospital characteristics. Two hundred forty thousand four hundred fifty-five newborns were included and 38,185 (15.9%) were classifiable as having either right or left subtypes. Between 2000 and 2014, the prevalence of right defects increased from 1.65 to 2.88 cases/1,000 live born infants (p right heart defect diagnosis compared to the West. When stratified by division, New England states had a significantly higher prevalence of right defects compared to the Pacific (RD adj .09, 95% CI .06, 0.11). No differences in the prevalence of left defects were seen. The prevalence of CHD diagnoses at birth in the US has increased, and regional differences in the prevalence of right defects appear to exist. © 2017 Wiley Periodicals, Inc.

[Topographological-anatomic changes in the structure of temporo-mandibular joint in case of fracture of the mandible condylar process at cervical level].

Science.gov (United States)

Volkov, S I; Bazhenov, D V; Semkin, V A

2011-01-01

Pathological changes in soft tissues surrounding the fracture site as well as in the structural elements of temporo-mandibular joint always occured in condylar process fracture with shift at cervical mandibular jaw level. Other changes were also seen in the joint on the opposite normal side. Modelling of condylar process fracture at mandibular cervical level by means of three-dimensional computer model of temporo-mandibular joint contributed to proper understanding of this pathology emergence as well as to prediction and elimination of disorders arising in adjacent to the fracture site tissues.

The left IPL represents stored hand-postures for object use and action prediction

Directory of Open Access Journals (Sweden)

Michiel evan Elk

2014-04-01

Full Text Available Action semantics enables us to plan actions with objects and to predict others’ object-directed actions as well. Previous studies have suggested that action semantics are represented in a fronto-parietal action network that has also been implicated to play a role in action observation. In the present fMRI study it was investigated how activity within this network changes as a function of the predictability of an action involving multiple objects and requiring the use of action semantics. Participants performed an action prediction task in which they were required to anticipate the use of a centrally presented object that could be moved to an associated target object (e.g. hammer - nail. The availability of actor information (i.e. presenting a hand grasping the central object and the number of possible target objects (i.e. 0, 1 or 2 target objects were independently manipulated, resulting in different levels of predictability. It was found that making an action prediction based on actor information resulted in an increased activation in the extrastriate body area (EBA and the fronto-parietal action observation network (AON. Predicting actions involving a target object resulted in increased activation in the bilateral IPL and frontal motor areas. Within the AON, activity in the left inferior parietal lobe (IPL and the left premotor cortex (PMC increased as a function of the level of action predictability. Together these findings suggest that the left IPL represents stored hand-postures that can be used for planning object-directed actions and for predicting other’s actions as well.

Love-related changes in the brain: a resting-state functional magnetic resonance imaging study.

Science.gov (United States)

Song, Hongwen; Zou, Zhiling; Kou, Juan; Liu, Yang; Yang, Lizhuang; Zilverstand, Anna; d'Oleire Uquillas, Federico; Zhang, Xiaochu

2015-01-01

Romantic love is a motivational state associated with a desire to enter or maintain a close relationship with a specific other person. Functional magnetic resonance imaging (fMRI) studies have found activation increases in brain regions involved in the processing of reward, motivation and emotion regulation, when romantic lovers view photographs of their partners. However, not much is known about whether romantic love affects the brain's functional architecture during rest. In the present study, resting state functional magnetic resonance imaging (rsfMRI) data was collected to compare the regional homogeneity (ReHo) and functional connectivity (FC) across an "in-love" group (LG, N = 34, currently intensely in love), an "ended-love" group (ELG, N = 34, ended romantic relationship recently), and a "single" group (SG, N = 32, never fallen in love). Results show that: (1) ReHo of the left dorsal anterior cingulate cortex (dACC) was significantly increased in the LG (in comparison to the ELG and the SG); (2) ReHo of the left dACC was positively correlated with length of time in love in the LG, and negatively correlated with the lovelorn duration since breakup in the ELG; (3) FC within the reward, motivation, and emotion regulation network (dACC, insula, caudate, amygdala, and nucleus accumbens) as well as FC in the social cognition network [temporo-parietal junction (TPJ), posterior cingulate cortex (PCC), medial prefrontal cortex (MPFC), inferior parietal, precuneus, and temporal lobe] was significantly increased in the LG (in comparison to the ELG and SG); (4) in most regions within both networks FC was positively correlated with the duration of love in the LG but negatively correlated with the lovelorn duration of time since breakup in the ELG. This study provides first empirical evidence of love-related alterations in brain functional architecture. Furthermore, the results shed light on the underlying neural mechanisms of romantic love, and demonstrate the

Love-related changes in the brain: A resting-state functional magnetic resonance imaging study

Directory of Open Access Journals (Sweden)

Hongwen eSong

2015-02-01

Full Text Available Romantic love is a motivational state associated with a desire to enter or maintain a close relationship with a specific other person. Studies with functional magnetic resonance imaging (fMRI have found activation increases in brain regions involved in processing of reward, emotion, motivation when romantic lovers view photographs of their partners. However, not much is known on whether romantic love affects the brain’s functional architecture during rest. In the present study, resting state functional magnetic resonance imaging (rsfMRI data was collected to compare the regional homogeneity (ReHo and functional connectivity (FC across a lover group (LG, N=34, currently intensely in love, ended-love group (ELG, N=34, romantic relationship ended recently, and single group (SG, N=32, never fallen in love.The results showed that:1 ReHo of the left dorsal anterior cingulate cortex (dACC was significantly increased in the LG (in comparison to the ELG and the SG; 2 ReHo of the left dACC was positively correlated with length of time in love in the LG, and negatively correlated with the lovelorn duration since breakup in the ELG; 3 functional connectivity (FC within the reward, motivation, and emotion network (dACC, insula, caudate, amygdala and nucleus accumbens and the social cognition network (temporo-parietal junction (TPJ, posterior cingulate cortex (PCC, medial prefrontal cortex (MPFC, inferior parietal, precuneus and temporal lobe was significantly increased in the LG (in comparison to the ELG and SG; 4 in most regions within both networks FC was positively correlated with the love duration in the LG but negatively correlated with the lovelorn duration in the ELG. This study provides first empirical evidence of love-related alterations of brain functional architecture. The results shed light on the underlying neural mechanisms of romantic love, and demonstrate the possibility of applying a resting state approach for investigating romantic love.

"Opening an emotional dimension in me": changes in emotional reactivity and emotion regulation in a case of executive impairment after left fronto-parietal damage.

Science.gov (United States)

Salas, Christian E; Radovic, Darinka; Yuen, Kenneth S L; Yeates, Giles N; Castro, O; Turnbull, Oliver H

2014-01-01

Dysexecutive impairment is a common problem after brain injury, particularly after damage to the lateral surface of the frontal lobes. There is a large literature describing the cognitive deficits associated with executive impairment after dorsolateral damage; however, little is known about its impact on emotional functioning. This case study describes changes in a 72-year-old man (Professor F) who became markedly dysexecutive after a left fron-to-parietal stroke. Professor F's case is remarkable in that, despite exhibiting typical executive impairments, abstraction and working memory capacities were spared. Such preservation of insight-related capacities allowed him to offer a detailed account of his emotional changes. Quantitative and qualitative tools were used to explore changes in several well-known emotional processes. The results suggest that Professor F's two main emotional changes were in the domain of emotional reactivity (increased experience of both positive and negative emotions) and emotion regulation (down-regulation of sadness). Professor F related both changes to difficulties in his thinking process, especially a difficulty generating and manipulating thoughts during moments of negative arousal. These results are discussed in relation to the literature on executive function and emotion regulation. The relevance of these findings for neuropsychological rehabilitation and for the debate on the neural basis of emotional processes is addressed.

Common brain areas engaged in false belief reasoning and visual perspective taking: A meta-analysis of functional brain imaging studies.

Directory of Open Access Journals (Sweden)

Matthias eSchurz

2013-11-01

Full Text Available We performed a quantitative meta-analysis of functional neuroimaging studies to identify brain areas which are commonly engaged in social and visuo-spatial perspective taking. Specifically, we compared brain activation found for visual-perspective taking to activation for false belief reasoning, a task which requires awareness of perspective to understand someone’s mistaken belief about the world which contrasts with reality. In support of a previous account by Perner & Leekam (2008, a meta-analytic conjunction analysis found activation for false belief reasoning and visual perspective taking in the left but not the right dorsal temporo-parietal junction. This fits with the idea that the left dorsal TPJ is responsible for representing different perspectives in a domain-general fashion. Moreover, the conjunction found activation in the precuneus and the left middle occipital gyrus close to the putative Extrastriate Body Area. The precuneus is linked to mental-imagery processes, which may aid in the construction of a different perspective. The Extrastriate Body Area may be engaged due to imagined body-transformations when another’s viewpoint is adopted.

Regional Cerebral Blood Flow during Wakeful Rest in Older Subjects with Mild to Severe Obstructive Sleep Apnea.

Science.gov (United States)

Baril, Andrée-Ann; Gagnon, Katia; Arbour, Caroline; Soucy, Jean-Paul; Montplaisir, Jacques; Gagnon, Jean-François; Gosselin, Nadia

2015-09-01

To evaluate changes in regional cerebral blood flow (rCBF) during wakeful rest in older subjects with mild to severe obstructive sleep apnea (OSA) and healthy controls, and to identify markers of OSA severity that predict altered rCBF. High-resolution (99m)Tc-HMPAO SPECT imaging during wakeful rest. Research sleep laboratory affiliated with a University hospital. Fifty untreated OSA patients aged between 55 and 85 years, divided into mild, moderate, and severe OSA, and 20 age-matched healthy controls. N/A. Using statistical parametric mapping, rCBF was compared between groups and correlated with clinical, respiratory, and sleep variables. Whereas no rCBF change was observed in mild and moderate groups, participants with severe OSA had reduced rCBF compared to controls in the left parietal lobules, left precentral gyrus, bilateral postcentral gyri, and right precuneus. Reduced rCBF in these regions and in areas of the bilateral frontal and left temporal cortex was associated with more hypopneas, snoring, hypoxemia, and sleepiness. Higher apnea, microarousal, and body mass indexes were correlated to increased rCBF in the basal ganglia, insula, and limbic system. While older individuals with severe obstructive sleep apnea (OSA) had hypoperfusion in the sensorimotor and parietal areas, respiratory variables and subjective sleepiness were correlated with extended regions of hypoperfusion in the lateral cortex. Interestingly, OSA severity, sleep fragmentation, and obesity correlated with increased perfusion in subcortical and medial cortical regions. Anomalies with such a distribution could result in cognitive deficits and reflect impaired vascular regulation, altered neuronal integrity, and/or undergoing neurodegenerative processes. © 2015 Associated Professional Sleep Societies, LLC.

Activation and integration are not the same: Changing effective connectivity in recovery from acute aphasia

Directory of Open Access Journals (Sweden)

David W Gow

2014-04-01

Full Text Available The relationship between BOLD activation and processing in recovering aphasics is complex. Patterns of shifting upregulation of perilesional and contralesional task-related BOLD response have been widely observed in patients during subacute and chronic phases of recovery (c.f. Saur et al., 2006. However, a number of studies have found a relatively weak relationship between these changes and performance in language tasks (e.g. Heiss et al., 1999; Cornelissen et al., 2003. In this work, we explore the evolving relationship between activation and effective connectivity in a patient with aphasia. The patient, a 53 year old left handed woman, presented with frequent phonemic paraphasias and word-finding difficulty following a patchy right-hemispheric ischemic stroke affecting the temporo-parietal region, basal ganglia, and portions of occipital cortex. These results suggest she showed right hemisphere linguistic dominance premorbidly. Screening using the PAL (Caplan& Bub, 1990 revealed deficits in phoneme discrimination and auditory word-picture matching with preserved auditory lexical decision. She was tested twice on a go/no-go auditory word picture matching task one month post-onset, and again six months later while simultaneous MEG and EEG data were acquired. She achieved 59% accuracy at the initial testing, and 85% accuracy on retest. Source space reconstructions of activity between 100-400 msec after the onset of the spoken word (before the visual probe stimulus showed strong perilesional activation with moderate activation of left hemisphere language areas. When tested 6 months later perilesional activation was significantly reduced, but left hemisphere activation was stronger. Kalman-filter enabled Granger analyses (Gow & Caplan, 2012 of the same MR-constrained MEG/EEG data showed little evidence of interaction or either intra- or interhemispheric interactions between activated regions at one month post onset. At seven months, the network

Short-Term Memory Impairment and Left Dorsolateral Prefrontal Cortex Dysfunction in the Orthostatic Position: A Single Case Study of Sinking Skin Flap Syndrome

Directory of Open Access Journals (Sweden)

Luca Sebastianelli

2015-01-01

Full Text Available We describe the case of a patient who underwent craniectomy for hemorrhage of the left parietal lobe. Three weeks later, orthostatic memory impairment was detected as initial symptom of sinking skin flap syndrome (SSFS. This deficit was examined by neuropsychological testing and associated with a posture-dependent increase in the delta/alpha ratio at the F3 electrode, an electroencephalographic (EEG index related to brain hypoperfusion. This EEG spectral alteration was detected in a brain region that includes the left dorsolateral prefrontal cortex, an area known to be involved in memory processing; therefore we hypothesize that SSFS induced reversible hypoperfusion of this otherwise undamaged cortical region. Neither of these findings was present after cranioplasty. This case suggests that SSFS may induce neuropsychological deficits potentially influencing outcome in the postacute phase and is further evidence supporting the clinical benefits of early cranioplasty.

Effect of myocardial viability in the infarct area on regional left ventricular function

International Nuclear Information System (INIS)

Ishii, Toshihiko; Watanabe, Takeshi; Usui, Mikio; Nagai, Yoshikazu

1990-01-01

This study explored the relationship between global left ventricular ejection fraction (LVEF), regional LVEF of infarct myocardium, and the viability of the myocardium due to the development of collaterals in the infarct area. Each was evaluated by exercise thallium-201 myocardial SPECT, multigated blood pool scintigraphy and coronary angiography. A total of 68 patients with old anteroseptal myocardial infarction and 23 normal persons were studied. The patients were found to have septal defect on exercise thallium images. According to the appearance of redistribution (RD) on delayed images, the patients were classified as having positive RD (n=42, 62%) or negative RD (n=26, 38%). The global LVEF was compared with regional LVEF of the basal, middle and apical areas within septum, as calculated by multigated blood pool scintigraphy. There was no significant difference in global LVEF between the groups of positive and negative RD patients. However, regional LVEF of the basal and middle areas was significantly larger in the group of positive RD than the group of negative RD. Collaterals were significantly observed in the group of positive RD, as compared with the group of negative RD (53% vs 25%). It was more frequent in cases of higher degree of stenosis. In the group of negative RD, none of the patients had collaterals when coronary stenosis was 90% or less. Redistribution may reflect myocardial viability. Myocardial viability within the infarct area had favorable influences on the regional left ventricular function. Therefore, not only global but also regional left ventricular function is necessary for better understanding of pathophysiology of myocardial infarction.(N.K.)

Sensory-parietal cortical stimulation improves motor recovery in severe capsular infarct.

Science.gov (United States)

Kim, Ra Gyung; Cho, Jongwook; Ree, Jinkyue; Kim, Hyung-Sun; Rosa-Neto, Pedro; Kim, Jin-Myung; Lee, Min-Cheol; Kim, Hyoung-Ihl

2016-12-01

The prevalence of subcortical white matter strokes in elderly patients is on the rise, but these patients show mixed responses to conventional rehabilitative interventions. To examine whether cortical electrical stimulation can promote motor recovery after white matter stroke, we delivered stimulation to a small or wide region of sensory-parietal cortex for two weeks in a rodent model of circumscribed subcortical capsular infarct. The sham-operated group (SOG) showed persistent and severe motor impairments together with decreased activation in bilateral sensorimotor cortices and striatum. In contrast, sensory-parietal cortex stimulation significantly improved motor recovery: final recovery levels were 72.9% of prelesion levels in the wide stimulation group (WSG) and 37% of prelesion levels in the small stimulation group (SSG). The microPET imaging showed reversal of cortical diaschisis in both groups: in both hemispheres for the WSG, and in the hemisphere ipsilateral to stimulation in the SSG. In addition, we observed activation of the corpus callosum and subcortical corticostriatal structures after stimulation. The results from the c-Fos mapping study were grossly consistent with the microPET imaging. Sensory-parietal cortex stimulation may therefore be a useful strategy for overcoming the limits of rehabilitative training in patients with severe forms of subcortical capsular infarct. © The Author(s) 2015.

Management of temporo-mandibular joint ankylosis in growing children.

Science.gov (United States)

Shashikiran, N D; Reddy, S V V; Patil, R; Yavagal, C

2005-03-01

Although temporo-mandibular joint (TMJ) ankylosis is one of the most common pathologies afflicting the facial skeleton, it is also the most overlooked and under-managed problem in children. The TMJ forms the very cornerstone of cranio-facial integrity and hence its ankylosis in growing children adversely affects the growth and development of the jaws and occlusion. Impairment of speech, difficulty in mastication, poor oral hygiene, rampant caries and acute compromise of the airway pose a severe psychologic burden on the tender minds of children. The aim of this article is to present an overview of efficient management strategies, based on a case report, so as to increase its awareness among all dental surgeons involved in the treatment of children.

Management of temporo-mandibular joint ankylosis in growing children

Directory of Open Access Journals (Sweden)

Shashikiran N

2005-03-01

Full Text Available Although temporo-mandibular joint (TMJ ankylosis is one of the most common pathologies afflicting the facial skeleton, it is also the most overlooked and under-managed problem in children. The TMJ forms the very cornerstone of cranio-facial integrity and hence its ankylosis in growing children adversely affects the growth and development of the jaws and occlusion. Impairment of speech, difficulty in mastication, poor oral hygiene, rampant caries and acute compromise of the airway pose a severe psychologic burden on the tender minds of children. The aim of this article is to present an overview of efficient management strategies, based on a case report, so as to increase its awareness among all dental surgeons involved in the treatment of children.

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

Science.gov (United States)

Cohen, Michael X; Ridderinkhof, K Richard

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz), followed by a later alpha-band (8-12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

EEG source reconstruction reveals frontal-parietal dynamics of spatial conflict processing.

Directory of Open Access Journals (Sweden)

Michael X Cohen

Full Text Available Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus conflict modulation in stimulus-contralateral parietal gamma (30-50 Hz, followed by a later alpha-band (8-12 Hz conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4-8 Hz, alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions.

EEG Source Reconstruction Reveals Frontal-Parietal Dynamics of Spatial Conflict Processing

Science.gov (United States)

Cohen, Michael X; Ridderinkhof, K. Richard

2013-01-01

Cognitive control requires the suppression of distracting information in order to focus on task-relevant information. We applied EEG source reconstruction via time-frequency linear constrained minimum variance beamforming to help elucidate the neural mechanisms involved in spatial conflict processing. Human subjects performed a Simon task, in which conflict was induced by incongruence between spatial location and response hand. We found an early (∼200 ms post-stimulus) conflict modulation in stimulus-contralateral parietal gamma (30–50 Hz), followed by a later alpha-band (8–12 Hz) conflict modulation, suggesting an early detection of spatial conflict and inhibition of spatial location processing. Inter-regional connectivity analyses assessed via cross-frequency coupling of theta (4–8 Hz), alpha, and gamma power revealed conflict-induced shifts in cortical network interactions: Congruent trials (relative to incongruent trials) had stronger coupling between frontal theta and stimulus-contrahemifield parietal alpha/gamma power, whereas incongruent trials had increased theta coupling between medial frontal and lateral frontal regions. These findings shed new light into the large-scale network dynamics of spatial conflict processing, and how those networks are shaped by oscillatory interactions. PMID:23451201

THE PRIMACY EFFECT IN AMNESTIC MILD COGNITIVE IMPAIRMENT: ASSOCIATIONS WITH HIPPOCAMPAL FUNCTIONAL CONNECTIVITY

Directory of Open Access Journals (Sweden)

Katharina Brueggen

2016-10-01

Full Text Available BackgroundThe primacy effect, i.e., increased memory recall for the first items of a series compared to the following items, is reduced in amnestic mild cognitive impairment (aMCI. Memory task-fMRI studies showed that primacy recall is associated with higher activation of the hippocampus and temporo-parietal and frontal cortical regions in healthy subjects. Functional magnetic resonance imaging (fMRI at resting state showed that hippocampus functional connectivity (FC with neocortical brain areas, including regions of the default mode network (DMN, is altered in aMCI. The present study aimed to investigate whether resting state fMRI FC between the hippocampus and cortical brain regions, especially the DMN, is associated with primacy recall performance in aMCI. MethodsA number of 87 aMCI patients underwent resting state fMRI and verbal episodic memory assessment. FC between the left or right hippocampus, respectively, and all other voxels in grey matter was mapped voxel-wise and used in whole-brain regression analyses, testing whether FC values predicted delayed primacy recall score. The delayed primacy score was defined as the number of the first four words recalled on the California Verbal Learning Test. Additionally, a partial least squares analysis (PLS was performed, using DMN regions as seeds to identify the association of their functional interactions with delayed primacy recall.ResultsVoxel-based analyses showed that delayed primacy recall was mainly (positively associated with higher FC between the left and right hippocampus. Additionally, significant associations were found for higher FC between the left hippocampus and bilateral temporal cortex, frontal cortical regions, and for higher FC between the right hippocampus and right temporal cortex, right frontal cortical regions, left medial frontal cortex and right amygdala (p < 0.01, uncorr.. PLS analysis revealed positive associations of delayed primacy recall with FC between regions of

Impact of Human like Cues on Human Trust in Machines: Brain Imaging and Modeling Studies for Human-Machine Interactions

Science.gov (United States)

2018-01-05

opponent had some human-likeness. In particular, the research shows that activity in the left parietal region correlating with a human players future ...human-likeness. In particular, our research shows that activity in the left parietal region correlating with a human player’s future behavior can be...this work. - Emotional Conversational Agent: The 4th Korean Flagship AI Project, from December 2016 to December 2020, about US$14,000,000 (Principal

Functional Heterogeneity in Posterior Parietal Cortex Across Attention and Episodic Memory Retrieval

Science.gov (United States)

Hutchinson, J. Benjamin; Uncapher, Melina R.; Weiner, Kevin S.; Bressler, David W.; Silver, Michael A.; Preston, Alison R.; Wagner, Anthony D.

2014-01-01

While attention is critical for event memory, debate has arisen regarding the extent to which posterior parietal cortex (PPC) activation during episodic retrieval reflects engagement of PPC-mediated mechanisms of attention. Here, we directly examined the relationship between attention and memory, within and across subjects, using functional magnetic resonance imaging attention-mapping and episodic retrieval paradigms. During retrieval, 4 functionally dissociable PPC regions were identified. Specifically, 2 PPC regions positively tracked retrieval outcomes: lateral intraparietal sulcus (latIPS) indexed graded item memory strength, whereas angular gyrus (AnG) tracked recollection. By contrast, 2 other PPC regions demonstrated nonmonotonic relationships with retrieval: superior parietal lobule (SPL) tracked retrieval reaction time, consistent with a graded engagement of top-down attention, whereas temporoparietal junction displayed a complex pattern of below-baseline retrieval activity, perhaps reflecting disengagement of bottom-up attention. Analyses of retrieval effects in PPC topographic spatial attention maps (IPS0-IPS5; SPL1) revealed that IPS5 and SPL1 exhibited a nonmonotonic relationship with retrieval outcomes resembling that in the SPL region, further suggesting that SPL activation during retrieval reflects top-down attention. While demands on PPC attention mechanisms vary during retrieval attempts, the present functional parcellation of PPC indicates that 2 additional mechanisms (mediated by latIPS and AnG) positively track retrieval outcomes. PMID:23019246

A robust automated left ventricle region of interest localization technique using a cardiac cine MRI atlas

Science.gov (United States)

Ben-Zikri, Yehuda Kfir; Linte, Cristian A.

2016-03-01

Region of interest detection is a precursor to many medical image processing and analysis applications, including segmentation, registration and other image manipulation techniques. The optimal region of interest is often selected manually, based on empirical knowledge and features of the image dataset. However, if inconsistently identified, the selected region of interest may greatly affect the subsequent image analysis or interpretation steps, in turn leading to incomplete assessment during computer-aided diagnosis or incomplete visualization or identification of the surgical targets, if employed in the context of pre-procedural planning or image-guided interventions. Therefore, the need for robust, accurate and computationally efficient region of interest localization techniques is prevalent in many modern computer-assisted diagnosis and therapy applications. Here we propose a fully automated, robust, a priori learning-based approach that provides reliable estimates of the left and right ventricle features from cine cardiac MR images. The proposed approach leverages the temporal frame-to-frame motion extracted across a range of short axis left ventricle slice images with small training set generated from les than 10% of the population. This approach is based on histogram of oriented gradients features weighted by local intensities to first identify an initial region of interest depicting the left and right ventricles that exhibits the greatest extent of cardiac motion. This region is correlated with the homologous region that belongs to the training dataset that best matches the test image using feature vector correlation techniques. Lastly, the optimal left ventricle region of interest of the test image is identified based on the correlation of known ground truth segmentations associated with the training dataset deemed closest to the test image. The proposed approach was tested on a population of 100 patient datasets and was validated against the ground truth

The parietal memory network activates similarly for true and associative false recognition elicited via the DRM procedure.

Science.gov (United States)

McDermott, Kathleen B; Gilmore, Adrian W; Nelson, Steven M; Watson, Jason M; Ojemann, Jeffrey G

2017-02-01

Neuroimaging investigations of human memory encoding and retrieval have revealed that multiple regions of parietal cortex contribute to memory. Recently, a sparse network of regions within parietal cortex has been identified using resting state functional connectivity (MRI techniques). The regions within this network exhibit consistent task-related responses during memory formation and retrieval, leading to its being called the parietal memory network (PMN). Among its signature patterns are: deactivation during initial experience with an item (e.g., encoding); activation during subsequent repetitions (e.g., at retrieval); greater activation for successfully retrieved familiar words than novel words (e.g., hits relative to correctly-rejected lures). The question of interest here is whether novel words that are subjectively experienced as having been recently studied would elicit PMN activation similar to that of hits. That is, we compared old items correctly recognized to two types of novel items on a recognition test: those correctly identified as new and those incorrectly labeled as old due to their strong associative relation to the studied words (in the DRM false memory protocol). Subjective oldness plays a strong role in driving activation, as hits and false alarms activated similarly (and greater than correctly-rejected lures). Copyright © 2016 Elsevier Ltd. All rights reserved.

Interleukin-17A Promotes Parietal Cell Atrophy by Inducing ApoptosisSummary

Directory of Open Access Journals (Sweden)

Kevin A. Bockerstett

Full Text Available Background & Aims: Atrophic gastritis caused by chronic inflammation in the gastric mucosa leads to the loss of gastric glandular cells, including acid-secreting parietal cells. Parietal cell atrophy in a setting of chronic inflammation induces spasmolytic polypeptide expressing metaplasia, a critical step in gastric carcinogenesis. However, the mechanisms by which inflammation causes parietal cell atrophy and spasmolytic polypeptide expressing metaplasia are not well defined. We investigated the role of interleukin-17A (IL-17A in causing parietal cell atrophy. Methods: A mouse model of autoimmune atrophic gastritis was used to examine IL-17A production during early and late stages of disease. Organoids derived from corpus glands were used to determine the direct effects of IL-17A on gastric epithelial cells. Immunofluorescent staining was used to examine IL-17A receptors and the direct effect of signaling on parietal cells. Mice were infected with an IL-17A-producing adenovirus to determine the effects of IL-17A on parietal cells in vivo. Finally, IL-17A neutralizing antibodies were administered to mice with active atrophic gastritis to evaluate the effects on parietal cell atrophy and metaplasia. Results: Increased IL-17A correlated with disease severity in mice with chronic atrophic gastritis. IL-17A caused caspase-dependent gastric organoid degeneration, which could not be rescued with a necroptosis inhibitor. Parietal cells expressed IL-17A receptors and IL-17A treatment induced apoptosis in parietal cells. Overexpressing IL-17A in vivo induced caspase-3 activation and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate nick-end labeling staining in parietal cells. Finally, IL-17A neutralizing antibody decreased parietal cell atrophy and metaplasia in mice with chronic atrophic gastritis. Conclusions: These data identify IL-17A as a cytokine that promotes parietal cell apoptosis during atrophic gastritis, a

Global left ventricular function in cardiac CT. Evaluation of an automated 3D region-growing segmentation algorithm

International Nuclear Information System (INIS)

Muehlenbruch, Georg; Das, Marco; Hohl, Christian; Wildberger, Joachim E.; Guenther, Rolf W.; Mahnken, Andreas H.; Rinck, Daniel; Flohr, Thomas G.; Koos, Ralf; Knackstedt, Christian

2006-01-01

The purpose was to evaluate a new semi-automated 3D region-growing segmentation algorithm for functional analysis of the left ventricle in multislice CT (MSCT) of the heart. Twenty patients underwent contrast-enhanced MSCT of the heart (collimation 16 x 0.75 mm; 120 kV; 550 mAseff). Multiphase image reconstructions with 1-mm axial slices and 8-mm short-axis slices were performed. Left ventricular volume measurements (end-diastolic volume, end-systolic volume, ejection fraction and stroke volume) from manually drawn endocardial contours in the short axis slices were compared to semi-automated region-growing segmentation of the left ventricle from the 1-mm axial slices. The post-processing-time for both methods was recorded. Applying the new region-growing algorithm in 13/20 patients (65%), proper segmentation of the left ventricle was feasible. In these patients, the signal-to-noise ratio was higher than in the remaining patients (3.2±1.0 vs. 2.6±0.6). Volume measurements of both segmentation algorithms showed an excellent correlation (all P≤0.0001); the limits of agreement for the ejection fraction were 2.3±8.3 ml. In the patients with proper segmentation the mean post-processing time using the region-growing algorithm was diminished by 44.2%. On the basis of a good contrast-enhanced data set, a left ventricular volume analysis using the new semi-automated region-growing segmentation algorithm is technically feasible, accurate and more time-effective. (orig.)

The Role of Insula-Associated Brain Network in Touch

Science.gov (United States)

Bao, Ruixue

2013-01-01

The insula is believed to be associated with touch-evoked effects. In this work, functional MRI was applied to investigate the network model of insula function when 20 normal subjects received tactile stimulation over segregated areas. Data analysis was performed with SPM8 and Conn toolbox. Activations in the contralateral posterior insula were consistently revealed for all stimulation areas, with the overlap located in area Ig2. The area Ig2 was then used as the seed to estimate the insula-associated network. The right insula, left superior parietal lobule, left superior temporal gyrus, and left inferior parietal cortex showed significant functional connectivity with the seed region for all stimulation conditions. Connectivity maps of most stimulation conditions were mainly distributed in the bilateral insula, inferior parietal cortex, and secondary somatosensory cortex. Post hoc ROI-to-ROI analysis and graph theoretical analysis showed that there were higher correlations between the left insula and the right insula, left inferior parietal cortex and right OP1 for all networks and that the global efficiency was more sensitive than the local efficiency to detect differences between notes in a network. These results suggest that the posterior insula serves as a hub to functionally connect other regions in the detected network and may integrate information from these regions. PMID:23936840

Phonological ambiguity modulates resolution of semantic ambiguity during reading: An fMRI study of Hebrew.

Science.gov (United States)

Bitan, Tali; Kaftory, Asaf; Meiri-Leib, Adi; Eviatar, Zohar; Peleg, Orna

2017-10-01

The current fMRI study examined the role of phonology in the extraction of meaning from print in each hemisphere by comparing homophonic and heterophonic homographs (ambiguous words in which both meanings have the same or different sounds respectively, e.g., bank or tear). The analysis distinguished between the first phase, in which participants read ambiguous words without context, and the second phase in which the context resolves the ambiguity. Native Hebrew readers were scanned during semantic relatedness judgments on pairs of words in which the first word was either a homophone or a heterophone and the second word was related to its dominant or subordinate meaning. In Phase 1 there was greater activation for heterophones in left inferior frontal gyrus (IFG), pars opercularis, and more activation for homophones in bilateral IFG pars orbitalis, suggesting that resolution of the conflict at the phonological level has abolished the semantic ambiguity for heterophones. Reduced activation for all ambiguous words in temporo-parietal regions suggests that although ambiguity enhances controlled lexical selection processes in frontal regions it reduces reliance on bottom-up mapping processes. After presentation of the context, a larger difference between the dominant and subordinate meaning was found for heterophones in all reading-related regions, suggesting a greater engagement for heterophones with the dominant meaning. Altogether these results are consistent with the prominent role of phonological processing in visual word recognition. Finally, despite differences in hemispheric asymmetry between homophones and heterophones, ambiguity resolution, even toward the subordinate meaning, is largely left lateralized. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Regional homogeneity of the resting-state brain activity correlates with individual intelligence.

Science.gov (United States)

Wang, Leiqiong; Song, Ming; Jiang, Tianzi; Zhang, Yunting; Yu, Chunshui

2011-01-25

Resting-state functional magnetic resonance imaging has confirmed that the strengths of the long distance functional connectivity between different brain areas are correlated with individual differences in intelligence. However, the association between the local connectivity within a specific brain region and intelligence during rest remains largely unknown. The aim of this study is to investigate the relationship between local connectivity and intelligence. Fifty-nine right-handed healthy adults participated in the study. The regional homogeneity (ReHo) was used to assess the strength of local connectivity. The associations between ReHo and full-scale intelligence quotient (FSIQ) scores were studied in a voxel-wise manner using partial correlation analysis controlling for age and sex. We found that the FSIQ scores were positively correlated with the ReHo values of the bilateral inferior parietal lobules, middle frontal, parahippocampal and inferior temporal gyri, the right thalamus, superior frontal and fusiform gyri, and the left superior parietal lobule. The main findings are consistent with the parieto-frontal integration theory (P-FIT) of intelligence, supporting the view that general intelligence involves multiple brain regions throughout the brain. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Optimizing estimation of hemispheric dominance for language using magnetic source imaging.

Science.gov (United States)

Passaro, Antony D; Rezaie, Roozbeh; Moser, Dana C; Li, Zhimin; Dias, Nadeeka; Papanicolaou, Andrew C

2011-10-06

The efficacy of magnetoencephalography (MEG) as an alternative to invasive methods for investigating the cortical representation of language has been explored in several studies. Recently, studies comparing MEG to the gold standard Wada procedure have found inconsistent and often less-than accurate estimates of laterality across various MEG studies. Here we attempted to address this issue among normal right-handed adults (N=12) by supplementing a well-established MEG protocol involving word recognition and the single dipole method with a sentence comprehension task and a beamformer approach localizing neural oscillations. Beamformer analysis of word recognition and sentence comprehension tasks revealed a desynchronization in the 10-18Hz range, localized to the temporo-parietal cortices. Inspection of individual profiles of localized desynchronization (10-18Hz) revealed left hemispheric dominance in 91.7% and 83.3% of individuals during the word recognition and sentence comprehension tasks, respectively. In contrast, single dipole analysis yielded lower estimates, such that activity in temporal language regions was left-lateralized in 66.7% and 58.3% of individuals during word recognition and sentence comprehension, respectively. The results obtained from the word recognition task and localization of oscillatory activity using a beamformer appear to be in line with general estimates of left hemispheric dominance for language in normal right-handed individuals. Furthermore, the current findings support the growing notion that changes in neural oscillations underlie critical components of linguistic processing. Published by Elsevier B.V.

Distributed patterns of occipito-parietal functional connectivity predict the precision of visual working memory.

Science.gov (United States)

Galeano Weber, Elena M; Hahn, Tim; Hilger, Kirsten; Fiebach, Christian J

2017-02-01

Limitations in visual working memory (WM) quality (i.e., WM precision) may depend on perceptual and attentional limitations during stimulus encoding, thereby affecting WM capacity. WM encoding relies on the interaction between sensory processing systems and fronto-parietal 'control' regions, and differences in the quality of this interaction are a plausible source of individual differences in WM capacity. Accordingly, we hypothesized that the coupling between perceptual and attentional systems affects the quality of WM encoding. We combined fMRI connectivity analysis with behavioral modeling by fitting a variable precision and fixed capacity model to the performance data obtained while participants performed a visual delayed continuous response WM task. We quantified functional connectivity during WM encoding between occipital and parietal brain regions activated during both perception and WM encoding, as determined using a conjunction of two independent experiments. The multivariate pattern of voxel-wise inter-areal functional connectivity significantly predicted WM performance, most specifically the mean of WM precision but not the individual number of items that could be stored in memory. In particular, higher occipito-parietal connectivity was associated with higher behavioral mean precision. These results are consistent with a network perspective of WM capacity, suggesting that the efficiency of information flow between perceptual and attentional neural systems is a critical determinant of limitations in WM quality. Copyright © 2016 Elsevier Inc. All rights reserved.

How specialized are writing-specific brain regions? An fMRI study of writing, drawing and oral spelling.

Science.gov (United States)

Planton, Samuel; Longcamp, Marieke; Péran, Patrice; Démonet, Jean-François; Jucla, Mélanie

2017-03-01

Several brain imaging studies identified brain regions that are consistently involved in writing tasks; the left premotor and superior parietal cortices have been associated with the peripheral components of writing performance as opposed to other regions that support the central, orthographic components. Based on a meta-analysis by Planton, Jucla, Roux, and Demonet (2013), we focused on five such writing areas and questioned the task-specificity and hemispheric lateralization profile of the brain response in an functional magnetic resonance imaging (fMRI) experiment where 16 right-handed participants wrote down, spelled out orally object names, and drew shapes from object pictures. All writing-related areas were activated by drawing, and some of them by oral spelling, thus questioning their specialization for written production. The graphemic/motor frontal area (GMFA), a subpart of the superior premotor cortex close to Exner's area (Roux et al., 2009), was the only area with a writing-specific lateralization profile, that is, clear left lateralization during handwriting, and bilateral activity during drawing. Furthermore, the relative lateralization and levels of activation in the superior parietal cortex, ventral premotor cortex, ventral occipitotemporal cortex and right cerebellum across the three tasks brought out new evidence regarding their respective contributions to the writing processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Coherence and phase synchrony analyses of EEG signals in Mild Cognitive Impairment (MCI): A study of functional brain connectivity

Science.gov (United States)

Handayani, Nita; Haryanto, Freddy; Khotimah, Siti Nurul; Arif, Idam; Taruno, Warsito Purwo

2018-03-01

This paper presents an EEG study for coherence and phase synchrony in mild cognitive impairment (MCI) subjects. MCI is characterized by cognitive decline, which is an early stage of Alzheimer's disease (AD). AD is a neurodegenerative disorder with symptoms such as memory loss and cognitive impairment. EEG coherence is a statistical measure of correlation between signals from electrodes spatially separated on the scalp. The magnitude of phase synchrony is expressed in the phase locking value (PLV), a statistical measure of neuronal connectivity in the human brain. Brain signals were recorded using an Emotiv Epoc 14-channel wireless EEG at a sampling frequency of 128 Hz. In this study, we used 22 elderly subjects consisted of 10 MCI subjects and 12 healthy subjects as control group. The coherence between each electrode pair was measured for all frequency bands (delta, theta, alpha and beta). In the MCI subjects, the value of coherence and phase synchrony was generally lower than in the healthy subjects especially in the beta frequency. A decline of intrahemisphere coherence in the MCI subjects occurred in the left temporo-parietal-occipital region. The pattern of decline in MCI coherence is associated with decreased cholinergic connectivity along the path that connects the temporal, occipital, and parietal areas of the brain to the frontal area of the brain. EEG coherence and phase synchrony are able to distinguish persons who suffer AD in the early stages from healthy elderly subjects.

Self vs. other: neural correlates underlying agent identification based on unimodal auditory information as revealed by electrotomography (sLORETA).

Science.gov (United States)

Justen, C; Herbert, C; Werner, K; Raab, M

2014-02-14

Recent neuroscientific studies have identified activity changes in an extensive cerebral network consisting of medial prefrontal cortex, precuneus, temporo-parietal junction, and temporal pole during the perception and identification of self- and other-generated stimuli. Because this network is supposed to be engaged in tasks which require agent identification, it has been labeled the evaluation network (e-network). The present study used self- versus other-generated movement sounds (long jumps) and electroencephalography (EEG) in order to unravel the neural dynamics of agent identification for complex auditory information. Participants (N=14) performed an auditory self-other identification task with EEG. Data was then subjected to a subsequent standardized low-resolution brain electromagnetic tomography (sLORETA) analysis (source localization analysis). Differences between conditions were assessed using t-statistics (corrected for multiple testing) on the normalized and log-transformed current density values of the sLORETA images. Three-dimensional sLORETA source localization analysis revealed cortical activations in brain regions mostly associated with the e-network, especially in the medial prefrontal cortex (bilaterally in the alpha-1-band and right-lateralized in the gamma-band) and the temporo-parietal junction (right hemisphere in the alpha-1-band). Taken together, the findings are partly consistent with previous functional neuroimaging studies investigating unimodal visual or multimodal agent identification tasks (cf. e-network) and extent them to the auditory domain. Cortical activations in brain regions of the e-network seem to have functional relevance, especially the significantly higher cortical activation in the right medial prefrontal cortex. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

Regional wall movement of the left ventricle in coronary heat diseases

International Nuclear Information System (INIS)

Schad, N.

1979-01-01

The regional wall movement of the left ventriculus is a substantial criterion for the treatment of coronary heart diseases. The non-invasive and riskless intravenous injections of a bolus of Technetium 99m-Pertechnetat and the recording of the first passage through the heart allow to present the regional wall movement of the left ventriculus and, in addition, to make a statement on the haemodynamic feed back effects on lungs and the right heart. The congruency with the wall movement determined invasively, in the contrast substance angiocardiogram, is high both for the normokinesis and for hypo-, A - and dyskinesis (90-92%). The examination proved good in following groups of patients and makes the decision on the further proceding easier: 1) After myocardial infarction. 2) In ishaemia-ECG or persistent ST-elevation. 3) In unstable progressive angina pectoris. 4) In unclear breast aches and negative ECG on exertion. 5) For course control after conservative and surgial therapy. The myocardial reserve can be shown using a after nitroglycerin administration. An investigation on exertion can find out affected vessel territories in the circulation. (orig.) [de

Mechanisms of recovery from aphasia: evidence from serial xenon 133 cerebral blood flow studies

International Nuclear Information System (INIS)

Knopman, D.S.; Rubens, A.B.; Selnes, O.A.; Klassen, A.C.; Meyer, M.W.

1984-01-01

In 21 patients who suffered aphasia resulting from left hemisphere ischemic infarction, the xenon 133 inhalation cerebral blood flow technique was used to measure cerebral blood flow within 3 months and 5 to 12 months after stroke. In addition to baseline measurements, cerebral blood flow measurements were also carried out while the patients were performing purposeful listening. In patients with incomplete recovery of comprehension and left posterior temporal-inferior parietal lesions, greater cerebral blood flow occurred with listening in the right inferior frontal region in the late studies than in the early studies. In patients with nearly complete recovery of comprehension and without left posterior temporal-inferior parietal lesions, early listening studies showed diffuse right hemisphere increases in cerebral blood flow. Later listening studies in this latter patient group showed greater cerebral blood flow in the left posterior temporal-inferior parietal region. The study provides evidence for participation of the right hemisphere in language comprehension in recovering aphasics, and for later return of function in left hemisphere regions that may have been functionally impaired early during recovery

Parietal Lobe Volume Deficits in Adolescents with Schizophrenia and Adolescents with Cannabis Use Disorders

Science.gov (United States)

Kumra, Sanjiv; Robinson, Paul; Tambyraja, Rabindra; Jensen, Daniel; Schimunek, Caroline; Houri, Alaa; Reis, Tiffany; Lim, Kelvin

2012-01-01

Objective: In early-onset schizophrenia (EOS), the earliest structural brain volumetric abnormalities appear in the parietal cortices. Early exposure to cannabis may represent an environmental risk factor for developing schizophrenia. This study characterized cerebral cortical gray matter structure in adolescents in regions of interest (ROIs) that…

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size.

Science.gov (United States)

Song, Chen; Sandberg, Kristian; Andersen, Lau Møller; Blicher, Jakob Udby; Rees, Geraint

2017-09-13

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Human Occipital and Parietal GABA Selectively Influence Visual Perception of Orientation and Size

Science.gov (United States)

Andersen, Lau Møller; Blicher, Jakob Udby

2017-01-01

GABA is the primary inhibitory neurotransmitter in human brain. The level of GABA varies substantially across individuals, and this variability is associated with interindividual differences in visual perception. However, it remains unclear whether the association between GABA level and visual perception reflects a general influence of visual inhibition or whether the GABA levels of different cortical regions selectively influence perception of different visual features. To address this, we studied how the GABA levels of parietal and occipital cortices related to interindividual differences in size, orientation, and brightness perception. We used visual contextual illusion as a perceptual assay since the illusion dissociates perceptual content from stimulus content and the magnitude of the illusion reflects the effect of visual inhibition. Across individuals, we observed selective correlations between the level of GABA and the magnitude of contextual illusion. Specifically, parietal GABA level correlated with size illusion magnitude but not with orientation or brightness illusion magnitude; in contrast, occipital GABA level correlated with orientation illusion magnitude but not with size or brightness illusion magnitude. Our findings reveal a region- and feature-dependent influence of GABA level on human visual perception. Parietal and occipital cortices contain, respectively, topographic maps of size and orientation preference in which neural responses to stimulus sizes and stimulus orientations are modulated by intraregional lateral connections. We propose that these lateral connections may underlie the selective influence of GABA on visual perception. SIGNIFICANCE STATEMENT GABA, the primary inhibitory neurotransmitter in human visual system, varies substantially across individuals. This interindividual variability in GABA level is linked to interindividual differences in many aspects of visual perception. However, the widespread influence of GABA raises the

Oclusión y estrés en el síndrome dolor disfunción temporo-mandibular

Directory of Open Access Journals (Sweden)

María del Carmen García Cubillas

2015-04-01

Full Text Available Se reporta el caso de una paciente femenina de 35 años con síndrome dolor disfunción temporo-mandibular, cuyo motivo de consulta fue el dolor relacionado con el lado no habitual de masticación y de dormir. Los datos fueron tomados de su historia clínica inicial. El diagnóstico se realizó fundamentalmente por el método clínico. Para ello se hizo interrogatorio y el examen clínico de músculos, articulaciones temporo-mandibulares y oclusión. Se detectaron como posibles causas el estrés y una interferencia oclusal grosera. Se realizó un tratamiento múltiple: laserterapia, exodoncias, control de las interferencias oclusales, control de placa dentobacteriana e higiene bucal, charlas educativas y remisión al psicólogo. La paciente evolucionó favorablemente

Estudos sobre thrombose cardiaca e endocardite parietal de origem não valvular On thrombosis of heart and on mural endocarditis of non-valvular origin

Directory of Open Access Journals (Sweden)

C. Magarinos Torres

1928-01-01

is foamy and blood-streaked than by the classic signs. Cerebral embolism was a terminal accident on various cases. Yet, in some of them, along with the signs of septicemia and of cardiac insufficiency, occurred vascular, arterial (abdominal aorta, common illiac and femurals arteries and venous (extern jugular veins thromboses. 5. The autopsy revealed an inflammatory process located on the parietal endocardium, accompanied by abundant formation of ancient and recent thrombi, being the apex of the left ventricle, the junction of the anterior wall of the same ventricle, with the interventricular septum, and the right auricular appendage, the usual seats of the inflammatory changes. The region of the left branch of HIS’ bundle is spared. The other changes found consist of fibrosis of the myocardium (healed infarcts and circumscribed interstitial myocarditis, of recent visceral infarcts chiefly in lungs, spleen and brain, of recent or old infarcts in the kidneys (embolic nephrocirrhosis and in the spleen, and of vascular thromboses (abdominal aorta, common illiacs and femurals arteries and external jugular veins, aside from hydrothorax, hydroperitoneum, cutaneous oedema, chronic passive congestion of the liver, lungs, spleen and kidneys and slight ictericia. 6. In the subacute parietal endocarditis the primary lesions sometimes locate themselves at the myocardium, depending on the ischemic necrosis associated to the arteriosclerosis of the coronariae arteries, or on an specific myocarditis. Other times, the absence of these conditions is suggestive of a primary attack to the parietal endocardium which is then the primary seat of the lesions. It matters little whatever may be the initial pathogenic mechanism; once injured the parietal endocardium and there being settled the infectious injury, the endocarditis develops with peculiar clinical and anatomical characters of remarkable uniformity, constituting an anatomo-clinical syndrome. 7.-The histologic sections show that

Altered regional homogeneity of spontaneous brain activity in idiopathic trigeminal neuralgia.

Science.gov (United States)

Wang, Yanping; Zhang, Xiaoling; Guan, Qiaobing; Wan, Lihong; Yi, Yahui; Liu, Chun-Feng

2015-01-01

The pathophysiology of idiopathic trigeminal neuralgia (ITN) has conventionally been thought to be induced by neurovascular compression theory. Recent structural brain imaging evidence has suggested an additional central component for ITN pathophysiology. However, far less attention has been given to investigations of the basis of abnormal resting-state brain activity in these patients. The objective of this study was to investigate local brain activity in patients with ITN and its correlation with clinical variables of pain. Resting-state functional magnetic resonance imaging data from 17 patients with ITN and 19 age- and sex-matched healthy controls were analyzed using regional homogeneity (ReHo) analysis, which is a data-driven approach used to measure the regional synchronization of spontaneous brain activity. Patients with ITN had decreased ReHo in the left amygdala, right parahippocampal gyrus, and left cerebellum and increased ReHo in the right inferior temporal gyrus, right thalamus, right inferior parietal lobule, and left postcentral gyrus (corrected). Furthermore, the increase in ReHo in the left precentral gyrus was positively correlated with visual analog scale (r=0.54; P=0.002). Our study found abnormal functional homogeneity of intrinsic brain activity in several regions in ITN, suggesting the maladaptivity of the process of daily pain attacks and a central role for the pathophysiology of ITN.

Highly religious participants recruit areas of social cognition in personal prayer

Science.gov (United States)

Stødkilde-Jørgensen, Hans; Geertz, Armin W.; Roepstorff, Andreas

2009-01-01

We used functional magnetic resonance imaging (fMRI) to investigate how performing formalized and improvised forms of praying changed the evoked BOLD response in a group of Danish Christians. Distinct from formalized praying and secular controls, improvised praying activated a strong response in the temporopolar region, the medial prefrontal cortex, the temporo-parietal junction and precuneus. This finding supports our hypothesis that religious subjects, who consider their God to be ‘real’ and capable of reciprocating requests, recruit areas of social cognition when they pray. We argue that praying to God is an intersubjective experience comparable to ‘normal’ interpersonal interaction. PMID:19246473

Acute hepatic encephalopathy presenting as cortical laminar necrosis: Case report

International Nuclear Information System (INIS)

Choi, Jong Mun; Kim, Yoon Hee; Roh, Sook Young

2013-01-01

We report on a 55-year-old man with alcoholic liver cirrhosis who presented with status epilepticus. Laboratory analysis showed markedly elevated blood ammonia. Brain magnetic resonance imaging (MRI) showed widespread cortical signal changes with restricted diffusion, involving both temporo-fronto-parietal cortex, while the perirolandic regions and occipital cortex were uniquely spared. A follow-up brain MRI demonstrated diffuse cortical atrophy with increased signals on T1-weighted images in both the basal ganglia and temporal lobe cortex, representing cortical laminar necrosis. We suggest that the brain lesions, in our case, represent a consequence of toxic effect of ammonia.

Acute hepatic encephalopathy presenting as cortical laminar necrosis: Case report

Energy Technology Data Exchange (ETDEWEB)

Choi, Jong Mun; Kim, Yoon Hee; Roh, Sook Young [Bundang Jesaeng General Hospital, Daejin Medical Center, Seongnam (Korea, Republic of)

2013-04-15

We report on a 55-year-old man with alcoholic liver cirrhosis who presented with status epilepticus. Laboratory analysis showed markedly elevated blood ammonia. Brain magnetic resonance imaging (MRI) showed widespread cortical signal changes with restricted diffusion, involving both temporo-fronto-parietal cortex, while the perirolandic regions and occipital cortex were uniquely spared. A follow-up brain MRI demonstrated diffuse cortical atrophy with increased signals on T1-weighted images in both the basal ganglia and temporal lobe cortex, representing cortical laminar necrosis. We suggest that the brain lesions, in our case, represent a consequence of toxic effect of ammonia.

Cerebral blood flow in normal and abnormal sleep and dreaming

International Nuclear Information System (INIS)

Meyer, J.S.; Ishikawa, Y.; Hata, T.; Karacan, I.

1987-01-01

Measurements of regional or local cerebral blood flow (CBF) by the xenon-133 inhalation method and stable xenon computerized tomography CBF (CTCBF) method were made during relaxed wakefulness and different stages of REM and non-REM sleep in normal age-matched volunteers, narcoleptics, and sleep apneics. In the awake state, CBF values were reduced in both narcoleptics and sleep apneics in the brainstem and cerebellar regions. During sleep onset, whether REM or stage I-II, CBF values were paradoxically increased in narcoleptics but decreased severely in sleep apneics, while in normal volunteers they became diffusely but more moderately decreased. In REM sleep and dreaming CBF values greatly increased, particularly in right temporo-parietal regions in subjects experiencing both visual and auditory dreaming

Effects of mental rotation on acalculia: differences in the direction of mental rotation account for the differing characteristics of acalculia induced by right and left hemispheric brain injury.

Science.gov (United States)

Asada, Tomohiko; Takayama, Yoshihiro; Oita, Jiro; Fukuyama, Hidenao

2014-04-01

We observed a 59-year-old right-handed man with an infarction in his right-middle cerebral artery that included the parietal lobe, who abnormally manipulated mental images in the horizontal direction, resulting in calculation disturbances. Three years later, the patient suffered an infarction in the left parietal lobe and displayed abnormalities during the creation of mental images; i.e., he rotated them in the vertical direction, which again resulted in calculation disturbances. These mental imagery disturbances might indicate that a common acalculia mechanism exists between the right and left hemispheres.

Effects of traumatic brain injury on regional cerebral blood flow in rats as measured with radiolabeled microspheres

International Nuclear Information System (INIS)

Yamakami, I.; McIntosh, T.K.

1989-01-01

To clarify the effect of experimental brain injury on regional CBF (rCBF), repeated rCBF measurements were performed using radiolabeled microspheres in rats subjected to fluid-percussion traumatic brain injury. Three consecutive microsphere injections in six uninjured control rats substantiated that the procedure induces no significant changes in hemodynamic variables or rCBF. Animals were subjected to left parietal fluid-percussion brain injury of moderate severity (2.1-2.4 atm) and rCBF values were determined (a) prior to injury and 15 min and 1 h following injury (n = 7); and (b) prior to injury and 30 min and 2 h following injury (n = 7). At 15 min post injury, there was a profound reduction of rCBF in all brain regions studied (p less than 0.01). Although rCBF in the hindbrain had recovered to near-normal by 30 min post injury, rCBF in both injured and contralateral (uninjured) forebrain areas remained significantly suppressed up to 1 h post injury. At 2 h post injury, recovery of rCBF to near-normal values was observed in all brain regions except the focal area of injury (left parietal cortex) where rCBF remained significantly depressed (p less than 0.01). This prolonged focal oligemia at the injury site was associated with the development of reproducible cystic necrosis in the left parietotemporal cortex at 4 weeks post injury. Our results demonstrate that acute changes in rCBF occur following experimental traumatic brain injury in rats and that rCBF remains significantly depressed up to 2 h post injury in the area circumscribing the trauma site

Multimodal responses induced by cortical stimulation of the parietal lobe: a stereo-electroencephalography study.

Science.gov (United States)

Balestrini, Simona; Francione, Stefano; Mai, Roberto; Castana, Laura; Casaceli, Giuseppe; Marino, Daniela; Provinciali, Leandro; Cardinale, Francesco; Tassi, Laura

2015-09-01

revision of electrical stimulation of the entire parietal cortex with the aim to evaluate the neurophysiology of this relevant brain region. Our analysis offers a general overview of the multiple roles of the parietal cortex and supports its crucial involvement in different networks related to complex integrative functions.media-1vid110.1093/brain/awv187_video_abstractawv187_video_abstract. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Using three-dimensional-computerized tomography as a diagnostic tool for temporo-mandibular joint ankylosis: a case report.

Science.gov (United States)

Kao, S Y; Chou, J; Lo, J; Yang, J; Chou, A P; Joe, C J; Chang, R C

1999-04-01

Roentgenographic examination has long been a useful diagnostic tool for temporo-mandibular joint (TMJ) disease. The methods include TMJ tomography, panoramic radiography and computerized tomography (CT) scan with or without injection of contrast media. Recently, three-dimensional CT (3D-CT), reconstructed from the two-dimensional image of a CT scan to simulate the soft tissue or bony structure of the real target, was proposed. In this report, a case of TMJ ankylosis due to traumatic injury is presented. 3D-CT was employed as one of the presurgical roentgenographic diagnostic tools. The conventional radiographic examination including panoramic radiography and tomography showed lesions in both sides of the mandible. CT scanning further suggested that the right-sided lesion was more severe than that on the left. With 3D-CT image reconstruction the size and extent of the lesions were clearly observable. The decision was made to proceed with an initial surgical approach on the right side. With condylectomy and condylar replacement using an autogenous costochondral graft on the right side, the range of mouth opening improved significantly. In this case report, 3D-CT demonstrates its advantages as a tool for the correct and precise diagnosis of TMJ ankylosis.

Amygdala, Pulvinar & Inferior Parietal Cortex Contribute to Early Processing of Faces without Awareness

Directory of Open Access Journals (Sweden)

Vanessa eTroiani

2013-06-01

Full Text Available The goals of the present study were twofold. First, we wished to investigate the neural correlates of stimulus-driven processing of stimuli strongly suppressed from awareness and in the absence of top-down influences. We accomplished this using a novel approach in which participants performed an orthogonal task atop a flash suppression noise image to prevent top-down search. Second, we wished to investigate the extent to which amygdala responses differentiate between suppressed stimuli (fearful faces and houses based on their motivational relevance. Using continuous flash suppression in conjunction with fMRI, we presented fearful faces, houses, and a no stimulus control to one eye while participants performed an orthogonal task that appeared atop the flashing Mondrian image presented to the opposite eye. In 29 adolescents, we show activation in subcortical regions, including the superior colliculus, amygdala, thalamus, and hippocampus for suppressed objects (fearful faces and houses compared to a no stimulus control. Suppressed stimuli showed less activation compared to a no stimulus control in early visual cortex, indicating that object information was being suppressed from this region. Additionally, we find no activation in regions associated with conscious processing of these percepts (fusiform gyrus and/or parahippocampal cortex as assessed by mean activations and multi-voxel patterns. A psychophysiological interaction analysis that seeded the amygdala showed task-specific (fearful faces greater than houses modulation of right pulvinar and left inferior parietal cortex. Taken together, our results support a role for the amygdala in stimulus-driven attentional guidance towards objects of relevance and a potential mechanism for successful suppression of rivalrous stimuli.

[Functional connectivity of temporal parietal junction in online game addicts:a resting-state functional magnetic resonance imaging study].

Science.gov (United States)

Yuan, Ji; Qian, Ruobing; Lin, Bin; Fu, Xianming; Wei, Xiangpin; Weng, Chuanbo; Niu, Chaoshi; Wang, Yehan

2014-02-11

To explore the functions of temporal parietal junction (TPJ) as parts of attention networks in the pathogenesis of online game addiction using resting-state functional magnetic resonance imaging (fMRI). A total of 17 online game addicts (OGA) were recruited as OGA group and 17 healthy controls during the same period were recruited as CON group. The neuropsychological tests were performed for all of them to compare the inter-group differences in the results of Internet Addiction Test (IAT) and attention functions. All fMRI data were preprocessed after resting-state fMRI scanning. Then left and right TPJ were selected as regions of interest (ROIs) to calculate the linear correlation between TPJ and entire brain to compare the inter-group differences. Obvious differences existed between OGA group (71 ± 5 scores) and CON group (19 ± 7 scores) in the IAT results and attention function (P online game addicts showed decreased functional connectivity with bilateral ventromedial prefrontal cortex (VMPFC), bilateral hippocampal gyrus and bilateral amygdaloid nucleus, but increased functional connectivity with right cuneus.However, left TPJ demonstrated decreased functional connectivity with bilateral superior frontal gyrus and bilateral middle frontal gyrus, but increased functional connectivity with bilateral cuneus (P online game addicts.It suggests that TPJ is an important component of attention networks participating in the generation of online game addiction.

Evaluating the roles of the inferior frontal gyrus and superior parietal lobule in deductive reasoning: an rTMS study.

Science.gov (United States)

Tsujii, Takeo; Sakatani, Kaoru; Masuda, Sayako; Akiyama, Takekazu; Watanabe, Shigeru

2011-09-15

This study used off-line repetitive transcranial magnetic stimulation (rTMS) to examine the roles of the superior parietal lobule (SPL) and inferior frontal gyrus (IFG) in a deductive reasoning task. Subjects performed a categorical syllogistic reasoning task involving congruent, incongruent, and abstract trials. Twenty four subjects received magnetic stimulation to the SPL region prior to the task. In the other 24 subjects, TMS was administered to the IFG region before the task. Stimulation lasted for 10min, with an inter-pulse frequency of 1Hz. We found that bilateral SPL (Brodmann area (BA) 7) stimulation disrupted performance on abstract and incongruent reasoning. Left IFG (BA 45) stimulation impaired congruent reasoning performance while paradoxically facilitating incongruent reasoning performance. This resulted in the elimination of the belief-bias. In contrast, right IFG stimulation only impaired incongruent reasoning performance, thus enhancing the belief-bias effect. These findings are largely consistent with the dual-process theory of reasoning, which proposes the existence of two different human reasoning systems: a belief-based heuristic system; and a logic-based analytic system. The present findings suggest that the left language-related IFG (BA 45) may correspond to the heuristic system, while bilateral SPL may underlie the analytic system. The right IFG may play a role in blocking the belief-based heuristic system for solving incongruent reasoning trials. This study could offer an insight about functional roles of distributed brain systems in human deductive reasoning by utilizing the rTMS approach. Copyright © 2011 Elsevier Inc. All rights reserved.

Abnormal resting state effective connectivity within the default mode network in major depressive disorder: A spectral dynamic causal modeling study.

Science.gov (United States)

Li, Liang; Li, Baojuan; Bai, Yuanhan; Liu, Wenlei; Wang, Huaning; Leung, Hoi-Chung; Tian, Ping; Zhang, Linchuan; Guo, Fan; Cui, Long-Biao; Yin, Hong; Lu, Hongbing; Tan, Qingrong

2017-07-01

Understanding the neural basis underlying major depressive disorder (MDD) is essential for the diagnosis and treatment of this mental disorder. Aberrant activation and functional connectivity of the default mode network (DMN) have been consistently found in patients with MDD. It is not known whether effective connectivity within the DMN is altered in MDD. The primary object of this study is to investigate the effective connectivity within the DMN during resting state in MDD patients before and after eight weeks of antidepressant treatment. We defined four regions of the DMN (medial frontal cortex, posterior cingulate cortex, left parietal cortex, and right parietal cortex) for each participant using a group independent component analysis. The coupling parameters reflecting the causal interactions among the DMN regions were estimated using spectral dynamic causal modeling (DCM). Twenty-seven MDD patients and 27 healthy controls were included in the statistical analysis. Our results showed declined influences from the left parietal cortex to other DMN regions in the pre-treatment patients as compared with healthy controls. After eight weeks of treatment, the influence from the right parietal cortex to the posterior cingulate cortex significantly decreased. These findings suggest that the reduced excitatory causal influence of the left parietal cortex is the key alteration of the DMN in patients with MDD, and the disrupted causal influences that parietal cortex exerts on the posterior cingulate cortex is responsive to antidepressant treatment.

Temporal Fourier transform of digital angiograms for left ventricular regional wall motion analysis

International Nuclear Information System (INIS)

Katayama, Kazuhiro; Guth, B.D.; Widmann, T.F.; Lee, Jong-Dae; Seitelberger, R.; Peterson, K.L.

1988-01-01

To determine whether or not the first harmonic of a temporal Fourier transform, applied pixel-by-pixel on time-intensity curves, can detect the subtle wall motion abnormalities due to ischemia, 6 dogs were instrumented with a micromanometer in the left ventricles, a hydraulic cuff occluder around the circumflex coronary artery, and sonomicrometers on the inferior (ischemic) and anterior (non-ischemic) walls. Left ventricular images, obtained after contrast injection via the pulmonary artery, were compared with dimension signals in control and 3 progressive levels of coronary stenosis (Stenosis I, II and III). Normalized, digital functional images (512 x 512 matrix, 256 shades of gray/pixel) were divided into anterior, apical, and inferior areas to acquire regional mean phase (degrees) and amplitude (intensity units) values. After inducing stenosis, phase in ischemic region significantly increased at all 3 levels of stenosis, whereas amplitude significantly decreased at Stenosis II and III. However, amplitude images showed clearly the topographic site of ischemia. There was a progressive increase in phase and decrease in amplitude in ischemic areas as the percent wall thickening (%WTh) fell (phase vs. %WTh: r = -0.55, p < 0.005; amplitude vs. %WTh: r = 0.71, p < 0.001). Heart rate and peak systolic pressure showed no significant changes during stenoses. We conclude that quantitative functional images, generated from a temporal Fourier transform, are sensitive to the detection of left ventricular regional wall motion abnormalities during mild, moderate, and severe degrees of ischemia. (author)

Prospective relations between resting-state connectivity of parietal subdivisions and arithmetic competence.

Science.gov (United States)

Price, Gavin R; Yeo, Darren J; Wilkey, Eric D; Cutting, Laurie E

2018-04-01

The present study investigates the relation between resting-state functional connectivity (rsFC) of cytoarchitectonically defined subdivisions of the parietal cortex at the end of 1st grade and arithmetic performance at the end of 2nd grade. Results revealed a dissociable pattern of relations between rsFC and arithmetic competence among subdivisions of intraparietal sulcus (IPS) and angular gyrus (AG). rsFC between right hemisphere IPS subdivisions and contralateral IPS subdivisions positively correlated with arithmetic competence. In contrast, rsFC between the left hIP1 and the right medial temporal lobe, and rsFC between the left AG and left superior frontal gyrus, were negatively correlated with arithmetic competence. These results suggest that strong inter-hemispheric IPS connectivity is important for math development, reflecting either neurocognitive mechanisms specific to arithmetic processing, domain-general mechanisms that are particularly relevant to arithmetic competence, or structural 'cortical maturity'. Stronger connectivity between IPS, and AG, subdivisions and frontal and temporal cortices, however, appears to be negatively associated with math development, possibly reflecting the ability to disengage suboptimal problem-solving strategies during mathematical processing, or to flexibly reorient task-based networks. Importantly, the reported results pertain even when controlling for reading, spatial attention, and working memory, suggesting that the observed rsFC-behavior relations are specific to arithmetic competence. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

Directory of Open Access Journals (Sweden)

Marjolijn Hoekert

Full Text Available In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms. Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction, revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become

Time course of the involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum in emotional prosody perception.

Science.gov (United States)

Hoekert, Marjolijn; Bais, Leonie; Kahn, René S; Aleman, André

2008-05-21

In verbal communication, not only the meaning of the words convey information, but also the tone of voice (prosody) conveys crucial information about the emotional state and intentions of others. In various studies right frontal and right temporal regions have been found to play a role in emotional prosody perception. Here, we used triple-pulse repetitive transcranial magnetic stimulation (rTMS) to shed light on the precise time course of involvement of the right anterior superior temporal gyrus and the right fronto-parietal operculum. We hypothesized that information would be processed in the right anterior superior temporal gyrus before being processed in the right fronto-parietal operculum. Right-handed healthy subjects performed an emotional prosody task. During listening to each sentence a triplet of TMS pulses was applied to one of the regions at one of six time points (400-1900 ms). Results showed a significant main effect of Time for right anterior superior temporal gyrus and right fronto-parietal operculum. The largest interference was observed half-way through the sentence. This effect was stronger for withdrawal emotions than for the approach emotion. A further experiment with the inclusion of an active control condition, TMS over the EEG site POz (midline parietal-occipital junction), revealed stronger effects at the fronto-parietal operculum and anterior superior temporal gyrus relative to the active control condition. No evidence was found for sequential processing of emotional prosodic information from right anterior superior temporal gyrus to the right fronto-parietal operculum, but the results revealed more parallel processing. Our results suggest that both right fronto-parietal operculum and right anterior superior temporal gyrus are critical for emotional prosody perception at a relatively late time period after sentence onset. This may reflect that emotional cues can still be ambiguous at the beginning of sentences, but become more apparent half

Aging and sex influence the permeability of the blood-brain barrier in the rat

International Nuclear Information System (INIS)

Saija, A.; Princi, P.; D'Amico, N.; De Pasquale, R.; Costa, G.

1990-01-01

The aim of the present study was to investigate the existence of aging- and sex-related alterations in the permeability of the blood-brain barrier (BBB) in the rat, by calculating a unidirectional blood-to-brain transfer constant (Ki) for the circulating tracer [ 14 C]-α-aminoisobutyric acid. The authors observed that: (a) the permeability of the BBB significantly increased within the frontal and temporo-parietal cortex, hypothalamus and cerebellum in 28-30 week old rats, in comparison with younger animals; (b) in several brain areas of female intact rats higher Ki values (even though not significantly different) were calculated at oestrus than at proestrus; (c) in 1-week ovariectomized rats there was a marked increase of Ki values at the level of the frontal, temporo-parietal and occipital cortex, cerebellum and brain-stem. One can speculate that aging and sex-related alterations in thee permeability of the BBB reflect respectively changes in brain neurochemical system activity and in plasma steroid hormone levels

Abnormal language-related oscillatory responses in primary progressive aphasia

Directory of Open Access Journals (Sweden)

A. Kielar

Full Text Available Patients with Primary Progressive Aphasia (PPA may react to linguistic stimuli differently than healthy controls, reflecting degeneration of language networks and engagement of compensatory mechanisms. We used magnetoencephalography (MEG to evaluate oscillatory neural responses in sentence comprehension, in patients with PPA and age-matched controls. Participants viewed sentences containing semantically and syntactically anomalous words that evoke distinct oscillatory responses. For age-matched controls, semantic anomalies elicited left-lateralized 8–30 Hz power decreases distributed along ventral brain regions, whereas syntactic anomalies elicited bilateral power decreases in both ventral and dorsal regions. In comparison to controls, patients with PPA showed altered patterns of induced oscillations, characterized by delayed latencies and attenuated amplitude, which were correlated with linguistic impairment measured offline. The recruitment of right hemisphere temporo-parietal areas (also found in controls was correlated with preserved semantic processing abilities, indicating that preserved neural activity in these regions was able to support successful semantic processing. In contrast, syntactic processing was more consistently impaired in PPA, regardless of neural activity patterns, suggesting that this domain of language is particularly vulnerable to the neuronal loss. In addition, we found that delayed peak latencies of oscillatory responses were associated with lower accuracy for detecting semantic anomalies, suggesting that language deficits observed in PPA may be linked to delayed or slowed information processing. Keywords: MEG oscillations, Primary progressive aphasia (PPA, Sentence comprehension

Socio-Cognitive Phenotypes Differentially Modulate Large-Scale Structural Covariance Networks.

Science.gov (United States)

Valk, Sofie L; Bernhardt, Boris C; Böckler, Anne; Trautwein, Fynn-Mathis; Kanske, Philipp; Singer, Tania

2017-02-01

Functional neuroimaging studies have suggested the existence of 2 largely distinct social cognition networks, one for theory of mind (taking others' cognitive perspective) and another for empathy (sharing others' affective states). To address whether these networks can also be dissociated at the level of brain structure, we combined behavioral phenotyping across multiple socio-cognitive tasks with 3-Tesla MRI cortical thickness and structural covariance analysis in 270 healthy adults, recruited across 2 sites. Regional thickness mapping only provided partial support for divergent substrates, highlighting that individual differences in empathy relate to left insular-opercular thickness while no correlation between thickness and mentalizing scores was found. Conversely, structural covariance analysis showed clearly divergent network modulations by socio-cognitive and -affective phenotypes. Specifically, individual differences in theory of mind related to structural integration between temporo-parietal and dorsomedial prefrontal regions while empathy modulated the strength of dorsal anterior insula networks. Findings were robust across both recruitment sites, suggesting generalizability. At the level of structural network embedding, our study provides a double dissociation between empathy and mentalizing. Moreover, our findings suggest that structural substrates of higher-order social cognition are reflected rather in interregional networks than in the the local anatomical markup of specific regions per se. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A region-specific quantitative profile of autonomic innervation of the canine left atrium and pulmonary veins.

Science.gov (United States)

Gao, Chong-han; Wang, Fei; Jiang, Rong; Zhang, Jin; Mou, Huamin; Yin, Yue-hui

2011-07-05

The aim of the present study was to determine and quantify the cardiac autonomic innervation of the canine atria and pulmonary vein. Tissue specimens were taken from the canine pulmonary veins (PVs), posterior left atrium (PLA), left atrial roof (LAR), anterior left atrium (ALA), interatrial septum (IAS), and left atrial appendage (LAA) respectively for immunohistochemical analysis and nerve density determination. Both sympathetic and parasympathetic nerve densities decreased in the order: PLA>PV>IAS>LAR>ALA>LAA. For sympathetic nerve, multiple comparisons between any two regions showed a significant difference (PIAS vs. LAR, and LAR vs. ALA; for parasympathetic nerve, all the differences between any pair of regions were statistically significant (PIAS vs. LAR, LAR vs. ALA, and ALA vs. LAA. For both nerve types, there was a decreasing gradient of nerve densities from the external to internal layer (P<0.001, for each comparisons). Nerve density at the ostia for either nerve type was significantly higher than at the distal segments of PVs (P<0.001). In summary, the LA and PVs are innervated by sympathetic and parasympathetic nerves in a regionally heterogeneous way, which may be important for the pathophysiological investigation and ablation therapy of atrial fibrillation (AF). Copyright © 2011 Elsevier B.V. All rights reserved.

Abnormal regional homogeneity in patients with essential tremor revealed by resting-state functional MRI.

Directory of Open Access Journals (Sweden)

Weidong Fang

Full Text Available Essential tremor (ET is one of the most common movement disorders in human adults. It can be characterized as a progressive neurological disorder of which the most recognizable feature is a tremor of the arms or hands that is apparent during voluntary movements such as eating and writing. The pathology of ET remains unclear. Resting-state fMRI (RS-fMRI, as a non-invasive imaging technique, was employed to investigate abnormalities of functional connectivity in ET in the brain. Regional homogeneity (ReHo was used as a metric of RS-fMRI to assess the local functional connectivity abnormality in ET with 20 ET patients and 20 age- and gender-matched healthy controls (HC. The ET group showed decreased ReHo in the anterior and posterior bilateral cerebellar lobes, the bilateral thalamus and the insular lobe, and increased ReHo in the bilateral prefrontal and parietal cortices, the left primary motor cortex and left supplementary motor area. The abnormal ReHo value of ET patients in the bilateral anterior cerebellar lobes and the right posterior cerebellar lobe were negatively correlated with the tremor severity score, while positively correlated with that in the left primary motor cortex. These findings suggest that the abnormality in cerebello-thalamo-cortical motor pathway is involved in tremor generation and propagation, which may be related to motor-related symptoms in ET patients. Meanwhile, the abnormality in the prefrontal and parietal regions may be associated with non-motor symptoms in ET. These findings suggest that the ReHo could be utilized for investigations of functional-pathological mechanism of ET.

The effects of background noise on dichotic listening to consonant-vowel syllables: An fMRI study.

Science.gov (United States)

Dos Santos Sequeira, Sarah; Specht, Karsten; Moosmann, Matthias; Westerhausen, Rene; Hugdahl, Kenneth

2010-11-01

The present fMRI study attempts to identify brain areas that may underlie the effect of different background noises on functional brain asymmetry in a dichotic listening task. Previous studies have shown that the prominent right ear advantage in dichotic listening to consonant-vowel syllables is affected by background noise. To explore the underlying neuronal processes, haemodynamic brain responses using fMRI were recorded while participants performed the dichotic listening task in two different noisy backgrounds (conversational "babble" and traffic noise). The behavioural results showed a reduction of the right ear advantage in the background noise conditions, especially in the traffic noise condition. The behavioural results are discussed in terms of alertness-attentional mechanisms. The effects of background noise on brain activation involved significant activations in a speech-processing network. Specifically the changes in activations in the peri-Sylvian region of the superior temporal gyrus and in the temporo-parietal junction part in the left hemisphere, as well as in the superior temporal gyrus/sulcus area in the right hemisphere may mirror the effects of noise on behavioural performance. The effects of noise on brain activation are discussed with regard to pre-activation mechanisms.

Differential involvement of left prefrontal cortex in inductive and deductive reasoning.

Science.gov (United States)

Goel, Vinod; Dolan, Raymond J

2004-10-01

While inductive and deductive reasoning are considered distinct logical and psychological processes, little is known about their respective neural basis. To address this issue we scanned 16 subjects with fMRI, using an event-related design, while they engaged in inductive and deductive reasoning tasks. Both types of reasoning were characterized by activation of left lateral prefrontal and bilateral dorsal frontal, parietal, and occipital cortices. Neural responses unique to each type of reasoning determined from the Reasoning Type (deduction and induction) by Task (reasoning and baseline) interaction indicated greater involvement of left inferior frontal gyrus (BA 44) in deduction than induction, while left dorsolateral (BA 8/9) prefrontal gyrus showed greater activity during induction than deduction. This pattern suggests a dissociation within prefrontal cortex for deductive and inductive reasoning.

Elaboration versus suppression of cued memories: influence of memory recall instruction and success on parietal lobe, default network, and hippocampal activity.

Science.gov (United States)

Gimbel, Sarah I; Brewer, James B

2014-01-01

Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7), posterior ventral (BA 39), and anterior ventral (BA 40) regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength.

Elaboration versus suppression of cued memories: influence of memory recall instruction and success on parietal lobe, default network, and hippocampal activity.

Directory of Open Access Journals (Sweden)

Sarah I Gimbel

Full Text Available Functional imaging studies of episodic memory retrieval consistently report task-evoked and memory-related activity in the medial temporal lobe, default network and parietal lobe subregions. Associated components of memory retrieval, such as attention-shifts, search, retrieval success, and post-retrieval processing also influence regional activity, but these influences remain ill-defined. To better understand how top-down control affects the neural bases of memory retrieval, we examined how regional activity responses were modulated by task goals during recall success or failure. Specifically, activity was examined during memory suppression, recall, and elaborative recall of paired-associates. Parietal lobe was subdivided into dorsal (BA 7, posterior ventral (BA 39, and anterior ventral (BA 40 regions, which were investigated separately to examine hypothesized distinctions in sub-regional functional responses related to differential attention-to-memory and memory strength. Top-down suppression of recall abolished memory strength effects in BA 39, which showed a task-negative response, and BA 40, which showed a task-positive response. The task-negative response in default network showed greater negatively-deflected signal for forgotten pairs when task goals required recall. Hippocampal activity was task-positive and was influenced by memory strength only when task goals required recall. As in previous studies, we show a memory strength effect in parietal lobe and hippocampus, but we show that this effect is top-down controlled and sensitive to whether the subject is trying to suppress or retrieve a memory. These regions are all implicated in memory recall, but their individual activity patterns show distinct memory-strength-related responses when task goals are varied. In parietal lobe, default network, and hippocampus, top-down control can override the commonly identified effects of memory strength.

Tinnitus in patients with temporo-mandibular joint disorder: Proposal for a new treatment protocol.

Science.gov (United States)

Attanasio, Giuseppe; Leonardi, Alessandra; Arangio, Paolo; Minni, Antonio; Covelli, Edoardo; Pucci, Resi; Russo, Francesca Yoshie; De Seta, Elio; Di Paolo, Carlo; Cascone, Piero

2015-06-01

The present study was designed to verify the correlation between tinnitus and temporomandibular joint dysfunction.86 consecutive patients were enrolled in the study, all affected by subjective tinnitus without hearing impairment, from both genders, age between 18 and 60 years old. The final number of patients included in the study was 55. All patients received a temporo-mandibular joint examination. All the patients were asked to rate the severity of their symptoms before and after treatment using a VAS scale and the Tinnitus Handicap Inventory (THI) and they followed a standardized protocol for the investigation of tinnitus. All the subjects were monitored by the same researcher and they underwent the same splint treatment. The comparison between pre- and posttreatment phase scores showed in patients with predisposition of TMD and with TMD a statistically significant decrease of THI and VAS values. The characteristics of tinnitus and the degree of response to treatment confirmed the relationship between tinnitus and TMD. The authors believe that, when the most common causes of tinnitus, such as otologic disorders and neurological diseases are excluded, it is correct to evaluate the functionality of the temporo-mandibular joint and eventually treat its pathology to obtain tinnitus improvement or even resolution. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Analysis of the relationship between myocardial viability and regional left ventricular wall motion

International Nuclear Information System (INIS)

Furutani, Yuhji; Ozaki, Masaharu; Yamamoto, Takeshi; Sato, Shinichi; Saiki, Atsushi; Kusukawa, Reizo

1993-01-01

Myocardial viability was determined by using postsystolic shortening (PSS) as an index, as obtained by cardiac blood pool scintigraphy with Tc-99m HSA. The findings were compared with those of thallium-201 myocardial SPECT. The study population was comparised of 41 patients with single blood vessel disease in the left anterior descending artery (34 with old myocardial infarction and 7 with effort angina pectoris). Left ventricular area was divided into 6 segments, and global and regional left ventricular blood volume curves were obtained. Delayed end-systole was the most common in the apex (41%), followed by the upper septum (37%) and lower septum (10%). PSS resulting from delayed end-systole was seen in 36 areas. PSS/end-diastolic volume (EDV) and PSS/systolic volume (SV) were obtained by adjusting end-diastolic and stroke counts, respectively. Thallium-201 myocardial SPECT images were divided into 5 segments to obtain defect score (DS) for visual Tl uptake. Both PSS/EDV and PSS/SV were greater in association with more delayed end-systole, greater DS, and lower reginal ejection fraction. Areas showing greater PSS were associated with less myocardial viability, as observed on Tl myocardial SPECT images. Thus, PSS seemed to reflect the degree of myocardial necrosis within the region of interest. (N.K.)

Unimodal and multimodal regions for logographic language processing in left ventral occipitotemporal cortex

Directory of Open Access Journals (Sweden)

Yuan eDeng

2013-09-01

Full Text Available The human neocortex appears to contain a dedicated visual word form area (VWFA and an adjacent multimodal (visual/auditory area. However, these conclusions are based on functional magnetic resonance imaging (fMRI of alphabetic language processing, languages that have clear grapheme-to-phoneme correspondence (GPC rules that make it difficult to disassociate visual-specific processing from form-to-sound mapping. In contrast, the Chinese language has no clear GPC rules. Therefore, the current study examined whether native Chinese readers also have the same VWFA and multimodal area. Two cross-modal tasks, phonological retrieval of visual words and orthographic retrieval of auditory words, were adopted. Different task requirements were also applied to explore how different levels of cognitive processing modulate activation of putative VWFA-like and multimodal-like regions. Results showed that the left occipitotemporal sulcus responded exclusively to visual inputs and an adjacent region, the left inferior temporal gyrus, showed comparable activation for both visual and auditory inputs. Surprisingly, processing levels did not significantly alter activation of these two regions. These findings indicated that there are both unimodal and multimodal word areas for non-alphabetic language reading, and that activity in these two word-specific regions are independent of task demands at the linguistic level.

Isolation, culture and adenoviral transduction of parietal cells from mouse gastric mucosa

International Nuclear Information System (INIS)

Gliddon, Briony L; Nguyen, Nhung V; Gunn, Priscilla A; Gleeson, Paul A; Driel, Ian R van

2008-01-01

Here we describe a method for the isolation of intact gastric glands from mice and primary culture and transfection of mouse gastric epithelial cells. Collagenase digestion of PBS-perfused mouse stomachs released large intact gastric glands that were plated on a basement membrane matrix. The heterogeneous gland cell cultures typically contain ∼60% parietal cells. Isolated mouse parietal cells remain viable in culture for up to 5 days and react strongly with an antibody specific to the gastric H + /K + ATPase. Isolated intact mouse gastric glands and primary cultures of mouse parietal cells respond to the secretagogue, histamine. Typical morphological changes from a resting to an acid-secreting active parietal cell were observed. In resting cultures of mouse parietal cells, the H + /K + ATPase displayed a cytoplasmic punctate staining pattern consistent with tubulovesicle element structures. Following histamine stimulation, an expansion of internal apical vacuole structures was observed together with a pronounced redistribution of the H + /K + ATPase from the cytoplasm to the apical vacuoles. A reproducible procedure to express genes of interest exogenously in these cultures of mouse parietal cells was also established. This method combines recombinant adenoviral transduction with magnetic field-assisted transfection resulting in ∼30% transduced parietal cells. Adenoviral-transduced parietal cells maintain their ability to undergo agonist-induced activation. This protocol will be useful for the isolation, culture and expression of genes in parietal cells from genetically modified mice and as such will be an invaluable tool for studying the complex exocytic and endocytic trafficking events of the H + /K + ATPase which underpin the regulation of acid secretion

The effect of dual-hemisphere transcranial direct current stimulation over the parietal operculum on tactile orientation discrimination

DEFF Research Database (Denmark)

Fujimoto, Shuhei; Tanaka, Satoshi; Laakso, Ilkka

2017-01-01

The parietal operculum (PO) often shows ipsilateral activation during tactile object perception in neuroimaging experiments. However, the relative contribution of the PO to tactile judgment remains unclear. Here, we examined the effect of transcranial direct current stimulation (tDCS) over...... bilateral PO to test the relative contributions of the ipsilateral PO to tactile object processing. Ten healthy adults participated in this study, which had a double-blind, sham-controlled, cross-over design. Participants discriminated grating orientation during three tDCS and sham conditions. In the dual......-hemisphere tDCS conditions, anodal and cathodal electrodes were placed over the left and right PO. In the uni-hemisphere tDCS condition, anodal and cathodal electrodes were applied over the left PO and contralateral orbit, respectively. In the tDCS and sham conditions, we applied 2 mA for 15 min and for 15 s...

Inferior parietal and right frontal contributions to trial-by-trial adaptations of attention to memory.

Science.gov (United States)

Kizilirmak, Jasmin M; Rösler, Frank; Bien, Siegfried; Khader, Patrick H

2015-07-21

The attention to memory theory (AtoM) proposes that the same brain regions might be involved in selective processing of perceived stimuli (selective attention) and memory representations (selective retrieval). Although this idea is compelling, given consistently found neural overlap between perceiving and remembering stimuli, recent comparisons brought evidence for overlap as well as considerable differences. Here, we present a paradigm that enables the investigation of the AtoM hypothesis from a novel perspective to gain further insight into the neural resources involved in AtoM. Selective attention in perception is often investigated as a control process that shows lingering effects on immediately following trials. Here, we employed a paradigm capable of modulating selective retrieval in a similarly dynamic manner as in such selective-attention paradigms by inducing trial-to-trial shifts between relevant and irrelevant memory representations as well as changes of the width of the internal focus on memory. We found evidence for an involvement of bilateral inferior parietal lobe and right inferior frontal gyrus in reorienting the attentional focus on previously accessed memory representations. Moreover, we could dissociate the right inferior from the parietal activation in separate contrasts, suggesting that the right inferior frontal gyrus plays a role in facilitating attentional reorienting to memory representations when competing representations have been activated in the preceding trial, potentially by resolving this competition. Our results support the AtoM theory, i.e. that ventral frontal and parietal regions are involved in automatic attentional reorienting in memory, and highlight the importance of further investigations of the overlap and differences between regions involved in internal (memory) and external (perceptual) attentional selection. Copyright © 2015 Elsevier B.V. All rights reserved.

Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

International Nuclear Information System (INIS)

Bueltmann, Eva; Lanfermann, Heinrich; Naegele, Thomas; Klose, Uwe

2017-01-01

We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging.

Science.gov (United States)

Bültmann, Eva; Nägele, Thomas; Lanfermann, Heinrich; Klose, Uwe

2017-01-01

We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic.

Changes of brain metabolite concentrations during maturation in different brain regions measured by chemical shift imaging

Energy Technology Data Exchange (ETDEWEB)

Bueltmann, Eva; Lanfermann, Heinrich [Hannover Medical School, Institute of Diagnostic and Interventional Neuroradiology, Hannover (Germany); Naegele, Thomas [University of Tuebingen, Department of Diagnostic and Interventional Neuroradiology, Radiological University Hospital, Tuebingen (Germany); Klose, Uwe [University of Tuebingen, Section of Experimental MR of the CNS, Department of Neuroradiology, Radiological University Hospital, Tuebingen (Germany)

2017-01-15

We examined the effect of maturation on the regional distribution of brain metabolite concentrations using multivoxel chemical shift imaging. From our pool of pediatric MRI examinations, we retrospectively selected patients showing a normal cerebral MRI scan or no pathologic signal abnormalities at the level of the two-dimensional 1H MRS-CSI sequence and an age-appropriate global neurological development, except for focal neurological deficits. Seventy-one patients (4.5 months-20 years) were identified. Using LC Model, spectra were evaluated from voxels in the white matter, caudate head, and corpus callosum. The concentration of total N-acetylaspartate increased in all regions during infancy and childhood except in the right caudate head where it remained constant. The concentration of total creatine decreased in the caudate nucleus and splenium and minimally in the frontal white matter and genu. It remained largely constant in the parietal white matter. The concentration of choline-containing compounds had the tendency to decrease in all regions except in the parietal white matter where it remained constant. The concentration of myoinositol decreased slightly in the splenium and right frontal white matter, remained constant on the left side and in the caudate nucleus, and rose slightly in the parietal white matter and genu. CSI determined metabolite concentrations in multiple cerebral regions during routine MRI. The obtained data will be helpful in future pediatric CSI measurements deciding whether the ratios of the main metabolites are within the range of normal values or have to be considered as probably pathologic. (orig.)

Individual variation in intentionality in the mind-wandering state is reflected in the integration of the default-mode, fronto-parietal, and limbic networks.

Science.gov (United States)

Golchert, Johannes; Smallwood, Jonathan; Jefferies, Elizabeth; Seli, Paul; Huntenburg, Julia M; Liem, Franziskus; Lauckner, Mark E; Oligschläger, Sabine; Bernhardt, Boris C; Villringer, Arno; Margulies, Daniel S

2017-02-01

Mind-wandering has a controversial relationship with cognitive control. Existing psychological evidence supports the hypothesis that episodes of mind-wandering reflect a failure to constrain thinking to task-relevant material, as well the apparently alternative view that control can facilitate the expression of self-generated mental content. We assessed whether this apparent contradiction arises because of a failure to consider differences in the types of thoughts that occur during mind-wandering, and in particular, the associated level of intentionality. Using multi-modal magnetic resonance imaging (MRI) analysis, we examined the cortical organisation that underlies inter-individual differences in descriptions of the spontaneous or deliberate nature of mind-wandering. Cortical thickness, as well as functional connectivity analyses, implicated regions relevant to cognitive control and regions of the default-mode network for individuals who reported high rates of deliberate mind-wandering. In contrast, higher reports of spontaneous mind-wandering were associated with cortical thinning in parietal and posterior temporal regions in the left hemisphere (which are important in the control of cognition and attention) as well as heightened connectivity between the intraparietal sulcus and a region that spanned limbic and default-mode regions in the ventral inferior frontal gyrus. Finally, we observed a dissociation in the thickness of the retrosplenial cortex/lingual gyrus, with higher reports of spontaneous mind-wandering being associated with thickening in the left hemisphere, and higher repots of deliberate mind-wandering with thinning in the right hemisphere. These results suggest that the intentionality of the mind-wandering state depends on integration between the control and default-mode networks, with more deliberation being associated with greater integration between these systems. We conclude that one reason why mind-wandering has a controversial relationship

The effects of left and right monocular viewing on hemispheric activation.

Science.gov (United States)

Wang, Chao; Burtis, D Brandon; Ding, Mingzhou; Mo, Jue; Williamson, John B; Heilman, Kenneth M

2018-03-01

Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing. High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes. There was a significantly less alpha power over the right hemisphere's parietal-occipital area with left and binocular viewing than with right-eye monocular viewing. The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.

Origin of parietal podocytes in atubular glomeruli mapped by lineage tracing.

Science.gov (United States)

Schulte, Kevin; Berger, Katja; Boor, Peter; Jirak, Peggy; Gelman, Irwin H; Arkill, Kenton P; Neal, Christopher R; Kriz, Wilhelm; Floege, Jürgen; Smeets, Bart; Moeller, Marcus J

2014-01-01

Parietal podocytes are fully differentiated podocytes lining Bowman's capsule where normally only parietal epithelial cells (PECs) are found. Parietal podocytes form throughout life and are regularly observed in human biopsies, particularly in atubular glomeruli of diseased kidneys; however, the origin of parietal podocytes is unresolved. To assess the capacity of PECs to transdifferentiate into parietal podocytes, we developed and characterized a novel method for creating atubular glomeruli by electrocoagulation of the renal cortex in mice. Electrocoagulation produced multiple atubular glomeruli containing PECs as well as parietal podocytes that projected from the vascular pole and lined Bowman's capsule. Notably, induction of cell death was evident in some PECs. In contrast, Bowman's capsules of control animals and normal glomeruli of electrocoagulated kidneys rarely contained podocytes. PECs and podocytes were traced by inducible and irreversible genetic tagging using triple transgenic mice (PEC- or Pod-rtTA/LC1/R26R). Examination of serial cryosections indicated that visceral podocytes migrated onto Bowman's capsule via the vascular stalk; direct transdifferentiation from PECs to podocytes was not observed. Similar results were obtained in a unilateral ureter obstruction model and in human diseased kidney biopsies, in which overlap of PEC- or podocyte-specific antibody staining indicative of gradual differentiation did not occur. These results suggest that induction of atubular glomeruli leads to ablation of PECs and subsequent migration of visceral podocytes onto Bowman's capsule, rather than transdifferentiation from PECs to parietal podocytes.

Potential role of monkey inferior parietal neurons coding action semantic equivalences as precursors of parts of speech.

Science.gov (United States)

Yamazaki, Yumiko; Yokochi, Hiroko; Tanaka, Michio; Okanoya, Kazuo; Iriki, Atsushi

2010-01-01

The anterior portion of the inferior parietal cortex possesses comprehensive representations of actions embedded in behavioural contexts. Mirror neurons, which respond to both self-executed and observed actions, exist in this brain region in addition to those originally found in the premotor cortex. We found that parietal mirror neurons responded differentially to identical actions embedded in different contexts. Another type of parietal mirror neuron represents an inverse and complementary property of responding equally to dissimilar actions made by itself and others for an identical purpose. Here, we propose a hypothesis that these sets of inferior parietal neurons constitute a neural basis for encoding the semantic equivalence of various actions across different agents and contexts. The neurons have mirror neuron properties, and they encoded generalization of agents, differentiation of outcomes, and categorization of actions that led to common functions. By integrating the activities of these mirror neurons with various codings, we further suggest that in the ancestral primates' brains, these various representations of meaningful action led to the gradual establishment of equivalence relations among the different types of actions, by sharing common action semantics. Such differential codings of the components of actions might represent precursors to the parts of protolanguage, such as gestural communication, which are shared among various members of a society. Finally, we suggest that the inferior parietal cortex serves as an interface between this action semantics system and other higher semantic systems, through common structures of action representation that mimic language syntax.

Reshaping the brain after stroke: The effect of prismatic adaptation in patients with right brain damage.

Science.gov (United States)

Crottaz-Herbette, Sonia; Fornari, Eleonora; Notter, Michael P; Bindschaedler, Claire; Manzoni, Laura; Clarke, Stephanie

2017-09-01

Prismatic adaptation has been repeatedly reported to alleviate neglect symptoms; in normal subjects, it was shown to enhance the representation of the left visual space within the left inferior parietal cortex. Our study aimed to determine in humans whether similar compensatory mechanisms underlie the beneficial effect of prismatic adaptation in neglect. Fifteen patients with right hemispheric lesions and 11 age-matched controls underwent a prismatic adaptation session which was preceded and followed by fMRI using a visual detection task. In patients, the prismatic adaptation session improved the accuracy of target detection in the left and central space and enhanced the representation of this visual space within the left hemisphere in parts of the temporal convexity, inferior parietal lobule and prefrontal cortex. Across patients, the increase in neuronal activation within the temporal regions correlated with performance improvements in this visual space. In control subjects, prismatic adaptation enhanced the representation of the left visual space within the left inferior parietal lobule and decreased it within the left temporal cortex. Thus, a brief exposure to prismatic adaptation enhances, both in patients and in control subjects, the competence of the left hemisphere for the left space, but the regions extended beyond the inferior parietal lobule to the temporal convexity in patients. These results suggest that the left hemisphere provides compensatory mechanisms in neglect by assuming the representation of the whole space within the ventral attentional system. The rapidity of the change suggests that the underlying mechanism relies on uncovering pre-existing synaptic connections. Copyright © 2017 Elsevier Ltd. All rights reserved.