The Experts below are selected from a list of 19989 Experts worldwide ranked by ideXlab platform
Neil G Muggleton - One of the best experts on this subject based on the ideXlab platform.
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modulating inhibitory control with direct current stimulation of the superior medial frontal cortex
NeuroImage, 2011Co-Authors: Daisy L Hung, Ovid J L Tzeng, Lin Yuan Tseng, Jiaxin Yu, Vincent Walsh, Neil G MuggletonAbstract:article i nfo Article history: The executive control of voluntary action involves not only choosing from a range of possible actions but also the inhibition of responses as circumstances demand. Recent studies have demonstrated that many clinical populations, such as people with attention-deficit hyperactivity disorder, exhibit difficulties in inhibitory control. One Prefrontal Area that has been particularly associated with inhibitory control is the pre- supplementary motor Area (Pre-SMA). Here we applied non-invasive transcranial direct current stimulation (tDCS) over Pre-SMA to test its role in this behavior. tDCS allows for current to be applied in two directions to selectively excite or suppress the neural activity of Pre-SMA. Our results showed that anodal tDCS improved efficiency of inhibitory control. Conversely, cathodal tDCS showed a tendency towards impaired inhibitory control. To our knowledge, this is the first demonstration of non-invasive intervention tDCS altering subjects' inhibitory control. These results further our understanding of the neural bases of inhibitory control and suggest a possible therapeutic intervention method for clinical populations.
Daisy L Hung - One of the best experts on this subject based on the ideXlab platform.
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modulating inhibitory control with direct current stimulation of the superior medial frontal cortex
NeuroImage, 2011Co-Authors: Tzu Yu Hsu, Lin Yua Tseng, Wen Jui Kuo, Daisy L Hung, Ovid J L Tzeng, Vince Walsh, Neil G MuggletoAbstract:The executive control of voluntary action involves not only choosing from a range of possible actions but also the inhibition of responses as circumstances demand. Recent studies have demonstrated that many clinical populations, such as people with attention-deficit hyperactivity disorder, exhibit difficulties in inhibitory control. One Prefrontal Area that has been particularly associated with inhibitory control is the pre-supplementary motor Area (Pre-SMA). Here we applied non-invasive transcranial direct current stimulation (tDCS) over Pre-SMA to test its role in this behavior. tDCS allows for current to be applied in two directions to selectively excite or suppress the neural activity of Pre-SMA. Our results showed that anodal tDCS improved efficiency of inhibitory control. Conversely, cathodal tDCS showed a tendency towards impaired inhibitory control. To our knowledge, this is the first demonstration of non-invasive intervention tDCS altering subjects' inhibitory control. These results further our understanding of the neural bases of inhibitory control and suggest a possible therapeutic intervention method for clinical populations.
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modulating inhibitory control with direct current stimulation of the superior medial frontal cortex
NeuroImage, 2011Co-Authors: Daisy L Hung, Ovid J L Tzeng, Lin Yuan Tseng, Jiaxin Yu, Vincent Walsh, Neil G MuggletonAbstract:article i nfo Article history: The executive control of voluntary action involves not only choosing from a range of possible actions but also the inhibition of responses as circumstances demand. Recent studies have demonstrated that many clinical populations, such as people with attention-deficit hyperactivity disorder, exhibit difficulties in inhibitory control. One Prefrontal Area that has been particularly associated with inhibitory control is the pre- supplementary motor Area (Pre-SMA). Here we applied non-invasive transcranial direct current stimulation (tDCS) over Pre-SMA to test its role in this behavior. tDCS allows for current to be applied in two directions to selectively excite or suppress the neural activity of Pre-SMA. Our results showed that anodal tDCS improved efficiency of inhibitory control. Conversely, cathodal tDCS showed a tendency towards impaired inhibitory control. To our knowledge, this is the first demonstration of non-invasive intervention tDCS altering subjects' inhibitory control. These results further our understanding of the neural bases of inhibitory control and suggest a possible therapeutic intervention method for clinical populations.
R E Passingham - One of the best experts on this subject based on the ideXlab platform.
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The Prefrontal cortex: response selection or maintenance within working memory?
5th IEEE EMBS International Summer School on Biomedical Imaging 2002., 2002Co-Authors: James B Rowe, I. Toni, O. Josephs, R.s.j. Frackowiak, R E PassinghamAbstract:It is controversial whether the dorsolateral Prefrontal cortex is involved in the maintenance of items in working memory or in the selection of responses. We used event-related functional magnetic resonance imaging to study the performance of a spatial working memory task by humans. We distinguished the maintenance of spatial items from the selection of an item from memory to guide a response. Selection, but not maintenance, was associated with activation of Prefrontal Area 46 of the dorsal lateral Prefrontal cortex. In contrast, maintenance was associated with activation of Prefrontal Area 8 and the intraparietal cortex. The results support a role for the dorsal Prefrontal cortex in the selection of representations. This accounts for the fact that this Area is activated both when subjects select between items on working memory tasks and when they freely select between movements on tasks of willed action.
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active maintenance in Prefrontal Area 46 creates distractor resistant memory
Nature Neuroscience, 2002Co-Authors: Katsuyuki Sakai, James B Rowe, R E PassinghamAbstract:How does the brain maintain information in working memory while challenged by incoming distractions? Using functional magnetic resonance imaging (fMRI), we measured human brain activity during the memory delay of a spatial working memory task with distraction. We found that, in the Prefrontal cortex (PFC), the magnitude of activity sustained throughout the memory delay was significantly higher on correct trials than it was on error trials. By contrast, the magnitude of sustained activity in posterior Areas did not differ between correct and error trials. The correlation of activity between posterior Areas was, however, associated with correct memory performance after distraction. On the basis of these findings, we propose that memory representations gain resistance against distraction during a period of active maintenance within working memory. This may be mediated by interactions between Prefrontal and posterior Areas.
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working memory for location and time activity in Prefrontal Area 46 relates to selection rather than maintenance in memory
NeuroImage, 2001Co-Authors: James B Rowe, R E PassinghamAbstract:The role of the dorsal Prefrontal cortex in working memory remains controversial. Influential proposals include a role in the maintenance of domain-specific information, and the processes of executive functions on remembered information. We used event-related functional magnetic resonance imaging to demonstrate a functional dissociation within Prefrontal cortex in terms of the components of complex working memory tasks. The maintenance in working memory of spatial locations and their temporal order was associated with activation of Area 8 and intraparietal cortex. In contrast, the selection of one location, according to its order, was associated with a distinct frontoparietal network, including dorsolateral Prefrontal Area 46, ventrolateral Prefrontal cortex and anterior cingulate cortex and medial parietal cortex. The different contributions of these Areas to selection are considered in the light of recent electrophysiological and lesion studies. We suggest a general role of the dorsolateral Prefrontal Area 46 in attentional selection, including selection from within working memory.
Lin Yuan Tseng - One of the best experts on this subject based on the ideXlab platform.
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modulating inhibitory control with direct current stimulation of the superior medial frontal cortex
NeuroImage, 2011Co-Authors: Daisy L Hung, Ovid J L Tzeng, Lin Yuan Tseng, Jiaxin Yu, Vincent Walsh, Neil G MuggletonAbstract:article i nfo Article history: The executive control of voluntary action involves not only choosing from a range of possible actions but also the inhibition of responses as circumstances demand. Recent studies have demonstrated that many clinical populations, such as people with attention-deficit hyperactivity disorder, exhibit difficulties in inhibitory control. One Prefrontal Area that has been particularly associated with inhibitory control is the pre- supplementary motor Area (Pre-SMA). Here we applied non-invasive transcranial direct current stimulation (tDCS) over Pre-SMA to test its role in this behavior. tDCS allows for current to be applied in two directions to selectively excite or suppress the neural activity of Pre-SMA. Our results showed that anodal tDCS improved efficiency of inhibitory control. Conversely, cathodal tDCS showed a tendency towards impaired inhibitory control. To our knowledge, this is the first demonstration of non-invasive intervention tDCS altering subjects' inhibitory control. These results further our understanding of the neural bases of inhibitory control and suggest a possible therapeutic intervention method for clinical populations.
Patricia S Goldmanrakic - One of the best experts on this subject based on the ideXlab platform.
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matching patterns of activity in primate Prefrontal Area 8a and parietal Area 7ip neurons during a spatial working memory task
Journal of Neurophysiology, 1998Co-Authors: Matthew V Chafee, Patricia S GoldmanrakicAbstract:Chafee, Matthew V. and Patricia S. Goldman-Rakic. Matching patterns of activity in primate Prefrontal Area 8a and parietal Area 7ip neurons during a spatial working memory task. J. Neurophysiol. 79...
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elevated neuronal density in Prefrontal Area 46 in brains from schizophrenic patients application of a three dimensional stereologic counting method
The Journal of Comparative Neurology, 1998Co-Authors: Lynn D Selemon, Grazyna Rajkowska, Patricia S GoldmanrakicAbstract:Neuropsychologic testing in schizophrenic patients has underscored the prominence of dysfunction in cognitive processes associated with the dorsolateral Prefrontal cortex. Quantitative cytometric analysis of Area 46 was undertaken in brains from schizophrenic patients to determine whether there are morphologic changes underlying these cognitive deficits. Postmortem brain specimens from 9 schizophrenic patients, 10 normal subjects, and 8 Huntington's diseased patients were fixed in formalin and celloidin embedded. A direct, three-dimensional counting method was used to determine cell density and cortical thickness in Nissl-stained sections of Area 46. Overall neuronal density was 21% greater in brains from schizophrenic patients in comparison to normal controls. Significant elevations in neuronal density were observed in layers II, III, IV, and VI. The cortical ribbon was slightly (8%) but not significantly thinner. However, layer II exhibited disproportionate thinning compared with all other layers. In brains from Huntington's diseased patients, increases in neuronal (35%) and glial (61%) density with substantial cortical thinning (30%) were observed. The neuropathology of Area 46 in schizophrenia is similar in direction and magnitude to that previously described in Area 9 (Selemon et al. [1995] Arch. Gen. Psychiatry 52:805–818), except for the abnormalities in layer II, which are specific to Area 46. In contrast to Huntington's disease, in which cortical atrophy and gliosis are present, no evidence for cortical cell loss was uncovered in the schizophrenic cohort. The observed elevation in neuronal density suggests that a reduction in interneuronal neuropil may constitute the anatomical substrate for Prefrontal cortical dysfunction in schizophrenia. J. Comp. Neurol. 392:402–412, 1998. Published 1998 Wiley-Liss, Inc.
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abnormally high neuronal density in the schizophrenic cortex a morphometric analysis of Prefrontal Area 9 and occipital Area 17
Archives of General Psychiatry, 1995Co-Authors: Lynn D Selemon, Grazyna Rajkowska, Patricia S GoldmanrakicAbstract:Background: In the past two decades, gross morphologic changes have been uncovered in the schizophrenic brain, eg, increased ventricular width and decreased cortical volume; however, relatively little is known about the Area-specific and laminar density of cells in the schizophrenic cortex, particularly in Prefrontal Areas. Method: A direct, three-dimensional counting method was used to determine cell density in 16 brains from patients with schizophrenia, 19 from normal subjects, six from patients with schizoaffective disorder, and nine from patients with advanced-stage Huntington's disease. Results: Increased neuronal density was found in Prefrontal Area 9 (17%) and occipital Area 17 (10%) in the schizophrenic brains. In Area 9, neuronal density was increased in layers III to VI; cell packing of pyramidal and nonpyramidal neurons was elevated. Cortical thickness in the schizophrenic brains was slightly but not significantly reduced in both Areas, with a disproportionate reduction in layer V in Area 9. In contrast, brains with Huntington's disease exhibited markedly higher glial density Abnormally high density in the cerebral cortices of schizophrenics suggests that neuronal atrophy is the anatomic substrate for deficient information processing in schizophrenia. Conclusion: Abnormally high density in the cerebral cortices of schizophrenics suggests that neuronal atrophy is the anatomic substrate for deficient information processing in schizophrenia.