Spatiotemporal brain dynamics during preparatory set shifting

Journal article


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Publication Details

Subtitle: MEG evidence
Author list: Barceló F
Publisher: Elsevier
Publication year: 2004
Volume number: 21
Issue number: 2
Start page: 687
End page: 695
Number of pages: 9
ISSN: 1053-8119
Languages: English-Great Britain (EN-GB)


Abstract

Humans can flexibly alter a plan of action to adjust their behavior
adaptively in changing environments. Functional neuroimaging has shown
distinct patterns of activation across a frontoparietal network
responsible for switching and updating such plans of action or 'task
sets.' However, little is known about the temporal order of activations
within prefrontal or across with posterior regions subserving
set-shifting operations. Here, whole-head magnetoencephalography (MEG)
was used to explore the spatiotemporal brain dynamics in a modified
version of the Wisconsin card-sorting test (WCST). Our task was designed
to examine preparation of set-shifting rather than set-acquisition
operations time locked to context-informative cues. Three cortical
regions showed a larger number of MEG activity sources in response to
shift and relative to nonshift cues: (a) inferior frontal gyrus (IFG; BA
45, 47/12), (b) anterior cingulate cortex (ACC; BA 24, 32), and (c)
supramarginal gyrus (SMG; BA 40). Importantly, the timing of MEG
activation differed across these regions. The earliest shift-related MEG
activations were detected at the IFG (100-300 ms postcue onset),
followed by two further peaks at the ACC (200-300 and 400-500 ms) and
the SMG (300-400 and 500-600 ms). Several other prefrontal and posterior
cortical areas were similarly activated by both shift and nonshift
preparatory cues. The resulting temporal pattern of interactions within
prefrontal and across with posterior association cortices is coherent
with current models of task switching and provides novel information
about the temporal course of brain activations responsible for the
executive control of attention.


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Last updated on 2019-13-08 at 00:16