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Abstract:
Stimulus-response compatibility is expected to introduce an
increased load in working memory and influence response preparation
and execution. We examined the brain regions involved in these sets
of processes by using an event-related fMRI approach. Stimuli were
arrows presented to the left and right of fixation and pointing
either to the left or to the right. Subjects had to respond on the
basis of the direction of the arrow and to ignore their location.
This created conditions in which the location and direction of the
arrow conflicted. Functional MRI data were recorded using a 1.5 T
Siemens-Vision system equipped for echoplanar imaging. Preliminary
analysis of the results indicated event-related BOLD responses in
(a) medial occipital cortex contralateral to the hemifield of
stimulation; (b) pre-central cortex contralateral to the responding
hand; (c) pre-SMA in the conflict with respect to the no-conflict
conditions. In addition, the contralateral pre-central response
appeared larger in the no-conflict conditions. These data indicate
that several areas may be activated in conflict conditions.
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