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Abstract:
Recent neuro-cognitve findings show that perception and
execution of action is intimately linked. The mere observation of
an action seems to evoke a tendency to execute that respective
action. Since imitation is not adaptive in many everyday situations
imitative response tendencies usually have to be inhibited. Such
inhibitory processes have never been investigated using brain
imaging techniques. Former work on response inhibition has focused
on tasks like the Stroop-task or the go/no-go task. We have carried
out an event-related functional magnetic-resonance imaging study
(efMRI) in order to investigate the cortical mechanisms underlying
the inhibition of imitative responses. The experiment utilizes a
simple response task in which subjects were instructed to execute
predefined finger movements (tapping or lifting of the index
finger) in response to an observed congruent or incongruent finger
movement (tapping or lifting). The comparison of brain activation
in incongruent and congruent trials revealed activation in the
right dorsolateral prefrontal cortex (middle frontal gyrus) as well
as the left precuneus. The prefrontal activation supports the
assumption of right hemispheric dominance in response inhibition
and extents this finding to a ?new? class of prepotent responses,
namely to imitative actions.
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