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Abstract:
Abstract: Using event related fMRI, we investigated the
spatio-temporal pattern of activation during language tasks that
involved listening to and then silently repeating speech. Previous
work has suggested both (i) that frontal (as well as temporal)
cortex participates in language perception, and (ii) that temporal
(as well as frontal) cortex participates in language expression. We
sought to address several questions: Would frontal and/or parietal
cortex be active during the receptive phase of the trial? Would
temporal lobe regions remain active during the expressive phase of
the trial? Are there areas active during both during receptive and
expressive phases? We employed two tasks. (1) Listening to
jabberwocky sentences and immediately repeating them. (2) Listening
to a list of pseudowords and then rehearsing the list for 12
seconds. We observed robust superior temporal lobe activation
during the receptive phase of each experiment, but no frontal or
parietal activation. During the expressive phase we observed
activation in frontal, parietal, and temporal regions. Some of the
temporal regions appeared to activate both during receptive and
expressive phases of the trial. We suggest that speech receptive
processes involve primarily temporal lobe structures, whereas
expressive processes recruit systems in frontal, parietal, and
temporal cortex.
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