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Abstract:
Overlapping regions of the left posterior supra-temporal
plane (pSTP) have been implicated both in the perception and
production of speech. This region corresponds to cytoarchitectonic
area Tpt of Galaburda and Sanides, and is typically considered an
auditory-related cortical field, although Galaburda and Sanides
refer to it as transitional between unimodal and polysensory
cortex. Previous studies of sign language comprehension in deaf
subjects have reported robust activation along the STS but not in
the pSTP. The goal of the present study was to determine whether
this region participates in the perception and/or production of
sign language in deaf individuals. Five deaf native signers
passively watched or watched and covertly repeated American Sign
Language sentences while hemodynamic responses were monitored using
an event-related fMRI paradigm. Data from the passive watch and
watch-and-repeat conditions were collected in separate fMRI runs.
The order of presentation was counterbalanced across subjects. When
the two conditions were collapsed, we observed robust activation in
ventral occipital-temporal and lateral posterior temporal cortex
(e.g., STS). Although less robust, activation was also found in the
left pSTP. The response of pSTP was modulated by the task
manipulation (watch-and-repeat > watch only) in some subjects
suggesting this region may play a role in sign language production,
as it does in spoken language.
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