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Abstract:
Abstract: The goal of the present study was to examine the
neural systems involved in sign language perception. A previous
study of deaf signers with unilateral brain lesions suggested that
damage to the temporal lobe, particularly on the left, was the best
predictor of deficits in sign language comprehension. However, the
distribution of lesions in that sample did not allow us to address
fully the role of parietal cortex. Here we use fMRI to determine
whether temporal and/or parietal cortex in deaf native signers is
activated during the perception of individual signs. Five subjects
were presented with blocks of single signs (concrete nouns) which
cycled with blocks of a fixation point. Subjects were instructed to
simply view the signs. Analyses revealed consistent areas of
activation across all subjects in ventral occipital-temporal cortex
and superior posterior temporal cortex bilaterally. In some
subjects activity was also noted in non-primary, auditory-related
fields the left supratemporal plane. There was no activity found in
parietal or frontal regions. These findings are consistent with the
hypothesis that temporal, but not parietal, cortex plays a major
role in the comprehension sign language at the lexical level. A
previously published fMRI study of perception of sign language
sentences also noted reliable activation of temporal, but not
parietal, structures, suggesting that temporal cortex involvement
extends to sentence-level stimuli as well.
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