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Abstract:
Abstract: Positron Emission Tomography was used to
investigate whether sign languages exhibit the same neural
organization for lexical retrieval within classical and
non-classical language areas. Ten deaf native ASL signers were
shown pictures of unique entities (famous persons) and non-unique
entities (animals) and were asked to name each stimulus with an
overt signed response. Signed responses to famous people were
fingerspelled, whereas responses to animals were either
fingerspelled or native ASL signs. In general, retrieving ASL signs
activated neural sites similar to those activated by hearing
subjects retrieving English words. Naming famous persons activated
the left temporal pole, whereas naming animals (either
fingerspelled or signed) activated left inferotemporal (IT) cortex.
The retrieval of fingerspelled and native signs generally engaged
the same cortical regions, but fingerspelled signs activated a
premotor region, and native signs activated portions of left
temporoparietal cortex. The results also suggested some differences
between retrieving ASL signs compared to English words: 1) naming
unique entities in ASL yielded activation in the posterior sector
of left IT, suggesting that naming famous faces may involve
additional posterior sites for deaf signers, and 2) naming animals
in ASL produced activation in right IT, with a trend for more right
hemisphere activation for native ASL signs, suggesting bilateral
engagement when retrieving signs for non-unique entities.
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