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Abstract:
Abstract: Speaking and fingerspelling words produces dynamic,
biological, visual signals that serve language communication.
However, fingerspelling is a manual encoding of orthography,
whereas the visible aspect of spoken language is a product of
speech articulation. These two stimulus types provide a revealing
contrast for examining the cortical substrate for language
perception. Functional magnetic resonance imaging (fMRI) was used
to investigate cortical activity due to visible (lipread) vs.
fingerspelled words. Young adults with prelingual-onset profound
hearing impairments were imaged with 10-mm thick slices in the
coronal plane at 1.5T. In Experiment 1, a sequence of silently
mouthed monosyllabic words was contrasted with a sequence of
colored shapes overlayed on a still frame of the talker's face. In
Experiment 2, a sequence of fingerspelled monosyllabic words was
contrasted with a sequence of colored shapes overlayed on a still
frame of the signer's hand. Common regions of activation for
fingerspelling and lipreading were observed, including areas of the
posterior superior temporal sulcus. Additional activation was
observed for fingerspelling including several dorsolateral parietal
areas. These results suggest that the perception of different forms
of biological motion (spoken and fingerspelled) occurs in partially
shared but partially distinct cortical networks.
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