Sign language aphasia following right hemisphere damage in a left-hander: A case of reversed cerebral dominance in a deaf signer?

Abstract

Recent lesion studies have shown that left hemisphere lesions often give rise to frank sign language aphasias in deaf signers, whereas right hemisphere lesions do not, suggesting similar patterns of hemispheric asymmetry for signed and spoken language. We present here a case of a left-handed, deaf, life-long signer who became aphasic after a right-hemisphere lesion. The subject exhibits deficits in sign language comprehension and production typically associated with left hemisphere damaged signers. He also exhibits evidence of local versus global deficits similar to left-hemisphere lesioned hearing patients. This case represents reversed lateralization for sign language and also may represent reversed lateralization for visuo-spatial abilities in a deaf signer.

Acknowledgments

This research was supported in part by NIH grant NIDCD-00201 to UB. Illustrations copyright Laboratory for Cognitive Neuroscience, The Salk Institute for Biological Studies, La Jolla, CA 92037.