Regional Cerebral Blood Flow During Sign Language Perception: Deaf & Hearing Subjects With Deaf Parents Compared

Cerebral activation was studied during sign language comprehension. Six deaf persons with deaf parents were studied and compared to nine hearing persons with deaf parents. The cerebral activation was measured by recordings of the regional cerebral blood flow (rCBF). The deaf group showed more activation than the hearing group in the right parieto-occipital region, indicating that they were more dependent on the spatial components in sign language. The results thus indicate that deaf persons with deaf parents are different from native hearing signers. The enhanced right hemisphere parieto-occipital activation in the deaf group is suggested to be an effect both of lack of auditory stimulation and of early learning of a visual-spatial language. This combination seems to create a cortical reorganization for language perception.