Does deafness lead to enhancement of visual spatial cognition in children? Negative evidence from deaf nonsigners

This study investigated whether deafness contributes to enhancement of visual spatial cognition independent of knowledge of a sign language. Congenitally deaf school children in India who were born to hearing parents and were not exposed to any sign language, and matched hearing controls, were given a test of digit span and five tests that measured visual spatial skills. The deaf group showed shorter digit span than the hearing group, consistent with previous studies. Deaf and hearing children did not differ in their performance on the visual spatial skills test, suggesting that deafness per se may not be a sufficient factor for enhancement of visual spatial cognition. Early exposure to a sign language and fluent sign skills may be the critical factors that lead to differential development of visual spatial skills in deaf people.