Auditory deprivation affects processing of motion, but not color.

Event-related potentials (ERPs) were recorded in response to color changes of isoluminant, high spatial frequency gratings and to motion of grayscale, low spatial frequency gratings in 11 normally hearing and 11 congenitally deaf adults. The stimuli were designed to activate preferentially the ventral and dorsal streams of visual processing, respectively. Color changes evoked prominent P1 and N1 components in the ERP; motion evoked an early, focal positivity (the P-INZ), a minimal P1, and a prominent N1. Color changes elicited similar ERP components in hearing and deaf participants. In contrast, motion elicited larger amplitude and more anteriorly distributed N1 components in deaf than hearing participants. These results suggest that early auditory deprivation may have more pronounced effects on the functions of the dorsal visual pathway than on functions of the ventral pathway.