Visual Perception in Hearing Sign Language Users
Abstract
Deaf signers exhibit superior visual perception compared to hearing controls in several domains, including the perception of faces and peripheral motion. These visual enhancements are thought to compensate for an absence of auditory input. However, it is also possible that they reflect experience using a visual-manual language, where signers must process complex moving hand signs and facial cues simultaneously. Thus, the current study sought to isolate the effects of sign language experience by examining how visual perception is altered as a function of American Sign Language (ASL) proficiency in hearing individuals. Hearing signers completed an online test of ASL proficiency and were compared to hearing non-signers on online behavioural measures of face perception and biological motion perception. No group-level differences in performance were observed, suggesting that the visual enhancements found in Deaf signers result from hearing loss itself rather than sign language. Potential neurodevelopmental mechanisms for these findings are discussed.