The Neurobiology of Reading Differs for Deaf and Hearing Adults

Recent neuroimaging and electrophysiological studies reveal how the reading system successfully adapts when phonological codes are relatively coarse-grained due to reduced auditory input during development. New evidence suggests that the optimal end-state for the reading system may differ for deaf versus hearing adults and indicates that certain neural patterns that are maladaptive for hearing readers may be beneficial for deaf readers. This chapter focuses on deaf adults who are signers and have achieved reading success. Although the left-hemisphere-dominant reading circuit is largely similar in both deaf and hearing individuals, skilled deaf readers exhibit a more bilateral neural response to written words and sentences than their hearing peers, as measured by event-related potentials and functional magnetic resonance imaging. Skilled deaf readers may also rely more on neural regions involved in semantic processing than hearing readers do. Overall, emerging evidence indicates that the neural markers for reading skill may differ for deaf and hearing adults.