Does Early Access to a Visual Language and Fingerspelling Predict Print-Tuning?

The N170 component is a temporo-occipital negativity that is observed around 170 ms after a visual stimulus is presented and is argued to be a marker of neural tuning. In skilled hearing readers, the N170 to words which is characterized by a left-lateralized response, is predicted by phonological skill, and is thought to reflect the process of mapping letters to sounds. Compared to skill-matched hearing readers, deaf readers produce a more bilateral N170, which is consistent with their phonological awareness not being an indicator of reading skill. Further, reading skills are positively correlated with the amplitude of a right hemisphere N170-like negativity for deaf but not hearing readers. To determine if the difference in N170 laterality is influenced by the acquisition of a visual language or from learning to read without relying on sound, this study will include a population of early signers who do rely on sound when learning to read. Hearing individuals born to deaf parents are typically exposed to sign language from their parents at birth. They have access to fingerspelling, a system in sign languages that uses handshapes to depict letters, before literacy, but also have full access to phonology to utilize when reading. The early access to fingerspelling may change the N170 component to be broader in terms of tuning. Testing hearing early signers can illuminate whether the relationship between fingerspelling and orthography influences print tuning in signers.