Perceptual Narrowing in Deaf Infants
All infants are highly attuned to the linguistic patterns found in natural language. Over the course of their first year of life, they acquire crucial information about the structure of their native language(s), which paves the way for the development of higher-level linguistic and cognitive skills. One part of typical development is a period of sensitivity during which infants are able to detect linguistic contrasts including those not found in their native language(s). At 10-12 months old, hearing children undergo perceptual narrowing where they become attuned only to the differences that are contrastive in their native language. To date, research on the early perceptual abilities of deaf children is largely unexplored. I will address this gap by investigating whether deaf infants can discriminate between two unknown sign languages. Data will be collected from deaf infants before and after the typical onset of perceptual narrowing. Testing the age at which deaf children lose sensitivity to nonnative contrasts offers important insights on language acquisition universals, and on how early experience affects development even before the child is able to produce language.