Doctoral Dissertation Research: Effects of early language deprivation on sentence processing: Mapping between syntactic and thematic roles in simple sentences

University Of California-San Diego, La Jolla CA

Investigators

Abstract

Language deprivation is common among individuals born deaf when they do not have early access to a sign or spoken language, which causes deficits in their ultimate language performance. Understanding the nature of these age of acquisition effects on sentence structure can illuminate the underlying mechanisms of the critical period for language development and provide clinicians and educators with important information about the nature of language deprivation in deaf students. The current proposal examines the effects of early language deprivation on language processing at the basic phrasal level. The participants are deaf adults and adolescents who experienced minimal early language and began to acquire American Sign Language (ASL) as their first language (L1) later in life. Study 1 investigates longitudinal development of basic word order in four case studies. Study 2 investigates whether late L1 learners rely on syntactic cues or use alternative strategies when comprehending and producing simple mono-clausal sentences using a sentence-picture verification task and an elicited word order production task. The participants are a group of deaf late L1 learners (n = 10, Age of Acquisition, AoA > 8) and a control group of deaf native signers (n = 10). Study 3 investigates these phenomena with adolescents who are deaf native signers (n = 10) and late L1 learners with early AoA (n = 10, AoA 4-6), as well as adolescents who are late L1 learners (AoA 8-10). This manipulation of AoA investigates the questions of 1) whether childhood vs adolescent L1 AoA has different effects on sentence processing strategies and 2) when late L1 learners reach a stable stage of processing basic phrasal structure. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.