Doctoral Dissertation Research: Late First Language Acquisition Effects on Phonological Processing in Sign Language

对于那些能够自动使用周围语言的听力正常的人来说，第一语言习得较晚是罕见的，但对于那些无法听到任何口语并且直到幼儿期才接触手语作为第一语言的聋人来说，这种情况经常发生。这些晚期的第一语言失聪者可以在生活的各个方面，包括语言的结果，经历戏剧性的影响。虽然以前关于这个主题的大部分研究都着眼于句子层面的语言结果，但这个项目旨在通过观察句子和单词层面下的签名者如何处理构成符号/单词的最小语言片段来更好地理解后期第一语言习得的影响。这项工作对于更全面地了解晚期第一语言习得的影响以及更好地了解人类大脑如何更广泛地处理语言是必要的。实际上，这项工作有助于那些与聋人一起工作的人，如言语语言病理学家和教育工作者，更好地了解晚期第一语言签名者如何处理构成语言的语言片段。在这篇论文中，参与者是聋人手语谁获得了手语在不同的年龄，从儿童早期到青少年后期。研究1通过符号重复和错误分析，探讨了手语者如何产生最小的手语片段（手形、动作和位置等手动形式）。研究二考察了手语者如何通过相似性判断来感知手语的手势形式。研究三通过形式监测和脑磁图（MEG）研究了手语者如何识别和加工手语的手动形式。总之，这些研究提供了对晚期第一语言签名者与早期第一语言签名者相比如何产生，感知和处理最小的手语片段的见解，提供了一个系统的看看晚第一语言习得的影响，在亚，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.

Late first language acquisition is rare for hearing individuals who have automatic access to spoken languages used around them, but it occurs frequently for deaf individuals who are unable to hear any spoken languages and who are not exposed to a sign language as a first language until after early childhood. These late first language deaf signers can experience dramatic effects on all aspects of life including language outcomes. While much of the previous research on this topic has looked at language outcomes at the sentence level, this project aims to better understand the effects of late first language acquisition by looking below the sentence and word levels at how signers process the smallest pieces of language that make up signs/words. This work is necessary for a more complete understanding of the effects of late first language acquisition and better insight into how the human brain processes language more broadly. Practically, this work helps those who work with deaf individuals, like speech language pathologists and educators, to better understand how late first language signers process the linguistic pieces that make up language. In this dissertation, participants are deaf signers who acquired a sign language at a variety of ages, from early in childhood to late in adolescence. Study 1 investigates how the signers produce the smallest pieces of the sign language (manual forms like handshape, movement, and location) through sign repetition and error analysis. Study 2 investigates how the signers perceive the manual forms of sign language through similarity judgments. Study 3 investigates how the signers identify and process the manual forms of sign language through form monitoring and using magnetoencephalography (MEG). Together, these studies provide insight into how late first language signers compared to early first language signers produce, perceive, and process the smallest pieces of sign language, providing a systematic look at the effects of late first language acquisition at the sub-word level.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.