Doctoral Dissertation Research: Effects of non-verbal working memory and spoken first language proficiency on sign language acquisition by deaf second language learners

聋人和听力障碍者（DHH）在接触手语时会经历很大的变化。例如，在美国，超过90%的DHH儿童的听力正常的父母在他们的DHH儿童出生时不知道手语。当这些儿童达到学龄时，只有26%的儿童在家中经常与家人使用手语，53%的儿童在学校使用某种手语。因此，许多DHH的人在年轻时第一次学习手语。尽管是DHH人学习手语的最常见方式之一，但研究人员对在这种学习环境中支持第二语言学习成功的因素知之甚少。例如，在其他语言学习环境中，第一语言和工作记忆的熟练程度是第二语言熟练程度的预测因素--这些预测因素对DHH学习者也很重要吗？此外，DHH患者接受的早期语言输入的质量和数量是高度可变的--这种变化会影响手语的第二语言学习吗？本博士论文旨在（1）将现有的关于第二语言水平预测因素的研究扩展到一个新的学习环境，DHH第二语言符号，（2）调查口语第一语言水平，非言语工作记忆和符号第二语言水平之间的关系。本研究进行了一项中介建模研究，评估在DHH人的口语阅读理解和非言语工作记忆谁长大使用口语作为主要语言，并开始学习手语作为年轻的成年人，并调查这些变量如何与手语的接受性理解。这项研究的结果将导致更普遍的第二语言学习理论，解释早期第一语言习得的质量和数量的变化。研究结果还为家庭和学校的语言政策DHH儿童以及第二语言教学课程和成人DHH第二语言signers.This奖的口译策略反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Deaf and hard of hearing (DHH) individuals experience substantial variability in exposure to a sign language. For example, more than 90% of DHH children in the US have hearing parents who do not know a sign language at the time of their DHH child’s birth. By the time these children are school-age, only 26% are using sign language regularly with their families at home and 53% are using some sign language at school. Consequently, a substantial number of DHH people are learning a sign language for the first time as young adults. Despite being one of the most common ways for DHH people to learn a sign language, researchers know very little about the factors that support second language learning success in this learning context. For example, proficiency in the first language and working memory are predictors of second language proficiency in other language learning contexts--are these predictors also important for DHH learners? Additionally, the quality and quantity of early language input that DHH people receive is highly variable--does this variation affect second language learning of a sign language?This doctoral dissertation study aims to (1) extend existing research on predictors of second language proficiency to a new learning context, DHH second language signers, and (2) investigate relationships between spoken first language proficiency, non-verbal working memory, and signed second language proficiency. This research conducts a mediation modeling study assessing spoken language reading comprehension and non-verbal working memory in DHH people who grew up using a spoken language as a primary language and started learning a sign language as young adults and investigate how these variables relate to sign language receptive comprehension. The results of this study will lead to more generalizable theories of second language learning that account for variability in the quality and quantity of early first language acquisition. The results also inform family and school language policy for DHH children as well as second language teaching curriculum and interpreting strategies for adult DHH second language signers.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.