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

聋人和重听人（DHH）在接触手语方面有很大的差异。例如，在美国，超过90%的DHH儿童的父母在他们的DHH儿童出生时不懂手语。当这些儿童达到学龄时，只有26%的人在家里经常与家人使用手语，53%的人在学校使用一些手语。因此，相当数量的DHH患者在成年后第一次学习手语。尽管这是DHH人群学习手语最常见的方式之一，但研究人员对在这种学习环境下支持第二语言学习成功的因素知之甚少。例如，母语熟练程度和工作记忆是在其他语言学习环境中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人群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)将现有的第二语言能力预测因素研究扩展到一个新的学习情境，DHH第二语言手语；(2)研究口语第一语言能力、非言语工作记忆和手语第二语言能力之间的关系。本研究通过中介模型研究，评估了以口语为主要语言长大并在年轻时开始学习手语的DHH患者的口语阅读理解和非言语工作记忆，并探讨了这些变量与手语接受性理解的关系。这项研究的结果将导致第二语言学习的更普遍的理论，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DHH儿童语言政策以及成人DHH第二语言手语的第二语言教学课程和口译策略提供了信息。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.