Bimodal Bilingualism

描述（申请人提供）：双语能力为理解语言处理及其潜在的神经认知机制提供了一个有价值的工具。然而，绝大多数双语研究都涉及口语。语言符号双语者或双峰双语者对每种语言使用不同的感知和运动系统。这种系统的分离提供了同时从两种语言中产生和感知元素的独特可能性，这种现象称为代码混合。相比之下，言语-言语或单模双语者一次只能产生一个词汇，因为两种语言依赖于相同的输出通道（声道）。该项目研究了双峰双语对语言产生模型的影响，双语如何影响认知，以及大脑管理和适应两种语言系统的能力。在一系列的心理语言学实验中，我们研究了双语激活对流利和失败的词汇获取的影响，并探讨了双峰双语者特有的加工效应（如代码弯曲、手语象似性、同语手势的变化和面部手势的解释）。第二个系列研究调查了双语如何导致认知能力的变化。在语音处理过程中持续控制两种语言的需要与单模双语者在认知控制方面的优势有关。双峰双语者提供了一个机会来考虑这些优势是来自两种语言系统的知识，还是来自对单一情态（言语）的竞争。我们研究了双峰双语者在空间工作记忆和跨模态监测方面是否表现出特殊的认知优势。第三系列研究调查了我们在行为中观察到的心理语言和认知效应是否会引起单峰和双峰双语者大脑功能和结构结构的特定变化，以及这些神经变化是否与早期大脑发育有关。这些研究将共同描述双峰双语者的独特特征，同时也揭示了双语者如何在单一认知系统中管理两种语言的激活。更广泛地说，研究结果将增强我们对所有说话者支持语言处理的语言、认知和神经系统的理解。

DESCRIPTION (provided by applicant): Bilingualism provides a valuable tool for understanding language processing and its underlying neurocognitive mechanisms. However, the vast majority of bilingual research has involved spoken languages. Speech-sign bilinguals or bimodal bilinguals use separate perceptual and motoric systems for each language. This separation of systems affords the unique possibility of producing and perceiving elements from two languages at the same time, a phenomenon called code-blending. In contrast, speech-speech or unimodal bilinguals are restricted to producing one lexical item at a time because both languages rely on the same output channel (the vocal tract). This project investigates the implications of bimodal bilingualism for models of language production, for how bilingualism affects cognition, and for the brain's ability to manage and adapt to two language systems. In a series of psycholinguistic experiments, we investigate the consequences of dual- language activation for fluent and failed lexical access and explore processing effects specific to bimodal bilinguals (e.g., code-bends, sign language iconicity, changes in co-speech gesture, and the interpretation of facial gestures). A second series of studies investigates how bilingualism leads to changes in cognitive ability. The need to continuously control two languages during speech processing has been linked to advantages in cognitive control for unimodal bilinguals. Bimodal bilinguals provide the opportunity to consider whether these advantages arise from knowledge of two linguistic systems or from competition for a single modality (speech). We examine whether bimodal bilinguals exhibit particular cognitive advantages in spatial working memory and cross-modal monitoring. A third series of studies investigates whether the psycholinguistic and cognitive effects that we observe in behavior give rise to specific changes in the functional and structural architecture of the brain in both unimodal and bimodal bilinguals and whether these neural changes are tied to early brain development. Together these studies will characterize properties unique to bimodal bilinguals, while also revealing how bilinguals manage the activation of two languages in a single cognitive system. More generally, the results will enhance our understanding of the linguistic, cognitive, and neural systems that support language processing in all speakers. PUBLIC HEALTH RELEVANCE: With the spread of bilingual approaches to deaf education and the passage of the Americans with Disabilities Act (which has resulted a great need for sign language interpreters), more and more people are becoming bilingual in American Sign Language (ASL) and English. This project documents the linguistic, cognitive, and neural consequences of such "bimodal" bilingualism. The findings will help clinicians gain a more complete and accurate assessment of cognition and language in these bilinguals, will inform education and health matters related to bilingualism in general, and will be important in designing appropriate interpreter training programs, which will benefit deaf individuals and their families.