The development of lexical competition in heritage speakers

该奖项是美国国家科学基金会社会、行为和经济科学博士后研究奖学金（SPRF）计划的一部分。SPRF计划的目标是为学术界、工业界或私营部门和政府的科学事业准备有前途的早期职业博士级科学家。SPRF奖励包括在知名科学家的赞助下进行为期两年的培训，并鼓励博士后进行独立研究。美国国家科学基金会寻求促进科学界各阶层的科学家，包括那些未被充分代表的群体的科学家，参与其研究项目和活动；博士后阶段被认为是实现这一目标的一个重要的专业发展阶段。每个博士后必须解决各自学科领域的重要科学问题。在爱荷华大学的鲍勃·麦克默里博士的赞助下，这个博士后奖学金奖支持一位研究传统语言儿童语言发展的早期职业科学家。在当前的地理、政治和全球气候下，预计世界各地的移民人口将继续增加。这些移民的孩子面临的一个关键障碍是语言，因为他们可能没有和单语儿童一样的机会来发展他们新家的主要语言（vald<s:1>, 2005）。因此，对理解传统语言儿童的语言发展提出了挑战，因为他们的第一语言（传统语言）随着年龄的增长（通常是在上学开始时）变得不那么占主导地位，而他们的第二语言（多数语言）最终成为主导地位，尽管起步较晚（Polinsky, 2011）。这往往使他们沦落到专门的英语学习教室，或者使他们得不到足够的支持。目前，传统语言使用者如何发展他们在多数语言中的主导地位，以及当这种语言主导地位发生变化时，会发生什么类型的神经变化，还没有得到很好的研究。本文提出的研究旨在通过眼动追踪、脑电图和机器学习，了解单语和传统语者在一年级、四年级和成年期的口语单词识别，这是早期语言发展的瓶颈过程（Perfetti, 2007; Verhoeven, Reitsma, & Siegel, 2011）。在这里，词汇处理——语言系统中的一个关键枢纽——被定位为一个模型系统，在这个模型系统中，研究传统语言的使用者如何在主流语言中成为更自动的语言处理者，并在他们的传统语言中保持这种状态。评估传统语言儿童的语言背景提出了一个独特的挑战，因为他们接触英语的机会与单语同龄人不同，他们的年龄和习得方式以及他们对多数语言和传统语言的熟练程度都不符合先前评估的双语标准。因此，典型的语言背景问卷可能无法充分捕捉到传统语者儿童的经历。相反，采用了一种更全面的方法，包括一种创新的记录工具（即LENA系统）和网络科学来量化两种语言的暴露。最后，本研究不仅旨在了解儿童时期延迟接触多数语言的影响，还旨在了解其对传统说话者成人语言表征的长期影响，并利用电生理和机器学习技术分离语义和听觉差异的贡献。这里的发现扩展了语言习得和语言处理的认知神经科学在不同的双语人群中（即，传统的发言者）。至关重要的是，传统演讲者提供了洞察力，以帮助回答词汇处理中理论上具有挑战性的问题，这些问题无法以其他方式解决。总体而言，本研究旨在扩大传统语言使用者对语言发展研究的参与，并为传统语言使用者寻找和创造更可持续的语言和教育计划。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。

This award was provided as part of NSF's Social, Behavioral and Economic Sciences Postdoctoral Research Fellowships (SPRF) program. The goal of the SPRF program is to prepare promising, early career doctoral-level scientists for scientific careers in academia, industry or private sector, and government. SPRF awards involve two years of training under the sponsorship of established scientists and encourage Postdoctoral Fellows to perform independent research. NSF seeks to promote the participation of scientists from all segments of the scientific community, including those from underrepresented groups, in its research programs and activities; the postdoctoral period is considered to be an important level of professional development in attaining this goal. Each Postdoctoral Fellow must address important scientific questions that advance their respective disciplinary fields. Under the sponsorship of Dr. Bob McMurray at the University of Iowa, this postdoctoral fellowship award supports an early career scientist examining language development in heritage speaker children. In the current geographical, political, and global climate, immigrant populations are expected to continue increasing around the world. A critical barrier faced by the children of these immigrants is language, as they may not have the same opportunities as monolingual children do to develop the majority language of their new home (Valdés, 2005). Thus, a challenge is posed for understanding the language development of heritage speaker children, as their first language (the heritage language) becomes their less dominant language as they age (often when schooling begins), and their second language (the majority language) eventually becomes dominant, despite a delayed start (Polinsky, 2011). This often relegates them to special English Language Learner classrooms or leaves them with insufficient support. Currently, how heritage speakers develop their dominancy in the majority language and what type of neural changes happen when this language dominancy shift occurs is not well-studied.The proposed research study aims to understand spoken word recognition, a bottleneck process of early language development (Perfetti, 2007; Verhoeven, Reitsma, &amp; Siegel, 2011), in monolingual and heritage speakers at Grade 1, Grade 4, and in adulthood by using eye-tracking, EEGs, and machine learning. Here, lexical processing—a critical hub in the language system—is being targeted as a model system in which to ask how heritage speakers become more automatic language processors in the majority language and maintain this in their heritage language. Assessing heritage speaker children’s linguistic backgrounds presents a unique challenge in that their exposure to English is not similar to their monolingual peers, and their age and manner of acquisition as well as their proficiency in the majority and the heritage language do not follow previously assessed bilingual norms. Therefore, typical language background questionnaires may not adequately capture heritage speaker children’s experience. Instead, a more holistic approach, including an innovative recording tool (i.e., the LENA system) and network science to quantify the exposure in both languages are employed. Finally, the proposed study aims to not only understand the impact of delayed exposure to the majority language in childhood but also its prolonged impact on heritage speaker adults’ language representation, and to separate the contributions of semantic and auditory differences using electrophysiological and machine learning techniques. Findings here expand on both language acquisition and the cognitive neuroscience of language processing in various bilingual populations (i.e., heritage speakers). Crucially, heritage speakers provide insight to help answer theoretically challenging questions in lexical processing which cannot be otherwise addressed. Overall, this study aims to broaden the participation of heritage speakers in language development research as well as find and create more sustainable language and educational programs for heritage speakers.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.