The consequences of early language experience and literacy for adult learning and brain structure

该奖项是作为NSF社会、行为和经济学博士后研究奖学金(SPRF)计划的一部分提供的。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职业生涯培养有前途的、早期职业博士水平的科学家。SPRF奖项包括在知名科学家的赞助下进行两年的培训，并鼓励博士后研究员进行独立研究。国家科学基金会致力于促进科学界所有阶层的科学家参与其研究方案和活动，包括那些来自代表性不足的群体的科学家；博士后阶段被认为是实现这一目标的专业发展的一个重要水平。每个博士后研究员都必须解决推动各自学科领域向前发展的重要科学问题。在童年早期接触过两种语言的双语成年人在学习这两种语言的方式和成年后说和读这两种语言的技能方面都有很大的不同。尽管两种语言在美国的存在越来越多，但人们对早期双语经历的差异对成年说话者的头脑和大脑的影响知之甚少。在国家科学基金会的支持下，Pi Atagi将在加州大学河滨分校进行博士后研究，这是一家西班牙裔服务机构，代表了研究这一问题所需的语言经验的多样性。这项计划中的研究考察了拥有广泛语言和识字技能的双语大学生，以了解童年的语言经历和识字如何影响语言学习能力、认知和大脑结构。该项目询问，在童年学习两种语言是否会对成年后的语言学习能力以及已被证明受到双语影响的大脑结构产生影响。在美国，越来越多的说传统文化的人在英语以外的母语环境中长大，这使得理解这些早期经历的重要性成为促进更多样化的学习者群体在学术和经济上取得成功的首要任务。这项计划中的研究还通过纳入本科生研究学生来帮助培训不同的语言和认知神经学家群体，他们中的大多数人自己都会说两种语言。通过确定早期语言和识字经历不同的人的大脑结构可能会发生什么变化，该项目还将让我们了解大脑是如何适应经验的。成年人的大脑对新语言学习的适应能力比之前认为的要强得多。对语言处理的研究表明，学习一门新语言，即使是在成年后，也是一个动态的过程，会改变母语的处理方式。然而，人们对早期语言体验对成人语言学习和认知的长期影响知之甚少，更不知道不同类型的双语体验，如两种语言的识字能力，如何影响成人的学习和认知。这项拟议的研究利用认知神经科学的方法来研究早期的双语经历和识字如何塑造后来的成人语言学习、认知和大脑结构。本研究考察并比较了传统双语大学生与早期同步双语者和英语-单语者的差异。讲传统语言的人是一个不同的双语群体，他们成年后说和读两种语言的技能各不相同。在该奖项的第一年，计划中的研究重点是确定对以后成人学习影响最大的语言和识字经历；因此，计划中的研究最初通过使用一系列语言、识字和认知测量以及一个新的单词学习任务来检查早期语言和识字的行为后果。在该奖项的第二年，一组结构成像研究将检查从这些群体中抽取的成年学习者，并确定最初发现的可重复性。这项研究的发现将开始确定早期双语体验的各个方面，这些方面可能会塑造大脑和大脑。尽管双语能力已经被发现与大脑的结构差异有关，尤其是皮质厚度，但双语素养的结构相关性尚不清楚。此外，通过研究识字，这项研究开始解开早期口语经历和识字对成年双语者的认知和神经后果的影响。识字是一种独特的语言体验，使学习者接触到比言语更多样化的单词和句子结构。如果两种语言的读写能力被发现以不同于会说两种语言的方式有利于语言学习和认知，可能会建议双语学生更好地支持两种语言的读写能力。

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. Bilingual adults who were exposed to two languages in early childhood vary considerably in the ways in which they learned the two languages and the skill they have as adults to speak and read both languages. Despite the increasing presence of two languages in the US, there is little known about the consequences of variation in early bilingual experience for the minds and brains of adult speakers. With the support of the National Science Foundation, PI Atagi will conduct postdoctoral studies at the University of California, Riverside, a Hispanic Serving Institution that represents the diversity of language experience required to investigate this issue. The planned research examines bilingual college students with a wide range of language and literacy skills to understand how childhood language experiences and literacy shape language learning abilities, cognition, and brain structure. This project asks whether learning to read in both languages in childhood has consequences for later language learning abilities in adulthood and for the brain structures that have been shown to be affected by bilingualism. The growing number of heritage speakers in the US who grew up with a home language other than English makes understanding the significance of these early experiences a high priority for promoting the academic and economic success of a more diverse group of learners. The planned research also contributes to the training of a diverse group of language and cognitive neuroscientists by the inclusion of undergraduate research students, most of whom are themselves bilingual. By identifying how brain structure may vary for individuals who differ in their early language and literacy experiences, the project will also inform our understanding of how the brain adapts to experience.The adult brain is far more adaptive to new language learning than previously thought. Studies examining language processing show that learning a new language, even as an adult, is a dynamic process that changes the way the native language is processed. However, little is known about the long-term consequences of early language experiences for adult language learning and cognition, and even less is known about how different types of bilingual language experiences, such as literacy in two languages, affect adult learning and cognition. The proposed research exploits cognitive neuroscience methods to examine how early bilingual language experiences and literacy shape later adult language learning, cognition, and brain structure. This study examines and compares bilingual college students who are heritage speakers to early simultaneous bilinguals and English-monolinguals. Heritage speakers are a diverse group of bilinguals, who vary in the skill they have as adults to speak and read both languages. In the first year of the award, the planned research focuses on identifying the language and literacy experiences that have the greatest impact on later adult learning; thus, the planned research initially examines the behavioral consequences of early language and literacy by using a battery of language, literacy, and cognitive measures, as well as a new word learning task. In the second year of the award, a set of structural imaging studies will examine adult learners drawn from those groups and to determine the replicability of the initial findings. Findings from this research will begin to identify the aspects of early bilingual experience that may shape the mind and brain. Though bilingualism has been found to be associated with structural differences in the brain, particularly in cortical thickness, the structural correlates of bilingual literacy are yet unknown. Additionally, by examining literacy, a distinct type of language experience that exposes learners to more varied words and sentence structures than speech, this research begins to disentangle what cognitive and neural consequences early spoken language experience and literacy have for adult bilinguals. If literacy in two languages is found to benefit language learning and cognition in ways distinct from speaking two languages, it may suggest that literacy in both languages should be better supported in bilingual students.