BRAIN AND BEHAVIOR INDEXES OF THE ARITHMETIC ORGANIZATION IN BILINGUALS

描述（由申请人提供）：学习一种以上的语言改变行为和大脑的结构和功能组织，其变化超出了语言的领域。因此，双语者不能被简单地视为一个大脑中有两个单语者，在一个五分之一的人在家说英语以外的语言的国家，了解双语者如何影响其他认知系统是至关重要的。本提案旨在了解算术事实，如乘法表，如何为每种语言的多种双语格式、数字和数字单词表示和访问。语言和算术被认为是紧密相连的，因为算术概念是通过语言来学习的。因此，掌握一种以上的语言可能会影响组织和处理这些概念的方式。我们建议进行一系列研究，使用事件相关电位(ERPs) -一种对大脑皮层活动的快速时间动态敏感的技术-以及行为分析的表现，以揭示在每种格式下处理算术概念的定性和定量差异。我们测量简单乘法问题（3x2=6）解决方案的响应时间（RT）和erp，其中操作数和解决方案之间的一致性被操纵。跨格式处理一致与不一致实验的差异可以揭示算术事实表示的联系和基本结构。初步数据表明，学习算术的语言（LolA），而不是主导语言（L1），比其他语言（LL2）具有更强和更精确的表征。目标1通过操作解决方案在代码之间创建语言切换来测试表示之间的码间连接。这将使我们能够根据开关的方向确定任何不对称开关成本，进而测试抑制机制。目标2将确定Ll2的熟练程度是否可以提高这种格式的算术事实的表示。在类似的情况下，Aim 3询问在Ll2中具体使用算术事实的经验是否可以改善该网络中的表示。也就是说，可以通过实践来重新学习，比如用第二语言教授数学的个人，扭转LolA和Ll2之间的强烈不对称。我们将首先测量每个目标的速度正确性判断和准确性，以揭示代码之间的任何明显的行为差异。然后，我们将测量2个对算术概念之间的算术一致性和相关性敏感的ERP分量，N400，一个在刺激后400毫秒达到峰值的负波，对心理词汇条目之间的激活传播敏感，以及晚积极分量，反映对意外解决方案的更可控处理。这些分量的振幅、延迟或分布的变化可以阐明代码内部和代码之间的联系。我们的研究将测试目前唯一的双语算术模型，并导致更好地理解大脑组织的算术，在正常和异常条件下的学习和使用的后果。

DESCRIPTION (provided by applicant): Learning more than one language alters behavior and the structural and functional organization of the brain, with changes extending beyond the realm of language. Thus the bilingual cannot be viewed as simply two monolinguals in one brain, and in a country where 1 in 5 people speak a language other than English at home, it is essential to understand how being bilingual can impact other cognitive systems. This proposal aims to understand how arithmetic facts, such as multiplication tables, are represented and accessed for the multiple bilingual formats, digits and number words in each language. Language and arithmetic are thought to be tightly linked because arithmetic concepts are learned through verbalization. Thus, knowing more than one language may affect the way in which these concepts are organized and processed. We propose a series of studies that use event related potentials (ERPs) - a technique sensitive to the rapid temporal dynamics of cortical brain activity - along with behavioral assays of performance, to uncover qualitative and quantitative differences in processing arithmetic concepts in each format. We measure response times (RT) and ERPs to the solutions of simple multiplication problems (3x2=6) in which the congruence between operands and solutions is manipulated. Processing differences between congruent and incongruent trials across formats can shed light on the connections and basic structure of arithmetic fact representation. Preliminary data indicate that the language of learning for arithmetic (LolA), rather than the dominant language (L1), has stronger and more precise representations than the other language (LL2). Aim 1 tests the intercode connections between representations by manipulating the solution to create language switches between codes. This will allow us to determine any asymmetrical switching costs based on the direction of a switch and in turn test inhibitory mechanisms. Aim 2 will determine if the level of proficiency in Ll2 can improve the representation of arithmetic facts in this format. In a similar vein, Aim 3 asks whether experience specifically using arithmetic facts in Ll2 can improve the representations in this network. That is, can relearning through practice, such as for individuals teaching math in their second language, reverse the strong asymmetries between LolA and Ll2. We will first measure the speeded correctness judgments and accuracy for each aim, to uncover any overt behavioral differences across the codes. We will then measure 2 ERP components that are sensitive to arithmetic congruency and relatedness between arithmetic concepts, the N400, a negative wave peaking 400 ms post-stimulus onset sensitive to the spread of activation between entries in the mental lexicon, and the Late Positive Component, reflecting more controlled processing of unexpected solutions. Changes in amplitude, latency or distribution of these components can elucidate the connections within and between codes. Our studies will test the only current model for bilingual arithmetic, and lead to a better understanding of the brain organization for arithmetic, with consequences for learning and use under normal and abnormal conditions. PUBLIC HEALTH RELEVANCE: Studies have focused on the connection between language and arithmetic concepts (e.g., Dehaene et al., 2003; Campbell, et al., 1999; Campbell and Epp, 2004), but have not been able to show the relationship between these definitively in a single language system, nor have they elucidated the unique circumstances surrounding arithmetic processing in a brain with more than one language. The current project uses a direct measure of electrical brain activity - event related potentials - along with behavioral assays to uncover the connections between the conceptual representations for simple arithmetic in a bilingual's three codes (first and second languages and Arabic digits), as well as to understand the nature of the underlying cognitive and neural processes within each code. These studies will begin to elucidate the basis of performance differences observed across a bilingual's languages, and at the same time inform models of language and arithmetic more generally, which can ultimately inform our understanding of impaired processing in childhood learning disabilities, such as dyscalculia, as well as to improve teaching and testing methodologies taking into account differential processing strategies for bilinguals and monolinguals alike.