Neural Correlates of Lexical Processing in Child L2 Learners

描述（由申请人提供）：该项目旨在揭示儿童早期双语者从初学者过渡到中级第二语言使用者时处理两种语言的神经关联。为了实现这一目标，拟议中的项目将使用近红外光谱（NIRS），它通过与血流和能量代谢相关的脱氧血红蛋白和血红蛋白的变化间接测量神经活动。这种方法是儿童友好的，允许我们将测试扩展到学龄前儿童。最近的研究发现，在生命早期学习第二语言的成年人在语言处理能力上表现出显著的可塑性。这些孩子在上学的前五年从第一语言向第二语言主导过渡，并保持第二语言主导的模式直到成年。为了阐明儿童二语学习者的双语神经关联的本质，该项目将测试3-8岁的双语儿童，他们对应的时间点对应于二语习得的早期阶段到更高级的二语知识。孩子们将被要求听听觉呈现的单词，同时用近红外光谱扫描。本研究的结果将有助于阐明儿童时期区分第一语言习得和第二语言习得的神经基础。最后，提出的研究将比较两种相互竞争的模型的预测，这两种模型认为第二语言习得涉及认知控制的不同使用或涉及感觉运动加工的变化。

DESCRIPTION (provided by applicant): The proposed project is designed to uncover the neural correlates of processing two languages as bilinguals transition from novice to intermediate L2 speakers in early childhood. To achieve this, the proposed project will use Near Infrared Spectroscopy (NIRS), which measures neural activity indirectly via changes in deoxyhemoglobin and hemoglobin which is correlated with blood flow and energy metabolism. This methodology is child friendly allow us to extend testing to children that are preschool age. Recent research has found that adults who learned a second language early in life exhibit remarkable plasticity in their language processing abilities. These children transition from L1 to L2 dominance during the first five years of schooling and maintain a pattern of L2 dominance into adulthood. To elucidate the nature of the neural correlates of bilingualism in child L2 learners, the proposed project will test bilingual children between the ages of 3-8, which correspond to time points corresponding to very early stages of L2 acquisition up to more advanced L2 knowledge. Children will be asked to listen to auditorily presented words while being scanned with NIRS. The results from the proposed studies will help to elucidate the neural substrates that differentiate first from second language acquisition during childhood. Finally, the proposed studies will compare predictions from two competing models which view L2 acquisition as involving differential use of cognitive control or as involving changes in sensorimotor processing. PUBLIC HEALTH RELEVANCE: The proposed project is designed to extend the scope of the parent grant by examining the neural correlates of processing two languages as bilinguals transition from novice to intermediate L2 speakers as they transition from preschool years to early grade school. The results from these studies should help to provide background which will help clinicians in the assessment and treatment of young L2 learners with language disorders.