The Cognitive Neuroscience of Bilingual Advantages in Executive Control

人类在两个或多个正在进行的任务之间切换注意力的能力令人惊叹。这种认知灵活性允许成功地导航日常生活的需求，但它随着年龄的增长而下降。最近的研究结果表明，这种与年龄相关的下降在终身双语者中并不严重;从童年开始经常说一种以上的语言似乎可以提供一些保护。目前的认知模型表明，这种提升的基础与双语者不断在多种语言之间切换的事实有关，这有助于加强任务切换和相关的执行控制过程。在国家科学基金会的支持下，肯塔基州大学的Brian Gold博士和他的同事将进行实验，旨在更全面地了解执行控制过程中双语优势的认知和神经生物学基础。所使用的方法将包括标准的行为实验和神经影像学研究进行单语和双语的参与者。在行为研究中，参与者将参与任务转换和工作记忆范式，并记录反应时间和准确性数据。研究结果将探讨双语是否只加强那些直接复制双语经验的过程，或者它是否有助于支持其他执行控制过程，如记忆更新。神经影像学研究将使用功能磁共振成像（fMRI）和扩散张量成像（DTI）的方法来了解双语性能优势的神经生物学基础。功能磁共振成像实验将确定双语大脑激活模式的变化，这些变化与他们在执行控制任务中的优势相关。DTI测量将识别双语者白色物质微结构的变化，这些变化与执行控制任务的优势相关。这些实验将提供对认知和神经生物学变量的更精确的理解，这些变量似乎受到终身双语能力的保护。本项目的结果将与可访问的生活方式变量如何影响神经可塑性和/或补偿性大脑储备老化的问题有关。它还将为一名博士后研究员和两名本科生研究助理提供研究培训和指导。学员将获得神经解剖学知识，以及神经影像学数据的分析。这个项目将提供有关第二语言学习和神经生物学之间关系的信息，这是我们日益多语言社会的一个基本相关问题。

Humans have an amazing facility in switching attention between two or more ongoing tasks. This kind of cognitive flexibility allows for successful navigation of the demands of everyday life, but it declines with aging. Recent results have shown that such age-related declines are not as severe in lifelong bilinguals; speaking more than one language on a regular basis since childhood seems to provide some protection from this general effect. Current cognitive models suggest that the basis of this boost relates to the fact that bilinguals are constantly switching between multiple languages, which serves to strengthen task switching and related executive control processes. With support from the National Science Foundation, Dr. Brian Gold and his colleagues at the University of Kentucky will conduct experiments designed to gain a more comprehensive understanding of the cognitive and neurobiological bases of bilingual advantages in executive control processes. The methods used will include standard behavioral experiments and neuroimaging studies conducted with monolingual and bilingual participants. In behavioral studies, participants will engage in task switching and working memory paradigms and reaction time and accuracy data will be recorded. Results will explore whether bilingualism strengthens just those processes that directly replicate the bilingual experience, or if it serves to bolster other executive control processes, such as memory updating. The neuroimaging studies will use functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) methods to understand the neurobiological bases of bilingual performance advantages. The fMRI experiment will identify variations in bilingual brain activation patterns that correlate with their advantages on executive control tasks. The DTI measures will identify variations in white matter microstructure in bilinguals, ones that correlate with the advantages on executive control tasks. The experiments will provide a more precise understanding of the cognitive and neurobiological variables that seem to be protected by lifelong bilingualism. Results from the present project will be relevant to the question of how accessible lifestyle variables can influence neuroplasticity and/or compensatory brain reserve in aging. It will also provide research training and mentoring to a postdoctoral fellow and two undergraduate research assistants. Trainees will acquire knowledge in neuroanatomy, and the analysis of neuroimaging data. This project will provide information about the relationship between second language learning and neurobiology, an issue of fundamental relevance in our increasingly multilingual society.