The Cognitive Neuroscience of Bilingual Advantages in Executive Control

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

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.