No area showed higher FA in monolinguals than bilinguals. Analysis of DTI data showed that bilinguals had higher fractional anisotropy (FA) than monolinguals in association tracts in the left hemisphere, specifically in the superior longitudinal fasciculus, inferior longitudinal fasciculus and inferior fronto-occipital fasciculus (corrected p <. Behavioral results showed equivalent group performance on the nonverbal task but slower performance by bilinguals in the verbal task. Groups differed in French proficiency, (Bilingual = 90.2%, Monolingual = 19.8%, t = 18.72, p <. Fourteen monolingual and 17 English-French bilingual young adults participated. Hence, we compared behavioral performance, functional connectivity, and brain structures of young adults who were unbalanced but proficient bilinguals and monolinguals who had minimal use of a second language on a verbal and nonverbal switching task in fMRI. Neuroimaging studies have found overlapping circuits for linguistic and nonlinguistic control in bilinguals, but no study to date has examined this in both monolingual and bilingual participants. Previous research has reported behavioral differences between monolingual and bilingual participants in executive control but the brain structures underlying those differences remain largely unknown.

Ashley Chung-Fat-Yim (York University), Matthias Berkes (York University), Laura Mesite (Harvard Graduate School of Education), Buddhika Bellana (Baycrest Rotman Research Institute), Gigi Luk (Harvard Graduate School of Education), and Ellen Bialystok (York Task switching fMRI White matter TBSS

Monolingual vs bilingual brain