ERP differences between monolinguals and bilinguals: The role of linguistic distance

A growing body of research suggests that bilingualism may afford benefits to certain aspects of cognitive functioning. Inconsistent findings may arise because of methodological differences within and across studies. One limitation is that studies often compare linguistically similar languages. The present study recorded brain activity (event-related potentials; ERPs) while English monolinguals, English–French bilinguals, and Arabic–English bilinguals completed an n-back task and a delayed matching-to-sample task. Group ERP differences were observed in the absence of behavioral differences. In the delayed matching-to-sample task, monolinguals exhibited smaller N2 amplitude compared to both bilingual groups, and smaller P3b amplitude compared to English–French bilinguals. In the n-back, English–French bilinguals displayed larger P3b amplitudes than monolinguals and Arabic–English bilinguals. P3b amplitude did not differ between Arabic–English bilinguals and monolinguals in either task. These results suggest that conflicting findings across studies may be due in part to the linguistic distance between the languages under study.