Neural differences between monolinguals and early bilinguals in their native languaje during comprehension

Research has shown that semantic processing of sentences engages more activity in the bilingual compared to the monolingual brain and, more specifically, in the inferior frontal gyrus. The present study aims to extend those results and examines whether semantic and also grammatical sentence processing involve different cerebral structures when testing in the native language. In this regard, highly proficient Spanish/Catalan bilinguals and Spanish monolinguals made grammatical and semantic judgments in Spanish while being scanned. Results showed that both types of judgments recruited more cerebral activity for bilinguals in language-related areas including the superior and middle temporal gyri. Such neural differences co-occurred with similar performance at the behavioral level. Taken together, these data suggest that early bilingualism shapes the brain and cognitive processes in sentence comprehension even in their native language; on the other hand, they indicate that brain over activation in bilinguals is not constrained to a specific area.This research was supported by Research Grants PSI 2009-10067 and PSI 2014-47604-R (Ministry of Science and Innovation of Spain) and by BRAINGLOT, a Spanish Research Network on Bilingualism and Cognitive Neuroscience (CSD2007-00012, Consolider-Ingenio 2010 Scheme, Ministry of Science and Technology of Spain)