Functional neuroanatomy of arithmetic in monolingual and bilingual adults and children

Prior studies on the brain bases of arithmetic have not focused on (or even described) their participants' language backgrounds. Yet, unlike monolinguals, early bilinguals have the capacity to solve arithmetic problems in both of their two languages. This raises the question whether this ability, or any other experience that comes with being bilingual, affects brain activity for arithmetic in bilinguals relative to monolinguals. Here, we used functional magnetic resonance imaging to compare brain activity in 44 English monolinguals and 44 Spanish‐English early bilinguals, during the solving of arithmetic problems in English. We used a factorial design to test for a main effect of bilingual Language Experience. Based on the known modulating roles of arithmetic operation and age, we used two arithmetic tasks (addition and subtraction) and studied two age groups (adults and children). When collapsing across operations and age, we found broad bilateral activation for arithmetic in both the monolingual group and the bilingual group. However, an analysis of variance revealed that there was no effect of Language Experience, nor an interaction of Language Experience with Operation or Age Group. Bayesian analyses within regions of interest chosen for their role in arithmetic further supported the finding of no effect of Language Experience on brain activity underlying arithmetic. We conclude that early bilingualism does not influence the functional neuroanatomy of simple arithmetic. Bilinguals can solve arithmetic problems in either of their two languages and it is possible that the bilingual experience affects skills that support arithmetic (executive function and phonological processing). Prior brain imaging studies of arithmetic have not addressed this possibility and most studies do not even characterize their participants' language experiences. In this study, we addressed this question for the first time and found no difference in brain activity underlying arithmetic when comparing Spanish‐English bilinguals with English monolinguals in the context of operation type (subtraction and addition) and age (adults and children). This finding suggests that the neural bases of simple arithmetic are not altered by early bilingual experience.