Bilingualism effects on executive functioning: the case of Irish-English and Catalan-Spanish bilinguals

Abstract

Based on the extensive research addressing the beneficial effects of speaking multiple languages, this study explored the impact of bilingualism on the executive functions of interference and switching. We did so by examining the role of interactional contexts of language switching (Green & Abutalebi, 2013), language typological distance and onset of bilingualism (early vs late bilinguals). We compared three groups of adults, (i) Catalan-Spanish bilinguals (ii) Irish-English bilinguals and Irish monolingual speakers of English (iii), on two interference tasks (Flanker and Multi-Source Interference Task) and two switching tasks (Trail-Making Test and Global-local task). Bilingual advantages in both interference and switching tasks were observed for Irish-English bilinguals compared to Irish monolinguals. However, the two bilingual groups performed similarly in interference tasks. In the switching tasks, we found that (a) Catalan high-switchers outperformed Irish high-switchers in the TMT, but (b) Irish bilinguals experienced reduced mixing costs compared to the Catalan bilinguals in the Global-local task. Finally, within the Irish high-switchers, late-sequential bilinguals had greater switching skills than early-sequential bilinguals. These findings suggest that the diversity of bilingual experiences affects different aspects of executive functions.