Examining the effects of active versus inactive bilingualism on executive control in a carefully matched non-immigrant sample

Bilinguals have been argued to show a cognitive advantage over monolinguals, although this notion has recently been called into question. In many studies, bilinguals and monolinguals vary on background variables. Moreover, most studies do not distinguish between potential effects of language knowledge and language use. We examined the effects of bilingualism on executive control in older adults by comparing active and inactive bilinguals and monolinguals matched on lifestyle, socio-economic status, education, IQ, gender, and age. In the Simon arrow task, no effect of bilingualism was observed on overall RTs or the Simon effect. In the task-switching paradigm, although there was a difference between active (but not inactive) bilinguals and monolinguals on raw switching costs, the groups did not differ on overall RTs and proportional switching or mixing costs. Thus, our findings do not reveal an overall cognitive advantage of bilingualism on executive control tasks in groups matched on background variables. (C) 2015 Elsevier Inc. All rights reserved.