Adult sequential bilingualism and its impact on executive functions: a study on Russian – English bilinguals

Abstract

The prevalence of bilingualism is continuing to increase in populations worldwide. The literature argues that bilingualism is associated with certain cognitive advantages, specifically in non-verbal tasks. Previous results consistently demonstrate that bilingual children score higher on non-verbal tasks when compared to monolingual children that speak the same language. The current study aimed to examine whether adults’ bilingualism results in enhanced executive function (EF). Based on prior literature, it was hypothesised that there will be a significant difference in EF between monolingual and bilingual groups, favouring the bilingual group. A between-participants design was used to compare performance of Russian-English bilinguals (age 18-50 yrs, n = 45) with English speaking monolinguals (age 18-50 yrs, n = 49) (total N = 94) on three EFs (inhibition, switch function, and working memory). Participants completed the tasks in a single test session on a computer. A Mann - Whitney U test was performed to examine group differences on five computerised psychological tests of EF (Simon Task, Stroop Colour Word Task, Tower of London Task, Trail-Making Task and Wisconsin Card Sorting Test). The hypothesis was unsupported by the results, as there was not a significant between-groups difference on EF apart from on working memory. These findings highlight that bilingualism does not necessarily lead to improved EF when the second language is learned later in life. The implications of the findings from the current study, along with suggestions for future research, are raised in the discussion.