Abstract/Summary

Most existing studies on the relationship between code-switching and executive functions have focused on experimentally induced language-switching, which differs fundamentally from naturalistic code-switching. This study investigated whether and how bilinguals’ code-switching practices modulate different aspects of executive functioning. Our findings suggest that existing processing models of code-switching should be extended by a dual control mode perspective, differentiating between reactive and proactive monitoring. Bilinguals engaging in code-switching types that keep languages more separate (Alternation) displayed inhibitory advantages in a flanker task inducing reactive control. Dense code-switching, which requires bilinguals to constantly monitor cross-linguistic competition, explained performance in proactive monitoring conditions. Furthermore, a correlation between Dense code-switching and response inhibition suggests that linguistic co-activation may persist during articulatory stages of language processing. Crucially, bilinguals outperformed monolinguals at those aspects of the executive system that were trained by their most frequent code-switching habits. This underlines the importance of sociolinguistic variables in bilingualism research.