Degree of conversational code-switching enhances verbal task switching in Cantonese–English bilinguals

The study examined individual differences in code-switching to determine the relationship between code-switching frequency and performance in verbal and non-verbal task switching. Seventy-eight Cantonese–English bilinguals completed a semi-structured conversation to quantify natural code-switching, a verbal fluency task requiring language switching, and two non-verbal switching tasks. Participants who engaged in more conversational code-switching showed smaller costs in verbal task switching than those who switched languages less frequently. Participants performed similarly to bilinguals in previous studies on non-verbal switching tasks, but in this case performance was not linked to the degree of conversational code switching. The difference in the influence of code-switching for verbal and non-verbal executive control tasks indicates a dissociation between domains for the mechanism of task switching.