Code-Switching patterns differentially shape cognitive control: Testing the predictions of the adaptive control hypothesis

Bilinguals engage in qualitatively different code-switching patterns (alternation, insertion, and congruent lexicalization) to different degrees, according to their engagement in different types of interactional contexts (single-language context, dual-language context, and dense code-switching context). Drawing on the adaptive control hypothesis, we examined whether bilinguals' code-switching patterns would differentially shape multiple aspects of cognitive control (interference control, salient cue detection, and opportunistic planning). We found that a dense code-switching context, which predominantly involves insertion and congruent lexicalization, was positively associated with verbal opportunistic planning but negatively associated with interference control and salient cue detection. In contrast, a dual-language context, which predominantly involves alternation, was not associated with interference control or salient cue detection, but with significantly reduced response times for opportunistic planning. Our findings partially corroborate the theoretical predictions of the adaptive control hypothesis. Altogether, our study illustrates the importance of bilinguals' disparate code-switching practices in shaping cognitive control outcomes.