Common neuroanatomical regions support mental switching across language switching, rule retrieval, and rule discoveryBrain activity during language switching shares patterns with mental flexibility

Bilinguals' language-switching ability is regulated by language control mechanisms associated with executive control system. Cognitive flexibility (CF), one of the executive functions, is closely linked to language switching. Existing functional magnetic resonance imaging data demonstrate diverse patterns of neural activity elicited in language-switching and CF tasks, and the degree of overlap between the respective brain networks remains obscure. To address this, we examined neural correlates of language switching in young late bilinguals, as well as common and distinct neural mechanisms of language-switching tasks and CF. To this end, we conducted activation likelihood estimation meta-analysis of 107 experiments, extracted from 83 eligible articles with a total of 1977 participants. These studies used the Wisconsin card sorting test (WCST) for assessing rule-discovery and the task-switching paradigm (TSP) for rule-retrieval switching-the two most common tasks in CF research. Language switching, in turn, was measured by language-switching paradigms (e.g., cued picture-naming task). We observed no differences in neural correlates of language switching and TSP (rule retrieval), whereas, when compared with WCST (rule discovery), language-switching-specific activity was detected in the left pre-supplementary motor area/anterior cingulate cortex complex. These results indicate a common nature of language switching and TSP, linking both kinds of switching to rule retrieval. Conjunction analysis of the three tasks revealed common activation in the left intraparietal sulcus/inferior parietal lobule, left superior parietal lobule, and pre-supplementary motor area. Based on our findings, we propose a unified neuroanatomical model of mental switching engaged across all three types of tasks.