Domain-general multitasking strategy developed from language experience: Neurobehavioral evidence from student interpreters.

Multitasking as a cognitive ability is significant, and yet few studies have investigated how to improve multitasking, especially by language experience. To investigate how language multitasking may enhance domain-general multitasking, this fMRI study compared interpreting students and matched bilingual controls in a non-linguistic dual-task (auditory Task 1, visual Task 2) and examined how their neural data may relate to behavioral performance. Behaviorally, interpreting students showed higher response-time costs in Task 1 but lower costs in Task 2, resulting in faster responses to dual-task trials. At the neural level, interpreting students exhibited greater dual-task-specific activation in the left postcentral gyrus, SMA, and cerebellum (areas subserving sensory processing, response selection, and motor-cognitive integration). Notably, greater engagement of these regions was correlated with greater Task 1 accuracy decrements in interpreting students but not in controls. These findings, together with slower Task 1 responses, indicate that interpreting students may have strategically activated task-set information from both tasks at trial onset. This strategy, while increasing load on motor-cognitive brain regions and coming at a cost to Task 1 performance, accelerated Task 2 responses by pre-activating subsequent task-set information. Hyperactivation was also observed in the left STG and bilateral MTG, with left STG activity negatively correlated with Task 2 time costs only in interpreting students, suggesting that interpreting may enhance recruitment of language-related networks for faster switching. The selectivity and consistency of these brain-behavior correlations demonstrate the significant effects of interpreting on domain-general multitasking, wherein interpreting students strategically trade initial response speed for overall efficiency.