The effect of cognitive flexibility on task switching and language switching

Aims: The present study aimed at investigating whether cognitive flexibility plays the same role in language switching as in task switching. Design: Cognitive flexibility (CF) of 52 low proficiency Chinese (L1)–English (L2) bilinguals was assessed by the Wisconsin Card Sorting Task. These bilinguals were then subdivided in 26 high- and 26 low-CF participants. Both groups performed a task-switching (Simon switch task) and a language-switching task (picture-naming task). The former task required participants to press a button congruent or incongruent to the pointing direction of an arrow, while in the latter participants had to name pictures in their L1 and L2. Data and analysis: Both response latencies and accuracy scores were obtained. Afterwards switch costs (i.e. longer latencies or reduced accuracy for switch in contrast to repeat trials) were calculated. Findings: Results of the Simon switch task showed that switch costs for congruent and incongruent trials were symmetrical in the high-CF group, whereas the low-CF group showed larger switch costs for congruent than incongruent trials. Similarly, results of the language-switch task showed symmetrical switch costs for naming pictures in their L1 and L2 for the high-CF group, but L1 switch costs were larger than L2 ones in the low-CF group. These findings indicate that cognitive flexibility can modulate switch costs of two different switching tasks. This is in line with the inhibitory control model and the task-set inertia theory which assume that cognitive flexibility might modulate the symmetry of different types of switch costs via inhibition. This study provides first direct evidence that cognitive flexibility plays a comparably important role in language switching as well as in task switching. Thus, cognitive flexibility can be beneficial for low proficiency bilinguals’ inhibitory control during task switching and language switching.