The effects of language switching experience and acute stress on bilingual advantages in cognitive flexibility

Aims: This study aimed to investigate how bilingual advantages in cognitive flexibility were modulated by language-use parameters (e.g., language switching experience) and psychological factors (e.g., acute stress).Design/methodology: Chinese-English unbalanced bilinguals with a high or low amount of language switching experience (HLS or LLS bilinguals) performed a cued color-shape switching task in stress-free condition (Experiment 1) or in acute stress condition induced by the Trier Social Stress Test (Experiment 2). Switching and mixing costs were calculated to denote two aspects of cognitive flexibility: transient and sustained switching abilities, respectively.Data and analysis: Differences in switching and mixing costs between HLS and LLS bilinguals were analyzed using repeated-measures analysis of variance (ANOVA). The predictive relationship between language switching experience and cognitive flexibility was examined using hierarchical regression models. The role of acute stress in the dynamics was tested by means of independent samples t-tests in a cross-analysis of Experiments 1 and 2.Findings/conclusions: HLS and LLS bilinguals showed similar switching and mixing costs in the stress-free condition, but in the acute stress condition, HLS bilinguals showed lower switching costs than LLS bilinguals. The result of cross-experimental analysis further revealed that higher switching costs were demanded in LLS bilinguals under acute stress. These findings suggest that language switching experience specifically influences transient switching ability under acute stress.Originality: This study was a first attempt to provide evidence that psychological stress may be a crucial determinant in exploring the theoretical implications of cognitive control in bilingualism.Significance: Our findings suggest that bilingual advantages in cognitive flexibility are conditional, shedding light on the ongoing debate about the ambiguous relationship between language experience and cognitive control in bilinguals.