The (dis)engagement of different components of inhibitory control in trilingual language control.

Abstract

Despite the worldwide prevalence of multilingualism, the knowledge of the relationship between domain-general cognitive control and multilingual language control remains scant. Here we provide new insights into this issue by examining systematically how different components of inhibitory control (i.e., response inhibition and interference suppression) contribute to language control in multilingual populations with high L2 proficiency. To this end, 65 Tibetan-Chinese-English trilinguals highly proficient in L2 were recruited to complete three tasks: a picture-naming task measuring the performance of online trilingual speech production, and two non-linguistic tasks, a go/no-go task, and a Simon task, as proxies for measuring response inhibition and interference suppression abilities, respectively.Using mixed-effects modeling, we analyzed both the trilingual language switching/non-switching performances and their correlations with these two components of inhibitory control. Our data revealed unexpected patterns of reversed language dominance effect and (a)symmetries in switch costs. Notably, interaction analysis revealed that while response inhibition was robustly engaged in trilingual language control, interference suppression did not appear to play a role. Taken together, our study suggests that, for trilingual speakers highly proficient in L2, the recruitment of different sub-processes of inhibitory control in lexical access was selective, and was constrained to reactive and local level language control. We conclude by discussing theoretical implications.