The Modulation Effect Of Dual-language Contexts On Inhibitory Control:Behavioral And Fmri Evidence

Executive control is important for us to achieve goal-directed behavior.Serving as one core component of the executive functions,the inhibitory control often refers to the ability to ignore interfering information and suppress the natural or habitual response,in order to make the suitable behavior.Factors that may modulate the inhibitory control have been explored by plenty of previous studies and recently,there has been an increasing interest in exploring the influence of language contexts on nonlinguistic functions,such as inhibitory control.However,few of these studies have investigated whether the language contexts might make immediately influence on the inhibitory control and the plasticity of its underlying neural mechanism.What's more,preliminary neuroscience studies on bilinguals' language control have proposed a hypothesis that the bilinguals language control network may overlap with the inhibitory control network.Therefore,to figure out the above uncertainty,in the present study,30 Cantonese–Mandarin–English trilinguals,who were highly proficient in Cantonese(L1)and Mandarin(L2),and moderately proficient in English(L3),participated in a functional magnetic resonance imaging(f MRI)experiment.During the f MRI scans,they were asked to name pictures in either two of the three languages(Cantonese,Mandarin,and English)and followed by each picture naming task,they were asked to complete a flanker task,measuring inhibitory control.Behavioral results showed a typical flanker effect in the L2-L3 and L1-L3 conditions,but not in the L1-L2 condition,which suggests facilitation effect of the L1-L2 context on inhibitory control.Whole brain analysis of the f MRI imaging data acquired during the flanker tasks showed more neural activation in the right prefrontal cortex(RIFC),bilateral insula,caudate and thalamus in the L2-L3 and L1-L3 conditions compared with that in the L1-L2 condition,which implies more involvement of inhibitory control brain areas when participants performed the same flanker task in unbalanced dual-language contexts compared with the L1-L2 context.Effective connectivity analyses showed a cortical-subcortical-cerebellar network of inhibitory control in the trilinguals.However,unlike the integrated multipath network in the L1-L2 condition,functional networks for inhibitory control in the L2-L3 and L1-L3 conditions are less integrated.These findings provide a novel perspective on investigating the interaction between bilingualism(multilingualism)and inhibitory control by demonstrating instant behavioral effects and neural plasticity as functional changes in global language contexts.