Language proficiency, sociolinguistic factors and inhibitory control among bilinguals

Bilingualism interacts with cognitive control mechanisms, particularly inhibitory control. It is believed that language proficiency as a measure of the degree of bilingualism may influence inhibitory control. However, this interaction is modulated by sociolinguistic factors associated with bilingual experience. We examined the relationship between language proficiency and inhibitory control and the influence of sociolinguistic factors by comparing high and low proficient Hindi–English bilinguals, and by using a correlational design. A standard go/no-go task with varying proportions of go and no-go trials was used. Study-1 showed that age of acquisition, language use in formal/informal setting, and bilingual switching influenced the interaction between L2 proficiency and inhibitory control. In general, high proficient bilinguals were better at regulating inhibitory control when the demand on inhibition was high compared to that of low proficient bilinguals. Study-2 showed that contextual switching and setting-based use of L2 predicted inhibitory control in a high monitoring condition while use of L1 predicted inhibitory control irrespective of inhibitory demands. However, contextual switching strengthened the interaction between L2 proficiency and inhibitory control whereas use of L1 moderated the relationship between L1 proficiency and inhibitory control. We did not find a significant effect of non-language variables such as fluid intelligence, socioeconomic status, and participation in skilled activities on the relationship between language proficiency and inhibitory control. We emphasize on the role of both L1 and L2 proficiency and the use of a correlational design to investigate the relationship between bilingualism and inhibitory control.