Behavioural and ERP correlates of bilingual language control and general-purpose inhibitory control predicted by L1 and L2 proficiency

Cognitive control is the ability to adapt flexibly to current demands by promoting task-relevant information in the face of interference, and this has been asserted as an advantage with bilinguals. Bilingual language control and general-purpose cognitive control are discussed in the literature using different types of stimuli, cognitive tasks, component processes (selection, interference, inhibition, switching) and groups (bilingual vs. monolingual; high proficient vs. low proficient bilingual). The present study was designed to investigate the neurocognitive correlates of inhibitory control with linguistic (i.e., words) and nonlinguistic (i.e., line drawings of objects) stimuli in Hindi-English bilingual adults. We conducted the behavioural experiment first to establish the linguistic version of identity negative priming paradigm followed by the Event-related potential (ERP) experiment using the linguistic and nonlinguistic negative priming task. Results show the presence of inhibition effect using mean reaction times as well as ERP data while comparing the control and ignored repetition conditions, and this pattern varied with different stimuli - linguistic vs. nonlinguistic. Thus, the current study suggests that bilingual language control is not entirely subsidiary to general-purpose cognitive control and shows differences based on the stimulus type. Also, proficiency in L1 and L2 differentially predicts performance on the nonlinguistic and linguistic negative priming paradigm, respectively. These results are indicative of a dynamic cognitive control system associated with bilingualism, which varies as a function of stimulus type as well as language proficiency.