Neural mechanisms of bilingual speech perception: the role of the executive control network in managing competing phonological representations

Abstract This study investigated the neural mechanisms underlying bilingual speech perception of competing phonological representations. A total of 57 participants were recruited, consisting of 30 English monolinguals and 27 Spanish-English bilinguals. Participants passively listened to stop consonants while watching movies in English and Spanish. Event-Related Potentials and sLORETA were used to measure and localize brain activity. Comparisons within bilinguals across language contexts examined whether language control mechanisms were activated, while comparisons between groups assessed differences in brain activation. The results showed that bilinguals exhibited stronger activation in the left frontal areas during the English context, indicating greater engagement of executive control mechanisms. Distinct activation patterns were found between bilinguals and monolinguals, suggesting that the Executive Control Network provides the flexibility to manage overlapping phonological representations. These findings offer insights into the cognitive and neural basis of bilingual language control and expand current models of second language acquisition.