Mixed language training enhances proactive language control in bilingual language production

The present study investigates the effect of mixed language training on the language control mechanism of bilingual language production. Two groups of unbalanced bilinguals were enrolled in pre- and post-tests using the picture naming task, but only the experimental group participated in an eight-day dual-language training session. Event-related potentials (ERPs) showed that, in the experimental group, the N2 mean magnitude was comparable between two languages in the pre-test, but it was larger in the native language (L1) than the second language (L2) in the post-test. In addition, the delta band power was similar between L1 and L2 in the pre-test, but L2 was associated with stronger power than L1 after training. In contrast, the control group showed no significant changes. These findings suggest that increased experience of language use in the dual-language context induces stronger proactive inhibitory control on L1, resulting in its lower activation.