Role of joint language control during cross-language communication: evidence from cross-frequency coupling.

How do bilingual interlocutors inhibit interference from the non-target language to achieve brain-to-brain information exchange in a task to simulate a bilingual speaker-listener interaction. In the current study, two electroencephalogram devices were employed to record pairs of participants' performances in a joint language switching task. Twenty-eight (14 pairs) unbalanced Chinese-English bilinguals (L1 Chinese) were instructed to name pictures in the appropriate language according to the cue. The phase-amplitude coupling analysis was employed to reveal the large-scale brain network responsible for joint language control between interlocutors. We found that (1) speakers and listeners coordinately suppressed cross-language interference through cross-frequency coupling, as shown in the increased delta/theta phase-amplitude and delta/alpha phase-amplitude coupling when switching to L2 than switching to L1; (2) speakers and listeners were both able to simultaneously inhibit cross-person item-level interference which was demonstrated by stronger cross-frequency coupling in the cross person condition compared to the within person condition. These results indicate that current bilingual models (e.g., the inhibitory control model) should incorporate mechanisms that address inhibiting interference sourced in both and (i.e., cross-language and cross-person item-level interference) synchronously through joint language control in dynamic cross-language communication.