Causal role of frontocentral beta oscillation in comprehending linguistic communicative functions

Abstract

Linguistic communication is often considered as an action serving the function of conveying the speakers goal to the addressee. Although neuroimaging studies have suggested a role of the motor system in comprehending communicative functions, the underlying mechanism is yet to be specified. Here, by 2 EEG experiments and a tACS experiment, we demonstrate that the frontocentral beta oscillation, which represents action states, plays a crucial part in linguistic communication understanding. Participants read scripts involving 2 interlocutors and rated the interlocutors attitudes. Each script included a critical sentence said by the speaker expressing a context-dependent function of either promise, request, or reply to the addressees query. These functions were behaviorally discriminated, with higher addressees will rating for the promise than for the reply and higher speakers will rating for the request than for the reply. EEG multivariate analyses showed that different communicative functions were represented by different patterns of frontocentral beta activity but not by patterns of alpha activity. Further tACS results showed that, relative to alpha tACS and sham stimulation, beta tACS improved the predictability of communicative functions of request or reply, as measured by the speakers will rating. These results convergently suggest a causal role of the frontocentral beta activities in comprehending linguistic communications. HighlightsO_LIThe frontocentral beta activity patterns discriminate communicative functions. C_LIO_LIThe frontocentral beta activity plays a causal role in comprehending the functions. C_LIO_LIThe comprehension could be subserved by the mental simulation of the communication. C_LIO_LIOur findings connect the idea of embedded semantics with the speech act theory. C_LI