EEG-based speaker-listener neural coupling reflects speech-selective attentional mechanisms beyond the speech stimulus

Abstract

AbstractWhen we pay attention to someone, do we focus only on the sound they make, the word they use, or do we form a mental space shared with the speaker we want to pay attention to? Some would argue that the human language is no other than a simple signal, but others claim that human beings understand each other not only by relying on the words that have been said but also formed a shared ground in the specific conversation. This debate was raised early, but the conclusion remains vague. Our study aimed to investigate how attention modulates the neural coupling between the speaker and the listener in a cocktail party paradigm. The temporal response function (TRF) method was employed to reveal how the listener was coupled to the speaker at the neural level. The results showed that the neural coupling between the listener and the attended speaker peaked 5 seconds before speech onset at the delta band over the left frontal region, and was correlated with speech comprehension performance. In contrast, the attentional processing of speech acoustics and semantics occurred primarily at a later stage after speech onset and was not significantly correlated with comprehension performance. These findings suggest that our human brain might have adopted a predictive mechanism to achieve speaker-listener neural coupling for successful speech comprehension.Three key pointsListener’s EEG signals coupled to the speaker’s 5 s before the speech onset, which revealed a “beyond the stimulus” attentional modulation.Speaker-listener attentional coupling is correlated to the listener’s comprehension performance, but the speech-listener’s coupling didn’t.The implementation of temporal response function methods and the neural language methods yielded novel perspectives to the analysis of the inter-brain studies.