Search Abstracts | Symposia | Slide Sessions | Poster Sessions
Linking linguistic and neural alignment: Meaning-specific theta coupling of words between interlocutors.
Poster Session F, Friday, October 2, 2:45 - 4:45 pm, Wangari Maathai
Kristof Strijkers1,2, Emilia Kerr1,2, Daria Goriachun1,2, Benjamin Morillon2,3; 1CNRS, 2Aix-Marseille University, 3INS
Traditionally, language research in psychology and neuroscience has focused on the individual, neglecting the dynamic interplay between interlocutors as the primary form of communication. In recent years, however, we are witnessing a paradigm shift towards multi-person neuroscience, where several studies have demonstrated neural alignment between interlocutors during conversation. Neural alignment refers to the phenomenon whereby the brains of listeners and speakers become correlated during communication. A similar phenomenon exists in language behavior, namely linguistic alignment, which refers to the observation that interlocutors copy each other’s language use. Given this correspondence, it is tempting to assume that neural alignment is the brain’s signature of linguistic alignment. However, at present there is no empirical evidence supporting this link, since neural alignment studies have investigated language from a global communicative perspective and did not test whether it emerges when interlocutors are actually aligning their speech behaviour. The current study set out to test this potential link between linguistic and neural alignment by introducing a simple semantic association game between two interlocutors while simultaneously recording their electroencephalography (EEG hyperscanning). Participants in the dyad engaged in semantic associations involving either tool or animal words. This allowed us to contrast the inter-brain synchrony (IBS) when the interlocutors were linguistically aligning on tool versus animal names, in order to trace whether meaning-specific neural alignment would emerge. The tool-animal contrast resulted in significant IBS between the interlocutors in the theta band (4–8 Hz). Examining the temporal dynamics of the effect with frequency-based multivariate pattern analyses, we found that the word categories could be decoded simultaneously from both interlocutors’ brains in the theta range during the interactional gap; that is, after one of the interlocutors named an animal or tool and before the partner responded with a semantically related word. By showing IBS specific to interactions about tool and animal words, our study provides empirical evidence in support of the hypothesis that neural alignment is the brain’s signature of linguistic alignment, at least at the level of word meaning. That we observed neural alignment in the theta band is particularly interesting, since theta reflects the syllable rate at which the speaker articulates and the listener perceives speech input, thereby naturally synchronizing the interlocutors’ brain rhythms during speech via sensory-motor coupling. Taken together, we argue that our study demonstrates meaning-specific neural alignment of words between interlocutors, with theta coupling potentially serving as the neurobiological mechanism to sustain linguistic alignment.
Topic Areas: Language Production, Speech Perception