fMRI hyperscanning reveals widespread neural coupling during natural conversations

Conversation is one of the most powerful tools that people have for building and maintaining social connections. How does conversation bring two minds together? Here we tracked the neural dynamics between dyads during real-time conversation using fMRI hyperscanning, where both people were scanned simultaneously, to explore whether and how conversation aligns brains. Dyads engaged in natural, free-flowing conversation as they co-constructed the content of their dialogue. In a control condition, partners read aloud scripted dialogue from another dyad’s conversation, preserving the turn-taking structure while removing the co-construction. To examine neural alignment, we compared whole-brain intersubject correlation between partners in each condition, assessing both synchronous and predictive neural dynamics. Results showed that naturalistic conversation led to significant widespread neural alignment across brain regions implicated in attention, affect, executive control, and social cognition, compared to scripted conversation. Temporally refined analyses showed that during naturalistic conversation, relative to scripted conversation, both speakers and listeners anticipated each other within a short temporal window, with brain activity preceding their partner’s in the same neural systems. Conversation may help people communicate by aligning neural activity. This work lays the foundation for future research into how neural alignment allows people to create shared understanding and form social bonds.