Love in the Time of Zoom: How Intimacy Modulates Brain and Behavior Synchrony in Face-to-Face vs. Video Communication.

This study explores how video-mediated communication (VMC) and face-to-face communication (FTF) affect social bonding in relationships of varying intimacy. Using hyperscanning fNIRS and dyadic behavioral analysis, data from 72 dyads (36 romantic couples and 36 friends) were analyzed. Results revealed an intimacy-by-modality interaction: couples showed better behavioral coordination and higher interpersonal neural synchrony (INS) in the 0.081-0.09 Hz band during FTF, while friends had better synchrony in VMC. In the 0.038-0.046 Hz band, friends exhibited greater INS during FTF, and couples showed better synchrony in VMC. These patterns suggest that high-frequency INS is associated with real-time social cue integration, while low-frequency INS relates to ongoing relational monitoring. Verbal behavior fully mediated the relationship between satisfaction and FTF-induced prefrontal INS, highlighting connections among psychological states, behavior, and neural alignment. Granger causality analysis showed a female-to-male neural influence during FTF, absent in VMC, likely due to reduced nonverbal signals. These results demonstrate that the influence of video mediation on interpersonal synchrony is relationship-specific and frequency-dependent, empirically supporting a relational-context model that links attachment-based sensorimotor tuning with channel-selection processes in the Communicative Interdependence Perspective.