Acoustic conditions also modulated IPS: low-to-moderate sound pressure levels (SPL) and moderate-to-high signal-to-noise ratios (SNR) enhanced synchrony, while high SPL reduced it to levels characteristic of non-interactive contexts.

Context matters. Synchrony emerged during close-proximity interactions and when people were exposed to common stimuli, but not during dispersed, non-interactive settings.

Synchrony was stronger for pairs who already knew each other — even after controlling for being in the same place.

People’s heart rates synchronized reliably when they were physically close, indicating that shared spatial and contextual exposure was sufficient to produce IPS.

To address this, we collected continuous heart rate, GPS, and acoustic recordings from 72 participants across three independent multi-day trips to New York City, totaling >1000 hours of multimodal data.

First time at #SANS2025!
Thrilled to hear about all the fascinating work and to present our own from @sinelabdtu.bsky.social
@ale-dabr.bsky.social!