Synchrony to a beat predicts synchrony with other minds

Abstract

Abstract Synchrony has been used to describe simple beat entrainment as well as correlated mental processes between people, leading some to question whether the term conflates distinct phenomena. Here we ask whether simple synchrony (beat entrainment) predicts more complex shared attentional states, consistent with a common mechanism. While eye-tracked, participants listened to regularly spaced tones and indicated changes in volume. Across multiple sessions, we found a reliable individual difference: some people entrained their attention more than others, as reflected in beat-matched pupil dilations that predicted performance. In a second study, eye-tracked participants completed the beat task and then listened to an eye-tracked storyteller. An individual’s tendency to entrain to a beat predicted how strongly their pupils synchronized with those of the storyteller, a measure of shared attention. The tendency to synchronize is a stable individual difference that predicts both beat entrainment and the coupling of minds, consistent with a common origin.