Inter-brain dynamics of interpersonal synchrony during continuous auditory-motor rhythm production

Interpersonal synchrony -the temporal coordination of actions between individuals - is fundamental to many human social behaviours, from group music-making to team sports. Emerging evidence from cognitive neuroscience suggests that interpersonal synchrony arises from inter-brain coupling of partners' cortical sensorimotor activity. One open question is how inter-brain coupling contributes to continuous dynamics of interpersonal synchrony during ongoing interaction. The proposed EEG hyperscanning project addresses this question using a novel joint musical rhythm production task. Pairs of human subjects will synchronously produce circular rhythmic motions on a circular touch-sensor; partners' touch locations on the sensor will be turned into sound (sonified) such that partners can synchronize movement via auditory feedback, as typically occurs during group music-making. EEG will be simultaneously recorded from partners Partners' behavioural synchrony will be assessed by computing the Continuous Relative Phase (CRP) of partners' movement on the touch sensor. Partners' inter-brain synchrony will be assessed by computing CRP of partners' cortical oscillatory activity in frequency bands typically associated with sensorimotor processes. Most critically, behavioural and neural CRP dynamics will be correlated to assess the fundamental question of how inter-brain coupling contributes to the continuous dynamics of interpersonal synchrony during ongoing interaction.