Interpersonal physiological synchrony during a two-player interactive game

Interpersonal Synchrony (IS) refers to the temporal alignment of behaviors and biological processes between individuals who are involved in a shared social context. In recent decades, the literature has highlighted the importance of the IS in the development of empathy, cooperation and social relationships. Synchrony may manifest at behavioral, conversational, neural and physiological levels; however, the present work investigates physiological synchrony. In particular, we evaluated the synchrony of respiratory rhythm and heart rate variability (HRV) in dyads of individuals during a collaborative two-player game. The recordings of 48 dyads were analysed. To evaluate the synchrony we implemented techniques in the time domain, based on windowed correlation and windowed cross-correlation, and in the time-frequency domain, based on cross-wavelet coherence. Statistical analyses were then applied to investigate whether there are significant differences in synchrony between the game and baseline (i.e. when the two individuals were not interacting) and between the different rounds of the game , also investigating differences related to the rounds’ outcomes. The findings show that physiological synchrony is a complex and multidimensional phenomenon. Higher stability in respiratory and cardiac coupling lags was found during the game, particularly in winning rounds, suggesting that more stable synchrony is associated with better performance. In addition, successful rounds present greater stability in HRV synchrony delays and stronger synchrony in breath rate. The analyses of the rounds show a reduction in respiratory coherence as players become more familiar with the task, while initial negative outcomes promote a subsequent increase in physiological coordination. This study contributes to explore the potential of the implemented game to elicit physiological synchrony, for possible use in interventions aimed at promoting social interaction in subjects with autism.