Cognitive drivers of interbrain synchrony during musical interaction

How do musicians achieve synchrony when they perform music together? Numerous cognitive processes – such as the alignment of internal timekeepers or the focusing of joint attention onto each other’s actions – are at play as shown in previous studies using joint tapping paradigms. However, the neural mechanisms underlying behavioural synchrony still remain unclear.

One neural correlate that has been increasingly associated with behavioural synchrony is interbrain synchrony, that is, the synchronization of neural rhythms between individuals involved in coordinated interactions such as ensemble musicians during performance. However, it remains open whether interbrain synchrony is functionally relevant for behavioural synchronization and if it reflects the alignment of cognitive processes relevant for interaction. In the past, it has been argued that brains of interacting people synchronize merely because both interactants are exposed to the same sensory input that is tracked similarly by each individual brain, making interbrain synchrony an “epiphenomenon” of social interaction. The current project aims to disentangle the sensory and cognitive contributions to interbrain synchrony and lend evidence for cognitive drivers of interbrain synchrony above and beyond shared sensory input.

Therefore, we invite pairs of pianists to perform duets together while we record EEG simultaneously in both players. We analyse and compare their interbrain synchrony during periods with different cognitive demands but similar sensory input to make the influence of sensory input on the neural processes comparable across conditions. On top of that, we measure interbrain synchrony during silent musical pauses – natural instances without shared sensory input in which musicians keep interacting by maintaining the jointly established tempo and by planning their next entry, aiming to be in synch.

Our results suggest that interbrain synchrony may indeed be modulated by cognitive factors, beyond simple locking to shared sensory input. This opens the door for further investigations of interbrain synchrony as a neural mechanism that may allow to achieve and maintain synchrony during music performance.