Intra- and Inter-Brain Synchronization during Musical Improvisation on the Guitar

Abstract

Humans interact with the environment through sensory and motor acts. Some of these interactions require synchronization among two or more individuals. Multiple-trial designs, which we have used in past work to study interbrain synchronization in the course of joint action, constrain the range of observable interactions. To overcome the limitations of multiple-trial designs, we conducted single-trial analyses of electroencephalography (EEG) signals recorded from eight pairs of guitarists engaged in musical improvisation. We identified hyper-brain networks based on a complex interplay of different frequencies. The intra-brain connections primarily involved higher frequencies (e.g., beta), whereas inter-brain connections primarily operated at lower frequencies (e.g., delta and theta). The topology of hyper-brain networks was frequency-dependent, with a tendency to become more regular at higher frequencies. We also found hyper-brain modules that included nodes (i.e., EEG electrodes) from both brains. Some of the observed network properties were related to musical roles during improvisation. Our findings replicate and extend earlier work and point to mechanisms that enable individuals to engage in temporally coordinated joint action.

Centrality of Social Interaction in Human Brain Function

“…The coordination of actions during music performance has also been studied using simultaneous EEG recordings, suggesting, for example, brain signatures for emotional empathy and musical roles during the performance (see, for example, Babiloni et al, 2012;Lindenberger et al, 2009;Mü ller et al, 2013).…”

Dangers and uses of cross-correlation in analyzing time series in perception, performance, movement, and neuroscience: The importance of constructing transfer function autoregressive models

“…An assessment of Granger causality is now becoming quite common in EEG studies, for investigating the relations between different parts of the brain or between different cooperating brains (Müller, Sänger, & Lindenberger, 2013), but sometimes the issue of stationarity is neglected in such work, and autocorrelation is often neglected as well. Given Granger causality, then, a first conclusion about likely causality can be made, but this does not provide the quantitative integration of impacts that may really be sought.…”

Origin of Hyperbolicity in Brain-to-Brain Coordination Networks

“…Social neurology uses the term social brain to distinguish the brain functions underlying the social conduct of humans [7,8]. Platforms for simultaneous recording of brain functions in pairs or groups of individuals are being developed generating the appropriate data that allow study of the social brain structure in various situations [5,[9][10][11][12]. Potentials of these experimental and theoretical approaches still remain elusive.…”

“…Compared to individual brain areas involved in processing specific information, for instance, distance and language interpretation [20], the social brain can include several brain regions. The structure of the social brain can vary from individual to individual, and depend on the subject and the way of communications [12,21].…”