Body sway reflects joint emotional expression in music ensemble performance

Abstract

Joint action is essential in daily life, as humans often must coordinate with others to accomplish shared goals. Previous studies have mainly focused on sensorimotor aspects of joint action, with measurements reflecting event-to-event precision of interpersonal sensorimotor coordination (e.g., tapping). However, while emotional factors are often closely tied to joint actions, they are rarely studied, as event-to-event measurements are insufficient to capture higher-order aspects of joint action such as emotional expression. To quantify joint emotional expression, we used motion capture to simultaneously measure the body sway of each musician in a trio (piano, violin, cello) during performances. Excerpts were performed with or without emotional expression. Granger causality was used to analyze body sway movement time series amongst musicians, which reflects information flow. Results showed that the total Granger-coupling of body sway in the ensemble was higher when performing pieces with emotional expression than without. Granger-coupling further correlated with the emotional intensity as rated by both the ensemble members themselves and by musician judges, based on the audio recordings alone. Together, our findings suggest that Granger-coupling of co-actors’ body sways reflects joint emotional expression in a music ensemble, and thus provide a novel approach to studying joint emotional expression.

Body sway predicts romantic interest in speed dating

“…We propose that directional body sway coupling reflects the quality of inter-partner communication, which reveals the degree of compatible personality characteristics. This is consistent with our music ensemble studies, in which directional body sway coupling reflected directional interpersonal communication and predicted the quality of ensemble musical performances (Chang et al, 2017(Chang et al, , 2019.…”

“…The preprocessing steps followed our previous studies (Chang et al, 2017(Chang et al, , 2019. Motion capture data were exported from Qualisys Track Manager (2.16) to MATLAB 2015b for analyses.…”

“…The recordings were further down-sampled to 8 Hz (GC prefers a low model order for capturing a given physical time length; Barnett and Seth, 2014), each participant's two markers were spatially averaged and projected to the anterior-posterior body orientation (referencing to the marker on the table and collapsing altitude), and then z-normalized (to exclude individual differences in movement magnitude) to produce one body sway time series for each participant on each date. We focused on the anterior-posterior body sway orientation, because our previous studies suggested it reflects interpersonal coordination (Chang et al, 2017(Chang et al, , 2019.…”

“…Such directional coupling dynamics have been shown to relate to social outcomes. For example, GC analyses of body sway among musicians have shown that body sway couplings reflect leader-follower relationships (leaders predict followers more than vice versa), the quality of joint performances (higher-rated performances have higher coupling strength) and aesthetic emotional expression (expressive performances have higher coupling strength than non-expressive performances) (Chang et al, 2017(Chang et al, , 2019.…”

Neurobehavioral Interpersonal Synchrony in Early Development: The Role of Interactional Rhythms

“…In fact, a growing body of evidence suggests that interpersonal neural synchrony facilitates communication and affective co-regulation in adults (Schippers et al, 2010; Hasson et al, 2012; Goldstein et al, 2018). In the behavioral domain, effective interpersonal transmission of information has been linked to both sequential (Wilson and Wilson, 2005) and concurrent behavioral synchrony (Chang et al, 2017, 2019).…”