Does Movement Amplitude of a Co-performer Affect Individual Performance in Musical Synchronization?

Abstract

Interpersonal coordination in musical ensembles often involves multisensory cues, with visual information about body movements supplementing co-performers’ sounds. Previous research on the influence of movement amplitude of a visual stimulus on basic sensorimotor synchronization has shown mixed results. Uninstructed visuomotor synchronization seems to be influenced by amplitude of a visual stimulus, but instructed visuomotor synchronization is not. While music performance presents a special case of visually mediated coordination, involving both uninstructed (spontaneously coordinating ancillary body movements with co-performers) and instructed (producing sound on a beat) forms of synchronization, the underlying mechanisms might also support rhythmic interpersonal coordination in the general population. We asked whether visual cue amplitude would affect nonmusicians’ synchronization of sound and head movements in a musical drumming task designed to be accessible regardless of musical experience. Given the mixed prior results, we considered two competing hypotheses. H1: higher amplitude visual cues will improve synchronization. H2: different amplitude visual cues will have no effect on synchronization. Participants observed a human-derived motion capture avatar with three levels of movement amplitude, or a still image of the avatar, while drumming along to the beat of tempo-changing music. The moving avatars were always timed to match the music. We measured temporal asynchrony (drumming relative to the music), predictive timing, ancillary movement fluctuation, and cross-spectral coherence of ancillary movements between the participant and avatar. The competing hypotheses were tested using conditional equivalence testing. This method involves using a statistical equivalence test in the event that standard hypothesis tests show no differences. Our results showed no statistical differences across visual cues types. Therefore, we conclude that there is not a strong effect of visual stimulus amplitude on instructed synchronization.