Sensorimotor Synchronization with Different Metrical Levels of Point-Light Dance Movements.

Yi-Huang Su

doi:10.3389/fnhum.2016.00186

Abstract

Rhythm perception and synchronization have been extensively investigated in the auditory domain, as they underlie means of human communication such as music and speech. Although recent studies suggest comparable mechanisms for synchronizing with periodically moving visual objects, the extent to which it applies to ecologically relevant information, such as the rhythm of complex biological motion, remains unknown. The present study addressed this issue by linking rhythm of music and dance in the framework of action-perception coupling. As a previous study showed that observers perceived multiple metrical periodicities in dance movements that embodied this structure, the present study examined whether sensorimotor synchronization (SMS) to dance movements resembles what is known of auditory SMS. Participants watched a point-light figure performing two basic steps of Swing dance cyclically, in which the trunk bounced at every beat and the limbs moved at every second beat, forming two metrical periodicities. Participants tapped synchronously to the bounce of the trunk with or without the limbs moving in the stimuli (Experiment 1), or tapped synchronously to the leg movements with or without the trunk bouncing simultaneously (Experiment 2). Results showed that, while synchronization with the bounce (lower-level pulse) was not influenced by the presence or absence of limb movements (metrical accent), synchronization with the legs (beat) was improved by the presence of the bounce (metrical subdivision) across different movement types. The latter finding parallels the “subdivision benefit” often demonstrated in auditory tasks, suggesting common sensorimotor mechanisms for visual rhythms in dance and auditory rhythms in music.

Highlights

Musical rhythms encompass multiple metrical levels of periodicity
Results of translational motion (TM) and tempo will be focused on whether they interact with the main variable of interest, the moving part, in order to verify whether the effect of moving part generalizes to different movement conditions
The dance movements were such that two metrical levels of periodicity were visually available, with the lateral leg movements being twice as slow as the vertical trunk bouncing, and the former more often perceived as beat (Su, 2016)

Summary

Introduction

Musical rhythms encompass multiple metrical levels of periodicity. While listeners can tune to different levels (each one termed a pulse) and different tempi in the same rhythm, each individual typically identifies a most salient periodicity as the beat (Drake et al, 2000; McKinney and Moelants, 2006). Perceptual grouping of alternating strongly and weakly accented events, or stronger and weaker beats, gives rise to the musical meter, which functions as a temporal reference frame and yields a distinct percept of patterning in music (London, 2012) These temporal modules define the structure of musical rhythms, but more importantly engage human behaviors. Visual SMS to Dance naturally to the musical beat, and the movements often consist of regular patterns (Toiviainen et al, 2010; Su and Pöppel, 2012; Manning and Schutz, 2013; Burger et al, 2014) This is an everyday example of coordinating one’s motor output with external sensory rhythms, known as sensorimotor synchronization (SMS; Repp and Su, 2013). The metrical structure of musical rhythm plays a functional role in SMS for humans, and this function may have evolutionary purposes shared by rhythmic behaviors in other species (Ravignani et al, 2014)

Methods

Results

Conclusion