(Dis-)Harmony in movement: effects of musical dissonance on movement timing and form

Abstract

While the origins of consonance and dissonance in terms of acoustics, psychoacoustics and physiology have been debated for centuries, their plausible effects on movement synchronization have largely been ignored. The present study aimed to address this by investigating whether, and if so how, consonant/dissonant pitch intervals affect the spatiotemporal properties of regular reciprocal aiming movements. We compared movements synchronized either to consonant or to dissonant sounds and showed that they were differentially influenced by the degree of consonance of the sound presented. Interestingly, the difference was present after the sound stimulus was removed. In this case, the performance measured after consonant sound exposure was found to be more stable and accurate, with a higher percentage of information/movement coupling (tau coupling) and a higher degree of movement circularity when compared to performance measured after the exposure to dissonant sounds. We infer that the neural resonance representing consonant tones leads to finer perception/action coupling which in turn may help explain the prevailing preference for these types of tones.

Fig. 1

a Musical notation. b Waveform. c Frequency spectra. d Spectrograms for the four chords (two consonant and two dissonant) used in the study

Fig. 2

Illustration of the experimental setup where the two black rectangles represent the target zones. The duration of the inter-stimulus interval is represented as the temporal gap on the diagram

Fig. 3

Examples of tau coupling between the tau of the movement gap and the intrinsic tau-guide. The R ² values displayed in the top left corner are the linear regression coefficients and k values are the coupling constants

Fig. 4

Absolute synchronization error means averaged across all 13 participants for both sound conditions (consonant and dissonant) in the two different stimuli presentation conditions (synchronization and continuation). Error bars denote standard errors. Significant comparisons between conditions are highlighted using an asterisk (*p < 0.05)

Fig. 5

Spread of error averaged across all 13 participants for both consonant and dissonant conditions in the two different stimuli presentation conditions (synchronization and continuation). Error bars denote standard errors. Significant comparisons between conditions are highlighted with an asterisk (*p < 0.05)

Fig. 6

Circularity index averaged across all 13 participants for both consonant and dissonant conditions in the two different stimuli presentation conditions (synchronization and continuation). Error bars denote standard errors. Significant comparisons between conditions are highlighted with an asterisk (*p < 0.05)

Fig. 7

a Average circularity index for all 13 participants for both consonant and dissonant conditions during the continuation phase. b Averaged data from two participants (6 and 8) when moving with consonant and dissonant metronomes during the continuation phase. The averaged normalized velocity profile plotted against normalized displacement, and shaded regions around the velocity profiles represent error bars (SEM). For subject number 6, movements are more circular in form for consonant (red dots) than dissonant intervals (black dots), while subject number 8 showed a similar pattern of movement circularity for both intervals. The blue dots indicate the velocity profile of a perfect sinusoidal movement (color figure online)

Fig. 8

R ² values from the tau-coupling regression analysis were averaged across all 13 participants for both consonant and dissonant conditions in the two different stimuli presentation conditions (synchronization and continuation). Error bars denote standard errors. Significant comparisons between conditions are indicated with an asterisk (*p < 0.05)