Coherence analysis – Arm movements.

<p>The histograms show the degree of synchronization between participants of the arm movement (accelerometer signal), during the five phases of the study: initial resting baseline, spontaneous movement, music-associated movement, metronome-associated movement and final resting baseline. Participants from the individual measurement group are shown in gray; participants from the collective measurement group are shown in colours, with different colours representing the repetition of the protocol over the course of two days. <i>Top panel</i>. Results of the coherence in the high frequency band (HF: 0.15–0.4 Hz). Movements were more synchronized in the collective measurement groups for the metronome-associated condition. The greater synchronization of the fluctuations of the accelerometer signal in the resting baseline for the individual measurement groups rules out the possibility that the superior synchronization of the collective in the metronome-associated condition was due to artifacts or differences in the baseline level of the accelerometer signal. <i>Bottom panel.</i> Results of the coherence in the very high frequency band (VHF: 0.4–2 Hz). Movements were overall more synchronized in the collective measurement groups than in the individual measurement groups. On the repetition of the protocol, the peak of synchronization previously observed in the metronome-associated condition decreases, while an increase of collective synchronization is observed for the spontaneous, un-cued movements.