Data from: Mutual stabilization of rhythmic vocalization and whole-body movement

The current study investigated the rhythmic coordination between vocalization and whole-body movement. Previous studies have reported that spatiotemporal stability in rhythmic movement increases when coordinated with a rhythmic auditory stimulus or other effector in a stable coordination pattern. Therefore, the present study conducted two experiments to investigate (1) whether there is a stable coordination pattern between vocalization and whole-body movement and (2) whether a stable coordination pattern reduces variability in whole-body movement and vocalization. In Experiment 1, two coordination patterns between vocalizations and whole-body movement (hip, knee, and ankle joint flexion-on-the-voice vs. joint extension-on-the-voice) in a standing posture were explored at movement frequencies of 80, 130, and 180 beats per minute. At higher movement frequencies, the phase angle in the extension-on-the-voice condition deviated from the intended phase angle. However, the angle of the flexion-on-the-voice was maintained even when movement frequency increased. These results suggest that there was a stable coordination pattern in the flexion-on-the-voice condition. In Experiment 2, variability in whole-body movement and voice-onset intervals was compared between two conditions: one related to tasks performed in the flexion-on-the-voice coordination (coordination condition) that was a stable coordination pattern, and the other related to tasks performed independently (control condition). The results showed that variability in whole-body movement and voice-onset intervals was smaller in the coordination condition than in the control condition. Overall, the present study revealed mutual stabilization between rhythmic vocalization and whole-body movement via coordination within a stable pattern, suggesting that coupled action systems can act as a single functional unit or coordinative structure.本研究探讨了发声与全身运动之间的节律协调关系。既往研究表明，当以稳定协调模式与节律性听觉刺激或其他效应器协同时，节律运动的时空稳定性会得到提升。据此，本研究开展两项实验，旨在探究两大问题：其一，发声与全身运动之间是否存在稳定协调模式；其二，稳定协调模式是否能够降低全身运动与发声的变异性。 在实验1中，本研究于站立姿势下，以每分钟80、130、180拍的运动频率，探究了发声与全身运动的两种协调模式：分别为发声时髋、膝、踝关节屈曲（flexion-on-the-voice），以及发声时关节伸展（extension-on-the-voice）。当运动频率升高时，发声时关节伸展条件下的相位角（phase angle）会偏离预设相位角；而发声时关节屈曲条件下的相位角则随运动频率升高保持稳定。上述结果表明，发声时关节屈曲条件下存在稳定协调模式。 在实验2中，本研究对两种条件下的全身运动变异性与发声起始间隔（voice-onset intervals）变异性进行了比较：其一为采用发声时关节屈曲协调模式（稳定协调模式）的协同条件组，其二为独立完成任务的对照组。结果显示，协同条件组的全身运动与发声起始间隔变异性均小于对照组。 综上，本研究揭示了节律发声与全身运动可通过稳定模式下的协同实现相互稳定，表明耦合动作系统可作为单一功能单元或协调结构发挥作用。