Auditory feedback to a keypress is used in many devices to facilitate the motor output. The timing of auditory feedback is known to have an impact on the motor output, yet it is not known if a keypress action can be modulated on-line by an auditory feedback or how quick an auditory feedback can influence an ongoing keypress. Furthermore, it is not clear if the prediction of auditory feedback already changes the early phase of a keypress action independent of sensory feedback, which would suggest that such prediction changes the motor plan. In the current study, participants pressed a touch-sensitive device with auditory feedback in a self-paced manner. The auditory feedback was given either after a short (60 msec) or long (160 msec) delay, and the delay was either predictable or not. Our results showed that the keypress peak force was modulated by the amount of auditory feedback delay even when the delay was unpredictable, thus demonstrating an on-line modulation effect. The latency of the on-line modulation was suggested to be as low as 70 msec, indicating a very fast sensory to motor mapping circuit in the brain. When the auditory feedback delay was predictable, a change in the very early phase of keypress motor output was found, suggesting that the prediction of sensory feedback is crucial to motor control. Therefore, even a simple keypress action contains rich motor dynamics, which depend on expected as well as on-line perceived sensory feedback.

许多设备都使用按键的听觉反馈来促进电机输出。已知听觉反馈的时间对运动输出有影响，但不知道按键动作是否可以通过听觉反馈在线调节，或者听觉反馈可以多快地影响正在进行的按键。此外，尚不清楚听觉反馈的预测是否已经改变了独立于感官反馈的按键动作的早期阶段，这表明这种预测会改变运动计划。在当前的研究中，参与者以自定进度的方式按下带有听觉反馈的触敏设备。在短（60 毫秒）或长（160 毫秒）延迟后给出听觉反馈，并且延迟是可预测的或不可预测的。我们的结果表明，即使延迟是不可预测的，按键峰值力也受到听觉反馈延迟量的调制，从而证明了在线调制效果。建议在线调制的延迟低至 70 毫秒，表明大脑中的感觉到运动映射电路非常快。当听觉反馈延迟是可预测的时，发现按键运动输出的非常早期阶段发生了变化，这表明感觉反馈的预测对运动控制至关重要。因此，即使是简单的按键动作也包含丰富的运动动态，这取决于预期以及在线感知的感官反馈。建议在线调制的延迟低至 70 毫秒，表明大脑中的感觉到运动映射电路非常快。当听觉反馈延迟是可预测的时，发现按键运动输出的非常早期阶段发生了变化，这表明感觉反馈的预测对运动控制至关重要。因此，即使是简单的按键动作也包含丰富的运动动态，这取决于预期以及在线感知的感官反馈。建议在线调制的延迟低至 70 毫秒，表明大脑中的感觉到运动映射电路非常快。当听觉反馈延迟是可预测的时，发现按键运动输出的非常早期阶段发生了变化，这表明感觉反馈的预测对运动控制至关重要。因此，即使是简单的按键动作也包含丰富的运动动态，这取决于预期以及在线感知的感官反馈。