Human Brain Research Center, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan; Parkinson-Klinik Ortenau, 77709 Wolfach, Germany.
Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto 606-8501, Japan; Japan Society for the Promotion of Science, Tokyo 102-0083, Japan.
Brain Res. 2021 Jul 1;1762:147433. doi: 10.1016/j.brainres.2021.147433. Epub 2021 Mar 15.
Interacting with objects in our environment usually leads to audible noise. Brain responses to such self-initiated sounds have been shown to be attenuated, in particular the so-called N1 component measured with electroencephalography (EEG). This attenuation has been proposed to be the effect of an internal forward model that allows for cancellation of the sensory consequences of a motor command. In the current study we asked whether the attenuation due to self-initiation of a sound also affects a later event-related potential - the so-called motion-onset response - that arises in response to moving sounds. To this end, volunteers were instructed to move their index fingers either left or rightward which resulted in virtual movement of a sound either to the left or to the right. In Experiment 1, sound motion was induced with in-ear head-phones by shifting interaural time and intensity differences and thus shifting the intracranial sound image. We compared the motion-onset responses under two conditions: a) congruent, and b) incongruent. In the congruent condition, the sound image moved in the direction of the finger movement, while in the incongruent condition sound motion was in the opposite direction of the finger movement. Clear motion-onset responses with a negative cN1 component peaking at about 160 ms and a positive cP2 component peaking at about 230 ms after motion-onset were obtained for both the congruent and incongruent conditions. However, the motion-onset responses did not significantly differ between congruent and incongruent conditions in amplitude or latency. In Experiment 2, in which sounds were presented with loudspeakers, we observed attenuation for self-induced versus externally triggered sound motion-onset, but again, there was no difference between congruent and incongruent conditions. In sum, these two experiments suggest that the motion-onset response measured by EEG can be attenuated for self-generated sounds. However, our result did not indicate that this attenuation depended on congruency of action and sound motion direction.
与环境中的物体相互作用通常会产生可听见的噪音。研究表明，大脑对这种自我启动声音的反应会减弱，特别是脑电图 (EEG) 测量的所谓 N1 成分。这种衰减被认为是内部前馈模型的效果，该模型允许消除运动指令的感觉后果。在当前的研究中，我们想知道由于自我启动声音而导致的衰减是否也会影响稍后出现的与运动相关的电位 - 即所谓的运动起始反应 - 该反应是对运动声音的反应。为此，志愿者被指示向左或向右移动食指，这导致声音向左或向右虚拟移动。在实验 1 中，通过改变双耳时间和强度差异，使用入耳式耳机诱导声音运动，从而改变颅内声音图像。我们比较了两种条件下的运动起始反应：a）一致，b）不一致。在一致条件下，声音图像朝着手指运动的方向移动，而在不一致条件下，声音运动与手指运动的方向相反。在一致和不一致条件下，都获得了清晰的运动起始反应，负 cN1 成分的峰值约为 160 毫秒，正 cP2 成分的峰值约为运动起始后 230 毫秒。然而，在振幅或潜伏期方面，运动起始反应在一致和不一致条件之间没有显著差异。在实验 2 中，使用扬声器呈现声音，我们观察到自我诱导与外部触发的声音运动起始之间的衰减，但在一致和不一致条件之间，这种衰减没有差异。总之，这两个实验表明，通过 EEG 测量的运动起始反应可以因自我产生的声音而减弱。然而，我们的结果并未表明这种衰减取决于动作和声音运动方向的一致性。
