Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London, WC1N 3AR, UK; Department of Precision Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan; Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan.
Institute of Cognitive Neuroscience, University College London, Alexandra House, 17 Queen Square, London, WC1N 3AR, UK.
Neuroimage. 2018 Jul 15;175:438-448. doi: 10.1016/j.neuroimage.2018.04.019. Epub 2018 Apr 12.
The sense of agency emerges when our voluntary actions produce anticipated or predictable outcomes in the external world. It remains unclear how the sense of control also influences our perception of the external world. The present study examined perceptual processing of self-generated motion versus non-self-generated motion using steady-state visual evoked potentials (SSVEPs). Participants continuously moved their finger on a touchpad to trigger the movements of two shapes (Experiment 1) or two groups of dots (Experiment 2) on a monitor. Degree of control was manipulated by varying the spatial relation between finger movement and stimulus trajectory across conditions. However, the velocity, onset time, and offset time of visual stimuli always corresponded to participants' finger movement. Stimuli flickered at a frequency of either 7.5 Hz or 10 Hz, thus SSVEPs of these frequencies and their harmonics provided a frequency-tagged measurement of perceptual processing. Participants triggered the motion of all stimuli simultaneously, but had greater levels of control over some stimuli than over others. Their task was to detect a brief colour change on the border(s) of one shape (Experiment 1) or of one group of dots (Experiment 2). Although control over shapes/dots was irrelevant to the visual detection task, we found stronger SSVEPs for stimuli that were under a high level of control, compared with the stimuli that were under a low level of control. Our results suggest that the spatial regularity between self-generated movements and visual input boosted the neural responses underlying perceptual processing. Our results support the preactivation account of sensory attenuation, suggesting that perceptual processing of self-generated events is enhanced rather than inhibited.
当我们的自主行动在外部世界产生预期或可预测的结果时，主体感就会出现。目前尚不清楚控制感如何也影响我们对外部世界的感知。本研究使用稳态视觉诱发电位（SSVEPs）来检查自我产生的运动与非自我产生的运动的感知处理。在实验 1 中，参与者在触摸板上连续移动手指，以触发两个形状的运动或两个组的点的运动；在实验 2 中，参与者连续移动手指，以触发两个形状的运动或两个组的点的运动。通过在不同条件下改变手指运动和刺激轨迹之间的空间关系来操纵控制程度。然而，视觉刺激的速度、起始时间和结束时间始终与参与者的手指运动相对应。刺激以 7.5 Hz 或 10 Hz 的频率闪烁，因此这些频率及其谐波的 SSVEPs 提供了感知处理的频率标记测量。参与者同时触发所有刺激的运动，但对某些刺激的控制程度大于对其他刺激的控制程度。他们的任务是检测一个形状（实验 1）或一组点（实验 2）边界上的短暂颜色变化。尽管对形状/点的控制与视觉检测任务无关，但我们发现，与低水平控制的刺激相比，高水平控制的刺激的 SSVEPs 更强。我们的结果表明，自我产生的运动和视觉输入之间的空间规律性增强了感知处理的神经反应。我们的结果支持感觉衰减的预激活理论，表明自我产生的事件的感知处理得到了增强而不是抑制。
