Experimental Psychology, Justus Liebig University Giessen, 35394 Giessen, Germany.
Center for Mind, Brain and Behavior, University of Marburg and Justus Liebig University, 35394 Giessen, Germany.
Proc Natl Acad Sci U S A. 2022 May 17;119(20):e2118445119. doi: 10.1073/pnas.2118445119. Epub 2022 May 9.
The ability to sample sensory information with our hands is crucial for smooth and efficient interactions with the world. Despite this important role of touch, tactile sensations on a moving hand are perceived weaker than when presented on the same but stationary hand. This phenomenon of tactile suppression has been explained by predictive mechanisms, such as internal forward models, that estimate future sensory states of the body on the basis of the motor command and suppress the associated predicted sensory feedback. The origins of tactile suppression have sparked a lot of debate, with contemporary accounts claiming that suppression is independent of sensorimotor predictions and is instead due to an unspecific mechanism. Here, we target this debate and provide evidence for specific tactile suppression due to precise sensorimotor predictions. Participants stroked with their finger over textured objects that caused predictable vibrotactile feedback signals on that finger. Shortly before touching the texture, we probed tactile suppression by applying external vibrotactile probes on the moving finger that either matched or mismatched the frequency generated by the stroking movement along the texture. We found stronger suppression of the probes that matched the predicted sensory feedback. These results show that tactile suppression is specifically tuned to the predicted sensory states of a movement.
用手采集感觉信息的能力对于与世界进行流畅高效的交互至关重要。尽管触觉起着重要的作用，但运动中的手的触觉感知比静止的手弱。这种触觉抑制现象可以用预测机制来解释，例如内部前馈模型，它根据运动指令来估计身体未来的感觉状态，并抑制相关的预测感觉反馈。触觉抑制的起源引发了很多争论，当代的观点认为抑制不依赖于感觉运动预测，而是由于一种非特异性机制。在这里，我们针对这一争论，并提供了由于精确的感觉运动预测而导致特定的触觉抑制的证据。参与者用手指在纹理物体上滑动，这会在该手指上产生可预测的振动触觉反馈信号。在触摸纹理之前，我们通过在移动手指上施加外部振动触觉探针来探测触觉抑制，这些探针的频率与沿着纹理的运动产生的频率匹配或不匹配。我们发现与预测的感觉反馈匹配的探针的抑制作用更强。这些结果表明，触觉抑制是专门针对运动的预测感觉状态进行调整的。
