Fritz Clara, Bayer Manuel, Zimmermann Eckart
Institute for Experimental Psychology, Heinrich Heine University Düsseldorf, 40225, Düsseldorf, Germany.
Exp Brain Res. 2025 Jan 11;243(1):42. doi: 10.1007/s00221-024-06982-w.
When we touch ourselves, the pressure appears weaker compared to when someone else touches us, an effect known as sensory attenuation. Sensory attenuation is spatially tuned and does only occur if the positions of the touching and the touched body-party spatially coincide. Here, we ask about the contribution of visual or proprioceptive signals to determine self-touch. By using a 3D arm model in a virtual reality environment, we dissociated the visual from the proprioceptive arm signal. When a virtual arm was visible indicating self-touch, we found that sensory attenuation generalized across different locations. When no virtual arm was visible, we found sensory attenuation to be strongest when subjects pointed to the position where they felt their arm to be located. We conclude that the spatial tuning of tactile attenuation depends on which signal determines the occurrence of self-touch. When observers can see their hand, the visual signal dominates the proprioceptive determining self-touch in a single visual snapshot. When only the proprioceptive signal is available, the positions of the touching and the touched body-part must be separately estimated and subsequently compared if they overlap in anatomical space.
当我们触摸自己时，与他人触摸我们相比，压力似乎较弱，这种效应被称为感觉衰减。感觉衰减在空间上是有调节的，并且只有当触摸和被触摸身体部位的位置在空间上重合时才会发生。在这里，我们探讨视觉或本体感觉信号对确定自我触摸的贡献。通过在虚拟现实环境中使用3D手臂模型，我们将视觉手臂信号与本体感觉手臂信号分离开来。当可见虚拟手臂指示自我触摸时，我们发现感觉衰减在不同位置普遍存在。当没有可见虚拟手臂时，我们发现当受试者指向他们感觉手臂所在的位置时，感觉衰减最强。我们得出结论，触觉衰减的空间调节取决于哪个信号决定自我触摸的发生。当观察者能看到他们的手时，在单个视觉快照中，视觉信号在确定自我触摸时占主导地位，超过本体感觉信号。当只有本体感觉信号可用时，必须分别估计触摸和被触摸身体部位的位置，然后比较它们在解剖空间中是否重叠。
