Sensory-Motor Lab (SeMoLa), Department of Ophthalmology-University of Lausanne, Jules Gonin Eye Hospital-Fondation Asile des Aveugles, Lausanne, Switzerland.
Rehabilitation Engineering Laboratory (RELab), Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
Cereb Cortex. 2022 Jan 10;32(2):312-328. doi: 10.1093/cercor/bhab210.
Fundamental human feelings such as body ownership ("this" body is "my" body) and vicariousness (first-person-like experience of events occurring to others) are based on multisensory integration. Behavioral links between body ownership and vicariousness have been shown, but the neural underpinnings remain largely unexplored. To fill this gap, we investigated the neural effects of altered body ownership on vicarious somatosensation. While recording functional brain imaging data, first, we altered participants' body ownership by robotically delivering tactile stimulations ("tactile" stroking) in synchrony or not with videos of a virtual hand being brushed ("visual" stroking). Then, we manipulated vicarious somatosensation by showing videos of the virtual hand being touched by a syringe's plunger (touch) or needle (pain). Only after the alteration of body ownership (synchronous visuo-tactile stroking) and specifically during late epochs of vicarious somatosensation, vicarious pain was associated with lower activation in premotor and anterior cingulate cortices with respect to vicarious touch. At the methodological level, the present study highlights the importance of the neural response's temporal evolution. At the theoretical level, it shows that the higher-level (cognitive) impact of a lower-level (sensory) body-related processing (visuo-tactile) is not limited to body ownership but also extends to other psychological body-related domains, such as vicarious somatosensation.
基本的人类情感，如身体所有权（“这个”身体是“我的”身体）和替代性（对他人经历的第一人称般的体验），都是基于多感觉整合的。已经显示出身体所有权和替代性之间的行为联系，但神经基础在很大程度上仍未得到探索。为了填补这一空白，我们研究了改变身体所有权对替代性体感的神经影响。在记录功能脑成像数据的同时，我们首先通过机器人同步或不同步地向虚拟手（“视觉”刷动）发送触觉刺激（“触觉”刷动）来改变参与者的身体所有权。然后，我们通过展示虚拟手被注射器柱塞（触摸）或针（疼痛）触碰的视频来操纵替代性体感。只有在改变身体所有权（同步视触刷动）之后，特别是在替代性体感的后期阶段，替代性疼痛与前运动皮质和前扣带皮质的激活降低有关，而替代性触摸则没有。在方法论层面上，本研究强调了神经反应时间演化的重要性。在理论层面上，它表明较低层次（感觉）与身体相关的处理（视触）的较高层次（认知）影响不仅限于身体所有权，还扩展到其他心理身体相关领域，如替代性体感。
