Aurucci Giuseppe Valerio, Preatoni Greta, Risso Gaia, Raspopovic Stanisa
Laboratory for Neuroengineering, Department of Health Science and Technology, Institute for Robotics and Intelligent Systems, ETH Zürich, 8092 Zürich, Switzerland.
Institute of Health, School of Health Sciences, HES-SO Valais-Wallis, 1950 Sion, Switzerland.
iScience. 2024 Dec 25;28(1):111685. doi: 10.1016/j.isci.2024.111685. eCollection 2025 Jan 17.
Our brain combines sensory inputs to create a univocal perception, enhanced when stimuli originate from the same location. Following amputation, distorted body representations may disrupt visuo-tactile integration at the amputated leg. We aim to unveil the principles guiding optimal and cognitive-efficient visuo-tactile integration at both intact and amputated legs. Hence, we designed a VR electro-stimulating platform to assess the functional and cognitive correlates of visuo-tactile integration in two amputees and sixteen healthy subjects performing a 2-alternative forced choice (2AFC) task. We showed that amputees optimally integrate non-spatially matched stimuli at the amputated leg but not the intact leg (tactile cue at the stump/thigh and visual cue under the virtual foot), while healthy controls only integrated spatially matched visuo-tactile stimuli. Optimal integration also reduced 2AFC task reaction times and was confirmed by cognitive EEG-based mental workload reduction. These findings offer insights into multisensory integration processes, opening new perspectives on amputees' brain plasticity.
我们的大脑整合感官输入以形成单一的感知，当刺激来自同一位置时，这种感知会得到增强。截肢后，身体表征的扭曲可能会破坏截肢腿部的视觉触觉整合。我们旨在揭示指导健全和截肢腿部实现最佳且认知高效的视觉触觉整合的原则。因此，我们设计了一个虚拟现实电刺激平台，以评估两名截肢者和十六名健康受试者在执行二选一强制选择（2AFC）任务时视觉触觉整合的功能和认知相关性。我们发现，截肢者在截肢腿部能够最佳地整合非空间匹配的刺激（残端/大腿处的触觉线索和虚拟足部下方的视觉线索），但在健全腿部则不能，而健康对照组仅整合空间匹配的视觉触觉刺激。最佳整合还缩短了2AFC任务的反应时间，并且基于认知脑电图的心理负荷降低也证实了这一点。这些发现为多感官整合过程提供了见解，为截肢者大脑可塑性开辟了新的视角。
