Svensson Pamela, Malešević Nebojša, Wijk Ulrika, Björkman Anders, Antfolk Christian
Department of Biomedical Engineering, Faculty of Engineering, Lund University, Lund, Sweden.
Department of Translational Medicine - Hand Surgery, Lund University and Skåne University Hospital, Malmö, Sweden.
Front Neurosci. 2023 Sep 14;17:1237053. doi: 10.3389/fnins.2023.1237053. eCollection 2023.
Tactile feedback plays a vital role in inducing ownership and improving motor control of prosthetic hands. However, commercially available prosthetic hands typically do not provide tactile feedback and because of that the prosthetic user must rely on visual input to adjust the grip. The classical rubber hand illusion (RHI) where a brush is stroking the rubber hand, and the user's hidden hand synchronously can induce ownership of a rubber hand. In the classic RHI the stimulation is modality-matched, meaning that the stimulus on the real hand matches the stimulus on the rubber hand. The RHI has also been used in previous studies with a prosthetic hand as the "rubber hand," suggesting that a hand prosthesis can be incorporated within the amputee's body scheme. Interestingly, previous studies have shown that stimulation with a mismatched modality, where the rubber hand was brushed, and vibrations were felt on the hidden hand also induced the RHI. The aim of this study was to compare how well mechanotactile, vibrotactile, and electrotactile feedback induced the RHI in able-bodied participants and forearm amputees. 27 participants with intact hands and three transradial amputees took part in a modified RHI experiment. The rubber hand was stroked with a brush, and the participant's hidden hand/residual limb received stimulation with either brush stroking, electricity, pressure, or vibration. The three latter stimulations were modality mismatched with regard to the brushstroke. Participants were tested for ten different combinations (stimulation blocks) where the stimulations were applied on the volar (glabrous skin), and dorsal (hairy skin) sides of the hand. Outcome was assessed using two standard tests (questionnaire and proprioceptive drift). All types of stimulation induced RHI but electrical and vibration stimulation induced a stronger RHI than pressure. After completing more stimulation blocks, the proprioceptive drift test showed that the difference between pre- and post-test was reduced. This indicates that the illusion was drifting toward the rubber hand further into the session.
触觉反馈在引发假肢手的拥有感以及改善其运动控制方面起着至关重要的作用。然而，市面上的假肢手通常不提供触觉反馈，因此假肢使用者必须依靠视觉输入来调整抓握动作。经典的橡胶手错觉（RHI）是指用刷子刷橡胶手时，使用者隐藏的手同时受到同步刺激，从而引发对橡胶手的拥有感。在经典的RHI中，刺激是模态匹配的，即真实手上的刺激与橡胶手上的刺激相匹配。RHI也曾在先前的研究中被用于将假肢手作为“橡胶手”的情况，这表明假肢手可以被纳入截肢者的身体图式中。有趣的是，先前的研究表明，采用不匹配模态的刺激，即刷橡胶手时，隐藏的手上能感觉到振动，也能引发RHI。本研究的目的是比较机械触觉、振动触觉和电触觉反馈在健全参与者和前臂截肢者中引发RHI的效果。27名手部健全的参与者和3名经桡骨截肢者参与了一项改良的RHI实验。用刷子刷橡胶手，参与者隐藏的手/残肢接受刷子刷、电刺激、压力或振动刺激。后三种刺激在笔触方面与刷橡胶手的刺激模态不匹配。对参与者进行了十种不同组合（刺激块）的测试，刺激分别施加在手的掌侧（无毛皮肤）和背侧（有毛皮肤）。使用两项标准测试（问卷和本体感觉漂移）评估结果。所有类型的刺激都能引发RHI，但电刺激和振动刺激引发的RHI比压力刺激更强。完成更多刺激块后，本体感觉漂移测试表明，测试前后的差异减小。这表明错觉在实验过程中进一步向橡胶手方向漂移。
Zotero 插件
