Le Franc Salomé, Fleury Mathis, Cogne Mélanie, Butet Simon, Barillot Christian, Lecuyer Anatole, Bonan Isabelle
Rehabilitation Medicine Unit, University Hospital of Rennes, Rennes, France.
Inria, Rennes, France.
PLoS One. 2020 Nov 20;15(11):e0242416. doi: 10.1371/journal.pone.0242416. eCollection 2020.
Illusion of movement induced by tendon vibration is an effective approach for motor and sensory rehabilitation in case of neurological impairments. The aim of our study was to investigate which modality of visual feedback in Virtual Reality (VR) associated with tendon vibration of the wrist could induce the best illusion of movement.
We included 30 healthy participants in the experiment. Tendon vibration inducing illusion of movement (wrist extension, 100Hz) was applied on their wrist during 3 VR visual conditions (10 times each): a moving virtual hand corresponding to the movement that the participants could feel during the tendon vibration (Moving condition), a static virtual hand (Static condition), or no virtual hand at all (Hidden condition). After each trial, the participants had to quantify the intensity of the illusory movement on a Likert scale, the subjective degree of extension of their wrist and afterwards they answered a questionnaire.
There was a significant difference between the 3 visual feedback conditions concerning the Likert scale ranking and the degree of wrist's extension (p<0.001). The Moving condition induced a higher intensity of illusion of movement and a higher sensation of wrist's extension than the Hidden condition (p<0.001 and p<0.001 respectively) than that of the Static condition (p<0.001 and p<0.001 respectively). The Hidden condition also induced a higher intensity of illusion of movement and a higher sensation of wrist's extension than the Static condition (p<0.01 and p<0.01 respectively). The preferred condition to facilitate movement's illusion was the Moving condition (63.3%).
This study demonstrated the importance of carefully selecting a visual feedback to improve the illusion of movement induced by tendon vibration, and the increase of illusion by adding VR visual cues congruent to the illusion of movement. Further work will consist in testing the same hypothesis with stroke patients.
肌腱振动诱发的运动错觉是神经功能障碍情况下运动和感觉康复的一种有效方法。我们研究的目的是探究虚拟现实（VR）中与手腕肌腱振动相关的哪种视觉反馈模式能够诱发最佳的运动错觉。
我们纳入30名健康参与者进行实验。在3种VR视觉条件下（每种条件10次），对他们的手腕施加诱发运动错觉的肌腱振动（手腕伸展，100Hz）：一个与参与者在肌腱振动期间能感觉到的运动相对应的移动虚拟手（移动条件）、一个静态虚拟手（静态条件）或根本没有虚拟手（隐藏条件）。每次试验后，参与者必须用李克特量表量化错觉运动的强度、手腕伸展的主观程度，然后回答一份问卷。
在李克特量表排名和手腕伸展程度方面，3种视觉反馈条件之间存在显著差异（p<0.001）。与隐藏条件相比，移动条件诱发的运动错觉强度更高，手腕伸展感觉更强（分别为p<0.001和p<0.001），与静态条件相比也是如此（分别为p<0.001和p<0.001）。隐藏条件诱发的运动错觉强度和手腕伸展感觉也比静态条件更高（分别为p<0.
