Ziadeh Hamzah, Gulyas David, Nielsen Louise Dørr, Lehmann Steffen, Nielsen Thomas Bendix, Kjeldsen Thomas Kim Kroman, Hougaard Bastian Ilsø, Jochumsen Mads, Knoche Hendrik
Human Machine Interaction Lab, Department of Architecture, Design, and Media Technology, Institute for Architecture and Media Technology, Aalborg University, Aalborg, Denmark.
Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
Front Psychol. 2021 Dec 24;12:806424. doi: 10.3389/fpsyg.2021.806424. eCollection 2021.
Motor imagery-based brain-computer interfaces (MI-BCI) have been proposed as a means for stroke rehabilitation, which combined with virtual reality allows for introducing game-based interactions into rehabilitation. However, the control of the MI-BCI may be difficult to obtain and users may face poor performance which frustrates them and potentially affects their motivation to use the technology. Decreases in motivation could be reduced by increasing the users' sense of agency over the system. The aim of this study was to understand whether embodiment (ownership) of a hand depicted in virtual reality can enhance the sense of agency to reduce frustration in an MI-BCI task. Twenty-two healthy participants participated in a within-subject study where their sense of agency was compared in two different embodiment experiences: 1) avatar hand (with body), or 2) abstract blocks. Both representations closed with a similar motion for spatial congruency and popped a balloon as a result. The hand/blocks were controlled through an online MI-BCI. Each condition consisted of 30 trials of MI-activation of the avatar hand/blocks. After each condition a questionnaire probed the participants' sense of agency, ownership, and frustration. Afterwards, a semi-structured interview was performed where the participants elaborated on their ratings. Both conditions supported similar levels of MI-BCI performance. A significant correlation between ownership and agency was observed ( = 0.47, = 0.001). As intended, the avatar hand yielded much higher ownership than the blocks. When controlling for performance, ownership increased sense of agency. In conclusion, designers of BCI-based rehabilitation applications can draw on anthropomorphic avatars for the visual mapping of the trained limb to improve ownership. While not While not reducing frustration ownership can improve perceived agency given sufficient BCI performance. In future studies the findings should be validated in stroke patients since they may perceive agency and ownership differently than able-bodied users.
基于运动想象的脑机接口（MI-BCI）已被提议作为中风康复的一种手段，它与虚拟现实相结合，能够将基于游戏的交互引入康复过程。然而，MI-BCI的控制可能难以实现，用户可能面临表现不佳的问题，这会让他们感到沮丧，并可能影响他们使用该技术的积极性。通过增强用户对系统的控制感，可以减少积极性的下降。本研究的目的是了解虚拟现实中描绘的手部的具身化（所有权）是否能增强控制感，以减少MI-BCI任务中的挫败感。22名健康参与者参与了一项自身对照研究，在两种不同的具身化体验中比较他们的控制感：1）虚拟化身手部（有身体），或2）抽象方块。两种表现形式都以相似的动作结束以实现空间一致性，并因此弹出一个气球。手部/方块通过在线MI-BCI进行控制。每个条件包括30次对虚拟化身手部/方块进行MI激活的试验。在每个条件之后，通过问卷调查探究参与者的控制感、所有权感和挫败感。之后，进行了一次半结构化访谈，参与者对他们的评分进行了详细说明。两种条件下的MI-BCI表现水平相似。观察到所有权感和控制感之间存在显著相关性（= 0.47，= 0.001）。如预期的那样，虚拟化身手部产生的所有权感比方块高得多。在控制表现的情况下，所有权感增强了控制感。总之，基于BCI的康复应用的设计者可以利用拟人化的虚拟化身来对训练的肢体进行视觉映射，以提高所有权感。虽然不能减少挫败感，但在BCI表现足够的情况下，所有权感可以改善感知到的控制感。在未来的研究中，这些发现应该在中风患者中得到验证，因为他们对控制感和所有权感的感知可能与身体健全的用户不同。
