Effects of Using Virtual Reality and Virtual Avatar on Hand Motion Reconstruction Accuracy and Brain Activity
Effects of Using Virtual Reality and Virtual Avatar on Hand Motion Reconstruction Accuracy and Brain Activity
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DOI：
10.1109/access.2017.2766174
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发表时间：
2017-01-01
期刊：
影响因子：
3.9
通讯作者：
Yu, Wenwei
中科院分区：
文献类型：
--
作者：
Fernandez-Vargas, Jacob;Tarvainen, Tapio V. J.;Yu, Wenwei
利用脑电(EEG)信号重建手的运动是一个尚未解决的挑战性问题。大多数相关研究依赖于运动跟踪系统来记录与生物信号配对的手坐标值序列，以便训练它们之间的映射函数。对于截肢者来说，这种方法是不可能的。关于不同的训练技术如何影响运动重建系统的准确性的研究也很少。开发了一种虚拟化身，用于呈现不同的上肢运动。受试者被要求跟随化身的动作，而受试者的脑电和肌电(EMG)信号被记录下来，并与化身的手部轨迹值配对。这项任务是在三种情况下进行的：通过记忆重复动作，在屏幕上观看时重复动作，在虚拟现实(VR)中观看时重复动作。我们没有发现这三种情况在相关值方面有任何显著差异。尽管如此，我们发现同时使用EEG和EMG会比只使用其中一种方法得到更好的结果。此外，在脑电活动中发现了显著的差异，这表明即使三种情况下的任务(移动手臂)是相同的，大脑动力学也是不同的。具体地说，我们发现，在运动过程中，使用VR会导致更高的阿尔法去同步化。最后，当只使用脑电信号时，我们的结果与使用运动跟踪系统的其他研究具有可比性。
Reconstruction of a hand's motion with electroencephalography (EEG) signals is a challenging problem that has not been solved yet. Most related studies rely on a motion tracking system to record a sequence of hand coordinate values paired with biosignals, in order to train a mapping function between them. For amputees, this approach is not possible. There are also only a few studies about how different training techniques may affect the accuracy of a motion reconstruction system. A virtual avatar for presenting different upper limb motions was developed. Subjects were asked to follow the avatar's motion, while the subject's EEG and electromyography (EMG) signals were recorded and paired with avatar's hand trajectory values. This task was performed under three conditions: repeating the motion by memory, repeating the motion while watching it on a screen, and repeating the motion while seeing it in virtual reality (VR). We did not find any significant difference between the three conditions in terms of correlation values. Still, we found that using both EEG and EMG at the same time led to a better result than using only one of them. Additionally, significant differences were found in the EEG activity, suggesting that even if the task (moving the arm) was the same for the three conditions, the brain dynamics were different. Specifically, we found that using the VR resulted in a higher alpha desynchronization during the motion. Finally, our results, when only EEG signals were used, were comparable with other studies that have used a motion tracking system.