School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, People's Republic of China.
State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an, People's Republic of China.
J Neural Eng. 2021 Oct 19;18(5). doi: 10.1088/1741-2552/ac2a6f.
Motor imagery (MI), based on the theory of mirror neurons and neuroplasticity, can promote motor cortical activation in neurorehabilitation. The strategy of MI based on brain-computer interface (BCI) has been used in rehabilitation training and daily assistance for patients with hemiplegia in recent years. However, it is difficult to maintain the consistency and timeliness of receiving external stimulation to neural activation in most subjects owing to the high variability of electroencephalogram (EEG) representation across trials/subjects. Moreover, in practical application, MI-BCI cannot highly activate the motor cortex and provide stable interaction owing to the weakness of the EEG feature and lack of an effective mode of activation.In this study, a novel hybrid BCI paradigm based on MI and vestibular stimulation motor imagery (VSMI) was proposed to enhance the capability of feature response for MI. Twelve subjects participated in a group of controlled experiments containing VSMI and MI. Three indicators, namely, activation degree, timeliness, and classification accuracy, were adopted to evaluate the performance of the task.Vestibular stimulation could significantly strengthen the suppression ofandbands of contralateral brain regions during MI, that is, enhance the activation degree of the motor cortex (< 0.01). Compared with MI, the timeliness of EEG feature-response achieved obvious improvements in VSMI experiments. Moreover, the averaged classification accuracy of VSMI and MI was 80.56% and 69.38%, respectively.The experimental results indicate that specific vestibular activity contributes to the oscillations of the motor cortex and has a positive effect on spontaneous imagery, which provides a novel MI paradigm and enables the preliminary exploration of sensorimotor integration of MI.
基于镜像神经元和神经可塑性理论的运动想象（MI）可以促进神经康复中的运动皮质激活。近年来，基于脑机接口（BCI）的 MI 策略已被用于偏瘫患者的康复训练和日常生活辅助。然而，由于脑电图（EEG）在试验/个体之间的表现高度可变，大多数个体难以保持对外来刺激到神经激活的一致性和及时性。此外，在实际应用中，由于 EEG 特征的弱点和缺乏有效的激活模式，MI-BCI 无法高度激活运动皮层并提供稳定的交互。
在这项研究中，提出了一种基于 MI 和前庭刺激运动想象（VSMI）的新型混合 BCI 范式，以增强 MI 的特征响应能力。12 名受试者参与了包含 VSMI 和 MI 的一组对照实验。采用三个指标，即激活程度、及时性和分类准确性，来评估任务的性能。
前庭刺激可以显著增强 MI 期间对侧大脑区域的抑制和波的强度，即增强运动皮质的激活程度（<0.01）。与 MI 相比，VSMI 实验中 EEG 特征响应的及时性有明显改善。此外，VSMI 和 MI 的平均分类准确率分别为 80.56%和 69.38%。
实验结果表明，特定的前庭活动有助于运动皮质的振荡，并对自发性想象有积极影响，为 MI 提供了一种新的 MI 范式，并初步探索了 MI 的感觉运动整合。
