Ramos-Murguialday Ander, Birbaumer Niels
Institute of Medical Psychology and Behavioral Neurobiology, University of Tubingen, Tubingen, Germany; TECNALIA, San Sebastian, Spain;
Institute of Medical Psychology and Behavioral Neurobiology, University of Tubingen, Tubingen, Germany; Ospedale San Camillo, Istituto di Ricovero e Cura a Carattere Scientifico, Lido de Venezia, Italy.
J Neurophysiol. 2015 Jun 1;113(10):3663-82. doi: 10.1152/jn.00467.2013. Epub 2015 Mar 25.
Noninvasive brain-computer-interfaces (BCI) coupled with prosthetic devices were recently introduced in the rehabilitation of chronic stroke and other disorders of the motor system. These BCI systems and motor rehabilitation in general involve several motor tasks for training. This study investigates the neurophysiological bases of an EEG-oscillation-driven BCI combined with a neuroprosthetic device to define the specific oscillatory signature of the BCI task. Controlling movements of a hand robotic orthosis with motor imagery of the same movement generates sensorimotor rhythm oscillation changes and involves three elements of tasks also used in stroke motor rehabilitation: passive and active movement, motor imagery, and motor intention. We recorded EEG while nine healthy participants performed five different motor tasks consisting of closing and opening of the hand as follows: 1) motor imagery without any external feedback and without overt hand movement, 2) motor imagery that moves the orthosis proportional to the produced brain oscillation change with online proprioceptive and visual feedback of the hand moving through a neuroprosthetic device (BCI condition), 3) passive and 4) active movement of the hand with feedback (seeing and feeling the hand moving), and 5) rest. During the BCI condition, participants received contingent online feedback of the decrease of power of the sensorimotor rhythm, which induced orthosis movement and therefore proprioceptive and visual information from the moving hand. We analyzed brain activity during the five conditions using time-frequency domain bootstrap-based statistical comparisons and Morlet transforms. Activity during rest was used as a reference. Significant contralateral and ipsilateral event-related desynchronization of sensorimotor rhythm was present during all motor tasks, largest in contralateral-postcentral, medio-central, and ipsilateral-precentral areas identifying the ipsilateral precentral cortex as an integral part of motor regulation. Changes in task-specific frequency power compared with rest were similar between motor tasks, and only significant differences in the time course and some narrow specific frequency bands were observed between motor tasks. We identified EEG features representing active and passive proprioception (with and without muscle contraction) and active intention and passive involvement (with and without voluntary effort) differentiating brain oscillations during motor tasks that could substantially support the design of novel motor BCI-based rehabilitation therapies. The BCI task induced significantly different brain activity compared with the other motor tasks, indicating neural processes unique to the use of body actuators control in a BCI context.
无创脑机接口（BCI）与假肢装置相结合，最近被引入到慢性中风和其他运动系统疾病的康复治疗中。这些BCI系统以及一般的运动康复都涉及多个用于训练的运动任务。本研究调查了一种由脑电图振荡驱动的BCI与神经假体装置相结合的神经生理学基础，以确定BCI任务的特定振荡特征。用相同动作的运动想象来控制手部机器人矫形器的运动，会产生感觉运动节律振荡变化，并且涉及中风运动康复中也使用的三个任务要素：被动和主动运动、运动想象以及运动意图。我们记录了9名健康参与者在执行由手部开合组成的五种不同运动任务时的脑电图，具体如下：1）无任何外部反馈且无明显手部运动的运动想象；2）随着产生的脑振荡变化成比例地移动矫形器的运动想象，并伴有通过神经假体装置（BCI条件）手部运动的在线本体感觉和视觉反馈；3）手部的被动运动；4）有反馈（看到并感觉到手部运动）的手部主动运动；5）休息。在BCI条件下，参与者收到感觉运动节律功率下降的偶然在线反馈，这会引起矫形器运动，从而产生来自运动手部的本体感觉和视觉信息。我们使用基于时频域自展法统计比较和Morlet变换分析了这五种条件下的大脑活动。将休息时的活动用作参考。在所有运动任务期间，均出现了显著的对侧和同侧事件相关感觉运动节律去同步化，在对侧中央后回、中央中部和同侧中央前回区域最为明显，这表明同侧中央前回皮质是运动调节的一个组成部分。与休息相比，各运动任务之间特定任务频率功率的变化相似，并且仅在时间进程和一些狭窄的特定频段上观察到运动任务之间存在显著差异。我们确定了代表主动和被动本体感觉（有和没有肌肉收缩）以及主动意图和被动参与（有和没有自主努力）的脑电图特征，这些特征区分了运动任务期间的脑振荡，这可以极大地支持基于运动BCI的新型康复治疗的设计。与其他运动任务相比，BCI任务诱发了显著不同的大脑活动，表明在BCI背景下使用身体执行器控制所特有的神经过程。
