Enhancement of left-right sensorimotor EEG differences during feedback-regulated motor imagery
Enhancement of left-right sensorimotor EEG differences during feedback-regulated motor imagery
复制标题
DOI：
10.1097/00004691-199907000-00010
复制
发表时间：
1999-07-01
影响因子：
2.4
通讯作者：
Pfurtscheller, G
中科院分区：
文献类型：
--
作者：
Neuper, C;Schlögl, A;Pfurtscheller, G
脑电反馈研究表明，人类受试者可以学习调节感觉运动皮质上的皮层活动。这种自我诱发的脑电变化可以作为脑机接口的控制信号。目前这项研究的实验任务是根据计算机显示器上的视觉提示刺激想象右手或左手的运动。这项想象任务的表现是通过反馈条在线控制的，反馈条代表了当前的脑电模式。从左右中央记录点记录的脑电信号用于在线分类。对于脑电参数的估计，采用了自适应自回归模型，并使用线性判别分类器来区分左右运动图像的脑电模式。在实验过程中，四个训练对象的分类准确率达到了85%到95%。为了研究持续反馈呈现的影响，计算了受试者特定频段的频段功率变化的时间进程。脑电数据显示，在所有受试者的对侧中央区域都有明显的与事件相关的去同步化。两名受试者在同侧同时显示了脑电活动的同步性(事件相关同步)。在反馈呈现期间，与没有反馈的初始对照相比，事件相关去同步/事件相关同步模式表现出更强的半球不对称性。
EEG feedback studies demonstrate that human subjects can learn to regulate electrocortical activity over the sensorimotor cortex. Such self-induced EEG changes could serve as control signals for a Brain Computer Interface. The experimental task of the current study was to imagine either right-hand or left-hand movement depending on a visual cue stimulus on a computer monitor. The performance of this imagination task was controlled on-line by means of a feedback bar that represented the current EEG pattern. EEG signals recorded from left and right central recording sites were used for on-line classification. For the estimation of EEG parameters, an adaptive autoregressive model was applied, and a linear discriminant classifier was used to discriminate between EEG patterns associated with left and right motor imagery. Four trained subjects reached 85% to 95% classification accuracy in the course of the experimental sessions. To investigate the impact of continuous feedback presentation, time courses of band power changes were computed for subject-specific frequency bands. The EEG data revealed a significant event-related desynchronization over the contralateral central area in all subjects. Two subjects simultaneously displayed synchronization of EEG activity (event-related synchronization) over the ipsilateral side. During feedback presentation the event-related desynchronization/event-related synchronization patterns showed increased hemispheric asymmetry compared to initial control sessions without feedback.