Ji Hongfei, Li Jie, Lu Rongrong, Gu Rong, Cao Lei, Gong Xiaoliang
Department of Computer Science and Technology, Tongji University, No. 4800 Caoan Highway, Shanghai 200092, China.
Department of Rehabilitation, Huashan Hospital, Fudan University, No. 12 Wulumuqi Middle Road, Shanghai 200040, China.
Comput Intell Neurosci. 2016;2016:1732836. doi: 10.1155/2016/1732836. Epub 2016 Jan 3.
Electroencephalogram- (EEG-) based brain-computer interface (BCI) systems usually utilize one type of changes in the dynamics of brain oscillations for control, such as event-related desynchronization/synchronization (ERD/ERS), steady state visual evoked potential (SSVEP), and P300 evoked potentials. There is a recent trend to detect more than one of these signals in one system to create a hybrid BCI. However, in this case, EEG data were always divided into groups and analyzed by the separate processing procedures. As a result, the interactive effects were ignored when different types of BCI tasks were executed simultaneously. In this work, we propose an improved tensor based multiclass multimodal scheme especially for hybrid BCI, in which EEG signals are denoted as multiway tensors, a nonredundant rank-one tensor decomposition model is proposed to obtain nonredundant tensor components, a weighted fisher criterion is designed to select multimodal discriminative patterns without ignoring the interactive effects, and support vector machine (SVM) is extended to multiclass classification. Experiment results suggest that the proposed scheme can not only identify the different changes in the dynamics of brain oscillations induced by different types of tasks but also capture the interactive effects of simultaneous tasks properly. Therefore, it has great potential use for hybrid BCI.
基于脑电图(EEG)的脑机接口(BCI)系统通常利用大脑振荡动力学中的一种变化进行控制,例如事件相关去同步化/同步化(ERD/ERS)、稳态视觉诱发电位(SSVEP)和P300诱发电位。最近有一种趋势是在一个系统中检测多种此类信号以创建混合BCI。然而,在这种情况下,EEG数据总是被分成组,并通过单独的处理程序进行分析。结果,当同时执行不同类型的BCI任务时,交互作用被忽略了。在这项工作中,我们提出了一种改进的基于张量的多类多模态方案,专门用于混合BCI,其中EEG信号被表示为多路张量,提出了一种非冗余的秩一张量分解模型以获得非冗余张量分量,设计了加权Fisher准则以选择多模态判别模式而不忽略交互作用,并将支持向量机(SVM)扩展到多类分类。实验结果表明,所提出的方案不仅可以识别不同类型任务引起的大脑振荡动力学的不同变化,还可以正确捕捉同时任务的交互作用。因此,它在混合BCI中有很大的潜在应用价值。