Cao Lei, Ju Zhengyu, Li Jie, Jian Rongjun, Jiang Changjun
Department of Computer Science and Technology, Tongji University, 201804 Shanghai, China; Institute of Medical Psychology and Behavioral Neurobiology, University of Tuebingen, D-72074 Tuebingen, Germany.
Department of Computer Science and Technology, Tongji University, 201804 Shanghai, China.
J Neurosci Methods. 2015 Sep 30;253:10-7. doi: 10.1016/j.jneumeth.2015.05.014. Epub 2015 May 23.
Steady-state visual evoked potential (SSVEP) has been widely applied to develop brain computer interface (BCI) systems. The essence of SSVEP recognition is to recognize the frequency component of target stimulus focused by a subject significantly present in EEG spectrum.
In this paper, a novel statistical approach based on sequence detection (SD) is proposed for improving the performance of SSVEP recognition. This method uses canonical correlation analysis (CCA) coefficients to observe SSVEP signal sequence. And then, a threshold strategy is utilized for SSVEP recognition.
The result showed the classification performance with the longer duration of time window achieved the higher accuracy for most subjects. And the average time costing per trial was lower than the predefined recognition time. It was implicated that our approach could improve the speed of BCI system in contrast to other methods. Comparison with existing method(s): In comparison with other resultful algorithms, experimental accuracy of SD approach was better than those using a widely used CCA-based method and two newly proposed algorithms, least absolute shrinkage and selection operator (LASSO) recognition model as well as multivariate synchronization index (MSI) method. Furthermore, the information transfer rate (ITR) obtained by SD approach was higher than those using other three methods for most participants.
These conclusions demonstrated that our proposed method was promising for a high-speed online BCI.
稳态视觉诱发电位(SSVEP)已被广泛应用于脑机接口(BCI)系统的开发。SSVEP识别的本质是识别受试者脑电图频谱中显著存在的目标刺激的频率成分。
本文提出了一种基于序列检测(SD)的新型统计方法,以提高SSVEP识别的性能。该方法使用典型相关分析(CCA)系数来观察SSVEP信号序列。然后,采用阈值策略进行SSVEP识别。
结果表明,对于大多数受试者,时间窗持续时间较长时的分类性能具有更高的准确率。并且每次试验的平均耗时低于预定义的识别时间。这意味着与其他方法相比,我们的方法可以提高BCI系统的速度。与现有方法的比较:与其他有效算法相比,SD方法的实验准确率优于广泛使用的基于CCA的方法以及两种新提出的算法,即最小绝对收缩和选择算子(LASSO)识别模型以及多变量同步指数(MSI)方法。此外,对于大多数参与者,SD方法获得的信息传输率(ITR)高于其他三种方法。
这些结论表明,我们提出的方法在高速在线BCI方面具有前景。