基于左右视野双频率刺激的SSVEP脑-机接口

Right-and-left field stimulation with two frequencies for a SSVEP-based brain-computer interface

当可使用频率有限时,基于稳态视觉诱发电位(SSVEP)的脑-机接口(BCI)系统所能呈现的目标数较少。为了有效地增加该目标数,该文提出了一种基于左右视野、使用两个频率闪烁块呈现目标的刺激方法。5名受试者参加了试验。用典型相关分析法处理数据,提取左右视野区与刺激对应的频率成分。离线正确率分析表明:4名受试目标识别率超过85%。采用该方法,在使用2个频率时,该系统所能呈现的目标个数提高了2倍。

Only a small number of targets can be presented when using limited frequencies in brain-computer interfaces（BCI） based on SSVEP（steady-state visual evoked potentials）.A method was developed for simultaneous right-and-left field stimulation with two frequencies to acquire more targets when using a screen display as the stimulator in SSVEP-BCIs.Canonical correlation analysis（CCA） was applied to extract the frequency components of the right-and-left visual fields.Offline analyses of 5 subjects show that the final accuracy for four of the subjects was more than 85%.Thus,the method with two frequencies can recognize more than twice as many targets as conventional SSVEP-BCIs.