不同复杂度汉字模式下运动想象脑机接口性能研究

Research on performance of motor-imagery-based brain-computer interface in different complexity of Chinese character patterns

传统运动想象脑机接口(BCI)的范式任务较为抽象,无法有效指导使用者调节大脑活动,从而限制了感觉运动皮层的激活程度。研究发现,汉字书写的运动想象任务能更好地被使用者接受,有助于指导使用者调节感觉运动节律;而不同的汉字具有不同的书写复杂度(笔画数),目前不同复杂度的汉字书写其运动想象任务对运动想象BCI性能的影响尚不清楚。基于此,本文共招募12名健康受试者参与两种不同复杂度(5笔画和10笔画)的汉字书写运动想象任务对运动想象BCI性能影响的研究。试验结果表明,与5笔画的汉字相比,10笔画的汉字书写运动想象任务获得了更强的感觉运动节律,以及更好的识别性能(P<0.05)。本文研究结果表明,适当增加汉字书写运动想象任务的复杂度,能获得更强的运动想象电位,提高运动想象BCI的识别准确率,期望本文研究可为今后运动想象BCI的范式设计提供一定的参考依据。

The traditional paradigm of motor-imagery-based brain-computer interface(BCI) is abstract, which cannot effectively guide users to modulate brain activity, thus limiting the activation degree of the sensorimotor cortex. It was found that the motor imagery task of Chinese characters writing was better accepted by users and helped guide them to modulate their sensorimotor rhythms. However, different Chinese characters have different writing complexity(number of strokes), and the effect of motor imagery tasks of Chinese characters with different writing complexity on the performance of motor-imagery-based BCI is still unclear. In this paper, a total of 12 healthy subjects were recruited for studying the effects of motor imagery tasks of Chinese characters with two different writing complexity(5 and 10 strokes)on the performance of motor-imagery-based BCI. The experimental results showed that, compared with Chinese characters with 5 strokes, motor imagery task of Chinese characters writing with 10 strokes obtained stronger sensorimotor rhythm and better recognition performance(P < 0.05). This study indicated that, appropriately increasing the complexity of the motor imagery task of Chinese characters writing can obtain stronger motor imagery potential and improve the recognition accuracy of motor-imagery-based BCI, which provides a reference for the design of the motorimagery-based BCI paradigm in the future.