Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084, People's Republic of China.
J Neural Eng. 2010 Feb;7(1):16010. doi: 10.1088/1741-2560/7/1/016010. Epub 2010 Jan 19.
In this paper, a novel independent brain-computer interface (BCI) system based on covert non-spatial visual selective attention of two superimposed illusory surfaces is described. Perception of two superimposed surfaces was induced by two sets of dots with different colors rotating in opposite directions. The surfaces flickered at different frequencies and elicited distinguishable steady-state visual evoked potentials (SSVEPs) over parietal and occipital areas of the brain. By selectively attending to one of the two surfaces, the SSVEP amplitude at the corresponding frequency was enhanced. An online BCI system utilizing the attentional modulation of SSVEP was implemented and a 3-day online training program with healthy subjects was carried out. The study was conducted with Chinese subjects at Tsinghua University, and German subjects at University Medical Center Hamburg-Eppendorf (UKE) using identical stimulation software and equivalent technical setup. A general improvement of control accuracy with training was observed in 8 out of 18 subjects. An averaged online classification accuracy of 72.6 +/- 16.1% was achieved on the last training day. The system renders SSVEP-based BCI paradigms possible for paralyzed patients with substantial head or ocular motor impairments by employing covert attention shifts instead of changing gaze direction.
本文描述了一种新颖的基于叠加的虚幻表面的隐蔽非空间视觉选择性注意的独立脑-机接口 (BCI) 系统。通过两组以相反方向旋转的不同颜色的点来诱导对两个表面的感知。表面以不同的频率闪烁，并在大脑的顶叶和枕叶区域引起可区分的稳态视觉诱发电位 (SSVEP)。通过选择性地关注两个表面之一，可以增强相应频率的 SSVEP 幅度。实现了利用 SSVEP 的注意力调制的在线 BCI 系统，并对健康受试者进行了为期 3 天的在线培训计划。该研究在中国清华大学的中国受试者和德国汉堡大学医学中心 (UKE) 的德国受试者中进行，使用相同的刺激软件和等效的技术设置。在 18 名受试者中有 8 名观察到控制精度随训练普遍提高。在最后一天的训练中，在线分类准确率平均达到 72.6 +/- 16.1%。该系统通过使用隐蔽的注意力转移而不是改变注视方向，为头部或眼部运动障碍严重的瘫痪患者提供了基于 SSVEP 的 BCI 范式。
