Li Yandong, Ma Zhongwei, Lu Wenkai, Li Yanda
Department of Automation, Tsinghua University, Beijing 100084, People's Republic of China.
Physiol Meas. 2006 Apr;27(4):425-36. doi: 10.1088/0967-3334/27/4/008. Epub 2006 Mar 14.
Independent component analysis (ICA) proves to be effective in the removing the ocular artifact from electroencephalogram recordings (EEG). While using ICA in ocular artifact correction, a crucial step is to correctly identify the artifact components among the decomposed independent components. In most previous works, this step of selecting the artifact components was manually implemented, which is time consuming and inconvenient when dealing with a large amount of EEG data. We present a new method which automatically selects the eye blink artifact components based on the pattern of their scalp topographies, which can be exemplified as a template matching approach. The feasibility of using a fixed template for singling out the eye blink component after ICA decomposition was validated by an experiment in which 18 subjects among the 21 subjects involved exhibited a highly consistent pattern of eye blink scalp topographies. Since only the spatial feature is employed for singling out the eye blink component, the proposed method is very efficient and easy to implement. Objective evaluation of the real results shows that the proposed algorithm can remove the eye blink artifact from the EEG while causing little distortion to the underlying brain activities.
独立成分分析(ICA)在去除脑电图(EEG)记录中的眼电伪迹方面被证明是有效的。在使用ICA进行眼电伪迹校正时,关键步骤是在分解出的独立成分中正确识别伪迹成分。在大多数先前的工作中,选择伪迹成分这一步骤是手动完成的,在处理大量EEG数据时既耗时又不方便。我们提出了一种新方法,该方法基于眼电头皮地形图的模式自动选择眨眼伪迹成分,这可以举例为一种模板匹配方法。通过一项实验验证了使用固定模板在ICA分解后挑选出眨眼成分的可行性,在参与实验的21名受试者中,有18名受试者表现出高度一致的眨眼头皮地形图模式。由于仅使用空间特征来挑选眨眼成分,因此所提出的方法非常高效且易于实现。对实际结果的客观评估表明,所提出的算法可以从EEG中去除眨眼伪迹,同时对潜在的大脑活动造成的失真很小。