基于OVR-CSP的情绪认知重评脑电信号晚正成分研究

Research of the Late Positive Potential of Emotional Cognitive Reappraisal Electroencephalogram Signal Based on OVR-CSP

晚正成分（LPP）作为事件相关电位（ERP）的一个重要成分,是研究情绪调节重评进程的理想成分。本研究主要对采集的情绪认知重评脑电信号的LPP进行处理分析。基于EGI64导脑电采集系统采集16名被试的情绪认知重评脑电数据,首先采用独立成分分析（ICA）算法去除脑电信号中的眼电、肌电等噪声;然后用一对多-公共空间模式（OVR-CSP）算法对Pz电极的脑电信号进行特征提取;最后对提取的LPP成分进行时域及空域分析。结果表明：1从波幅的角度来比较：认知重评诱发的波幅显著大于观看中性诱发的波幅,而小于观看负性诱发的波幅。2从时间进程的角度来比较：经过OVR-CSP特征提取处理后,认知重评与自由观看组的差异发生在0.3~1.5s;而经过叠加平均方法处理后,认知重评与自由观看组的差异发生在0.3~1.25s。以上结果说明OVR-CSP算法不仅能以较少的试验次数准确提取LPP,为后续研究认知重评策略调节LPP提供较好的方法,同时也能为认知重评在情绪调节方面提供神经生理学依据。

As an important component of the event related potential （ERP）, late positive potential （LPP） is an ideal component for studying emotion regulation. This study was focused on processing and analysing the LPP component of the emotional cognitive reappraisal electroencephalogram （EEG） signal. Firstly, we used independent component analysis （ICA） algorithm to remove electrooculogram, electromyogram and some other artifacts based on 16 sub- jects＇ EEG data by using EGI 64-channal EEG acquisition system. Secondly, we processed feature extraction of the EEG signal at Pz electrode by using one versus the rest common spatial patterns （OVR-CSP） algorithm. Finally, the extracted LPP component was analysed both in time domain and spatial domain. The results indicated that ①From the perspective of amplitude comparison, the LPP amplitude, which was induced by cognitive reappraisal, was much higher than the amplitude under the condition of watching neural stimuli, but lower than the amplitude under condi- tion of watching negative stimuli; ② from the perspective of time process, the difference between cognitive reap- praisal and watching after processing with OVR-CSP algorithm was in the process of range between 0.3 s and 1.5 s; but the difference between cognitive reappraisal and watching after processing with averaging method was during theprocess between 0.3 s and 1.25 s. The results suggested that OVR-CSP algorithm could not only accurately extract the LPP component with fewer trials compared with averaging method so that it provided a better method for the fol- low-up study of cognitive reappraisal strategy, but also provide neurophysiologieal basis for cognitive reappraisal in emotional regulation.