Keil A, Müller M M, Gruber T, Wienbruch C, Stolarova M, Elbert T
Department of Psychology, University of Konstanz, D-78434, Konstanz, Germany.
Clin Neurophysiol. 2001 Nov;112(11):2057-68. doi: 10.1016/s1388-2457(01)00654-x.
The present study aimed at examining the time course and topography of oscillatory brain activity and event-related potentials (ERPs) in response to laterally presented affective pictures.
Electroencephalography was recorded from 129 electrodes in 10 healthy university students during presentation of pictures from the international affective picture system. Frequency measures and ERPs were obtained for pleasant, neutral, and unpleasant pictures.
In accordance with previous reports, a modulation of the late positive ERP wave at parietal recording sites was found as a function of emotional arousal. Early mid gamma band activity (GBA; 30-45 Hz) at 80 ms post-stimulus was enhanced in response to aversive stimuli only, whereas the higher GBA (46-65 Hz) at 500 ms showed an enhancement of arousing, compared to neutral pictures. ERP and late gamma effects showed a pronounced right-hemisphere preponderance, but differed in terms of topographical distribution.
Late gamma activity may represent a correlate of widespread cortical networks processing different aspects of emotionally arousing visual objects. In contrast, differences between affective categories in early gamma activity might reflect fast detection of aversive stimulus features.
本研究旨在探究对侧向呈现的情感图片作出反应时，振荡脑电活动和事件相关电位（ERP）的时间进程及地形图。
在向10名健康大学生呈现国际情感图片系统中的图片时，通过129个电极记录脑电图。获取了愉快、中性和不愉快图片的频率测量值及ERP。
与先前报告一致，发现顶叶记录部位的晚期正ERP波会根据情绪唤醒程度进行调制。仅对厌恶刺激而言，刺激后80毫秒时的早期中伽马波段活动（GBA；30 - 45赫兹）增强，而与中性图片相比，500毫秒时更高频率的GBA（46 - 65赫兹）在唤醒时增强。ERP和晚期伽马效应显示出明显的右半球优势，但在地形图分布方面存在差异。
晚期伽马活动可能代表广泛皮层网络处理情绪唤起视觉对象不同方面的一个关联指标。相比之下，早期伽马活动中情感类别之间的差异可能反映了对厌恶刺激特征的快速检测。
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