Using a rapid serial visual presentation paradigm, we previously showed that the average amplitudes of six event-related potential (ERP) components were affected by different categories of emotional faces. In the current study, we investigated the six discriminating components on a single-trial level to clarify whether the amplitude difference between experimental conditions results from a difference in the real variability of single-trial amplitudes or from latency jitter across trials. It is found that there were consistent amplitude differences in the single-trial P1, N170, VPP, N3, and P3 components, demonstrating that a substantial proportion of the average amplitude differences can be explained by the pure variability in amplitudes on a single-trial basis between experimental conditions. These single-trial results verified the three-stage scheme of facial expression processing beyond multitrial ERP averaging, and showed the three processing stages of "fear popup", "emotional/unemotional discrimination", and "complete separation" based on the single-trial ERP dynamics.
目的 探讨述情障碍个体的情绪调节注意转移策略及加工机制.方法 纳入述情障碍组21例,正常对照组22例,完成注意转移实验任务,自动记录被试的反应时及正确率,Neuroscan64导脑电仪同时记录其事件相关电位.结果 ①行为学结果显示,计算任务下两组对中性图片的反应时,正确率[（1840.17±204.44） ms vs（1845.17±252.97） ms;（0.859±0.073） vs （0.884±0.068）],对负性图片的反应时,正确率[（1888.94±200.09） ms vs （1890.38±263.72） ms;（0.845±0.088） vs （0.845±0.091）]差异无统计学意义（均P＞0.05）.效价任务下两组反应时、正确率差异无统计学意义（均P＞0.05）.②反应时及正确率任务主效应有统计学意义（F（1,42）=637.40,P＜0.01;F（1,42）=15.00,P＜0.01）,情绪主效应有统计学意义（F（1,42）=30.23,P＜0.01;F1,42）=47.87,P＜0.01）,任务与情绪交互效应有统计学意义（F2,41）=5.20,P＜0.05;F（2,41）=6.01,P＜0.05）.③计算任务中性和负性情绪图片诱发的P3波幅差异无统计学意义（均P＞0.05）,情绪任务下负性情绪图片诱发的P3波幅大于中性图片,差异有统计学意义[（-0.138±0.463）μV vs （0.789±0.541）μV,P＜0.05].组间差异无统计学意义.结论 注意转移策略可以有效调节负性情绪图片的加工,并且该调节效应发生在图片加工的晚期阶段.述情障碍个体在该调节策略上没有缺陷.
