中文摘要：

目的探讨伴抑郁症状个体指向遗忘任务（the directed forgetting）的事件相关电位特征，探寻可能存在的认知抑制机制。方法采用德国BrainProduct公司生产的BrainAmp型ERP系统进行数据采集，11名伴抑郁症状和20名正常被试者完成实验，对其ERP的潜伏期和波幅进行统计分析。结果（1）指向遗忘任务下有意义的ERPs出现在枕顶部、枕颞部，以右侧相应脑区最为明显，分别为P100、N170、P200、N400。（2）组间因素、指示类型对N170潜伏期、波幅，以及指示类型对P100、P200、N400潜伏期有显著的主效应（F=5．86、9．18、5．30；F=17．94、10．51、4．28；P〈0．05）。（3）TBR条件下，伴抑郁症状组N170、P100、P200潜伏期长于正常组（172．40ms vs179．9ms，130．8ms vs142．36ms，257．50ms vs279．64ms，P〈0．05）。TBF条件下，P200潜伏期在大多数记录点明显长于正常组（240．20ms vs265．60ms，P〈0．05），N170潜伏期在P6记录点与正常组有统计学意义（172．30ms vs183．27ms，P〈0．05）。（4）正性词组N170、P200潜伏期在多个记录点，N170、P100波幅在部分记录点有统计学意义（257．50ms vs279．64ms，235．69ms vs265．45ms，P〈0．05）；负性词组P100、P200潜伏期在部分记录点有统计学意义（120．2ms vs136．54ms，236．8ms vs255．45ms，P〈0．05）。结论指向遗忘范式下的情绪词信息加工具有独特的ERPs特征，伴抑郁症状组在早期的信息加工存在着选择、注意水平上的差异。

英文摘要：

Objective To study the characteristics of the event-related potentials in the directed forgetting between non-depressed and depressed individuals. Methods 20 non-depressed and 11 depressed individuals performed a parametric ERP design with the directed forgetting task. They were required to forget or remember the words, while the EEG was recorded during they performed the task. Results （ 1 ） P100, N170, P200, N400 were evoked during the directed forgetting task, especially in right occipital-parietal,occipital temporal cortex of the brain. （2）There were significant main effects in both intergroup factors and type of instructions for N170 latency and amplitude（F：5.86,9.18,5.30,P〈0.05） ,type of instructions for P100,P200,N400 latency （F 17.94,10.51,4.28,P〈0.05）. （3）The latency of N170,P100,P200 with the depressed were obviously longer than the non depressed under the TBR（172.40 ms vs 179.9 ms,130.80 ms vs 142.36 ms,257.50 ms vs 279.64 ms,P〈O. 05）. And P200,N170 were longer under the TBF（240.20 ms vs 265.60 ms,172.30 ms vs 183.27 ms,P〈0. 05）. （4）The latency of N170,P200 and the amplitude of N170,PI00 evoked by positive words,the latency of P100,P200 by negative words in the depressed were longer than the non-depressed（257.50 ms vs 279.64 ms,235.69 ms vs 265.45 ms;120.20 ms vs 136.54 ms,236.80 ms vs 255.45 ms,P〈 0.05）. Conclusion There are characteristic features in ERPs of emotional words in the directed forgetting task. The selection and attention on the early stage of information process with the depressed subjects have the significant differences.