PTSD症状个体自传体记忆的提取抑制——来自ERP的证据

Retrieval and Inhibition of Autobiographical Memory in PTSD:Evidence from ERP

目的探究创伤后应激障碍(post-traumatic stress disorder,PTSD)症状个体自传体记忆提取抑制功能的神经机制,以期在预后评估中建立更准确的指标,同时为PTSD症状个体制定更有效的治疗方案。方法使用PTSD症状自评量表筛选PTSD症状组和对照组被试各25人。采用事件相关电位(event-related potential,ERP)技术及记忆提取抑制范式,评估两组被试在记忆提取抑制任务上的脑电信号(electroencephalogram,EEG)。结果PTSD症状组在负性刺激条件的正确率显著高于中性刺激,负性刺激诱发的反应时显著长于中性刺激的反应时。在抑制指令条件下,PTSD症状组被试中性情绪诱发了比负性情绪偏转更大的N2波幅。结论PTSD症状个体由于其自上而下的抑制控制机制缺陷,在记忆提取抑制阶段虽然调用更多认知资源,付出更大的认知努力,但无法对记忆进行成功的抑制,这一缺陷可能是导致其闯入性记忆症状的原因或高风险因素。

Objective To explore the neurome chanism of retrieval and inhibition function of autobiographical memory in post-traumatic stress disorder(PTSD),so as to establish more accurate indicators and more effective therapeutic schedule for PTSD prognosis assessment and treatment.Methods A total of 25 participants in PTSD symptom group and 25 in the control group were screened by self-rating PTSD symptom scale.The electroencephalogram(EEG)signals of the two groups were evaluated by event-related potential(ERP)and paradigm of memory retrieval and inhibition.Results The correct rate of PTSD in negative stimulus was significantly higher than that in neutral stimulus.The response time of negative stimulus was significantly longer than that of neutral stimulus.Under the inhibition instruction condition,the N2 amplitude of neutral emotion was more negative than that of negative emotion.Conclusion Because of the deficiency of top-down inhibition control mechanism,the memory retrieval and inhibition stage in PTSD group can not inhibit memory successfully,although more cognitive resources were used and more cognitive efforts were made,this defect may be a cause or a high-risk factor for intrusive memory symptoms.