Wessa Michèle, Jatzko Alexander, Flor Herta
Department of Clinical and Cognitive Neuroscience at the University of Heidelberg, Central Institute of Mental Health, J 5, 68159 Mannheim, Germany.
Neuropsychologia. 2006;44(10):1683-96. doi: 10.1016/j.neuropsychologia.2006.03.024. Epub 2006 May 22.
Posttraumatic stress disorder (PTSD) is thought to be characterized by dysfunctional memory processes, i.e., the automatic re-experiencing of the traumatic event and the inability to consciously recall facts about the traumatic event, as well as altered emotional processing of trauma-relevant cues. The present study examined the cerebral mechanisms underlying the cued recall of trauma-specific memories and the emotional processing of the presented cues in 16 PTSD patients, 15 trauma-exposed subjects without PTSD and 16 healthy controls. Subjects received questions about their specific trauma as well as other disastrous and neutral events while the electroencephalogram and heart rate were measured. The PTSD patients showed no impairment in trauma-specific declarative memory compared to non-PTSD subjects but had some deficits in general declarative memory as assessed by the Wechsler Memory Scale-Revised. Compared to healthy control subjects, PTSD patients displayed increased P300 and late positive complex amplitudes to trauma-specific questions, indicating enhanced emotional processing of these cues. In line with their behavioral performance, both trauma-exposed groups showed decreased terminal contingent negative variation amplitudes to trauma-specific questions over frontal electrodes reflecting altered memory retrieval. Within-group comparisons revealed that only the PTSD group but not the other groups showed a differentiation between trauma-specific and neutral questions with respect to the LPC, tCNV and P300. Concordantly with previous studies, PTSD patients showed elevated resting heart rate compared to the healthy controls. These findings are discussed in the context of current models of the role of declarative memory in the development and maintenance of PTSD.
创伤后应激障碍（PTSD）被认为具有记忆过程功能失调的特征，即创伤事件的自动重现以及无法有意识地回忆起有关创伤事件的事实，同时对与创伤相关线索的情绪加工也发生改变。本研究考察了16名创伤后应激障碍患者、15名有创伤暴露史但无创伤后应激障碍的受试者以及16名健康对照者在提示性回忆创伤特异性记忆和对所呈现线索进行情绪加工时的脑机制。受试者在接受关于其特定创伤以及其他灾难性和中性事件的提问时，同时测量脑电图和心率。与非创伤后应激障碍受试者相比，创伤后应激障碍患者在创伤特异性陈述性记忆方面没有受损，但根据韦氏记忆量表修订版评估，他们在一般陈述性记忆方面存在一些缺陷。与健康对照受试者相比，创伤后应激障碍患者对创伤特异性问题表现出P300和晚期正复合波振幅增加，表明对这些线索的情绪加工增强。与他们的行为表现一致，两个有创伤暴露史的组在额叶电极上对创伤特异性问题的终末伴随负变化振幅降低，反映出记忆提取的改变。组内比较显示，只有创伤后应激障碍组在长潜伏期正电位、终末伴随负变化和P300方面，创伤特异性问题和中性问题之间存在差异。与先前的研究一致，创伤后应激障碍患者与健康对照相比静息心率升高。这些发现将在陈述性记忆在创伤后应激障碍的发生和维持中所起作用的当前模型背景下进行讨论。
