National Center for PTSD, VA Boston Healthcare System, Boston, MA, USA; Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA.
National Center for PTSD, VA Boston Healthcare System, Boston, MA, USA; Department of Psychiatry, Boston University School of Medicine, Boston, MA, USA.
J Psychiatr Res. 2019 May;112:30-37. doi: 10.1016/j.jpsychires.2019.02.015. Epub 2019 Feb 26.
Previous work has shown that healthy individuals can actively suppress emotional memories through recruitment of the lateral prefrontal cortex. By contrast, individuals with posttraumatic stress disorder (PTSD) frequently experience unwanted memories of their traumatic experiences, even when making explicit efforts to avoid them. However, little is known regarding the behavioral and neural effects of memory suppression among individuals with PTSD. We examined memory suppression associated with PTSD using the Think-No-Think paradigm in an event-related functional magnetic resonance imaging (fMRI) study. We studied three groups: PTSD (n = 16), trauma exposure without PTSD (n = 19), and controls (i.e., no trauma exposure or PTSD; n = 13). There was a main effect of memory suppression such that participants remembered fewer face-picture pairs during the suppress condition than the remember condition. However, trauma-exposed participants (regardless of PTSD status) were less likely to successfully suppress memory than non-trauma-exposed controls. Neuroimaging data revealed that trauma-exposed individuals showed reduced activation in the right middle frontal gyrus during memory suppression. These results suggest that trauma exposure is associated with neural and behavioral disruptions in memory suppression and point to the possibility that difficulty in active suppression of memories may be just one of several likely factors contributing to the development of PTSD.
先前的研究表明，健康个体可以通过招募外侧前额叶皮层来主动抑制情绪记忆。相比之下，创伤后应激障碍（PTSD）患者经常会不由自主地回忆起创伤经历，即使他们明确试图避免回忆。然而，对于 PTSD 患者的记忆抑制的行为和神经影响知之甚少。我们使用与 PTSD 相关的 Think-No-Think 范式在事件相关功能磁共振成像 (fMRI) 研究中检查了记忆抑制。我们研究了三组人群：PTSD（n=16）、有创伤暴露但无 PTSD（n=19）和对照组（即无创伤暴露或 PTSD；n=13）。记忆抑制存在主要效应，即参与者在抑制条件下记住的面孔-图片对少于记忆条件。然而，与无创伤暴露的对照组相比，创伤暴露的参与者（无论是否患有 PTSD）成功抑制记忆的可能性较低。神经影像学数据显示，创伤暴露个体在记忆抑制期间右侧额中回的激活减少。这些结果表明，创伤暴露与记忆抑制的神经和行为障碍有关，并表明主动抑制记忆的困难可能只是导致 PTSD 发展的几个可能因素之一。
