Bisby James A, Burgess Neil, Brewin Chris R
Division of Psychiatry, University College London.
Institute of Cognitive Neuroscience, University College London.
Curr Dir Psychol Sci. 2020 Jun;29(3):267-272. doi: 10.1177/0963721420917691. Epub 2020 Jun 4.
Posttraumatic stress disorder (PTSD) is characterized by disruptions in memory, including vivid sensory images of the trauma that are involuntarily reexperienced. However, the extent and nature of disruptions to deliberate memory for trauma remain controversial. A unitary account posits that all aspects of memory for a traumatic event are strengthened. In contrast, a dual-representation account proposes up-modulation of sensory and affective representations of the negative content and down-modulation of hippocampal representations of the context in which the event occurred. We take a neuroscientific approach and review the literature concerning the mechanisms required to produce coherent episodic memories and how they are affected in experiments involving negative content. We find, in healthy volunteers, that negative content can reduce associative binding and the coherence of episodic memories. Finally, we bring these findings together with the literature on PTSD to highlight how similar associative mechanisms are affected in patients, consistent with hippocampal impairment, supporting a dual-representation view of disrupted memory coherence.
创伤后应激障碍（PTSD）的特征是记忆紊乱，包括不由自主地反复体验到创伤的生动感官图像。然而，对创伤的有意记忆的破坏程度和性质仍存在争议。一种单一的观点认为，创伤事件记忆的所有方面都会得到强化。相比之下，一种双重表征观点则提出，对负面内容的感官和情感表征进行上调，而对事件发生背景的海马体表征进行下调。我们采用神经科学方法，回顾了有关产生连贯情景记忆所需机制的文献，以及它们在涉及负面内容的实验中是如何受到影响的。我们发现，在健康志愿者中，负面内容会降低情景记忆的联想绑定和连贯性。最后，我们将这些发现与关于PTSD的文献结合起来，以突出类似的联想机制在患者中是如何受到影响的，这与海马体损伤一致，支持了记忆连贯性破坏的双重表征观点。
