Center for Computational Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
Nat Neurosci. 2023 Dec;26(12):2226-2236. doi: 10.1038/s41593-023-01483-5. Epub 2023 Nov 30.
For people with post-traumatic stress disorder (PTSD), recall of traumatic memories often displays as intrusions that differ profoundly from processing of 'regular' negative memories. These mnemonic features fueled theories speculating a unique cognitive state linked with traumatic memories. Yet, to date, little empirical evidence supports this view. Here we examined neural activity of patients with PTSD who were listening to narratives depicting their own memories. An intersubject representational similarity analysis of cross-subject semantic content and neural patterns revealed a differentiation in hippocampal representation by narrative type: semantically similar, sad autobiographical memories elicited similar neural representations across participants. By contrast, within the same individuals, semantically similar trauma memories were not represented similarly. Furthermore, we were able to decode memory type from hippocampal multivoxel patterns. Finally, individual symptom severity modulated semantic representation of the traumatic narratives in the posterior cingulate cortex. Taken together, these findings suggest that traumatic memories are an alternative cognitive entity that deviates from memory per se.
对于创伤后应激障碍（PTSD）患者来说，创伤记忆的回忆常常表现为侵入性的，与“普通”负面记忆的处理方式有很大的不同。这些记忆特征为推测与创伤记忆相关的独特认知状态的理论提供了依据。然而，迄今为止，很少有实证证据支持这种观点。在这里，我们研究了 PTSD 患者在听描述自己记忆的叙述时的大脑活动。对跨被试语义内容和神经模式的代表性相似性分析显示，叙述类型对海马体的代表有不同的影响：语义相似的悲伤自传记忆在参与者中引起相似的神经反应。相比之下，在同一个人内部，语义相似的创伤记忆没有表现出相似的反应。此外，我们还能够从海马体的多体素模式中解码记忆类型。最后，个体症状严重程度调节了后扣带皮层中创伤性叙述的语义表示。总之，这些发现表明，创伤性记忆是一种与记忆本身不同的替代认知实体。
