Episodic integration under stress

压力下的情景整合

• 批准号: 424871835
• 负责人: Professor Dr. Lars Schwabe
• 金额: --
• 依托单位: Arbeitsbereich Kognitionspsychologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/424871835?language=en
• 关键词: Episodic; integration; under; stress

The integration of separate events to episodes is a fundamental process for episodic-autobiographical memory. Recent research shows that this integration is critically mediated by the medial prefrontal cortex (mPFC) and hippocampus, with different subregions of the hippocampus representing episodes at a different degree of abstraction. Both the mPFC and the hippocampus are highly sensitive to stressful events and the hormones and neurotransmitters that are released in response to stressful encounters; stress is thought to reduce the activity in those areas. Whether stress affects the integration of events to episodes and which neural mechanisms are involved in the putative stress effect is completely unknown, despite the considerable implications of this issue, also for applied contexts. We hypothesize that stress impairs the integration of events to episodes and the neural processes supporting this integration, mainly in the mPFC and hippocampus. More specifically, we predict that stress will reduce the hippocampal mismatch-reaction and the hippocampal-prefrontal reorganization after insight into the relationship of previously unrelated episodes. Furthermore, we assume a stress-induced decrease in the hierarchical representation of episodic relationships along the hippocampal long axis. These stress-induced changes should result in impaired memory for the encoded episodes and their relationships after one week. In order to test these hypotheses, healthy volunteers will be exposed to a stressor or a control manipulation before they complete, in a MRI scanner, a task that probes episodic integration processes. The successful integration is tested immediately after the task as well as one week later. Beyond their crucial relevance for our understanding of episodic-autobiographical memory in general, the findings of this project might have important implications for stress-related mental disorders, such as post-traumatic stress disorder, in which disintegrated and fragmented memories for events encoded under high stress conditions are very common.

独立事件与情节的整合是情景自传体记忆的基本过程。最近的研究表明，这种整合是由内侧前额叶皮层（mPFC）和海马体介导的，海马体的不同亚区代表不同程度的抽象事件。mPFC和海马体对压力事件以及在遇到压力时释放的激素和神经递质都高度敏感；压力被认为会减少这些区域的活动。应激是否影响事件到情节的整合，以及哪些神经机制参与了假定的应激效应，这是完全未知的，尽管这个问题具有相当大的意义，也适用于应用环境。我们假设压力损害了事件到情节的整合以及支持这种整合的神经过程，主要是在mPFC和海马体中。更具体地说，我们预测，在了解之前不相关事件的关系后，压力会减少海马错配反应和海马-前额叶重组。此外，我们假设压力导致海马长轴上情景关系的等级表征减少。这些压力引起的变化会在一周后导致对编码事件及其关系的记忆受损。为了验证这些假设，健康的志愿者将在完成一项探测情景整合过程的任务之前，在MRI扫描仪中暴露于压力源或控制操作。成功的集成将在任务完成后立即以及一周后进行测试。除了它们对我们理解情节自传式记忆的重要意义之外，这个项目的发现可能对与压力相关的精神障碍有重要的意义，比如创伤后应激障碍，在这种疾病中，在高压力条件下编码的事件的分裂和碎片记忆非常常见。