Heinbockel Hendrik, Quaedflieg Conny W E M, Schneider Till R, Engel Andreas K, Schwabe Lars
Department of Cognitive Psychology, Universität Hamburg, 20146, Hamburg, Germany.
Department of Neuropsychology and Psychopharmacology, Maastricht University, Maastricht, 6229 ER, the Netherlands.
Neurobiol Stress. 2021 Aug 21;15:100383. doi: 10.1016/j.ynstr.2021.100383. eCollection 2021 Nov.
Stressful events impact memory formation, in particular for emotionally arousing stimuli. Although these stress effects on emotional memory formation have potentially far-reaching implications, the underlying neural mechanisms are not fully understood. Specifically, the temporal processing dimension of the mechanisms involved in emotional memory formation under stress remains elusive. Here, we used magnetoencephalography (MEG) to examine the neural processes underlying stress effects on emotional memory formation with high temporal and spatial resolution and a particular focus on theta oscillations previously implicated in mnemonic binding. Healthy participants (n = 53) underwent a stress or control procedure before encoding emotionally neutral and negative pictures, while MEG was recorded. Memory for the pictures was probed in a recognition test 24 h after encoding. In this recognition test, stress did not modulate the emotional memory enhancement but led to significantly higher confidence in memory for negative compared to neutral stimuli. Our neural data revealed that stress increased memory-related theta oscillations specifically in medial temporal and occipito-parietal regions. Further, this stress-related increase in theta power emerged during memory formation for emotionally negative but not for neutral stimuli. These findings indicate that acute stress can enhance, in the medial temporal lobe, oscillations at a frequency that is ideally suited to bind the elements of an ongoing emotional episode, which may represent a mechanism to facilitate the storage of emotionally salient events that occurred in the context of a stressful encounter.
应激事件会影响记忆形成，尤其是对引起情绪波动的刺激而言。尽管这些应激对情绪记忆形成的影响可能具有深远意义，但其潜在的神经机制尚未完全明确。具体来说，应激状态下情绪记忆形成所涉及机制的时间加工维度仍不清楚。在此，我们使用脑磁图（MEG）以高时间和空间分辨率研究应激对情绪记忆形成影响的神经过程，并特别关注先前与记忆绑定有关的θ振荡。健康参与者（n = 53）在对情绪中性和负面图片进行编码之前接受了应激或对照程序，同时记录MEG。在编码24小时后的识别测试中探测对图片的记忆。在该识别测试中，应激并未调节情绪记忆增强，但与中性刺激相比，应激导致对负面刺激的记忆信心显著更高。我们的神经数据显示，应激特别在内侧颞叶和枕顶叶区域增加了与记忆相关的θ振荡。此外，这种与应激相关的θ功率增加出现在对情绪负面而非中性刺激的记忆形成过程中。这些发现表明，急性应激可在内侧颞叶增强一种频率的振荡，该频率非常适合绑定正在进行的情绪事件的元素，这可能代表一种促进存储在应激遭遇背景下发生的情绪突出事件的机制。
