Department of Psychiatry, Harvard Medical School, Boston, MA, United States; Centre for Sleep and Cognition, Beth Israel Deaconess Medical Center, Boston, MA, United States; Department of Psychology and Neuroscience, Boston College, Chestnut Hill, MA, United States.
Department of Psychology, University of Notre Dame, Notre Dame, IN, United States(1).
Neurobiol Learn Mem. 2021 Apr;180:107411. doi: 10.1016/j.nlm.2021.107411. Epub 2021 Feb 17.
Emotional experiences create durable memory traces in the brain, especially when these memories are consolidated in the presence of stress hormones such as cortisol. Although some research suggests cortisol elevation can increase long-term memory for emotional relative to neutral content, the impact of stress and cortisol on the consolidation of emotional and neutral aspects of memories when they are part of the same experience remains unknown. Here, after encoding complex scenes consisting of negative or neutral objects placed on neutral backgrounds, participants were exposed to a psychosocial stressor (or matched control condition) in order to examine the impact of stress and cortisol on early consolidation processes. The next day, once cortisol levels had returned to baseline, specific and gist recognition memory were tested separately for objects and backgrounds. Results indicate that while there was a numerical increase in memory for negative objects in the stress group, higher endogenous cortisol concentrations were specifically associated with decreased memory for the neutral backgrounds originally paired with negative objects. Moreover, across all participants, cortisol levels were positively correlated with the magnitude of the emotional memory trade-off effect. Specifically, while memory for negative objects was preserved, elevated cortisol during early consolidation was associated with decreased memory for neutral backgrounds that were initially paired with negative objects. These memory effects were observed in both the stricter specific measure of memory and the less conservative measure of gist memory. Together, these findings suggest that rather than influencing all aspects of an experience similarly, elevated cortisol during early consolidation selectively preserves what is most emotionally salient and adaptive to remember while allowing the loss of memory for less important neutral information over time.
情绪体验会在大脑中产生持久的记忆痕迹，尤其是当这些记忆在应激激素（如皮质醇）存在的情况下得到巩固时。尽管一些研究表明，皮质醇水平升高可以增加情绪相对于中性内容的长期记忆，但当情绪和中性方面的记忆作为同一体验的一部分时，应激和皮质醇对它们的巩固的影响仍不清楚。在这里，在对由放置在中性背景上的负面或中性物体组成的复杂场景进行编码后，参与者接受了心理社会应激源（或匹配的对照条件）的暴露，以检查应激和皮质醇对早期巩固过程的影响。第二天，一旦皮质醇水平恢复到基线，就分别对物体和背景进行特定和主旨识别记忆测试。结果表明，尽管应激组对负面物体的记忆有数值上的增加，但内源性皮质醇浓度较高与最初与负面物体配对的中性背景的记忆减少有关。此外，在所有参与者中，皮质醇水平与情绪记忆权衡效应的幅度呈正相关。具体来说，虽然负面物体的记忆得到了保留，但在早期巩固过程中皮质醇水平升高与最初与负面物体配对的中性背景的记忆减少有关。这些记忆效应在记忆的严格特定测量和主旨记忆的不太保守测量中都有观察到。总之，这些发现表明，在早期巩固过程中升高的皮质醇并没有同等地影响体验的各个方面，而是选择性地保留了最具情绪显著性和适应性的记忆，同时随着时间的推移允许对不太重要的中性信息的记忆丧失。
