Center for Healthy Minds, University of Wisconsin-Madison, USA.
Center for Healthy Minds, University of Wisconsin-Madison, USA.
Neurobiol Learn Mem. 2022 Sep;193:107648. doi: 10.1016/j.nlm.2022.107648. Epub 2022 Jun 6.
Previous research has demonstrated hippocampal alterations in individuals experiencing elevated stress. The Mnemonic Similarity Task (MST) is a hippocampal-dependent task sensitive to age-related hippocampal decline, but it is unknown how performance on this task is related to one's experience of daily stress. We conducted separate discovery and replication analyses in 510 participants who completed the MST across four different Mechanical Turk studies. We hypothesized that higher scores on the Perceived Stress Scale would be associated with poorer discrimination of "lure" items from previously seen targets - a behavioral index of pattern separation - but not with recognition memory. The zero-order relationship between perceived stress and lure discrimination was not significant in the discovery or replication sample. Exploratory analyses involving anhedonic depression symptoms (from the Mood and Anxiety Symptoms Questionnaire) revealed a robust perceived stress*anhedonic depression interaction in the discovery sample that was confirmed in the replication sample. In both samples, individuals with low but not high anhedonic depression symptoms showed an inverse association between perceived stress and lure discrimination ability. Contrary to hypotheses, a similar interaction was observed for recognition memory. The novel association between perceived stress and behavioral pattern separation suggests a candidate behavioral process associated with stress-related hippocampal deficits. The specificity of this effect for individuals with low anhedonic depression symptoms - and the lack of behavioral specificity - highlight the need for additional research to unpack the clinical and neurobiological significance of these findings.
先前的研究表明，经历压力升高的个体的海马体发生了改变。记忆相似任务（MST）是一种依赖于海马体的任务，对与年龄相关的海马体衰退敏感，但尚不清楚该任务的表现与个体日常压力体验之间的关系。我们在 510 名参与者中进行了单独的发现和复制分析，这些参与者在四个不同的 Mechanical Turk 研究中完成了 MST。我们假设，感知压力量表上的得分较高与从先前看到的目标中区分“诱饵”项目的能力较差有关——这是模式分离的行为指标——但与识别记忆无关。在发现或复制样本中，感知压力与诱饵区分之间的零阶关系不显著。涉及快感缺失抑郁症状（来自情绪和焦虑症状问卷）的探索性分析在发现样本中显示出强烈的感知压力*快感缺失抑郁相互作用，在复制样本中得到了证实。在两个样本中，低快感缺失抑郁症状而不是高快感缺失抑郁症状的个体表现出感知压力与诱饵区分能力之间的反向关联。与假设相反，对于识别记忆也观察到了类似的相互作用。感知压力与行为模式分离之间的新关联表明，这是一种与应激相关的海马体缺陷相关的候选行为过程。这种效应对于低快感缺失抑郁症状个体的特异性——以及缺乏行为特异性——突出了需要进一步研究来剖析这些发现的临床和神经生物学意义。
