A daytime nap with REM sleep is linked to enhanced generalization of emotional stimuli REM sleep and the generalization of emotional stimuli

How memory representations are shaped during and after their encoding is a central question in the study of human memory. Recognition responses to stimuli that are similar to those observed previously can hint at the fidelity of the memories or point to processes of generalization at the expense of precise memory representations. Experimental studies utilizing this approach showed that emotions and sleep both influence these responses. Sleep and more specifically REM sleep, is assumed to facilitate the generalization of emotional memories. We studied mnemonic discrimination by the emotional variant of the Mnemonic Separation Task (MST) in participants (N = 113) who spent a daytime nap between learning and testing compared to another group that spent an equivalent time awake between the two sessions. Our findings indicate that the discrimination of similar but previously not seen items from previously seen ones is enhanced in case of negative compared to neutral and positive stimuli. Moreover, whereas the sleep and the wake groups did not differ in memory performance, participants entering REM sleep exhibited increased generalization of emotional memories. Our findings indicate that entering into REM sleep during a daytime nap shapes emotional memories in a way that enhances recognition at the expense of detailed memory representations. This work was supported by the Hungarian National Research, Development and Innovation Office Grant NKFI FK 142945. PS and ÁS were supported by the Bolyai János Research Scholarship of the Hungarian Academy of Sciences. notReviewed other

人类记忆表征在编码过程中及编码后如何被塑造，是人类记忆研究的核心议题。对与先前呈现刺激相似的新异刺激的识别反应，既可反映记忆的保真度，也可体现以牺牲精确记忆表征为代价的记忆泛化过程。采用该范式开展的实验研究表明，情绪与睡眠均会对这类识别反应产生影响。睡眠，尤其是快速眼动（REM）睡眠，被认为可促进情绪性记忆的泛化。本研究采用情绪版记忆分离任务（Mnemonic Separation Task, MST），招募113名被试开展记忆辨别实验：其中一组在学习与测试阶段间进行日间小睡，另一组则在相同时长内保持清醒状态。结果显示，相较于中性与正性刺激，被试对负性相似新异刺激与先前呈现刺激的辨别能力显著更强。此外，尽管小睡组与清醒组的整体记忆表现无显著差异，但进入快速眼动睡眠的被试，其情绪性记忆的泛化程度有所提升。本研究结果表明，日间小睡期间进入快速眼动睡眠，会以牺牲精细记忆表征为代价，增强对情绪性记忆的识别能力，从而重塑情绪性记忆。本研究受匈牙利国家研究、发展与创新办公室NKFI FK 142945号项目资助。PS与ÁS获匈牙利科学院博莱伊·亚诺什研究奖学金支持。其余内容未审核。