Department of NEUROFARBA, University of Florence, Florence, Italy.
Department of Psychology, University of Campania L. Vanvitelli, Caserta, Italy.
J Sleep Res. 2023 Oct;32(5):e13896. doi: 10.1111/jsr.13896. Epub 2023 Apr 4.
False memories are a possible by-product of sleep-related memory consolidation processes when delayed testing is performed after a retention interval spent asleep. To date, the effect of a retention period spent asleep or awake on false memories formation has been addressed only in healthy subjects, while neglecting sleep-disordered populations. In the present study, we investigated this effect in 17 insomniacs and 15 good sleepers through the Deese-Roediger-McDermott paradigm. In both groups, the encoding phase was followed by an 8-h retention period spent in polysomnography monitored sleep (S-condition) or wake (WK-condition). We observed that, at free recall, insomniacs produced more false recalls in the WK-condition compared to the S-condition, whereas the good sleepers showed more false recalls in S-condition than in the WK-condition. Moreover, false recalls were higher in good sleepers than in insomniacs in the S-condition. Both groups produced more veridical recalls in the S-condition than in the WK-condition. For recognition, hits (correctly recognised words) were more numerous in the S-condition than in the WK-condition. Our results confirm previous data on sleep-related false memories production in good sleepers. Additionally, they show that, in insomniacs, false memories production is reduced after a sleep relative to remaining awake. These data suggest that false memories formation, reflecting adaptive memory reshaping processes going on during sleep, could occur at awakening as long as the sleep episode is efficient enough. A notable methodological issue was also identified, in that the Deese-Roediger-McDermott paradigm can be useful to investigate sleep-dependent memory processes for false memories only when a more cognitively demanding task is employed (i.e., free-recall instead of recognition tasks).
虚假记忆是睡眠相关记忆巩固过程的一种可能产物，当在睡眠间隔后进行延迟测试时。迄今为止，关于在睡眠或清醒状态下保留期对虚假记忆形成的影响，仅在健康受试者中得到了研究，而忽略了睡眠障碍人群。在本研究中，我们通过 Deese-Roediger-McDermott 范式研究了 17 名失眠症患者和 15 名睡眠良好者的这种影响。在两组中，编码阶段后进行了 8 小时的多导睡眠图监测睡眠（S 条件）或清醒（WK 条件）的保留期。我们观察到，在自由回忆时，与 S 条件相比，失眠症患者在 WK 条件下产生更多的虚假回忆，而睡眠良好者在 S 条件下产生的虚假回忆比 WK 条件下多。此外，在 S 条件下，睡眠良好者的虚假回忆比失眠症患者多。两组在 S 条件下的真实回忆比 WK 条件下多。对于识别，在 S 条件下的命中（正确识别的单词）比 WK 条件下多。我们的结果证实了以前关于睡眠相关虚假记忆在睡眠良好者中产生的研究。此外，它们表明，与保持清醒相比，失眠症患者在睡眠后虚假记忆的产生减少。这些数据表明，虚假记忆的形成，反映了睡眠期间进行的适应性记忆重塑过程，只要睡眠事件足够有效，就可能在觉醒时发生。还确定了一个值得注意的方法学问题，即只有当使用更具认知挑战性的任务（即自由回忆而不是识别任务）时，Deese-Roediger-McDermott 范式才能用于研究睡眠依赖性虚假记忆过程。
