Barsky Murray M, Morgan Alexandra, Stickgold Robert
Harvard University, Cambridge, MA 02138USA.
Beth Israel Deaconess Medical Center, Boston, MA 02215USA.
Sleep Adv. 2025 May 24;6(2):zpaf035. doi: 10.1093/sleepadvances/zpaf035. eCollection 2025 Apr.
In a dynamic process that ultimately affords memories their persistence, memory reconsolidation can serve to strengthen associations following reactivation, particularly in sleep, where active processes may effect overnight enhancement. Reactivation can also occur in wake, where improvement would be unexpected. In an earlier study using performance on the Weather Prediction Task (WPT) as a measure of probabilistic category learning, we looked at the effect of sleep and found significant improvement after a daytime nap, where improvement correlated with the amount of REM sleep obtained. When we introduced interference training following sleep, this REM sleep benefit vanished: post-learning task memory was otherwise preserved. Here, we follow up on these results and test whether reactivation itself-wake reactivation-might be sufficient to induce the improvement found after REM sleep. Our results show that it is not: we saw no improvement on the WPT following reactivation in wake, suggesting sleep may be unique in supporting memory improvement. When we looked at interference effects, we saw unexplained differences between wake and sleep that suggest that while interference is uniformly destabilizing of WPT memories during wake, interference after REM show effects on the memory trace formed during initial learning that are distinctly different from its effects on the subsequently sleep-enhanced memory.
在一个最终赋予记忆持久性的动态过程中，记忆再巩固可用于在重新激活后强化关联，尤其是在睡眠中，活跃过程可能会导致夜间记忆增强。重新激活也可能发生在清醒状态下，而在这种情况下出现记忆改善是出乎意料的。在一项早期研究中，我们以天气预报任务（WPT）的表现作为概率类别学习的衡量标准，研究了睡眠的影响，发现白天小睡后有显著改善，且这种改善与快速眼动睡眠（REM）的时长相关。当我们在睡眠后引入干扰训练时，这种REM睡眠的益处消失了：学习后任务记忆在其他方面得以保留。在此，我们对这些结果进行跟进，测试重新激活本身——清醒状态下的重新激活——是否足以引发在REM睡眠后发现的记忆改善。我们的结果表明并非如此：在清醒状态下重新激活后，我们在WPT上未看到改善，这表明睡眠在支持记忆改善方面可能具有独特性。当我们研究干扰效应时，我们发现清醒和睡眠状态下存在无法解释的差异，这表明虽然干扰在清醒状态下会一致地破坏WPT记忆的稳定性，但REM睡眠后的干扰对初始学习期间形成的记忆痕迹的影响，与它对随后经睡眠增强的记忆的影响明显不同。
