Department of Psychological & Brain Sciences, University of Massachusetts, Amherst, MA, 01003, USA.
Neuroscience & Behavior Program, University of Massachusetts, Amherst, MA, 01003, USA.
Sci Rep. 2022 May 4;12(1):7307. doi: 10.1038/s41598-022-11135-6.
Consolidated memories can be returned to a labile state upon reactivation. The re-stabilization of reactivated memories, or reconsolidation, can allow for change in previously established memories. Given the role of sleep in the initial consolidation of memories, sleep may be important for reconsolidation as well. However, effects of sleep on reconsolidation and specific aspects of sleep that may contribute are unclear. Here, participants learned 30 picture-location pairs. After overnight sleep, initial consolidation was tested. Following either one day (Experiment 1) or one week (Experiment 2), participants were tested again to reactivate their memory and then learned 30 novel picture-location pairs. Control groups (Experiment 1) received no reactivation prior to new learning. Twelve hours later, after daytime wakefulness or overnight sleep, participants completed a final memory test. Sleep participants underwent polysomnography between reactivation and final tests. In Experiment 1, reactivation led to preservation of memory compared to no reactivation. Sleep was associated with less post-reactivation memory decline than waking, with memory preservation positively related to time spent in non-rapid-eye movement sleep. In Experiment 2, sleep was associated with greater post-reactivation memory improvement than waking, with improvement positively related to sigma activity. These results suggest sleep enhances reconsolidation-based strengthening of episodic memories.
巩固的记忆可以在重新激活后回到不稳定状态。重新激活记忆的再稳定，或再巩固，可以允许对先前建立的记忆进行改变。鉴于睡眠在记忆初始巩固中的作用，睡眠对再巩固也可能很重要。然而，睡眠对再巩固的影响以及可能起作用的特定睡眠方面尚不清楚。在这里，参与者学习了 30 个图片-位置对。经过一夜的睡眠，测试了初始巩固。在一天（实验 1）或一周（实验 2）后，参与者再次接受测试以重新激活他们的记忆，然后学习 30 个新的图片-位置对。实验组（实验 1）在新学习之前没有重新激活。12 小时后，在白天清醒或夜间睡眠后，参与者完成了最后一次记忆测试。睡眠组在重新激活和最终测试之间接受了多导睡眠图监测。在实验 1 中，与无重新激活相比，重新激活导致记忆保存。与清醒相比，睡眠与再激活后记忆下降较少有关，记忆保存与非快速眼动睡眠时间呈正相关。在实验 2 中，与清醒相比，睡眠与再激活后记忆改善较多有关，改善与西格玛活动呈正相关。这些结果表明睡眠增强了基于再巩固的情景记忆的强化。
