Schechtman Eitan, Antony James W, Lampe Anna, Wilson Brianna J, Norman Kenneth A, Paller Ken A
Department of Psychology, Northwestern University, Evanston, IL, 60208, USA.
Princeton Neuroscience Institute and Department of Psychology, Princeton University, Princeton, NJ, 08544, USA.
Commun Biol. 2021 Jan 4;4(1):25. doi: 10.1038/s42003-020-01512-0.
Memory consolidation involves the reactivation of memory traces during sleep. If different memories are reactivated each night, how much do they interfere with one another? We examined whether reactivating multiple memories incurs a cost to sleep-related benefits by contrasting reactivation of multiple memories versus single memories during sleep. First, participants learned the on-screen location of different objects. Each object was part of a semantically coherent group comprised of either one, two, or six items (e.g., six different cats). During sleep, sounds were unobtrusively presented to reactivate memories for half of the groups (e.g., "meow"). Memory benefits for cued versus non-cued items were independent of the number of items in the group, suggesting that reactivation occurs in a simultaneous and promiscuous manner. Intriguingly, sleep spindles and delta-theta power modulations were sensitive to group size, reflecting the extent of previous learning. Our results demonstrate that multiple memories may be consolidated in parallel without compromising each memory's sleep-related benefit. These findings highlight alternative models for parallel consolidation that should be considered in future studies.
记忆巩固涉及睡眠期间记忆痕迹的重新激活。如果每晚重新激活不同的记忆，它们会在多大程度上相互干扰呢？我们通过对比睡眠期间多个记忆与单个记忆的重新激活情况，研究了重新激活多个记忆是否会对与睡眠相关的益处产生不利影响。首先，参与者学习不同物体在屏幕上的位置。每个物体都是一个语义连贯组的一部分，该组由一个、两个或六个物品组成（例如，六只不同的猫）。在睡眠期间，会以不显眼的方式呈现声音，以重新激活一半组的记忆（例如，“喵”）。线索提示项目与非线索提示项目的记忆益处与组内物品数量无关，这表明重新激活是以同时且杂乱的方式发生的。有趣的是，睡眠纺锤波和δ-θ功率调制对组大小敏感，反映了先前学习的程度。我们的结果表明，多个记忆可以并行巩固，而不会损害每个记忆与睡眠相关的益处。这些发现突出了并行巩固的替代模型，应在未来研究中加以考虑。
