Department of Psychology, University of California, San Diego.
Psychol Bull. 2015 Jul;141(4):812-34. doi: 10.1037/bul0000009. Epub 2015 Mar 30.
It is widely believed that sleep is critical to the consolidation of learning and memory. In some skill domains, performance has been shown to improve by 20% or more following sleep, suggesting that sleep enhances learning. However, recent work suggests that those performance gains may be driven by several factors that are unrelated to sleep consolidation, inviting a reconsideration of sleep's theoretical role in the consolidation of procedural memories. Here we report the first comprehensive investigation of that possibility for the case of motor sequence learning. Quantitative meta-analyses involving 34 articles, 88 experimental groups and 1,296 subjects confirmed the empirical pattern of a large performance gain following sleep and a significantly smaller gain following wakefulness. However, the results also confirm strong moderating effects of 4 previously hypothesized variables: averaging in the calculation of prepost gain scores, build-up of reactive inhibition over training, time of testing, and training duration, along with 1 supplemental variable, elderly status. With those variables accounted for, there was no evidence that sleep enhances learning. Thus, the literature speaks against, rather than for, the enhancement hypothesis. Overall there was relatively better performance after sleep than after wakefulness, suggesting that sleep may stabilize memory. That effect, however, was not consistent across different experimental designs. We conclude that sleep does not enhance motor learning and that the role of sleep in the stabilization of memory cannot be conclusively determined based on the literature to date. We discuss challenges and opportunities for the field, make recommendations for improved experimental design, and suggest approaches to data analysis that eliminate confounds due to averaging over online learning. (PsycINFO Database Record
人们普遍认为睡眠对于学习和记忆的巩固至关重要。在某些技能领域，睡眠后表现已经被证明提高了 20%或更多，这表明睡眠可以促进学习。然而，最近的研究表明，这些表现上的提高可能是由几个与睡眠巩固无关的因素驱动的，这使得人们重新考虑睡眠在程序性记忆巩固中的理论作用。在这里，我们报告了第一个针对运动序列学习案例的这种可能性的全面调查。涉及 34 篇文章、88 个实验组和 1296 名被试的定量荟萃分析证实了睡眠后表现显著提高且在清醒后提高较小的经验模式。然而，结果还证实了 4 个先前假设变量的强烈调节作用：在计算预-后增益得分时的平均、训练过程中反应性抑制的积累、测试时间和训练持续时间，以及 1 个补充变量，即年龄。考虑到这些变量后，没有证据表明睡眠可以促进学习。因此，文献支持而不是支持增强假说。总体而言，睡眠后表现相对优于清醒后，这表明睡眠可能稳定记忆。然而，这种效应在不同的实验设计中并不一致。我们得出的结论是，睡眠并没有增强运动学习，而且睡眠在记忆稳定中的作用不能根据迄今为止的文献来确定。我们讨论了该领域面临的挑战和机遇，为改进实验设计提出了建议，并提出了消除在线学习平均产生的混淆的数据分析方法。
