The role of dreaming in REM and NREM sleep-dependent memory functions

强有力的证据表明，REM和NREM睡眠对离线记忆的改善有不同的贡献，例如，快速眼动睡眠与情绪记忆，非快速眼动睡眠与陈述记忆。尽管最近的研究表明，梦到一项学习任务预示着后来在这项任务上的进步，但还没有研究确定快速眼动和非快速眼动做梦是否与不同的记忆系统有关。尽管有充分的证据表明REM/NREM做梦特征与不同的记忆类型（即，快速眼动期的梦比非快速眼动期的梦在情感上更丰富，而非快速眼动期的梦在本质上更像思考。快速眼动期梦的情感本质特别有趣，因为在学习任务之前、期间或之后（清醒时），仅仅呈现情感刺激就可以改善后来对该任务的记忆--无论情感刺激是积极的还是消极的，或者在概念上与任务无关。以类似的方式，快速眼动期的梦的情绪可以促进对新信息的记忆，这些新信息在时间上很接近的情况下被重新激活。拟议的研究旨在：1）确定关于学习任务的梦是否与该任务的离线改进相关，2）评估REM和NREM梦是否分别与情绪和陈述性记忆任务不同地相关，以及3）测试REM梦情绪的实验强化是否会增强非情绪任务的记忆。健康受试者将参与一系列研究，这些研究使用已知诱导REM和NREM睡眠依赖性记忆效应的方案，并进行修改以包括REM和NREM做梦的标准化评估。在睡眠前进行的学习任务将在第二天重新测试，同时在实验室中监测和量化干预睡眠的夜晚。即使REM/NREM睡眠与学习改善之间的相关性在统计学上被删除，情绪强度和概念内容的梦评级预计与学习的夜间改善有关。这些发现将有助于揭示做梦的功能和更普遍的记忆机制，并可能为改善记忆的策略提供见解。

Strong evidence now shows that REM and NREM sleep contribute differentially to offline improvements in memory, e.g., REM sleep to emotional memory and NREM sleep to declarative memory. And although a recent surge of studies suggests that dreaming about a learning task predicts later improvement on this task, no studies have yet determined if REM and NREM dreaming are implicated in different memory systems. This, despite ample evidence of parallels between REM/NREM dreaming features and different memory types, i.e., REM dreaming is more emotionally rich than NREM dreaming, while the latter is more thoughtlike in nature. The emotional nature of REM dreaming is of particular interest because the mere presentation of emotional stimuli prior to, during, or following a learning task (when awake) improves later memory for that task--regardless of whether the emotional stimuli are positive or negative or conceptually unrelated to the task. In a similar manner, REM dream emotions may facilitate memory for new information that is reactivated in close temporal proximity. The proposed research aims to: 1) determine if dreaming about a learning task is correlated with offline improvement on that task, 2) assess if REM and NREM dreaming are differentially associated with emotional and declarative memory tasks respectively, and 3) test whether the experimental intensification of REM dream emotions will enhance memory for a non-emotional task. Healthy subjects will participate in a series of studies that use protocols known to induce REM and NREM sleep-dependent memory effects, and that are modified to include standardized assessments of REM and NREM dreaming. Learning tasks given before sleep will be retested the next day while the intervening night of sleep is monitored and quantified in the laboratory. Dream ratings of emotional intensity and conceptual content are expected to be associated with overnight improvements in learning, even when correlations between REM/NREM sleep and improvement are statistically removed. Findings will help uncover the functions of dreaming and the mechanisms of memory more generally and may provide insights into strategies for memory improvement.