The role of memory strength for processes of sleep-associated memory consolidation

虽然最近的研究结果表明，与睡眠相关的记忆巩固过程可以稳定记忆，但尚不清楚这种巩固是否会随着记忆表征的最基本特征之一（即记忆的初始强度）而变化。这个项目的目的是通过检查记忆强度在记忆巩固中的作用，从行为和神经科学的角度来填补这一经验上的空白。在13个实验中，记忆强度将通过有意和偶然的编码过程来操纵；在配对联想任务和列表学习任务中，有意的力量操作将通过学习诱导强化和检索诱导强化来实现；在列表学习任务中，我们将通过使用不同的定向任务来研究力量的偶然操纵。在行为上，记忆巩固的效果将通过时间依赖性遗忘和记忆干扰敏感性的研究来衡量。在神经方面，脑电图（EEG）将用于研究编码强度的操作如何改变编码后以及12小时睡眠或清醒后初始记忆形成和变化检索加工的神经相关。此外，睡眠脑电图将被用于研究被认为直接参与新形成记忆的再激活和重组的睡眠机制。这一结果将为记忆强度在与睡眠相关的记忆巩固中所起的作用提供第一个全面的图景。

While recent findings demonstrate that processes of sleep-associated memory consolidation can stabilize memories, it is unclear whether such consolidation varies with one of the most basic features of memory representations, i.e., memories’ initial strength. The aim of this project is to fill this empirical gap by examining the role of memory strength for memory consolidation, behaviorally and neuroscientifically. Across 13 experiments, memory strength will be manipulated using intentional and incidental encoding procedures; intentional manipulations of strength will be examined in the paired associate task and the list learning task and will be implemented by study-induced and retrieval-induced strengthening; incidental manipulations of strength will be investigated in the list learning task by using different orienting tasks. Behaviorally, effects of memory consolidation will be measured via investigations of time-dependent forgetting and memories’ interference susceptibility. Neuronally, electroencephalography (EEG) will be used to study how manipulations of encoding strength change the neural correlates of initial memory formation and change retrieval processing right after encoding as well as following 12 hours of sleep or wakefulness. In addition, sleep EEG will be employed to examine sleep mechanisms believed to be directly involved in the reactivation and restructuring of newly formed memories. The results will provide a first overall picture on the role of memory strength for sleep-associated memory consolidation.