Dept. of Neurology, University of Lübeck, D 23538 Lübeck, Germany.
Biol Psychol. 2011 Mar;86(3):219-29. doi: 10.1016/j.biopsycho.2010.12.002. Epub 2010 Dec 21.
Previous research has indicated that information acquired before sleep gets consolidated during sleep. This process of consolidation might be reflected after sleep in changed extent and topography of cortical activation during retrieval of information. Here, we designed an experiment to measure those changes by means of slow event-related EEG potentials (SPs). Retrieval of newly learnt verbal or spatial associations was tested both immediately after learning and two days later. In the night directly following immediate recall, participants either slept or stayed awake. In line with previous studies, SPs measured during retrieval from memory had parietal or left-frontal foci depending on whether the retrieved associations were spatial or verbal. However, contrary to our expectations, sleep-related consolidation did not further accentuate these content-specific topographic profiles. Rather, sleep modified SPs independently of the spatial or verbal type of learned association: SPs were reduced more after sleep than after waking specifically for those stimulus configurations that had been presented in the same combination at retrieval before sleep. The association-independent stimulus-specific effect might generally form a major component of sleep-related effects on memory.
先前的研究表明，睡眠前获取的信息在睡眠过程中得到巩固。这种巩固过程可能会在睡眠后反映出来，即在信息检索过程中，大脑皮层的激活程度和拓扑结构发生变化。在这里，我们设计了一个实验，通过慢事件相关脑电图电位（SPs）来测量这些变化。在学习后立即和两天后，我们测试了新学习的言语或空间联想的检索。在立即回忆后的当晚，参与者要么睡觉，要么保持清醒。与先前的研究一致，根据检索的联想是空间的还是言语的，在记忆检索过程中测量的 SPs 具有顶叶或左额叶焦点。然而，与我们的预期相反，与睡眠相关的巩固并没有进一步强调这些特定内容的拓扑结构。相反，睡眠独立于空间或言语类型的学习联想来改变 SPs：与睡眠后相比，睡眠后 SPs 减少得更多，特别是对于那些在睡眠前检索时以相同组合呈现的刺激配置。这种与联想无关的刺激特异性效应可能通常是睡眠对记忆影响的主要组成部分。
