Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Manchester M13 9PL, United Kingdom, and Department of Psychology, Royal Holloway, University of London, Egham TW20 0EX, United Kingdom.
J Neurosci. 2013 Sep 25;33(39):15376-81. doi: 10.1523/JNEUROSCI.5093-12.2013.
Assimilating new information into existing knowledge is a fundamental part of consolidating new memories and allowing them to guide behavior optimally and is vital for conceptual knowledge (semantic memory), which is accrued over many years. Sleep is important for memory consolidation, but its impact upon assimilation of new information into existing semantic knowledge has received minimal examination. Here, we examined the integration process by training human participants on novel words with meanings that fell into densely or sparsely populated areas of semantic memory in two separate sessions. Overnight sleep was polysomnographically monitored after each training session and recall was tested immediately after training, after a night of sleep, and 1 week later. Results showed that participants learned equal numbers of both word types, thus equating amount and difficulty of learning across the conditions. Measures of word recognition speed showed a disadvantage for novel words in dense semantic neighborhoods, presumably due to interference from many semantically related concepts, suggesting that the novel words had been successfully integrated into semantic memory. Most critically, semantic neighborhood density influenced sleep architecture, with participants exhibiting more sleep spindles and slow-wave activity after learning the sparse compared with the dense neighborhood words. These findings provide the first evidence that spindles and slow-wave activity mediate integration of new information into existing semantic networks.
将新信息整合到现有知识中是巩固新记忆并使其能够最佳地指导行为的基础，对于概念知识（语义记忆）至关重要，概念知识是多年来积累的。睡眠对记忆巩固很重要，但它对新信息融入现有语义知识的影响却很少受到关注。在这里，我们通过在两个单独的会话中对具有语义记忆中密集或稀疏区域含义的新词进行训练，来研究整合过程。在每次训练后，整夜睡眠均进行多导睡眠图监测，并在训练后立即、睡眠一夜后和一周后进行回忆测试。结果表明，参与者学习了两种类型的单词数量相等，从而使条件下的学习量和难度均等。单词识别速度的测量表明，在密集语义邻域中的新词具有劣势，这可能是由于许多语义相关概念的干扰，这表明新词已成功地融入了语义记忆。最重要的是，语义邻域密度影响睡眠结构，与学习密集邻域单词相比，参与者在学习稀疏邻域单词后表现出更多的睡眠纺锤波和慢波活动。这些发现首次提供了证据表明，纺锤波和慢波活动介导了新信息融入现有语义网络的过程。
