Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary; Department of Psychology, University of Cambridge, Cambridge, United Kingdom.
Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary; Centre of Thinking and Learning, Institute for Lifecourse Development, School of Human Sciences, University of Greenwich, London, United Kingdom.
Cortex. 2024 Oct;179:168-190. doi: 10.1016/j.cortex.2024.07.008. Epub 2024 Aug 14.
Spontaneous reactivation of brain activity from learning to a subsequent off-line period has been implicated as a neural mechanism underlying memory consolidation. However, similarities in brain activity may also emerge as a result of individual, trait-like characteristics. Here, we introduced a novel approach for analyzing continuous electroencephalography (EEG) data to investigate learning-induced changes as well as trait-like characteristics in brain activity underlying memory consolidation. Thirty-one healthy young adults performed a learning task, and their performance was retested after a short (∼1 h) delay. Consolidation of two distinct types of information (serial-order and probability) embedded in the task were tested to reveal similarities in functional networks that uniquely predict the changes in the respective memory performance. EEG was recorded during learning and pre- and post-learning rest periods. To investigate brain activity associated with consolidation, we quantified similarities in EEG functional connectivity between learning and pre-learning rest (baseline similarity) and learning and post-learning rest (post-learning similarity). While comparable patterns of these two could indicate trait-like similarities, changes from baseline to post-learning similarity could indicate learning-induced changes, possibly spontaneous reactivation. Higher learning-induced changes in alpha frequency connectivity (8.5-9.5 Hz) were associated with better consolidation of serial-order information, particularly for long-range connections across central and parietal sites. The consolidation of probability information was associated with learning-induced changes in delta frequency connectivity (2.5-3 Hz) specifically for more local, short-range connections. Furthermore, there was a substantial overlap between the baseline and post-learning similarities and their associations with consolidation performance, suggesting robust (trait-like) differences in functional connectivity networks underlying memory processes.
大脑活动从学习到随后的离线期的自发再激活被认为是记忆巩固的神经机制。然而，个体特质相似的特征也可能导致大脑活动相似。在这里，我们引入了一种新的方法来分析连续脑电图（EEG）数据，以研究记忆巩固过程中学习诱导的变化以及大脑活动的特质特征。31 名健康的年轻成年人执行了一项学习任务，然后在短暂（约 1 小时）延迟后对他们的表现进行了重新测试。在任务中嵌入了两种不同类型的信息（序列顺序和概率），以测试巩固的相似性，以揭示独特预测各自记忆表现变化的功能网络中的相似性。在学习和学习前及学习后休息期间记录脑电图。为了研究与巩固相关的大脑活动，我们量化了学习和学习前休息（基线相似性）以及学习和学习后休息（学习后相似性）之间脑电图功能连接的相似性。如果这两种相似性的模式相似，则表明存在个体特质相似性；如果从基线到学习后相似性的变化，则表明存在学习诱导的变化，可能是自发再激活。α 频带连接（8.5-9.5 Hz）的学习诱导变化与序列顺序信息的更好巩固相关，特别是对于中央和顶叶部位之间的远程连接。概率信息的巩固与 delta 频带连接（2.5-3 Hz）的学习诱导变化相关，特别是对于更局部、短程的连接。此外，基线和学习后相似性及其与巩固表现的关联之间存在很大的重叠，这表明记忆过程的功能连接网络存在显著的（特质相似）差异。
