Donders Institute for Brain, Cognition and Behaviour, Faculty of Sciences, Radboud University, Nijmegen, The Netherlands.
Department of Neuroscience, Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada.
Nat Rev Neurosci. 2022 Oct;23(10):628-640. doi: 10.1038/s41583-022-00620-6. Epub 2022 Aug 15.
The spontaneous replay of patterns of activity related to past experiences and memories is a striking feature of brain activity, as is the coherent activation of sets of brain areas - particularly those comprising the default mode network (DMN) - during rest. We propose that these two phenomena are strongly intertwined and that their potential functions overlap. In the 'cascaded memory systems model' that we outline here, we hypothesize that the DMN forms the backbone for the propagation of replay, mediating interactions between the hippocampus and the neocortex that enable the consolidation of new memories. The DMN may also independently ignite replay cascades, which support reactivation of older memories or high-level semantic representations. We suggest that transient cortical activations, inducing long-range correlations across the neocortex, are a key mechanism supporting a hierarchy of representations that progresses from simple percepts to semantic representations of causes and, finally, to whole episodes.
大脑活动的一个显著特征是与过去的经验和记忆相关的活动模式的自发回放，在休息时大脑区域的活动也具有一致性，特别是那些包含默认模式网络 (DMN) 的区域。我们提出这两种现象是紧密交织的，它们的潜在功能是重叠的。在我们在这里概述的“级联记忆系统模型”中，我们假设 DMN 为回放的传播形成了主干，介导了海马体和新皮层之间的相互作用，从而实现了新记忆的巩固。DMN 也可能独立引发回放级联，从而支持对旧记忆或高级语义表示的重新激活。我们认为，短暂的皮层激活会在新皮层中产生长程相关性，这是支持从简单感知到因果关系的语义表示，最终到整个事件的表示层次结构的关键机制。
