Department of Psychology, University of York, York, UK.
Institute of Cognitive Neuroscience, UCL, London, UK; Institute of Neurology, UCL, London, UK.
Curr Opin Neurobiol. 2021 Apr;67:50-57. doi: 10.1016/j.conb.2020.08.004. Epub 2020 Sep 1.
Rich episodic experiences are represented in a hierarchical manner across a diverse network of brain regions, and as such, the way in which episodes are forgotten is likely to be similarly diverse. Using novel experimental approaches and statistical modelling, recent research has suggested that item-based representations, such as ones related to the colour and shape of an object, fragment over time, whereas higher-order event-based representations may be forgotten in a more 'holistic' uniform manner. We propose a framework that reconciles these findings, where complex episodes are represented in a hierarchical manner, from individual items, to small-scale events, to large-scale episodic narratives. Each level in the hierarchy is represented in distinct brain regions, from the perirhinal cortex, to posterior hippocampus, to anterior hippocampus and ventromedial prefrontal cortex. Critically, forgetting may be underpinned by different mechanisms at each level in the hierarchy, leading to different patterns of behaviour.
丰富的情景体验以分层的方式分布在大脑区域的广泛网络中，因此，情景被遗忘的方式可能也多种多样。最近的研究使用新颖的实验方法和统计建模表明，基于项目的表示形式，例如与物体的颜色和形状有关的表示形式，会随着时间的推移而碎片化，而基于更高阶事件的表示形式可能会以更“整体”的统一方式被遗忘。我们提出了一个框架来协调这些发现，其中复杂的情景体验以分层的方式呈现，从单个项目到小规模事件再到大规模情景叙事。层次结构中的每个级别都由不同的大脑区域表示，从边缘皮层到后海马体，再到前海马体和腹内侧前额叶皮层。至关重要的是，遗忘可能是由层次结构中每个级别不同的机制所支撑的，从而导致不同的行为模式。
