Details, gist and schema: hippocampal–neocortical interactions underlying recent and remote episodic and spatial memory. (October 2017) - Robin, Jessica
Highlights: The nature of a memory trace, not its age, determines its hippocampal dependence. Remote memories rich in perceptual detail still engage the hippocampus (HPC). Ventromedial prefrontal cortex (vmPFC) represents schemas. Anterior HPC represents the gist of spatial and episodic memories. Posterior HPC and posterior neocortex mediate fine-grained detailed representations. Abstract : Memories are complex and dynamic, continuously transforming with time and experience. In this paper, we review evidence of the neural basis of memory transformation for events and environments with emphasis on the role of hippocampal–neocortical interactions. We argue that memory transformation from detail-rich representations to gist-like and schematic representation is accompanied by corresponding changes in their neural representations. These changes can be captured by a model based on functional differentiation along the long-axis of the hippocampus, and its functional connectivity to related posterior and anterior neocortical structures, especially the ventromedial prefrontal cortex (vmPFC). In particular, we propose that perceptually detailed, highly specific representations are mediated by the posterior hippocampus and neocortex, gist-like representations by the anterior hippocampus, and schematic representations by vmPFC. These representations can co-exist and the degree to which each is utilized is determined by its availability and by task demands.