A Neural State-Space for Episodic Memories

Episodic memories are highly dynamic and change in non-linear ways over time. This dynamism isn’t captured by existing systems consolidation theories that predict a unidirectional process where memories are first supported by the hippocampus and then the neocortex. I propose a three-dimensional state-space for episodic memories. The first two dimensions relate to whether episodic retrieval is driven by the hippocampus and the neocortex, critically allowing for independent and additive contributions from both regions. The third dimension relates to the episodic-specificity of retrieval. Memories can be located at any point in this state-space and move to any other location. The state-space captures the dynamic nature of episodic memory and broadens the search space of possible memory states and transformations across time.