Beyond phenomenological similarities between episodic memory and egocentric travel, recent work in humans indicates an extensive overlap in the brain networks supporting navigation, remembering the past and thinking about the future52,53. The key properties of episodic memory involve binding disparate and often arbitrary details together into a coherent event and the recollection of self-centered past experiences in the context of time and space in which the events occurred1,14. Characteristically, snippets of cues can trigger a long process of recollection, which is often grouped or chunked into shorter sub-episodes. Although re-experiencing the past appears as a continuous process, we are consciously aware of only short segments of the episodes at any one time, pointing to an important cooperation between structures and mechanisms responsible for long-term storage of declarative knowledge and working memory. Many excellent reviews have summarized the overlapping nature of brain systems involved in navigation, episodic memory, imagination and planning of actions1,10,18,52,53. Below we will discuss the physiological mechanisms that may support these seemingly disparate functions, focusing on self-organized cell assembly sequences, multiple-timescale representation and theta oscillations.
