Together with Ignacio Polti and Christian Doeller, I have written a review on sequence memory in the hippocampus and entorhinal cortex. It’s now out in the Journal of Cognitive Neuroscience.
Sequences of events unfolding in time form the basis of episodic memory. In our review, we describe how the human brain supports such sequence memories. We summarize the central role of the hippocampus in the formation and retrieval of sequence memories. Further, we incorporate recent evidence about the role of the adjacent entorhinal cortex in temporal processing. The rodent lateral entorhinal cortex carries temporal information during ongoing behavior, which could be well-suited to underlie episodic memory of unique event sequences. Consistently, its human homologue region, the anterior-lateral entorhinal cortex, has recently been implicated in sequence memory recall: Increased univariate activity related to precise recall of when events took place and similarity analyses of multi-voxel patterns demonstrate that activity profiles of the anterior-lateral entorhinal cortex reflect temporal relationships between the elements of an event sequence. Thus, these findings allow us to take a new perspective on how the hippocampal-entorhinal region subserves sequence memory. Furthermore, we introduce the idea of temporal scaling – the flexible adaptation of the speed at which a sequence is traversed – to episodic memory. Inspired by studies of sensory and motor timing, which have uncovered cellular and network mechanisms underlying such temporal computations in different brain regions, we suggest that temporal scaling of event sequences in the hippocampal-entorhinal region could support episodic memory and mental simulation.
JLS Bellmund, I Polti, CF Doeller (2020). Sequence memory in the hippocampal-entorhinal region. Journal Of Cognitive Neuroscience.