Plasticity of hippocampal memories in humans

- Hippocampal neurons can rapidly associate to form event engrams.
- Pattern separation at encoding decreases interference between engrams.
- Pattern completion allows for the retrieval of an entire event.
- The hippocampus is constantly encoding and altering engrams.
- The plasticity and malleability of engrams is critical to supporting future decisions.

The human hippocampus is a brain region that supports episodic and spatial memory. Recent experiments have drawn on animal research and computational modelling to reveal how the unique computations and representations of the hippocampus support episodic and spatial memory. Invasive electrophysiological recordings and non-invasive functional brain imaging have provided evidence for the rapid formation of hippocampal representations, as well as the ability of the hippocampus to both pattern-separate and pattern-complete input from the neocortex. Further, recent evidence has shown that hippocampal representations are in constant flux, undergoing a continual process of strengthening, weakening and altering. This research offers a glimpse into the highly plastic and flexible nature of the human hippocampal system in relation to episodic memory.