Data from: Hippocampal replay of experience at real-world speeds

Representations related to past experiences play a critical role in memory
and decision-making processes. The rat hippocampus expresses these types
of representations during sharp-wave ripple (SWR) events, and previous
work identified a minority of SWRs that contain “replay” of spatial
trajectories at ~20x the movement speed of the animal. Efforts to
understand replay typically make multiple assumptions about which events
to examine and what sorts of representations constitute replay. We
therefore lack a clear understanding of both the prevalence and the range
of representational dynamics associated with replay. Here we develop a
state space model that uses a combination of movement dynamics of
different speeds to capture the spatial content and time evolution of
replay during SWRs. Using this model, we find that the large majority of
replay events contain spatially coherent, interpretable content.
Furthermore, many events progress at real-world, rather than accelerated,
movement speeds, consistent with actual experiences.