Shin JD*, Tang W*, Jadhav SP (2019), “Dynamics of awake hippocampal-prefrontal replay for spatial learning and memory-guided decision making”, Neuron, 104(6), 1110-1125.
This study builds on previous findings about sharp-wave ripples (SWRs) and replay to show how coordinated brain activation in hippocampal-prefrontal circuits during awake replay supports spatial learning and memory-guided decision making. In awake replay, place cells show specific patterns of activity during navigation that can be “replayed” later in forward or reverse order, as if the brain were internally fast-forwarding or rewinding through routes the rats have taken. We tracked this replay process by monitoring brain activity continuously throughout the course of learning, and showed that reverse replay mediates the ability to evaluate past actions leading to reward, in order to learn and form memories. In contrast, forward replay supports the ability to think ahead, and imagine and plan choices that will lead to goals in the future. Coordinated activation in the prefrontal cortex uses these retrospective and prospective replay evaluations to recall specific past experiences to make ongoing decisions.
These findings unify brain mechanisms of past memories and future imagination, which are thought to be linked in the human brain. The involvement of ‘replay’ in memory processes has been observed across many species, including humans, and our study establishes that replay serves as a key neural substrate underlying an internal dialogue across multiple brain regions to support our ability to learn, plan, choose, and imagine.
Featured in a NIMH news article:
“Reading the Brain’s Map: Coordinated Brain Activation Supports Spatial Learning and Decision-Making”.
Featured in a Brandeis news article:
“The neuroscience behind remembering the past and plotting the future.”.
Also, we have some neat replay decoding videos on twitter @Jadhavlab at this link:
Replay Decoding Videos on Twitter.