The Role of the Hippocampus in Memory

In the hippocampus you have these neurons that have this sparse code. They're active in particular locations while animals are exploring. When they're asleep or when they stop moving, you get these bursts of activity. And during those periods, if you like zoom in at the spikes, they're not disordered. They're actually often re-activating or replaying the sequence of spikes that happened on a time scale of milliseconds. This replay is what an animal uses to remember that food is in one arm of a maze and not in another arm for example.