Rem Rebound

Most people have a sleep pattern more or less like this. Each of these cycles will take, you know, somewhere from 90 minutes through maybe to 60 minutes at the very end of the night. And so one might pass through four or five or so of these cycles over the course of the night of a full eight hours sleep. One interesting phenomenon that's associated with this is a phenomenon called rem rebound. It seems that the body catches up not only on sort of sleep, but it disproportionately catches up on rem sleep as well.