Our brains don’t shut down when we go to sleep. Turns out, all three types of memory–declarative (fact-based info), episodic (life events), and procedural–are strengthened during sleep. Tests done on each type reveal that people who learn something and sleep for several hours have a better chance of remembering it later. A much better chance.
Evidently, it is during sleep that the two memory systems in the brain–the hippocampus and the neocortex–talk to each other. When we learn something, it sit sin the hippocampus. If it’s something that will be retained, it moves over the neocortex. When we sleep, the hippocampus is not distracted by the new things going on, so it can focus on moving things out to the neocortex.
But sleep also makes connections between facts already in memory. That damned table of elements was apparently the result of this: Dimitri Mendeleev, its creator, came up with the idea right after waking up from a dream.
The article states that researchers believe that for every two hours of being awake, the brain needs one hour to process what has happened during that time.