Sleep as Brain Cleaning: Why Memory Gets Stronger at Night
Over the course of a day, the brain accumulates impressions the way a room accumulates stuff. At night, during deep sleep, it doesn't just rest: it tidies up: it sorts through the day's events and decides what to keep and what to toss. Scientists built a computer model of the brain that learns from a few examples during the day and 'replays' them at night, as if dreaming.