Dreams' roles in learning

To peek into dreams' roles in learning, researchers tested 99 college students with a three-dimensional computer maze task. The subjects were instructed to do their best to navigate through the maze as quickly as possible. After about an hour, the subjects spent the next 90 minutes either taking a nap or sitting quietly (watching videos or just relaxing). The sleep subjects, who were not allowed to go into REM sleep (which has previously been linked to learning and problem solving), reported if they had dreamed and what they had dreamed about, and the awake group periodically told researchers what they were thinking about. Five hours after the first test, all the subjects were tested again.
from:To sleep, perchance to dream--and learn; By Katherine Harmon