“We think what’s happening during sleep is that you open the aperture of memory and are able to see this bigger picture,” said the study’s senior author, Matthew Walker, a neuroscientist who is now at the University of California, Berkeley. He added that many such insights occurred “only when you enter this wonder-world of sleep.”

Keep a copy of this study on your desk, so you can point to it the next time your boss catches you napping in your cube.

An Active, Purposeful Machine That Comes Out at Night to Play