Dreaming: Sleeping Your Problems Away

People often credit dreams as founts of creative inspiration, but only now have we acquired experimental evidence that dreaming aids problem-solving.

In a study, people completed analogies, then either napped without dreaming, napped while dreaming, or rested quietly. Afterward, they attempted to solve problems requiring creative associations whose solutions overlapped with the analogies task. Those who'd dreamed made the connection and performed on the problem set better than the other two groups, who performed as if they'd never seen the clues—even though in a memory check all three groups remembered the clues equally well.

In REM sleep, cortical activation spreads from whatever one's been pondering to marshal associated ideas, thanks to changes in levels of the neurotransmitters norepinephrine and acetylcholine, Sara Mednick of UCSD and her collaborators hypothesize.

Co-author Denise Cai suggests dreams might relieve tip-of-the-tongue frustrations: "So many times, we already have the solution somewhere in our brain. It just needs an extra 'boost' before it can be accessed."

Dreams Do Come True

• Art: The idea for Jasper Johns's most famous painting, Flag, came to him after he dreamed about an American flag.
• Science: In 1920, the German pharmacologist Otto Loewi dreamed up an experiment that proved nerve impulses were chemical, netting him a Nobel.
• Sports: Jack Nicklaus once pulled out of a slump by taking notes on how he held the club in a dream.