Dreaming makes perfect

By Stephen Ornes

Dreams can be familiar and strange, fantastical or boring. No one knows for certain why people dream, but some dreams might be connected to the mental processes that help us learn. In a recent study, scientists found a connection between nap-time dreams and better memory in people who were learning a new skill.

So perhaps one way to learn something new is to practice, practice, practice — and then sleep on it. (Warning: This research still doesn’t provide an excuse for falling asleep during class.)

“I was startled by this finding,” Robert Stickgold told Science News. He is a cognitive neuroscientist at Harvard Medical School who worked on the study. Neuroscience is the study of how the brain and nervous system work, and cognitive studies look at how people learn and reason. So a cognitive neuroscientist may study the brain processes that help people learn.

Volunteers who dreamed about a new task showed significant improvement in skill.

kodachrome25 / iStockphoto

In the study, 99 college students between the ages of 18 and 30 each spent an hour on a computer, trying to get through a virtual maze. The maze was difficult, and the study participants had to start in a different place each time they tried — making it even more difficult. They were also told to find a particular picture of a tree and remember where it was.

For the first 90 minutes of a five-hour break, half of the participants stayed awake and half were told to take a short nap. Participants who stayed awake were asked to describe their thoughts. Participants who took a nap were asked about their dreams before sleep and after sleep — and they were awakened within a minute of sleep to describe their dreams.

Stickgold and his colleagues wanted to know about NREM, or non-REM sleep. REM stands for “rapid eye movement,” which is what happens during REM sleep. This period of sleep often brings bizarre dreams to a sleeper, although dreams can happen in both modes of sleep. Stickgold wanted to know what people were dreaming about when their eyes weren’t moving, during NREM sleep. In other studies, scientists had found a connection between NREM brain activity and learning ability in rats and in people.

Four of the 50 people who slept said their dreams were connected to the maze. Some dreamed about the music that had been playing when they were working; others said they dreamed about seeing people in the maze. When these four people tried the computer maze again, they were able to find the tree faster than before their naps.

Stickgold suggests the dream itself doesn’t help a person learn — it’s the other way around. He suspects that the dream was caused by the brain processes associated with learning.

All four of the people who dreamed about the task had done poorly the first time, which makes Stickgold wonder if the NREM dreams show up when a person finds a new task particularly difficult. People who had other dreams, or people who didn’t take a nap, didn’t show the same improvement.

Going Deeper:

Bower, Bruce. 2010. “Dream a little dream of recall,” Science News, April 22. http://www.sciencenews.org/view/generic/id/58525/title/Dream_a_little_dream_of_recall

Gaidos, Susan. 2010. “Making light of sleep,” Science News for Kids, March 3. http://sciencenewsforkids.org/articles/20100303/Feature1.asp

Ornes, Stephen. 2009. “Brain cells take a break,” Science News for Kids, May 27. http://www.sciencenewsforkids.org/articles/20090527/Feature1.asp