EVANSTON, Ill., June 25 (UPI) -- A musical tune someone has been practicing can become better fixed in their memory if it is played to them while they sleep, U.S. researchers say.
The study builds on existing evidence suggesting memories can be reactivated during sleep and storage of them can be strengthened in the process, Northwestern University reported Sunday.
In the study, research learned how to play two artificially generated musical tunes requiring well-timed key presses. Then while the participants took a 90-minute nap, the researchers played one of the tunes that had been practiced, but not the other.
Afterward, participants made fewer errors when pressing the keys to produce the melody that had been presented while they slept, compared with the melody not presented, researchers said.
"Our results extend prior research by showing that external stimulation during sleep can influence a complex skill," Northwestern psychology Professor Ken A. Paller said.
That doesn't mean you can learn something like a foreign language while you sleep, researchers cautioned.
"The critical difference is that our research shows that memory is strengthened for something you've already learned," study co-author Paul J. Reber said. "Rather than learning something new in your sleep, we're talking about enhancing an existing memory by re-activating information recently acquired."
However, Reber said, "If you were learning how to speak in a foreign language during the day, for example, and then tried to reactivate those memories during sleep, perhaps you might enhance your learning."