Sound cues during lucid dreams helped sleepers solve puzzles the next day
When you solve a riddle, the answer might be in your dreams.
In a study of lucid dreamers, playing soundtracks related to unsolved puzzles helped sleepers solve problems the next daythe researchers report on February 5 in Neuroscience of Consciousness.
Stories of brilliant discoveries after a nap or daydream abound, but scientists have struggled to successfully influence people’s dreams and rigorously test the idea. “This study provides one of the first experimental demonstrations of such a link,” says Giulio Bernardi, a cognitive neuroscientist at the IMT School for Advanced Studies in Lucca, Italy, who was not involved in the work.
Whether we remember our dreams or not, we have countless dreams while we sleep, according to Karen Konkoly, a cognitive neuroscientist who led the study at Northwestern University in Evanston, Illinois. “Your dreams are such an important part of your inner life,” she says.
And in the right circumstances, manipulating these dreams could help people look at problems from a new perspective.
While some scientists have shown that sleeping through a problem increases the chances of solving it the next day, others have shown no benefit. Of course, this can only be helpful if you actually think about the problem in your sleep.
Konkoly and his colleagues were particularly interested in helping sleepers think about specific topics using targeted memory reactivation, or TMR. “It’s this search technique where you have a sensory stimulus associated with a memory,” Konkoly explains. “It can be a very soft sound or smell presented to a sleeper, and it functions to remind the sleeping brain of the complete memory.” While people dream at every stage of sleep, the effects of TMR were strongest in deep, slow-wave sleep, she says. Konkoly wanted to examine the effects of TMR at a different stage of sleep – rapid eye movement sleepwhich could be useful for creative thinking.
She and her colleagues recruited 20 volunteers who could lucid dream — where someone realize they are dreamingand can even potentially change the dream as they dream it.
Participants were given a series of puzzles to solve, some they could solve, and some they couldn’t. Each was accompanied by a specific soundtrack unrelated to the task itself, such as a brief extract of instrumental music. The scientists then connected the participants to electrodes to monitor their sleep and put them to bed.
At 4 a.m., participants were awakened and encouraged to lucid dream as they went back to sleep. Next, the scientists began playing sounds associated with the puzzles the participants couldn’t solve, asking them to sniff to indicate that they were working on the puzzles while they slept. The next morning, 75 percent of the sleepers reported dreaming about the unsolved puzzles, although participants were only able to lucidly dream about the problems nine times.
Sleepers who heard the beeps while sleeping and dreamed the puzzles—even if they didn’t lucid dream—solved the puzzles they dreamed about 42 percent of the time, while those who didn’t dream the suggested puzzles solved them only 17 percent of the time.
Although the effects are modest, the idea of hacking your dreams to increase productivity and solve problems might tempt some people. But that’s not why Konkoly is doing this research. “I don’t think all of our dreams should be corrupted in favor of creative solutions to problems,” she says. “I want people to value dreams more,” for their own sake, as disjointed reflections of our inner lives and experiences.
