Most people have heard the advice to “sleep on it” when faced with a tough decision. New research suggests that guidance may be grounded in science. While many people report breakthrough ideas emerging from dreams, researchers have struggled to test this phenomenon because dreams are difficult to control in a lab setting.
A new study from neuroscientists at Northwestern University shows that it is possible to influence what people dream about. The findings support the idea that REM sleep, the rapid eye movement stage of sleep when vivid and sometimes lucid dreams occur, may be especially helpful for creative problem solving.
Using Sound Cues to Shape Dreams
The researchers used a technique called targeted memory reactivation (TMR). During sleep, they played sounds that reminded participants of earlier attempts to solve specific puzzles. These audio cues were delivered only after brain monitoring confirmed that participants were asleep.
As a result, 75% of participants reported dreams that included elements or ideas related to the unsolved puzzles. Puzzles that appeared in dreams were solved at a much higher rate than those that did not. Participants solved 42% of the dream-related puzzles compared to 17% of the others.
Even so, the results do not prove that dreaming directly causes better solutions. Other factors, such as heightened curiosity about certain puzzles, could have influenced both dreaming and performance. Still, successfully guiding dream content marks an important advance in understanding how sleep may support creative thinking.
“Many problems in the world today require creative solutions. By learning more about how our brains are able to think creatively, think anew and generate creative new ideas, we could be closer to solving the problems we want to solve, and sleep engineering could help,” said senior author Ken Paller, the James Padilla Professor of Psychology and director of the cognitive neuroscience program in the Weinberg College of Arts and Sciences at Northwestern.
Inside the REM Sleep Experiment
The study included 20 participants who had prior experience with lucid dreaming, meaning they sometimes realized they were dreaming while still asleep. In the lab, each person attempted to solve a series of brain teaser puzzles, with three minutes allotted per puzzle. Each puzzle was paired with its own distinctive soundtrack. Most puzzles remained unsolved due to their difficulty.
Participants then spent the night in the lab while researchers recorded their brain activity and other physiological signals using polysomnography. During REM sleep, scientists replayed the soundtracks linked to half of the unsolved puzzles to selectively reactivate those memories.
Some participants used prearranged signals, such as specific in and out sniffing patterns, to indicate that they heard the sounds and were actively working on the puzzles within their dreams.
The next morning, participants described their dreams. Many reported imagery or ideas connected to the puzzles. In 12 out of 20 participants, dreams referred more often to the puzzles associated with sound cues than to uncued puzzles. These same participants were more likely to solve the reactivated puzzles after waking, improving their success rate from 20% to 40% — which was significant.
Dreams Respond Even Without Lucidity
Karen Konkoly, the study’s lead author and a postdoctoral researcher in Paller’s Cognitive Neuroscience Laboratory, said one of the biggest surprises was how strongly the cues influenced dreams even when participants were not lucid.
“Even without lucidity, one dreamer asked a dream character for help solving the puzzle we were cueing. Another was cued with the ‘trees’ puzzle and woke up dreaming of walking through a forest. Another dreamer was cued with a puzzle about jungles and woke up from a dream in which she was fishing in the jungle thinking about that puzzle,” Konkoly said.
“These were fascinating examples to witness because they showed how dreamers can follow instructions, and dreams can be influenced by sounds during sleep, even without lucidity.”
What This Means for Creativity and Mental Health
The team plans to use targeted memory reactivation and interactive dreaming methods to explore other possible roles of dreaming, including emotional regulation and broader learning processes.
“My hope is that these findings will help move us towards stronger conclusions about the functions of dreaming,” Konkoly said. “If scientists can definitively say that dreams are important for problem solving, creativity and emotion regulation, hopefully people will start to take dreams seriously as a priority for mental health and well-being.”
The study, “Creative problem-solving after experimentally provoking dreams of unsolved puzzles during REM sleep” was published in the journal Neuroscience of Consciousness on Feb. 5.
Northwestern co-authors include Daniel Morris, Kaitlyn Hurka, Alysiana Martinez and Kristin Sanders.
