The structure of benzene, Google and Frankenstein: What do these icons of science, technology and literature all share? They are among the numerous discoveries and inventions that are said to have been inspired through the act of dreaming.
For decades sleep scientists have mulled over the link between dreaming and creative inspiration. They have long thought these insights came from the rapid eye movement stage of sleep, which is rich with dreams and begins an hour or more into the sleep cycle. But new evidence puts the spotlight on a much earlier sleep phase—the twilight zone that separates sleep and wakefulness—as fertile ground for a creative burst.
In a study published on May 15 in Scientific Reports, a team of researchers show that people who take brief naps that usher in the onset of sleep score higher on several measures of creativity than those who undertake the same creative tasks after staying awake. “There’s been speculation of the importance of this early sleep state for creativity, but as far as I know, this is the best study to demonstrate its value,” says Jonathan Schooler, a cognitive psychologist at the University of California, Santa Barbara, who was not involved with the study.
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What’s more, the scientists found they could even exercise some measure of control over the dreaming process. They did so by directing people’s dreams toward a specific topic. The more people dreamed about that theme, the more creative they were on tasks related to it. “That’s about as close as we can come to saying that dreaming about a topic enhances your subsequent creativity on that topic,” says Robert Stickgold, a cognitive neuroscientist and dream researcher at Harvard Medical School, who was a member of the study team.
The experiment took advantage of a glovelike sleep detector called Dormio, which was developed by a team that included co-lead investigator Adam Haar Horowitz, a postdoctoral fellow at the Massachusetts Institute of Technology. Dormio tracks sleep onset by monitoring muscle tone, skin conductance and heart rate through contacts on the wrist and hand. It communicates with an app that issues voice prompts for dreams and records dream reports.
More than one famous thinker has capitalized on the first transitional phase into sleep, called non-rapid eye movement sleep stage 1, or N1, to generate creative insights. The painter Salvador Dalí would deliberately doze while holding a set of keys above a metal plate when mulling over an idea for a painting. As he nodded off, the muscles in his hand would relax. He’d drop the keys, which would hit the plate and wake him up, and he’d hold onto the image from his dream. Thomas Edison is said to have used a similar technique with metal balls instead of keys to gain insights to be incorporated into his inventions.
In 2021 a team of researchers at the Paris Brain Institute reported some of the first solid evidence that Dalí and Edison were onto something. They had people take short naps after exposing them to math problems for which there was a hidden shortcut. Among the vast majority who did not see the shortcut right away, those who took naps in the N1 sleep stage were nearly three times more likely as those who did not nap to figure out the better solution when tackling new problems that required bringing to bear the same math knowledge.
Stickgold, Haar Horowitz and their colleagues wanted to test the notion that dreaming was the key intermediary in generating bursts of insight during N1. Before the 2021 math study came out, the researchers set out to do a controlled study of dreaming in which they coaxed people to dream about something specific, such as a tree.
They recruited 50 individuals for an afternoon “nap study”—a moniker that presumably drew people who like to nap, although the researchers actually instructed only half of the participants to sleep in the study. While wearing Dormio, the actual nappers drifted off, and as they did, the Dormio-linked app told them to either “remember to think of a tree” or “remember to observe your thoughts.” One to five minutes later, the app woke them up requesting a dream report. This cycle repeated for 45 minutes, producing an average of five dream reports per person. The people who were told to stay awake were left to let their mind wander while receiving similar instructions. (The researchers have created a simplified, Web-based version of this dream incubation protocol that you can try at home.)
Of the nappers who received the tree prompt, all but one reported dreaming of trees or parts of trees, compared with just a single person among the nappers who received the more general instruction. One tree-cued dreamer described “trees splitting into infinite pieces” and being in the desert with “a shaman sitting under the tree with me.”
Participants then took three creativity tests: They wrote a creative story that included the word “tree.” They listed “all the creative alternative uses” they could think of for a tree. And they wrote down the first verb that came to mind for each of 31 nouns that related, more or less, to trees. The creativity of the responses was rated by people who were not aware of who napped or who got the “tree” prompt. These ratings were combined into an index of overall creativity.
The people who napped and got the tree cue had the highest composite creativity scores. “There is an objective and experimental link between incubation of some specific dream and postsleep creativity around that topic,” Haar Horowitz says. “This validates centuries of anecdotal reports from people who are in the creative space.”
In addition, the more references to trees a person reported, the higher that person’s creativity score was. “The more you dream about a tree, the better your performance is later,” says Kathleen Esfahany, an M.I.T. undergraduate who co-led the study with Haar Horowitz. People seemed to use their dreams to get ideas for those tasks, Esfahany adds. For example, a person who dreamed that their body was made of wood wrote a story about an “oak king” who wore a “crown of leaves” and whose body was at times “made of wood” and at times “made of light.”
Together, the data indicate that dreaming during N1 is an active ingredient for creativity as the researchers hypothesized. “It’s a pioneering study,” says Tore Nielsen, a dream researcher at the University of Montreal, who was not involved with the study. “No one has shown experimentally that dreaming about something at [sleep onset] is actually related to the creativity that follows it.”
The study is small and needs to be replicated, Nielsen and others say. In addition, scores on the individual creativity tasks (as opposed to the composite score) were not significantly higher for the prompted nappers than for the unprompted ones, says Penny Lewis, a neuroscientist at Cardiff University in Wales, who was not involved with the research. “I think their data do convincingly show that spending some time in stage 1 sleep—that’s the very light sleep that happens when you’re falling asleep—leads to better performance in all three of these tasks,” Lewis says. But the idea “that prompting is leading to these effects should be treated with caution because the stats are not that strong.”
An objective, automated creativity measure called “semantic distance” indicated that brief napping helped spur inventiveness but that there was no additional benefit when a tree prompt was added. In this measure, a computer assessed the similarity of pairs of words produced in each creativity task, with less similarity linked to higher creativity. Still, the measure hints at a mechanism for the creativity boost during N1. “It suggests people are capable of making more distant associations and thereby finding [conceptual] bridges that they might not otherwise discover,” Schooler says.
The study included just a single prompt involving a tree, so it needs to be tested with other topics and eventually used on real problems. “It’s exciting because, in principle, this is a technology that people could use themselves to foster their own creativity,” Schooler says.
There seems to be no shortage of folks wanting to give it a try. “So many different kinds of people have come knocking on the lab door and asking to have dreams,” Haar Horowitz says.