Waking up just after nodding off — even for just 15 seconds, can unlock the answer to difficult problems, a new study has revealed.

It found that sleeping on a difficult math problem for as little as 15 seconds conferred a 3-fold higher chance of solving it, an effect that wasn’t observed for those who actually took a full nap.

An old story, whose protagonist changes between Albert Einstein and Thomas Edison depending on who’s telling it, goes that when one of the great minds was confronted with a difficult problem, they would have a quick nod off at their desk. In their hand, they would hold a ball bearing, which after sleep relaxed the muscles in their hand, would fall to the floor waking them up.

Writing down every shred of memory left in their brain, they believed the brief dip into the phase between sleep and wakefulness gave them a spark of creativity needed to find the answers to whatever they were working on. It’s a nice story, but it seems entirely true.

“The ability to think creatively is paramount to facing new challenges, but how creativity arises remains mysterious,” the authors of the study write. “Here, we show that the brain activity common to the twilight zone between sleep and wakefulness (nonrapid eye movement sleep stage 1 or N1) ignites creative sparks”.

N1 seems to be a state of unconsciousness characterized by a version of hyper-creative quasi-wakeful activity such as daydreaming, but which goes away in a short time as we enter further periods of sleep.

Creative force

It’s long been thought that sleep inspires creativity, but previous studies tend to look at full nights of sleep rather than mere minutes. Study author Delphine Oudiette and her colleagues pick up the narrative.

“N1 is accompanied by involuntary, spontaneous, dream-like perceptual experiences that incorporate recent wake experiences in a creative way by binding them with loosely associated memories,” they write in the corresponding paper.

In a study aptly titled “Sleep Inspires Insight” German researchers found that creatively active sleep states like N1 work to break down the barriers in association between objects, leading to insights that the waking brain can’t achieve.

In her study, Oudiette and her team took 100 easy sleepers and gave them the difficult task of turning a series of 8-digit numbers into 7-digit numbers according to a set of rules. Hidden within the challenge however was a kind of cheat code in the way each number series was set up that, if discovered, would make each conversion obvious. After 30 failed attempts the participants took a 20-minute nap in a dark room.

They held a water bottle, rather than a ball bearing, in their hands and their brain activity was monitored by sensory equipment. Asked to describe what they saw while they napped, the participants often reported series of numbers and geometric patterns, and occasionally bizarre one-off scenes like the Colosseum in Rome, or a horse dancing in a hospital room.

Afterwards though, 20 out of 24 of these nappers (83%) found the cheat code, versus only 15 out of the 59 (30%) who didn’t nap. Those who napped through N1 into a deeper stage had a likewise unremarkable discovery rate.

Oudiette et al. note that the discovery didn’t come in a eureka moment, but rather took 94 attempts on average. Regardless, it shows that whether it was Einstein, Edison, or as Science reports, Salvador Dali, the trick seemed to work.

Oudiette, who admitted to Science that she practices the trick herself, said that now that the phenomenon is more or less confirmed, she and her team look to work on other studies of its effects.

Continue exploring this topic — Sleep — Sleeping on a Problem is Actually a Remarkable Evolutionary Adaptation

Continue exploring this topic — Neurology — Blue Light Exposure After Dark Creates Lasting Depressive Symptoms in Rats

Continue exploring this topic — Sleep — Even More Evidence Links Shorter Sleep Duration to Increased Risks of Dementia