Renowned surrealist Salvador Dalí had a somewhat unusual method for sleeping. When he was ready to go to bed (which in his case was a chair) after a long day of imagining "what if clocks could bend" or painting a picture of what it would look like if skulls contained further skulls, he would take with him a set of keys or a spoon.

He would hold the metal objects out in his hand, which he hung over the edge of his chair. On the floor was a metal plate. As he went to sleep, the object would fall from his hand, hit the plate, and wake him up. 

Like American inventor Thomas Edison, who used the same technique, Dalí believed that this kind of sleep gave him a creative boost (rather than just a fright followed by a feeling of being knackered), and would begin work immediately after the spoon hit the plate. Dalí was undeniably creative, but researchers recently explored whether this technique would work on ordinary members of the population.

Remarkably, it did.

Publishing their work in Science Advances, the team gave participants math problems that each had a hidden rule that would allow them to solve the problem "almost instantly" should they find it.

After attempting the problem, the participants were split into three groups before attempting the problem again: people who remained awake, people who were allowed to sink into shallow nonrapid eye movement sleep stage (known as N1) for over 30 seconds, and those who were allowed to drift deeper into nonrapid eye movement sleep for at least 30 seconds.

They were then given math problems once more to see if they could identify the hidden rule.

The researchers found that the participants who spent at least 15 seconds in N1 sleep tripled their chances of finding the hidden rule, which implies increased creative thinking, than those who had remained awake during the break. Eighty-three percent of people who went into N1 sleep were able to spot the rule compared to just 30 percent of the awake group.

"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," the authors write, adding that "we believe that N1 presents an ideal cocktail for creativity".

However, if they reached deeper levels of sleep, known as N2 — monitored in the experiment with an electroencephalogram (EEG) — the effect went away. 

"These results demonstrate that an incubation period containing a brief period of N1 has a marked effect on insight, but that this beneficial effect vanishes if participants reach a deeper state of sleep."

The team says that the technique of Dalí and Edison can be easily employed.

"Because it does not require any material besides an everyday object, Edison’s technique can be applied by anyone eager to summon their creative muse, either at home or in workplaces."

As for why this effect may happen, more study is needed, though the team has ideas.

"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.

"Such hypnagogic experiences could be considered as an exacerbated version of awake spontaneous thoughts (e.g., mind-wandering) and similarly foster the generation of novel ideas."

So, if you can hack the frustration of an incredibly abrupt end to a nap, this may be a way of giving your creativity a boost. Just don't tell your boss that you owe it all to napping.