The relationship between sleeping and creativity is the subject of much folklore and even admonitions to problem-solving such as advice to "sleep on it" when faced with a tough decision. Artists have long pointed to sleep and related bodily phenomena as a source and parallel to their creative pursuits.
Creators often talk of inspiration coming during a waking period similar to a dream and daydreams have long been connected with new ideas or syntheses of existing idea or applying existing ideas in new ways. Sleep brings a different approach.
Samuel Taylor Coleridge allegedly wrote the poem Kubla Khan after waking from an opium-induced dream, although some doubt this claim. Coleridge related the story years after he wrote the poem. Creativity may be easier to bring to fruition when the creator is in touch with unconscious and that happens during and around sleep. Scientists have found a connection between sleep and "aha!" creativity. Setting aside a problem for an incubation period can spur creativity and sleep can be such a period.
The American Psychological Association’s Monitor on Psychology
magazine (http://www.apa.org/monitor/nov03/canvas.aspx) featured an article that said people prone to openness and fantasy are more likely to remember dreams and that people with those personality traits are also more likely to be creative. University of Iowa researchers found the personality trait of openness is the strongest predictor of whether people could remember their dreams. Another thought is that open creative people are more perceptive to the world’s inputs in general, including dreams. These people remember their dreams better, but there is no cause and effect relationship with their creativity.
Many people report being able to do their best work immediately after awakening. What is so special about early morning? Is it just that the events of the day have yet to clutter up the mind and the creative spark can come through more clearly? Or is the proximity to recent sleep the key, especially given that most people have their longest stage of REM sleep just before waking in the morning.
If REM is a key enabler in the creative process, that might explain why creative people don’t so often mention the period following a brief daytime nap as a fertile time. While naps can be useful for improving mental performance, the kind of mental energy gained after a nap is more geared toward cranking things out rather than developing new ideas and concepts. People who do manage to get to REM in their daytime naps likewise test better at creativity after awakening than those who do not.
Artists have claimed that they are creative when suffering bouts of insomnia. This could be due to having more undirected time to fill than their well-sleeping peers. Or the insomnia could cause a general unrest in the mind that the creative person seeks to fill with product/art. This evidence is anecdotal and unfortunately attempts to show insomniacs are more creative have not been successful. Even if they were successful, the causal direction or connection would not be clear and we are a long way from having any theoretical explanation for insomnia and creativity. Further, sleep deprivation generally degrade mental agility and higher-order brain functions, so we would expect someone running short on sleep for an extended period to NOT be creative.
So here’s all we can say about insomnia and creativity. Occasional insomnia appears to help some people produce new art and work, but is a detriment to others. It is perhaps true that more people find it a detriment than find it useful. Long-term insomnia and the accompanying sleep debt are almost surely negative for creativity.
The dreams in REM are the most narratively coherent of any during the night. These are the dreams people most often remember.
Salvador Dali famously connected surreal paintings to dreams, and Paul McCartney says the melody for the song Yesterday came to him in a dream
There is a lot of pseudoscience nonsense about dreams in the bookstores. At Sleepdex we do not pay attention to the alleged mysticism or signs of dreams. However, by reframing the conscious mind, dreams can clearly spur creativity in people prone to that type of stimulus.
In a letter in Nature in 2010, scientists reported that subjects can solve 30% more anagram word puzzles when they are given the test after waking up from REM sleep than they could after non-REM sleep. More recent research published in 2012 found that sleep is particularly good at helping people solve complex problems.
Science has confirmed that REM sleep helps people be creative. At the University of California at Davis, researchers used a protocol called a Remote Associates Test (RAT) to quantify increases in creativity. They divided test subjects into three groups. One rested but did not sleep, one slept in NREM, and one slept in REM right before taking the test. Those in the waking/rest and NREM groups showed no increased in creativity as measured by RAT, whereas those recently woken from REM sleep showed an increase in capacity.
UC San Diego scientists looked at the effect of sleep on solving
difficult problems, http://ucsdnews.ucsd.edu/newsrel/health/06-09Mednick.asp
The psychiatrists concluded that REM sleep enhanced creative problem solving. REM seems to spark solutions to new creative problems. Older creative problems that the person has been working on – the person was able to make progress on these over time, but they did not respond to REM sleep as readily as the new problems did. Is it possible that the lack of focus and control by the dreamer combined with the reduced external input to the brain from the senses makes REM a unique crucible for solving problems?
A Swiss study of adolescents found that people who are able to recall dreams (and recallable dreams typically happen in REM) tend to be more creative. (Coincidentally, girls were found to be better at recalling dreams than boys.)
Italian researchers looked at the duration of the various stages of sleep. They found a positive correlation between deep sleep and both "originality" and "figural creativity". There was a negative correlation between REM sleep duration and originality. This finding stands in contrast to other work showing a positive correlation between REM and measures of creativity such as the UC Davis study.
The Italian scientists speculated that the low levels of the stress marker cortisol during NREM sleep play a role in allowing people to access information from deep memories and make connections that would not otherwise make. One speculation is that during REM brain levels of the neurotransmitters norepinephrine and acetylcholine and lower than when we are awake, and that the lower levels somehow permit associations in the mind.
Creative solutions are often said to involve the right lobe of the brain, especially as insights for normally analytical (left brain dominant) people. Some European scientists http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2829083/ did tests of learning and brain activity during sleep and found support for the hypothesis that the right side of the brain is "heard" more after sleep. (In other words, the right brain has a bigger say in consciousness.) The consolidation of memory during a night’s sleep occurs before an change in functional activation states in the morning. These scientists concluded the restructuring of memory responsible for this right brain boost occurred during slow-wave sleep in the first half of the night. REM sleep was said to not affect.this mechanism which the scientists speculated may contribute to insight after sleep.
Scientists have found that an "incubation period" can help in solving difficult problems when the brain does not focus on the problem. When the incubation period includes some sleep time, people are more likely to make connections among disparate ideas and facts.
For many difficult problems, the solution may come after periods of focus and periods of relaxation and mind-wandering. The wandering is important because it goes down many paths, most of which are unproductive but some of which could lead to insight or a solution. The waking brain, when faced with a tough problem, may be too focused to get to a solution that requires a circuitous route.
Daydreaming isn’t dreaming the way dreams happen during sleep. The mind is unfocused and wanders and this may be slightly more likely when one is tired, although it can happen any time during the day. One reason we advocate quality sleep is to have quality waking, and that is often interpreted as sharp concentration. But humans benefit from daydreaming, too, as creativity is often spurred during these times.