The story goes that in the 1790s, Samuel Coleridge fell asleep one
evening at his desk, and when he woke he had the poem "Kubla Khan" in
his head. More recently, Paul McCartney went to sleep and dreamed the
tune to his hit song, "Yesterday." What is it about dreaming that spurs
creativity? Some researchers from the University of California at San
Diego are looking for clues.
Sleep researcher Sara Mednick explains that sleep has different parts. Sleepers can spend time in a deep dreamless sleep. They can also experience something called rapid eye movement, or REM sleep - that's when dreams occur. Mednick says scientists have long suspected a connection between REM sleep, dreams and the creative process.
"If dreams are playing a role in creative discovery, we should be able to find it somehow, but for some reason, that's kind of confounded scientists for awhile," she says.
Mednick and her colleagues tried to find this connection by studying three groups of people: a control group which is a non-sleep group, a group in which subjects were able to nap but only had only non-REM sleep, and the third group, that has REM sleep.
Mednick explains that the control group was also not allowed to sleep. They just sat quietly in a dark room with electrodes on their head, not sleeping, but very quiet during the whole 90 minutes that everyone else is taking a nap.
All the people in each group were given a mental task to do before their rest period or nap. Mednick asked them to find the associations between groups of words. One example of such a word group: heart, sixteen, cookie.
In the afternoon, after resting, Mednick asked them to come back and complete the mental task - finding the word that connects the other three.
"And what we find is that in the REM group, people are performing better if they have had REM sleep than if they have had non-REM or quiet rest," she says.
Mednick says the mechanism of this creative word association isn't clear, but she and her colleagues think that this kind of creativity is housed in a part of the brain called the neocortex - that's where we bring our experiences and world-view together. Another part of the brain involved in this process is the hippocampus, which is where scientists think memory is processed.
"At some point... and this is probably this influence of REM sleep, is that REM sleep allows this information to travel from the hippocampus to the neocortex, where it enters into this big field of this associative network," Mednick says. "In there, information becomes more accessible to creativity, because you begin to associate items and bits of information that hadn't really been associated before."
Mednick says there are probably ways to use sleep to one's advantage. She would like to work on devising a model where REM sleep could be used consistently to help people solve difficult problems - such as realizing that the link for the words cookie, sixteen and heart is… sweet.
Mednick's research is published in the Proceedings of the National Academy of Sciences.