Creative problem solving enhanced by REM sleep (6/8/09)
Research led by a leading expert on the positive benefits of napping at the University of California, San Diego School of Medicine suggests that Rapid Eye Movement (REM) sleep enhances creative problem-solving. The findings may have important implications for how sleep, specifically REM sleep, fosters the formation of associative networks in the brain.
The study by Sara Mednick, PhD, assistant professor of psychiatry at UC San Diego and the VA San Diego Healthcare System, and first author Denise Cai, graduate student in the UC San Diego Department of Psychology, shows that REM directly enhances creative processing more than any other sleep or wake state. ...
"We found that - for creative problems that you've already been working on - the passage of time is enough to find solutions," said Mednick. "However, for new problems, only REM sleep enhances creativity."
Mednick added that it appears REM sleep helps achieve such solutions by stimulating associative networks, allowing the brain to make new and useful associations between unrelated ideas. Importantly, the study showed that these improvements are not due to selective memory enhancements.
It might be supposed that sleep in general can aid problem solving by several mechanisms. For instance, sleep might be helpful simply by enabling avoidance of distractions that occur during wakeful periods. It is also known that memory consolidation occurs during sleep, and memories that are better established may also assist in problem solving. But there could be other benefits of sleep as well, especially specific phases of sleep.
A critical issue in sleep and cognition is whether improvements in behavioral performance are the result of sleep-specific enhancement or simply reduction of interference - since experiences while awake have been shown to interfere with memory consolidation. The researchers controlled for such interference effects by comparing sleep periods to quiet rest periods without any verbal input. ...
"Participants grouped by REM sleep, non-REM sleep and quiet rest were indistinguishable on measures of memory," said Cai. "Although the quiet rest and non-REM sleep groups received the same prior exposure to the task, they displayed no improvement on the RAT test. Strikingly, however, the REM sleep group improved by almost 40 percent over their morning performances."
The authors hypothesize that the formation of associative networks from previously unassociated information in the brain, leading to creative problem-solving, is facilitated by changes to neurotransmitter systems during REM sleep.
Here's the research abstract:
REM, not incubation, improves creativity by priming associative networks
The hypothesized role of rapid eye movement (REM) sleep, which is rich in dreams, in the formation of new associations, has remained anecdotal. We examined the role of REM on creative problem solving, with the Remote Associates Test (RAT). Using a nap paradigm, we manipulated various conditions of prior exposure to elements of a creative problem. Compared with quiet rest and non-REM sleep, REM enhanced the formation of associative networks and the integration of unassociated information. Furthermore, these REM sleep benefits were not the result of an improved memory for the primed items. This study shows that compared with quiet rest and non-REM sleep, REM enhances the integration of unassociated information for creative problem solving, a process, we hypothesize, that is facilitated by cholinergic and noradrenergic neuromodulation during REM sleep.
Problems are solved by sleeping (6/9/09) – BBC news article
Stages of sleep have distinct influence on process of learning and memory (2/25/09) – press release concerning prior reseach on REM sleep
Tags: creativity, problem solving
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