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.
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.
Photo by ywel.