Need to solve a problem? Try sleeping on it.
Trying to solve a problem? New research by the EU-funded SolutionSleep project suggests that the best way to find the answer could be to sleep on it. According to Penny Lewis(opens in new window), a professor of Psychology at Cardiff University(opens in new window) and SolutionSleep project coordinator, this is because creative thinking often requires an individual to suppress preconceptions and restructure existing knowledge. “We tend to replay recent experiences when we sleep, and this replay allows us to integrate new knowledge with old information,” explains Lewis. “This integration is our brain’s way of connecting the dots, and those dots could add up to the answer to our problem.”
Use of memory cues shown to reactivate memories
The project, which received support from the European Research Council(opens in new window) (ERC), focused its work on understanding the role that different stages of sleep play in memory reactivation. Specifically, researchers studied how non-rapid eye movement (NREM) and rapid eye movement (REM) sleep impact both creative problem-solving and making links between distantly related ideas. Using a state-of-the-art sleep lab established at Cardiff University, researchers introduced memory cues to the sleeping subjects and then monitored them for signs of memory reactivation. “We found that cueing memories during REM sleep can promote gist abstraction, essentially finding meaning from complex information, while cueing memories at the peaks of the huge slow oscillations that characterise NREM sleep can promote the formation of new linkages and schemas,” says Lewis. Researchers also demonstrated that these effects can increase over time – for up to 20 days – and are associated with ongoing functional and structural plasticity in the brain.
Manipulating sleep for cognitive benefit
While the SolutionSleep project was ambitious in scope, Lewis says it achieved much more than thought possible. “The project was a huge success, with our work showing that manipulating sleep for cognitive benefit is a powerful tool with significant potential,” adds Lewis. “This ERC grant has done a lot to advance this exciting and rapidly expanding field of research.” The project also helped establish the Cardiff sleep lab as one of the world’s premiere facilities. It now hosts a biennial international conference on memory replay and a regular sleep science podcast, the latter of which boasts over 20 000 downloads. The research team is currently expanding its sleep studies into the realm of emotion. “We hope to use our knowledge about memory reactivation in sleep and how to control it to develop treatments for post-traumatic stress disorder and depression,” concludes Lewis.
