If you're struggling to solve a particularly difficult problem in your waking hours, it might be time to take a break and snooze instead.
A recent study in the U.K. found that sleep could help facilitate difficult problem-solving by helping the brain transfer information from the hippocampus, a region where recent experiences are stored, t0 the neocortex, where long-term memories are kept. On the flip side, it also established that sleep makes little difference when it comes to addressing easier problems.
The study was led by Padraic Monaghan, a professor of cognition at Lancaster University's Centre for Research in Human Development and Learning. He and his team gave a group of volunteers a set of word problems, each including three words for which the participants were asked to find the relation and then pick a fourth word to fit within the grouping.
Half of the puzzles were considered easy, and the other half were considered difficult. The volunteers were separated into four groups: One saw the problems in the evening and then tried to solve them again in the morning after sleeping, another saw them in the morning and tried to solve them again later that evening, another saw them and completed them in the same morning session, and another saw them and completed them in the same evening.
When it came to the easy problems, the group that first saw the problems in the morning and then solved them in the evening (the "wake" group) proved most effective. But when it came to the difficult problems, the group that first saw the problems in the evening and then solved them in the morning (the "sleep" group) showed substantial improvement in the ability to find the right answers.
"This research gives us some guidance on improving our day-to-day approach to solving problems," wrote Monaghan. "If it is a difficult problem, set it aside overnight, and return to it the next day. Even if you’ve already made a complex decision, reappraising it briefly the next day is more likely to result in the best choice you can make."
Previous research has addressed how a person's problem-solving abilities improved after sleep, but hasn't determined if that sleep was actually benefitting the problem-solving process or just mitigating the interferences and distractions that arise when a person is awake and working to find a solution. Monaghan's research is a step in that direction.
While further research is needed to replicate and expand upon these findings, more and more evidence points to the fact that even though we are at rest, the brain is surprisingly active and accomplishing some pretty amazing things.