Ever had a conundrum that seemed to magically worked itself out after a good night of sleep? Or a 3am "Eureka!" moment? Turns out that there’s solid scientific evidence behind that old piece of advice: when in doubt, just sleep on it.
Sleep is crucial for learning and memory. In particular, the process of consolidating information, or making it stable and accessible, seems to occur primarily during sleep. When you’re resting, your brain organizes what you’ve learned that day—almost like sorting through a messy filing cabinet.
Imagine that ideas in your brain are connected in a network. For instance, "apple" may immediately call to mind "red," because those ideas are closely associated in your concept network. These relationships are one avenue researchers use to test creative problem solving. In remote-associate tests (RATS), they’ll provide three words that are supposed to call to mind a fourth related word. The words night, wrist, and stop, for example, are associated with "time."
To come up with solutions for RATs, your mind sifts through related concepts. One theory about how this works is "spreading activation." Essentially, when you’re presented with a set of words, related ideas in your mental network become "activated" until you reach the solution.
Researchers had participants attempt a series of RATs of varying difficulty. Then, they were separated into three groups before reattempting unsolved problems: sleep, wake, or no delay. The results? Participants who slept through the night before trying difficult problems again solved more than the other groups. The researchers suspected that when you’re asleep, more weakly associated concepts in your mental network become accessible.
If this works with word association tests, it stands to reason that more complex problems can be solved the same way. That tricky issue you can’t seem to work out may be stumping you because you’re stuck in the shallow levels of your associative network. According to this research, sleeping may broaden the horizons of your thought. The next day, the solution may come to you when you’re not even thinking about it.