The sleep stage sometimes characterized by vivid dreams is when your mind goes to work for you. A study presented at the Annual Convention of the American Psychological Association demonstrated how REM sleep can boost memory and creative problem solving.
Sleep researchers at the University of California, San Diego, used a word association test to show the difference REM sleep makes on memory. Participants took the test in the morning and the afternoon, after either a nap with REM sleep, a short nap without REM sleep or a quiet rest period.
The first part of the test resembled SAT word-analogy questions. One sample question was:
After a 90 minute rest period, the subjects moved onto the second round. That involved using the first round’s answers as a response to three seemingly unrelated words.
Q: cookie: heart: sixteen
The participants who were allowed REM sleep performed better in the afternoon, while the people who didn’t nap or get any REM sleep saw no improvement.
The authors believe REM sleep helped connect networks of previously unassociated information in the brain, which helped creative problem solving.
The findings are similar another recent study involving dreams and memory. Both results suggest REM sleep is when we pull together all the information from the day and turn it into memory.