This month researchers reported online in Current Biology, a Cell Press publication, that good study habits should include a lot of napping. When compared to those who didn’t sleep, or slept but didn’t report dreams, study subjects who napped after learning a task and dreamed about it recalled it the best.
The study subjects were required to sit in front of a computer screen and learn the layout of a three-dimensional maze that lead to a landmark (a tree). Five hours later they were dropped at a random location within the virtual space and had the task to find the tree. Those who napped and dreamed about it were the quickest to find the tree compared to those who didn’t sleep, or slept and didn’t report dreams.
"We at first thought that dreaming must reflect the memory process that’s improving performance," said Robert Stickgold of Harvard Medical School. "But when you look at the content of the dreams, it was hard to argue that." In a couple of cases, dreamers only recalled the music from the computer maze. One subject reported dreaming of people at particular check points of the maze, even though the maze didn’t have people at checkpoints. Another dreamed about memories exploring caves, and thinking that caves were like mazes. "We think that the dreams are a marker that the brain is working on the same problem at many levels," Stickgold said. "The dreams might reflect the brain’s attempt to find associations for the memories that could make them more useful in the future."
So it’s possible that the dreams themselves do not lead to better memory, but are an indication that unconscious parts of the brain are working hard to remember how to get through the virtual maze. According to Stickgold, this suggests ways to take advantage of the phenomenon to improve learning and memory. For example, it may be better to study hard right before you go to sleep than in the afternoon, or to take a nap right after a period of intense study. In general, people might take notice of study habits or mental processes while awake that lead them to dream about something they want to remember. There may be other more directed ways to guide dreams to work on what you want to at night.
The most exciting thing to Stickgold is the notion that this line of study might clarify a deeper question that has seemed almost impossible to tackle: Why do we dream? What is its function? "Some have viewed dreaming as entertainment, but this study suggests it is a by-product of memory processing," he said. It is not clear whether you have to remember the dream to get the benefits, but Stickgold suspects not. People generally remember no more than 10 to 15 percent of their dreams.
The researchers hope to follow up their study by manipulating the learning environment in ways that boost incorporation into dreams. They also plan to study the same phenomenon following a full night of sleep as opposed to a nap.
C. Kirven Weekley, Ph.D. is a clinical psychologist with offices in Covington and Norcross. He specializes in the evaluation and treatment of adults for depression, anxiety, relationship problems and medical issues. He can be reached at (770) 441-9244.