The researchers reporting online on 22 April in Current Biology, a publication of Cell Press, provides further evidence that the habits of successful study should include a lot of naps. They found that people taking a nap and dream about a task they have just learned to make better wake up than any of those who do not sleep at all, or those who sleep, but do not report any sleep partners.

The students in the study were asked to sit in front of a computer screen and learn to design a three dimensional maze so that they could find their way to a mark (a tree) when dropped into a randomly selected the virtual space of five hours later. Those who were allowed to take a nap and dream also reminded the task of finding the tree in less time.

“First thought that dreaming must reflect the process of memory performance is improving,” said Robert Stickgold of Harvard Medical School. “But if you look at the content of dreams, it was hard to argue that.”

In a few cases, the dreamers, said he remembers only the music of the maze computer. One of the subjects said they were dreaming that there were people at checkpoints, particularly in the maze, but the real maze had no town or at checkpoints. Another said he dreamed that he had experience tromping through a bat cave and thought that the caves were like labyrinths.

“We believe that dreams are an indication that the brain is working on the same problem on many levels,” said Stickgold. “Dreams can reflect the brain’s attempt to find associations for the memories that may make them more useful in the future.”

In other words, it is that dreams, such as improved memory, but are a sign that other unconscious parts of the brain are working hard to remember how to get through the virtual maze. Dreams are essentially a side effect of this process of memory.

Stickgold says he still may be ways to exploit this phenomenon to improve learning and memory. For example, it may be best to study hard right before going to bed that evening, or take a nap after a period of intense study in the afternoon. More generally, people could take note of the study habits or mental processes during wakefulness that lead them to dream of something that needs to remember. Perhaps other direct ways to lead the dreams, even could be useful for their intellectual work as desired in the night.

But Stickgold said, the most exciting thing for him is the idea that this line of evidence could clear up a deeper issue that has seemed almost impossible to address: Why do we dream? What is your role?

“Some have been dreaming as entertainment, but this study suggests that is a byproduct of memory processing,” he said. Whether you have to remember their dreams of obtaining the benefits is still not entirely clear, but no suspects Stickgold. After all, he said, people generally remember only a small fraction, no more than 10-15 percent of their dreams.

The researchers hope to follow up their study by manipulating the learning environment so as to promote the incorporation of dreams. They also plan to study the same phenomenon following a full night’s sleep as compared with a nap.