Dreams have been linked to prophesies and the unconscious welling up to the surface or dismissed as the brain's equivalent of a PC's screensaver but new research by scientists at the Beth Israel Deaconess Medical Center in Boston suggests that they may play an important part in learning and memory. The researchers studied 99 people who spent an hour training on a virtual maze. After their initial training the participants either had a nap or took part in quiet activities but stayed awake. When they attempted the maze again the participants who had stayed awake or who had had a nap but had not dreamt about the maze showed very little signs of improvement. However, those people who had dreamt about the maze showed 10 times the level of improvement of the other participants. The participants who dreamt about the maze were the ones who had done particularly poorly in their initial training.