Scientists say that napping after learning can help a person commit it to memory - as long as you dream.

They found out that people who dream about a new task perform better upon waking up than those who do not sleep or dream at all.

To support the study, volunteers were asked to learn the layout of a new 3D computer maze so they could find their way within the virtual space several hours later.

Those who were allowed to take a nap and who also remembered dreaming of the task found their way to a landmark faster than others.

Researchers think that dreams are a sign that unconscious parts of the brain are working hard to process the information gathered from a recent task done.

One of the authors of the paper from the Harvard Medical School, Dr Robert Stickgold, said that dreams may be a marker that the brain is working on the same problem at many levels.

Dreams may reflect the brain's attempt to find relations for the memories that can make them more useful in the future. he said