11:43 26 April 2010
If you're found napping at your desk, you could have a new excuse as scientists have discovered that by having a kip after study can help us remember new things more effectively.
However, the key is to dream about the task in hand to commit it to memory.
In a study by Harvard Medical School, volunteers were asked to learn the layout of a 3D computer maze so they could find their way within the virtual space several hours later.
The results showed that those who had slept after the test performed better than those who did not have a nap afterwards.
And those who were allowed to get some shut eye and remembered dreaming of the task, found their way to a landmark quicker.
Scientists believe that dreaming may be a sign that unconscious parts of our brain is working hard in our sleep to process information about the task
Dr Robert Stickgold of Harvard Medical School, one of the authors of the paper, said: "The dreams might reflect the brain's attempt to find associations for the memories that could make them more useful in the future."
Co-author Dr Erin Wamsley said the study suggests our brain unconsciously works on the things that it deems are most important.
She said: "Every day we are gathering and encountering tremendous amounts of information and new experiences.
"It would seem that our dreams are asking the question, 'How do I use this information to inform my life?'"
The research, published in academic journal Cell Biology, could have practical implications.
Scientists say there may be ways to take advantage of this phenomenon for improving learning and memory – for example, studying hard before bedtime, or taking a nap after an afternoon of study.