Sleep improves memory

Apr 23 2010

By Candy Lashkari

The next time you want to remember what you were taught, take a nap and dream about it. You may just remember it better. That is what scientists at the Center for Sleep and Cognition at Beth Israel Deaconess Medical Center in Boston, Massachusetts had to say after a new study. Robert Stickgold the lead author confirmed that a nap would improve the chances of your remembering stuff if you dream it.

"When you dream, your brain is trying to look at connections that you might not think of or notice when [you're] awake," said Robert Stickgold, "In the dream...the brain tries to figure out what's important and what it should keep or dump because it's of no value."

To test the theory that you perform better after a nap, the scientists showed the volunteer participants how to find a specific structure in a 3D computer generated maze. The group was then split into three smaller groups which were all given different stimuli.

The first was allowed to nap before trying the task again. The second was kept awake and allowed to try the task after some time. The third group was allowed to sleep, but were woken up periodically to check if they were dreaming. The ones who reported that they were dreaming about the task were the ones who found the specific structure fastest.

Co-author Dr Erin Wamsley felt the non conscious brain worked on things that it deemed important when we are sleeping. “Every day we are gathering and encountering tremendous amounts of information and new experiences," she said. "It would seem that our dreams are asking the question, 'How do I use this information to inform my life?"

The research findings were published in the journal Cell Biology and will have practical implications. Many students believe studying all night is good in the exam season, but if they are not getting enough sleep, they might be under performing. A fact that some university teachers will vouch for.

"Cramming and getting it into your head is probably better than not studying at all. On the other hand, studying and getting a good night's sleep is probably better again," said Drew Dawson, director of the Centre for Sleep Research at the University of South Australia. Dr Dawson is reviewing a study that researchers from Harvard Medical School have published.

"Seven and a half and eight hours sleep is fairly normal but we do also know that probably most people in the modern day get less probably by about an hour than what they need," said Colin Sullivan, a Professor of Medicine at the University of Sydney who specialises in sleep.

So the next time you want to really do well at a task you have already learnt take a short power nap before you get back to it. The results may surprise you.