A new study shows that sleep protects memories, meaning people who have a good night's sleep have better memories than people who sleep poorly.

The study will be presented May 2 at the American Academy of Neurology annual meeting in Boston, media reports said Saturday.

"There was a very large benefit of sleep for memory consolidation, even larger than we were anticipating," said study author Dr. Jeffrey Ellenbogen, an associate neurologist at Brigham and Women's Hospital, Boston, and a postdoctoral fellow in sleep medicine at Harvard Medical School.

Researchers at Harvard Medical School asked 48 subjects between the ages of 18 and 30, who all had normal, healthy sleep routines and were not taking any medications to learn a list of 20 pairs of words and then tested them 12 hours later on their recall of the pairs.

These subjects were divided into four groups: a wake group without interference (competing information); a wake group with interference; a sleep group without interference and a sleep group with interference.

Two of the groups (the wake groups) were taught the words at 9 a.m. and then tested on the pairings at 9 p.m., after being awake all day. The other two groups (the sleep groups) learned the words at 9 p.m., went to sleep, and were then tested at 9 a.m.

Researchers found that the students who slept at home before the tests performed best, correctly identifying three-quarters of the word pairs. The students who took the test before going home for the evening correctly identified one-third of the word pairs.

"These results provide important insights into how the sleeping brain interacts with memories. It appears to strengthen them," Ellenbogen said. "Perhaps, then, sleep disorders might worsen memory problems seen in dementia."
(Agencies)