Searching the Internet may help middle-aged and older adults keep their memories sharp, U.S. researchers said on Tuesday.

"This suggests that just searching on the Internet may train the brain -- that it may keep it active and healthy," said Small, whose research appears in the American Journal of Geriatric Psychiatry.

Many studies have found that challenging mental activities such as puzzles can help preserve brain function, but few have looked at what role the Internet might play.

His team studied 24 normal volunteers between the ages of 55 and 76. Half were experienced at searching the Internet and the other half had no Web experience. Otherwise, the groups were similar in age, gender and education.

In the aging brain, atrophy and reduced cell activity can take a toll on cognitive function. Activities that keep the brain engaged can preserve brain health and thinking ability.

Small thinks learning to do Internet searches may be one of those activities.

"It tells us we probably can teach an old brain new Internet tricks," he said.