The busy brain

Use It or Lose It

If the human body came with an owner's manual, one of the primary
recommendations would be use it or lose it: inactive muscles wither,
underexercised hearts grow feeble. Aging brains atrophy as well--but a
recent study suggests that lifelong mental activity can partially halt
the process.

To test whether a busy brain wards off deterioration, a team of
psychology professors put their fellow academics through a five-part
mental workout and compared how young, middle-aged, and senior faculty
performed.

First, the bad news. The senior faculty's performance on a
reaction-time test (pressing a key as soon as a computer flashed the word
"go") demonstrated that neurons slow down as they age--and studying
particle physics for 40 years won't help. Older professors also had more
trouble matching pairs of names or faces.

But the over-60 crowd fared just as well as their younger
col-leagues--and far better than non-professors of the same age--when
asked to remember details of an informational paragraph about tribal
cultures or atmospheric gases. And they did an equally fine job
remembering the order in which 15 words or pictures were presented.
Performance on both tests normally sags with age.

The final test, in which subjects pointed to previously unchosen
patterned squares in a continually reshuffled array, produced a split
decision. Older professors made more errors than the juniors and just as
many mistakes as same-age controls. But they improved slightly on a
second trial, while performance of the older controls declined.

"No matter how mentally active you are, you're going to slow down,"
says University of California at Berkeley psychologist Arthur Shimamura,
Ph.D. But a brain kept busy may better compensate for age-related
decline.

ILLUSTRATION