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Monday, October 29, 2007

Good news for the aging brain

Good news for the aging brain

The aging brain is subject to a dreary litany of changes. It shrinks, Swiss cheeselike holes grow, connections between neurons become sparser, blood flow and oxygen supply fall. That leads to trouble with short-term memory and rapidly switching attention, among other problems. And that's in a healthy brain.

But it's not all doom and gloom. An emerging body of research shows that a surprising array of mental functions hold up well into old age, while others get better. Vocabulary improves, as do other verbal abilities such as skill with synonyms and antonyms. Older brains are packed with more so-called expert knowledge -- information relevant to your occupation or hobby. (Older bridge enthusiasts have at their mental beck-and-call many more bids and responses.) They also store more "cognitive templates," or mental outlines of generic problems and solutions that can be tapped when confronting new problems.

Eric Kandel, 77, who shared the 2000 Nobel Prize in medicine, maintains an active lab at Columbia University and mentors younger scientists. "I think I do science better than I did when I was younger," he says. "In science, judgment is so important, and I now have a better understanding of which problems are important and which aren't."

Growing awareness that old brains aren't necessarily senile brains is already fueling a slew of consumer offerings. Brain exercises developed for older adults by Posit Science Corp. in San Francisco are being offered by retirement communities, senior centers and assisted-living facilities, as well as by insurers such as Humana to their Medicare enrollees. The computer-based program includes exercises intended to improve memory and attention, as well as sharpness of hearing. Continuing, peer-reviewed studies conducted by Posit scientists suggest it can roll back the mental agility calendar by at least a decade.

Some retirement communities and assisted-living centers are installing a touch-screen-based cognitive fitness program developed by Dakim Inc. of Santa Monica, Calif., that gives seniors practice on seven cognitive skills, including language and the kind of visual-spatial processing that helps you read a map.

Discoveries of brain functions that hold up, or even improve, through the decades could affect corporate and public policy. As baby boomers age, many are resisting mandatory retirement. Air-traffic controllers are asking federal agencies to reconsider the requirement that they retire at age 55, and the Federal Aviation Administration in January proposed pushing back the mandatory retirement age for commercial pilots, currently at 60.

The emerging neuroscience is on their side. One of the most robust cognitive abilities is semantic memory, which is recollection of facts and figures. "Semantic memory is relatively resistant to the effects of aging," says psychology professor Arthur Kramer of the University of Illinois at Urbana-Champaign. Semantic memory includes vocabulary, which increases with age so reliably (at least in people who continue reading) that a younger person should never challenge a sharp 75-year-old to a crossword puzzle.

Expert knowledge -- information about an occupational or even hobbyist specialty -- resists the effects of aging, too, which is why mumbling "accrued post-retirement liabilities" to an 80-year-old actuary makes his relevant synapses fire as robustly as they did at age 40. Synapses that encode expert knowledge "are written in stone," says neuroscientist John Morrison of the Mount Sinai School of Medicine in New York.

The longevity of expert knowledge and cognitive templates lies behind the finding that air-traffic controllers in their 60s are at least as skilled as those in their 30s. When Kramer and a colleague at the Massachusetts Institute of Technology gave older controllers standard lab tests for reaction speed, memory, attention and the like, they found the usual: Performance declined compared with that of 30-somethings.

But on more fast-paced, complex -- and hence realistic -- tests in which they juggled multiple airliners and handled emergencies, the senior controllers did as well as or better than the young ones. They kept simulated planes safely away from each other, and when they ordered planes to change their altitude, heading or speed to avoid a collision, they used fewer commands than younger ones. It was as if their experience had equipped them with the most efficient algorithm for keeping the planes safely spaced.

The findings, Kramer says, suggest the need to revisit "the whole notion of when we need to retire people."

That 60-somethings can mentally juggle multiple 747s seems to go against the idea that aging hurts the ability to pay attention. But studies show that selective attention, the ability to focus on something and resist distractions, doesn't decline with age. For controllers, that means they can focus on planes in their sector despite a hubbub of activity in the control tower.

For other seniors, it means no problem keeping eyes and mind on a highway despite flashing road signs or noisy passengers.

The biggest benefit of an older brain is that fewer real-life challenges require deliberate, effortful problem-solving. Where once it took hours of methodical scrutiny to understand a prospectus, for instance, older lawyers and investment bankers can zoom in on crucial sections and fit them into what they already know.

While younger brains solve problems step-by-step, older brains call on cognitive templates, those generic outlines of a problem and a solution that worked before. Yes, older people forget little things, and may have occasional attention lapses, but their cognitive templates are so rich that they more than hold their own. Their brains can keep up even with a diminished supply of blood and oxygen.

As a result, older professionals can readily separate what's important from what's not, a big reason so many of them fire on all cognitive cylinders well past age 65.

"Some things you just need to grind into your system for many years until they become automatic and seemingly effortless," says Naftali Raz of the Institute of Gerontology at Wayne State University in Detroit. "Automatic functions are least sensitive to aging. So, if the decisions are based on knowledge and skill, older folks may have an advantage over younger decision makers just because they have to do less mental heavy lifting."

More research is coming.

The National Institutes of Health, the nation's leading funder of biomedical research, doesn't break out "healthy aging" as a separate budget item, but spokeswoman Linda Joy says more funding is going to studies of people who reach their 60s, 70s and beyond with little or no disease. Scientists hope that by identifying which mental functions are largely untouched by aging, they will be able to develop treatments or exercises to shore up functions that do deteriorate.

The benefits that come to the mind and brain with age extend beyond thinking. They also include a greater ability to put yourself in another person's mind, empathizing and understanding his thought processes -- emotional wisdom.

Civil engineer Samuel Florman, 81, remains active in his Scarsdale, N.Y., construction company and says that as he has grown older, he "has gotten better with people, more understanding of young people and more patient with aggressive ones."

That likely reflects the older brain's greater control over emotions, especially negative ones such as impatience and anger. A 2006 study of 250 people ranging in age from adolescence to their late 70s documented for the first time "positive changes in the emotional brain," according to the Society for Neuroscience, which publishes the Journal of Neuroscience. In the experiment, Leanne Williams of the University of Sydney showed the volunteers pictures of faces expressing emotions. Using fMRI brain imaging, it was found that circuits in "medial prefrontal" areas -- right behind the forehead -- were more active in older people than younger people when processing negative emotional expressions. The greater activity suggests better control of reactions to other people's anger, fear and the like.

Older brains often show a keen emotional intelligence and ability to judge character. Elderly volunteers given a list of behaviors that describe a made-up person ignored irrelevant information (favorite color, place of birth) when asked to judge the person's character and focused on revealing traits better than younger people did, according to research by Thomas Hess, a professor of psychology at North Carolina State University. They were more likely to infer correctly that the person was dishonest, kind or intelligent -- a skill that is arguably more important than the ability to memorize a list of words in a lab experiment.

Mind games

A number of companies have recently introduced brain exercises meant to stop or even reverse the mental decline that comes with normal aging. Few have undergone rigorous testing to measure their effectiveness, but scientists agree that they do at least target abilities, such as short-term memory and attention, that tend to get worse with age.

Adapted from Dakim Inc.:

1. If you get 120 Japanese yen for a U.S. dollar, and a euro is worth $1.25 U.S., how many yen do you get for 20 euros?

A. 300 yen B. 3,000 yen C. 500 yen D. 5,000 yen

2. 40 subtracted from the square of this number is a perfect square. What is the number?

A. 5 B. 7 C. 8 D. 9

3. Each of the following nonsense words can be turned into a common two-word phrase by dividing the word in two and adding the same letter at the beginning of each. For example, "obtory" becomes "sob story."

A. readasket B. encilusher

C. ofthoe D. oonsense

4. Which of the following is NOT a definition of this word: weigh.

A. The watery part of milk separated from the curd.

B. To have importance or consequence.

C. To raise an anchor.

D. To bear down as a burden.

5. Find the word that can be used to fill both blanks -- one using the entire word, and the other using just a portion of the word: She told me my painting of the gods standing watch over Scranton was , not realizing I had only painted it in .

A. inspiring B. breathtaking

C. majestic D. wonderful

Timed exercises from Nintendo Brain Age:

6. Take two minutes to memorize this list of 30 words. Then write down as many as you can remember.

talk city ween jaws fans lime

tail face town claw mule hair

heat card girl this nail tail

roof wait poof tags inch heap

zoom hold band hump card dead

7. Count the number of syllables in the following sentence as quickly as possible: The proof of the pudding is in the eating.

Answer key: 1. B 2. B 3. bread basket, pencil pusher, soft shoe, no-nonsense 4. A 5. C 6. The more, the better. 7. 11

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