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Study Finds Life’s Jolts Speeds Process of Aging

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From Associated Press

Aging is characterized by abrupt declines in mental ability often caused by personal experiences like forced retirement or a heart attack, according to a long-term study that suggests some precautions.

The 33-year Seattle Longitudinal Study has tracked the intellectual ability of more than 4,000 people ranging in age from their 20s to their 90s.

“What we have to do now is document scientifically what anecdotally we have seen all along--that people don’t age the same way,” said K. Warner Shaie, head of Penn State University’s Gerontology Center.

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Most aging studies have looked at group averages for different age groups, rather than tracking changes in individuals over time, Shaie said. Every seven years, the Seattle study researchers test five areas: verbal meaning, spatial orientation, inductive reasoning, and number and word fluency.

People maintain their mental abilities, on average, into their 60s, Shaie said. “From then on, on average, you can find some decline.”

By 67 more than half the participants showed declines in reasoning ability, though verbal ability didn’t decline for most until their late 70s.

“Inductive reasoning tends to decline sooner because it involves speed of response,” Shaie said. “Between age 20 and 60, reaction time approximately doubles, so any skill requiring high levels of speed is vulnerable.”

Researchers recently looked at 838 participants who had suffered a significant drop in one or more of the five abilities over the previous seven years, and found a link to jarring events in their lives, such as the death of a spouse, Shaie said. People who are open to change and continue to learn either formally or informally tend to age more slowly.

“It’s more of a use-it-or-lose-it proposition,” he said.

Some of the major risk factors are an unstimulating or sedentary life, low education level with no effort to continue learning and heart disease, he said.

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As part of his research, Shaie also studied 120 people age 60 or older who had shown significant declines in mental ability.

Their abilities in many cases were improved by five hours of cognitive training sessions, in which trainers led subjects in a series of increasingly difficult mental exercises. For example, to improve spatial orientation, the subjects were told to mentally rotate increasingly abstract objects.

“Can you teach an old dog new tricks? The answer to that is of course you can teach an old dog new tricks,” Shaie said.

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