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While elderly people have slower response times when they have to make quick decisions in some settings, new research suggests much of it is a conscious choice to emphasize accuracy over speed (Child Development, online, Dec. 26).
"Some think it is natural for older people's brains to slow down as they age, but that isn't always true," said co-author Roger Ratcliff, PhD, of Ohio State University. "In some situations 70-year-olds have response times similar to those of 25-year-olds."
"Older people don't want to make errors," so they slow down, said co-author Gail McKoon, PhD. "It is difficult to get them out of the habit, but they can with practice."
The researchers used a model developed by Dr. Ratcliff that considers both reaction time and accuracy. In one experiment asterisks appear on a computer screen, and subjects have to decide quickly if the number is small (31-50) or large (51-70). In another experiment a string of letters appears, and subjects have to decide if the letters form a word.
There was little difference in accuracy between college-age adults and two groups of older adults, ages 60-74 and 75-90. However, the college students had faster response times. But when the older adults were encouraged to go faster, the difference in response times decreased significantly.
"Decision-making speed and accuracy is intact even up to 85 and 90 years old," Dr. McKoon said.
While accuracy for associative memory declines as people age, the new research suggests greater optimism about the cognitive skills of seniors, Dr. Ratcliff said. "There isn't a uniform decline. Older people do some things nearly as well as young people."
The research was supported by the National Institutes of Health.
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