Contrary to popular belief, aging doesn't necessarily lead to slower brain function.

Two Ohio State University psychology professors recently summarized a decade’s worth of research concluding that healthy older people can be trained to respond as quickly in some decision-making tasks as younger adults and children. In fact, their conclusions suggest that when older adults exhibit slower reactions to situations it may be due to a desire to be accurate rather than fast.

“Many people think that it is just natural for older people’s brains to slow down as they age, but we’re finding that isn’t always true,” said Roger Ratcliff, professor of psychology at Ohio State University. “At least in some situations, 70-year-olds may have response times similar to those of 25-year-olds.” Ratcliff’s studies, in collaboration with Gail McKoon, also a psychology professor at Ohio State and co-author, appear in December’s Child Development journal.

For almost 10 years, Ratcliff and his colleagues have studied cognitive processes and aging in their lab. Their work focused primarily on the elderly and young adults comparing cognitive responses. Only recently did they begin to include children in their research. Ratcliff said the results in children are what most scientists would expect: very young children have slower response times and poorer accuracy compared to adults and these improve as children mature.

The more interesting finding, however, is that older adults don’t always have slower brain processes compared to younger people, said McKoon.

“Older people don’t want to make any errors at all and that causes them to slow down. We found that it is difficult to get them out of that habit, but they can with practice,” McKoon said.

Ratcliff, McKoon and others who participated in the studies over the years conducted similar experiments in children, young adults, and the elderly. In one study, participants were seated in front of a computer screen. Asterisks appeared on the screen and the participants had to decide as quickly as possible whether there was a “small” number (31-50) or a “large” number (51-70) of asterisks. They pressed one of two keys on the keyboard, depending on their answer. In another experiment, participants were again seated in front of a computer screen and were shown a string of letters. They had to decide whether those letters represented a word in English or not. Some strings were easy and some were hard. In the child development study, the researchers used the asterisk test on second and third graders, fourth and fifth graders, ninth and tenth graders, and college-age adults. Third graders and college-age adults participated in the word/non-word test as well.

In another study published in the journal Cognitive Psychology, Ratcliff compared college-age subjects, adults aged 60–74, and others aged 75-90 using the asterisk and word/non-word tests. They found that there was little difference in accuracy among the groups, even the oldest of participants.

“For these simple tasks, decision-making speed and accuracy is intact even up to 85 and 90 years old,” McKoon said.

The findings don’t mean there aren’t effects of aging on decision-making speed and accuracy, however. In an article for the Journal of Experimental Psychology, Ratcliff, McKoon and another colleague found that accuracy for “associated memory” does decline as people age. For example, older people were much less likely to remember if they had studied a pair of words together than did younger adults.

Overall, Ratcliff and McKoon’s studies should provide optimism that the cognitive skills of seniors can remain intact and active throughout their later years.

“We’re finding that there isn’t a uniform decline in cognitive processes as people age,” Ratcliff said. “There are some things that older people do nearly as well as young people.”

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Creative Commons image by By Shaun D Metcalfe. Used with permission.