Older really can mean wiser, new analysis shows

FILE--This is a 1955 file photo of Albert Einstein. In the only study ever conducted of the overall anatomy of Einstein's brain, to be published in this week's issue of The Lancet, a British medical journal, scientists at McMaster University in Ontario, Canada, discovered that the part of the brain thought to be related to mathematical reasoning _ the inferior parietal region _ was 15 percent wider on both sides than normal, making Einstein's brain anatomically distinct. (AP Photo/File)
FILE--This is a 1955 file photo of Albert Einstein. In the only study ever conducted of the overall anatomy of Einstein's brain, to be published in this week's issue of The Lancet, a British medical journal, scientists at McMaster University in Ontario, Canada, discovered that the part of the brain thought to be related to mathematical reasoning _ the inferior parietal region _ was 15 percent wider on both sides than normal, making Einstein's brain anatomically distinct. (AP Photo/File)

Behind all those canned compliments for older adults -- spry! wily! wise! -- is an appreciation for something that scientists have had a hard time characterizing: mental faculties that improve with age.

Knowledge is a large part of the equation, of course. People who are middle-aged and older tend to know more than young adults, by virtue of having been around longer, and to score higher on vocabulary tests, crossword puzzles and other measures of crystallized intelligence.

Still, young adults who consult their elders (perhaps when desperate) don't do so just to gather facts, solve crosswords or borrow a credit card. Nor, generally, are they looking for help finding quick solutions to logic problems posed by unfamiliar circumstances. Those abilities, called fluid intelligence, peak in the 20s.

No, the older brain offers something more, according to a new paper in the journal Psychological Science. It suggests that elements of social judgment and short-term memory, important pieces of the cognitive puzzle, peak later in life than previously thought.

Postdoctoral fellows Joshua Hartshorne of MIT and Laura Germine of Harvard and Massachusetts General Hospital analyzed a huge trove of scores on cognitive tests taken by people of all ages. The researchers found that the broad split in age-related cognition -- fluid in the young, crystallized in the old -- masked several important nuances.

"This dichotomy between early peaks and later peaks is way too coarse," Hartshorne said. "There are a lot more patterns going on, and we need to take those into account to fully understand the effects of age on cognition."

The new paper is hardly the first challenge to the scientific literature on age-related decline, and it won't be the last. A year ago, German scientists argued that cognitive "deficits" in aging were caused largely by the accumulation of knowledge -- that is, the brain slows down because it has to search a larger mental library of facts. That idea has stirred some debate among scientists.

Experts said the new analysis raised a different question: Are there distinct, independent elements of memory and cognition that peak at varying times of life?

"I think they have more work to do to demonstrate that that's the case," said Denise Park, a professor of behavior and brain science at the University of Texas at Dallas. "But this is a provocative paper, and it's going to have an impact on the field."

IQ TESTS

The study evaluated historic scores from the popular Wechsler intelligence test, and compared them with more recent results from tens of thousands of people who took short cognitive tests on the authors' websites, testmybrain.org and gameswithwords.org. One drawback of this approach is that, because it didn't follow the same people over a lifetime, it might have missed the effect of different cultural experiences, said K. Warner Schaie, a researcher at Penn State University.

But most earlier studies have not been nearly as large, or had such a range of ages. Participants on the websites were 10 to 89 years old, and they took a large battery of tests, measuring skills like memory for abstract symbols and strings of digits, problem solving and facility in reading emotions from strangers' eyes.

At least as important, the researchers looked at the effect of age on each type of test. Earlier research had often grouped related tests together, on the assumption that they captured a single underlying attribute in the same way a coach might rate athleticism based on a person's speed, strength and leaping ability.

The result of the new approach? "We found different abilities really maturing or ripening at different ages," Germine said. "It's a much richer picture of the life span than just calling it aging."

Processing speed -- the quickness with which someone can manipulate digits, words or images, as if on a mental sketch board -- generally peaks in the late teens, Germine and Hartshorne confirmed, and memory for some things, like names, does so in the early 20s. But the capacity of that sketch board, called working memory, peaks at least a decade later and is slow to decline. In particular, the ability to recall faces and do some mental manipulation of numbers peaked about age 30, the study found.

SIZING UP STRANGERS

The researchers also analyzed results from the Reading the Mind in the Eyes test. The test involves looking at snapshots of strangers' eyes on a computer screen and determining their moods from a menu of options like "tentative," "uncertain" and "skeptical."

People in their 40s or 50s consistently did the best, the study found, and the skill declined very slowly later in life.

The picture that emerges from these findings is of an older brain that moves more slowly than its younger self, but is just as accurate in many areas and more adept at reading others' moods -- on top of being more knowledgeable.

The older mind may be better able to head off interpersonal misjudgments and to navigate tricky situations. "As in, 'That person's not happy with all your quick thinking and young person's processing speed -- he's about to punch you,'" said Zach Hambrick, a psychology professor at Michigan State University.

The details of this more textured picture of the aging brain are still far from clear, and it is not apparent from the new analysis exactly what causes changes in cognition with age.

But for now, the research at least gives credence to the notion that older people can be wily.

ActiveStyle on 04/20/2015

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