Older People’s Brains Notice More But Filter Less

A small study shows that elderly people notice patterns even when those patterns aren’t useful

brain older man
Ben Hupfer/Corbis

In recent years, as researchers have begun to appreciate of the workings of an aging mind, the old saying "you can’t teach an old dog a new trick" has turned out to be wrong—for both canines and humans. Learning may be harder for adults than it is for children—possibly because adult brains hold on to extra information—but the benefits of experience can beat out the slowing of the brain’s gears. And, when they need to be, the brains of older people are actually quite flexible.

In a new study, published in Current Biology, seniors were just as good at a visual learning task as younger people. In fact, they were better at seeing some obvious but seemingly irrelevant patterns. Ten young people and ten seniors looked at slides with six letters and two numerals against a background of moving dots. They were asked what numbers they saw. Geogrey Mohan writes for the Los Angeles Times:

But it was perception of the dots that was being tested. Researchers tinkered with how many of those wandering dots moved in a “coherent” way from frame to frame. Some proportions were so small that they were below the threshold of conscious detection, while others were too obvious to ignore. But it turns out these too-obvious patterns were ignored — but only among the young, the study showed.

The older participants noted the dots even when they didn’t think that information would be important. That habit could be helpful in some cases but distracting in others, the researchers told the Times. “If you learn more unnecessary things, then there is a risk of replacing important, existing information in the brain with something trivial," said researcher Takeo Watanabe of Brown University. Further tests revealed that the more irrelevant information there was, the less able older people were able to filter, according to a news release

This might explain why new tasks, especially those that come with a lot of distractions (ahem, the internet) might be more challenging for older people. But Watanabe has hope that some kind of training could teach people how to ignore the unnecessary. (That skill would probably be helpful for people of all ages, actually.)