Older people can actually take in and learn from visual information more readily than younger people, according to a new study.
This surprising discovery is explained by a decline in the ability to filter out irrelevant information as we get older, according to researchers at Brown University.
“It is quite counterintuitive that there is a case in which older individuals learn more than younger individuals,” said cognitive scientist Takeo Watanabe, Ph.D.
“Older people take in more at the same time as the stability of their visual perceptual learning declines. That’s because the brain’s capacity to learn is limited,” Watanabe said. When we learn something new, there is always a risk that information already stored in the brain may be replaced with new and less-important information.
For the new study, Watanabe and his research team recruited a group of 10 people between 67 and 79 years old and another group of 10 people between the ages of 19 and 30 for an experiment.
Over a nine-day period, they trained on a simple visual exercise. Shown a quick sequence of six symbols — four letters and two numerals — the volunteers were asked to report the numerals they saw. Their performance on a test at the end of training was compared to their score on a pre-test.
The volunteers were instructed to only bother with spotting the two numerals, but each symbol they saw had a background of moving dots, which would move with varying degrees of cohesiveness of direction. In the pre- and post-tests the researchers also asked the volunteers to report the direction of dot movement when they saw the numerals.
The researchers found that older people improved as much as younger people on the relevant task of identifying the two numerals.
But the researchers also found that the older volunteers also took in more about the directional movement of the irrelevant dots than the younger individuals.
The researchers explained that our brains normally have the ability to detect and suppress our attention to obvious and irrelevant features. As features become harder to pick up on, we simply tend to miss them altogether. As a result, we are usually able to ignore or filter out information that is not pertinent to the task at hand.
The fact that older people continued to pick up on irrelevant information suggests a failure of their brains’ attentional systems to suppress task-irrelevant signals, the researchers said.
Watanabe added that the findings will likely apply in other areas of life, since the ability to filter out irrelevant information is generally important to all forms of learning.
The researchers are now using brain-imaging techniques to observe what’s happening in the brains of older people as they learn. With greater understanding, it may be possible to devise strategies not only to help older people learn more effectively, but also to keep them from learning things they really shouldn’t, the researchers concluded.
The study was published in the Cell Press journal Current Biology.
Source: Cell Press