A study in 2014 showed that older learners retained the mental flexibility needed for a visual perception task but were not as good as younger people at filtering out irrelevant information.
The findings undermine the conventional wisdom that the brains of older people lack flexibility, or “plasticity,” but highlight a different reason why learning may become more difficult as people age: They learn more than they need to.
Researchers call this the “plasticity and stability dilemma.”
“Plasticity may be kept okay, in contrast with the view of many researchers on aging who have said that the degree of plasticity of older people gets lower,” says Takeo Watanabe, professor at Brown University and corresponding author of the study, which was published in Current Biology.
“However, we have found that the stability is problematic. Our learning and memory capability is limited. You don’t want older, existing, important information that is already stored to be replaced with trivial information.”
Distracting Dots
To conduct the study, Watanabe and his team enrolled a group of 10 people between the ages of 67 and 79 and another group of 10 people ages 19 to 30 for an experiment.
Over a nine-day period, they trained on a simple visual exercise: After they were shown a quick sequence of six symbols—four letters and two numerals—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.
