Our brains might slow down as we age, but we compensate for it by paying more attention to what we do. A new study from the Ruhr University in Germany shows how the clever tricks our brains use to effectively slow the effects of aging.
One ability that changes as we age is our brain's ability to categorize the information streaming in. This is essential, because it helps us to avoid doing things like eating poison berries. Categorization learning is largely visual, but also relies on attention. When we are young, we find it easy to add new things to our internal categories. However, as we age, this ability slows down.
In a test, conducted with 10 elderly subjects and 17 young subjects, participants were asked to sort colored circles into two categories. Both groups found it easy to sort circles which were similar—their performance was equal. But when asked to sort "exceptions," or circles which were significantly different from the norms established in the test, the elderly participants had problems.
The essential finding here, though, is that the old folks still performed the tasks properly in the end. They just got there in a different way. In order to compensate for the brain’s decreased ability to categorize on the fly, they paid more attention to the exceptions. That is, as we age, we have to pay closer attention to things than when we’re young. Attention was measured using and EEG and eye-tracking.
And it’s not just categorization that suffers. The authors cite previous studies which show other age-related changes, including a "decline in processes involved in maintaining and updating information in declarative memory." Declarative memory is the kind of long-term memory we use when we consciously recall facts and experiences.
Paying more attention isn’t the only way we work around our brain’s slow decline. We also minimize the effort needed to complete a task. In the same way as person on crutches might carefully plan any journeys to other rooms in the house to minimize wasted trips, our brains plan our eye movement to be more efficient. We’re also better at suppressing task-irrelevant information, in part due to better knowledge of what is and isn’t relevant to the task at hand.
So, really, you could sum this up as youth versus experience. Our brains run at full-tilt when we’re young, but waste a lot of that energy. Not that it matters, because—at that age—we have energy to spare. As we get older, we make better use of our limited resources. If only we could have both. One is put in mind of that great quote from George Bernard Shaw (or perhaps Oscar Wilde), that "youth is wasted on the young."
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