Cognitive Aging

I think that many of us who work in the field of aging and mental abilities sometimes may forget to explain some key terms and phrases to patients. One of the most general and frequently used is the phrase cognitive aging. What does it mean?

Cognitive Aging refers to how our mental capacities change over time. It may seem as though all of our abilities go downhill after age 30 or 40, but research shows that isn’t completely true. The truth is that some abilities decline over time, some stay about the same, and some actually improve as we get older. For example, psychomotor speed is an ability in which most people perform more poorly over time. The precise definition of psychomotor speed varies from study to study, but it’s often assessed by tests that ask you to do some kind of task that requires that you think and to something with your hands as quickly as you can. One task is called a pegboard. A piece of metal attached to a block of wood has rows of holes in it, a little like the kind of pegboard you might put up in your workshop to hold tools. The person being evaluated is asked to put small metal pegs in the board as quickly as he or she can. This is the sort of thing that younger persons in general do much better than older persons do.

Another ability that may decline over time is called working memory. This ability is usually assessed by asking someone to keep a couple of things in their minds and then do something with them. The person being evaluated might be given a series of numbers and then asked to repeat them backwards –  he or she has to remember the numbers and then somehow mentally read them backwards. Being asked to do mental arithmetic problems also taps working memory. Here, the person being assessed might have to remember some elements of the problem that are given, might have to access some existing knowledge (like how many quarts are in a gallon), and then do a calculation.

What abilities may actually get better over time? Things that don’t require speed or working memory, but may benefit from life experience. The most common example is vocabulary. Many older adults score better than their younger counterparts on tests of how many words they know. Older adults probably have had more opportunities to learn words, and once a word is in long-term memory, older adults can recall it pretty well. Some people have also suggested that because of the benefits of experience, older adults are better able to discern patterns in events around them. Finally, some research has shown that older adults are better than younger persons at certain kinds of problem solving, especially when it involves social skills or awareness of social issues.