The aging brain

Despite the fact I am still an astonishingly young man, I do find that I occasionally have more trouble remembering things than I did twenty years ago (when, as a precocious six-year-old, I was news editor of the Weyburn Review).

It is, alas, an indisputable fact that our brains change as we age.  However, as I wrote in a previous column on this topic a few years ago (since when I have hardly aged at all) those changes aren’t as drastic as once thought.

About 40 years ago Harold Brody, a New York anatomist, published a study that indicated that the cortex, the “thinking” part of the brain, loses up to 40 percent of its neurons (brain cells) through aging. From those studies came the “common knowledge” that we lose a million brain cells a day.

Fortunately, that common knowledge appears to be incorrect. It is true that the brain shrinks with age. Men’s brains shrink more than women’s: they start out 15 percent larger, on average, but by age 45 they’re the same size–and after that the women’s brains are larger. (I’m 46. My wife is younger. I’m doomed.) But more recent anatomical studies have revealed that the neurons themselves shrink, rather than disappear. 

Decade by decade, the typical cognitive changes caused by aging go something like this: in your 30s, changes in the hippocampus, which helps convert short-term thought to long-term memories, mean you’re a little less likely to remember what you heard on the radio this morning or the names of people you just met.

In your 40s, you may find it harder to discern shapes and colors. As well, if you’re introduced to 14 people at a party, by the time you leave, you’ll remember only 11, whereas in your 20s you would have remembered 13. (Personally, I’d be lucky to remember three.)

By the time you’re in your 50s, you probably couldn’t score as high on an IQ test as you did in your 20s. Your coordination may suffer. You may also find it harder to place an event or remember where you were when it happened.

These changes continue as you grow older.

But now for the good news: Dr. Dennis Foth, a professor in the University of Alberta Faculty of Extension, and his research colleague, Dr. Gordon Thompson of the University of Saskatchewan, recently conducted a meta-study–a study of studies–that revealed that age-related mental declines don’t affect everybody the same way–and, to a certain extent, can be forestalled or even reversed.

It’s true there are pathological forms of cognitive decline about which we can still do little, Alzheimer’s Disease being the best-known example.

But the vast majority–90 percent–of people over 65 do not suffer from a pathological form of cognitive decline. The research indicates that people who are mentally active throughout their lives are those who are less likely to lose mental ability–and better yet, that with a little effort, even people in their 70s and 80s can improve their cognitive skills.

The activities that protect and improve cognitive abilities are those that people do regularly, as part of their everyday lives, such as reading, traveling, memorizing poetry, doing crossword puzzles, playing card games, surfing the Web, learning to play a musical instrument or taking continuing education courses.

In future studies, Foth and his colleagues will try to determine which cognitive skills these various activities improve.  That could lead to mental training programs targeting specific kinds of mental declines.

Foth says people consistently think their memory has declined more than it has. This,  in turn, can sometimes discourage them from undertaking the very activities that might prevent further decline or even improve their cognitive ability.

It appears that in mental training, as in physical training, it’s a case of “use it or lose it.”

Now if you’ll excuse me, I think I’ll do a crossword puzzle… …if only I can remember where I put the book.

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