Think about the people in your life who are 65 or older. Some are experiencing the usual mental difficulties of old age, like forgetfulness or a dwindling attention span. Yet others somehow manage to remain mentally sharp.
Why do some older people remain mentally nimble while others decline? “Superagers” (a term coined by the neurologist Marsel Mesulam) are those whose memory and attention isn’t merely above average for their age, but is actually on par with healthy, active 25-year-olds. Physicians at Massachusetts General Hospital recently studied superagers to understand what made them tick.
Researchers used functional magnetic resonance imaging to scan and compare the brains of 17 superagers with those of other people of similar age and succeeded in identifying a set of brain regions that distinguished the two groups. These regions were thinner for regular agers, a result of age-related atrophy, but in superagers they were indistinguishable from those of young adults, seemingly untouched by the ravages of time.
What are these crucial brain regions? If you asked most scientists to guess, they might nominate regions that are thought of as “cognitive” or dedicated to thinking. However, that’s not what was found. Nearly all the action was in “emotional” regions. The researchers were not surprised by this discovery, because they’ve seen modern neuroscience debunk the notion that there is a distinction between “cognitive” and “emotional” brain regions.
This distinction originally emerged in the 1940s, when a model of the human brain with three layers was devised and named the triune brain. An ancient inner layer, inherited from reptiles, was presumed to contain circuits for basic survival. The middle layer, the “limbic system,” supposedly contained emotion circuitry inherited from mammals. And the outermost layer was said to house rational thinking that is uniquely human.
The triune brain became (and remains) popular in the media, but experts in brain evolution discredited it decades ago. The human brain didn’t evolve like a piece of sedimentary rock, rather it evolved by reorganizing as it expanded. Brain areas that were considered emotional, are now known to be major hubs for general communication throughout the brain. They’re important for many functions besides emotion, such as language, stress, regulation of internal organs, and even the coordination of the five senses into a cohesive experience. Research demonstrates that these major hub regions play a meaningful role in superaging. The thicker these regions of cortex are, the better a person’s performance on tests of memory and attention.
Of course, the big question is; how do you become a superager? Which activities, if any, will increase your chances of remaining mentally sharp into old age? The question is still being studied, but the best answer at the moment is: work hard at something. You can help keep these regions thick and healthy through vigorous exercise and bouts of strenuous mental effort.
Our impulse, as we age, may be to avoid hard work. As people get older, research shows, they cultivate happiness by avoiding unpleasant situations. This is sometimes a good idea, as when you avoid a rude neighbor. But if people consistently sidestep the discomfort of mental effort or physical exertion, this restraint can be detrimental to the brain. All brain tissue gets thinner from disuse. If you don’t use it, you lose it.
This means that pleasant puzzles like Sudoku are not enough to provide the benefits of superaging. Neither are the popular diversions of various “brain game” websites. If you want to become a superager you have to really work that brain. One of the top suggested ways to do that is to master a musical instrument. It is never too late!
(this is an excerpt from the NY Times Sunday Review of the book, “Gray Matter” by Lisa Feldman Barrett, a professor of psychology at Northeastern University, is the author of the forthcoming “How Emotions Are Made: The Secret Life of the Brain.”)