Editor: one becomes exhausted just reading this. Sit down and have a nice
cup of tea while you're reading it. Then take a nap.
How to Become a ‘Superager
Think
about the people in your life who are 65 or older. Some of them are
experiencing the usual mental difficulties of old age, like
forgetfulness or a dwindling attention span. Yet others somehow manage
to remain mentally sharp. My father-in-law, a retired doctor, is 83 and
he still edits books and runs several medical websites.
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. My colleagues
and I at Massachusetts General Hospital recently studied superagers to understand what made them tick.
Our
lab used functional magnetic resonance imaging to scan and compare the
brains of 17 superagers with those of other people of similar age. We
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, such as the lateral prefrontal cortex. However,
that’s not what we found. Nearly all the action was in “emotional”
regions, such as the midcingulate cortex and the anterior insula.
My
lab was not surprised by this discovery, because we’ve seen modern
neuroscience debunk the notion that there is a distinction between
“cognitive” and “emotional” brain regions.
This
distinction emerged in the 1940s, when a doctor named Paul MacLean
devised a model of the human brain with three layers. 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. Dr.
MacLean called this model “the triune brain.”
The
triune brain became (and remains) popular in the media, the business
world and certain scientific circles. But experts in brain evolution
discredited it decades ago. The human brain didn’t evolve like a piece
of sedimentary rock, with layers of increasing cognitive sophistication
slowly accruing over time. Rather (in the words of the neuroscientist
Georg Striedter), brains evolve like companies do: they reorganize as
they expand. Brain areas that Dr. MacLean considered emotional, such as
the regions of the “limbic system,” 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.
And
now, our 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, such
as memorizing a list of nouns and recalling it 20 minutes later.
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? We’re still studying this question, but our best
answer at the moment is: work hard at something. Many labs have observed
that these critical brain regions increase in activity when people
perform difficult tasks, whether the effort is physical or mental.
You can therefore help keep these regions thick and healthy through
vigorous exercise and bouts of strenuous mental effort. My
father-in-law, for example, swims every day and plays tournament bridge.
The
road to superaging is difficult, though, because these brain regions
have another intriguing property: When they increase in activity, you tend to feel pretty bad
— tired, stymied, frustrated. Think about the last time you grappled
with a math problem or pushed yourself to your physical limits. Hard
work makes you feel bad in the moment. The Marine Corps has a motto that
embodies this principle: “Pain is weakness leaving the body.” That is,
the discomfort of exertion means you’re building muscle and discipline.
Superagers are like Marines: They excel at pushing past the temporary
unpleasantness of intense effort. Studies suggest that the result is a more youthful brain that helps maintain a sharper memory and a greater ability to pay attention.
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. You must expend enough effort that you feel some “yuck.” Do it till it hurts, and then a bit more.
In
the United States, we are obsessed with happiness. But 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.
So,
make a New Year’s resolution to take up a challenging activity. Learn a
foreign language. Take an online college course. Master a musical
instrument. Work that brain. Make it a year to remember.
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