SINCE AT LEAST THE 1500s, THE ADAGE
“You can’t teach an old dog new tricks” has
preached the impossibility of schooling older
folks. The trope still manages to color stereotypes
of aging as more of a downhill slide than a jour-
ney toward wisdom. But 16th-century know-it-alls
didn’t have access to 21st-century neuroscience,
and a growing body of research suggests that
late-in-life learning is likelier than Renaissance
pundits could ever have imagined. In fact, educa-
tion does an aging noggin good.
Our brains are bafflingly complex at any age.
The average adult has around 86 billion neurons,
connected by synapses—tiny gaps where these
cells exchange chemical signals. Each head hums
with hundreds of trillions of these connections, all
sending and receiving tiny bits of information and
instructions. During the 20th century, imaging
tools like MRIs and EEGs finally let neurologists
examine how those paths change as our minds
mature, and they revealed that ageist notions of
doddering seniors were quite mistaken.
Throughout life, our noggins constantly re-
wire themselves. Some scientists suspected as
much as far back as the late 1800s. But it wasn’t
until the late 1960s, when British neuroscien-
tist Geoffrey Raisman spied growth in damaged
cerebral regions of rats through an electron
micro scope, that anyone managed to catch them
forging new connections—an ability called neuro-
plasticity. “Molecular changes occur each time we
learn something new,” says Kaitlin Casaletto, a
neuropsychologist at the Memory and Aging Cen-
ter at the University of California, San Francisco
(UCSF). As we encounter novel information, our
brains release chemicals that subtly alter our
synapses and change the organ’s physical form by
blazing new neural pathways. Such tweaks stop
only with degenerative disease or death.
Of course, gray matter isn’t completely im-
pervious to the ravages of time. Just as stature
usually declines over the years, so does brain vol-
ume: Humans lose about 4 percent every decade
starting in their 40s. But that shrinkage doesn’t
necessarily make us slower on the uptake, says
Kristen Kennedy, a cognitive neuroscientist at
the University of Texas at Dallas. “As long as
we are alive and functioning,” she says, we can
alter our neurons with new information and ex-
periences. In ongoing studies in her lab, Kennedy
POPSCI.COM / WINTER 2020 27gives subjects ranging in age from 20 to
98 tests that measure reasoning, execu-
tive function, memory, and information
processing speed. She’s found compara-
ble dexterity across the board.
Starting in late middle age, though,
there does seem to be variation in which
cerebral regions do the work. “On the
outside it might look exactly the same,”
she says. Inside, though, the picture is
quite different. As areas like the cere-
bellum, hippocampus, and prefrontal
cortex— the seat of decision-making and
planning—get smaller, our brains auto-
matically recruit other locations, like a
left-brain region’s right-side partner, to
help carry the cognitive load. PET and
fMRI studies that track blood flow and
oxygenation have spied activity migrat-
ing into those areas during cognitive
tests. How long these cerebral detours
can continue varies from person to per-
son, but brains seem to generally get less
efficient at redirecting traffic as they age.
We can, however, buy more time.
Based on imaging and long-term cog-
nitive research, neuroscientists now
suspect that loading up on novel expe-
riences, facts, and skills can keep our
minds more plastic. New pathways can
strengthen our ever-morphing mental
scaffolding, even as gray matter shrinks.
Conventional fixes like crossword
puzzles and brain-training apps can con-
tribute to mental longevity. In a 2002
study published in Journal of the Ameri-
can Medical Association of 2,800 people
between ages 65 and 94, 87 percent of
the seniors given these games im-
proved processing speed over a six-week
training period. Three-quarters of the
participants assigned reasoning games
improved their scores over the same
period— and surviving subjects main-
tained those gains a full decade later.
Even something as simple as taking a
different route to the grocery store or go-
ing somewhere new on vacation can also
keep the noggin healthy, says Kennedy.
“Anything that’s novel drives your brain
to pay attention,” she says. “At the cel-
lu lar level, it spurs new expression, new
signaling. That’s really good for you.”
A lust for life can further boost brain-
power. Research about aging adults
who take on new enterprises like Latindance, quilting, or traveling with friends
show improved function and memory
as well as a reduced risk of dementia.
One 2002 study of elderly Swedes found
that people who participated in regular
social activities had a 40 percent lower
risk of exhibiting symptoms of dementia
over a nine-year period. And in a 2014
paper in the journal The Gerontologist,
60-to-90-year-old adults who learned to
use iPads performed better on memory
tests than those who didn’t play with the
tablets. “Challenging yourself might be
one of the activities that is most benefi-
cial,” says UCSF’s Casaletto.
Openness—a trait defined by curios-
ity and a desire for knowledge—may also
help folks ace cognitive tests. In one 20-
year study of Swedish adults published in
2010, a group of aging twins who scored
high on personality tests for openness
performed significantly better on vo-
cabulary, memory, and spatial reasoning
assessments than those who weren’t as
adventurous. And a group of middle-aged
and 65-plus adults in a 2019 Japanese pa-
per who reported enjoying trying new
things experienced fewer declines in ab-
stract thinking, logic, and knowledge
retention over a 13-year period than
peers who were more fixed in their ways.
Some folks are born with this take-in-
the-world attitude, but those who aren’t
as genetically gifted aren’t necessarily
out of luck. While genes can encourage an
interest in doing new things, a 2012 study
in the journal Psychology and Aging found
that completing reasoning tasks like puz-
zles and number games can enhance that
zeal for novel experiences—which can,
in turn, invigorate the brain. That’s why
neuroscientist Kennedy hopes we can
kick the “old dogs, new tricks” canard to
the curb. “It’s not that old dogs can’t learn
tricks,” she says, “it’s that maybe old dogs
don’t realize why they should.”