The author says Rubbish to the idea that
the brain after 40, or even 50, is all about depreciation and reduction. Older
brains tend to be dense with learning, and use both sides, as opposed to
younger brains that use more of the left or right hemispheres. Enjoy!
kwc
The
Myth of the Midlife Crisis
It's
time we stopped dismissing middle age as the beginning of the end. Research
suggests that at 40, the brain's best years are still
ahead.
By
Gene Cohen, M.D., PH.D.,
Newsweek, Jan. 16, 2006
I
was taken by surprise several years ago when my colleagues started to worry
that I was going through some sort of midlife crisis. I was in my late 40s,
and after two decades as a gerontologist I was pursuing a new passion:
designing games for older adults. My first game, a joint effort with artist
Gretchen Raber, was a finalist in an internationally juried show on games as
works of art. Though I still had a day job directing George Washington
University's Center on Aging, Health & Humanities, I was now working hard
on a second game.
"Are
you turning right on us?" one friend, a neuroscientist, kidded me. He wasn't
talking about politics. He was asking whether I'd scrapped the logical,
analytical tendencies of the brain's left hemisphere to embrace the more
creative, less disciplined tendencies of the right brain. But I wasn't
scrapping anything. As a researcher, I had spent years documenting the
psychological benefits of intergenerational play. Now I was using both sides
of my brain to create new opportunities for myself. Instead of just measuring
and studying the benefits of mental stimulation, I was finding creative ways
to put my findings to work. What my friends perceived as a crisis was, in
truth, the start of a thrilling new phase of my life.
In
thinking about this experience, I realized that our view of human development
in the second half of life was badly outmoded. We tend to think of aging in
purely negative terms, and even experts often define "successful" aging as the
effective management of decay and decline. Rubbish. No one can deny that aging
brings challenges and losses. But recent
discoveries in neuroscience show that the aging brain is more flexible and
adaptable than we previously thought. Studies suggest that the brain's left
and right hemispheres become better integrated during middle age, making way
for greater creativity. Age also seems to dampen some negative emotions. And a
great deal of scientific work has confirmed the "use it or lose it"
adage,
showing that the aging brain grows stronger from use and challenge. In short,
midlife is a time of new possibility. Growing old can be filled with positive
experiences. The challenge is to recognize our potential—and nurture
it.
Until
recently, scientists paid little attention to psychological development in the
second half of life, and those who did pay attention often drew the wrong
conclusions. "About the age of 50," Sigmund Freud wrote in 1907, "the
elasticity of the mental processes on which treatment depends is, as a rule,
lacking. Old people are no longer educable." Freud—who wrote those words at 51
and produced some of his best work after 65—wasn't the only pioneer to
misconstrue the aging process. Jean Piaget, the great developmental
psychologist, assumed that cognitive development stopped during young
adulthood, with the acquisition of abstract thought. Even Erik Erikson, who
delineated eight stages of psychosocial development, devoted only two pages of
his classic work "Identity and the Life Cycle" to later
life.
My
own work picks up where these past giants left off. Through studies involving
more than 3,000 older adults, I have identified four
distinct developmental phases that unfold in overlapping 20-year periods
beginning in a person's early 40s:
§
a midlife re-evaluation (typically encountered between 40
and 65) during which we set new goals and priorities;
§
a liberation phase (55 to 75) that involves shedding past
inhibitions to express ourselves more freely;
§
a summing-up phase (65 to 85) when we begin to review our
lives and concentrate on giving back, and
§
an encore phase (75 and beyond) that involves finding
affirmation and fellowship in the face of adversity and loss. I refer to
"phases" instead of "stages" because people vary widely during later life. We
don't all march through these phases in lock step, but I've seen thousands of
older adults pass through them—each person driven by a unique set of inner
drives and ideals.
What
sparks this series of changes? Why, after finding our places in the world, do
so many of us spend our 40s and 50s re-evaluating our lives? The impulse stems
partly from a growing awareness of our own mortality. As decades vanish behind
us, and we realize how relatively few we have left, we gain new perspective on
who we are and what we really care about. This awakening isn't always easy—it
often reveals conflicts between the lives we've built and the ones we want to
pursue—but only 10 percent of the people I've studied describe the midlife
transition as a crisis. Far
more say they're filled with a new sense of quest and personal
discovery.
"I'm looking forward to pursuing the career I always wanted," one 49-year-old
woman told me. "I'm tired of just working on other people's visions, rather
than my own, even if I have to start on a smaller scale."
While
changing our perspective, age also remodels our brains, leaving us better
equipped to fulfill our own dreams. The
most important difference between older brains and younger brains is also the
easiest to overlook: older brains have learned more than young
ones.
Throughout life, our brains encode thoughts and memories by forming new
connections among neurons. The neurons themselves may lose some processing
speed with age, but they become ever more richly intertwined.
Magnified
tremendously, the brain of a mentally active 50-year-old looks like a dense
forest of interlocking branches, and this density reflects both deeper
knowledge and better judgment. That's why age is such an advantage in fields
like editing, law, medicine, coaching and management. There is no substitute
for acquired learning.
Knowledge
and wisdom aren't the only fruits of age. New research suggests that as our
brains become more densely wired, they also become less
rigidly bifurcated.
As I mentioned earlier, our brains actually consist of two separate
structures—a right brain and a left brain—linked by a row of fibers called the
corpus
callosum.
In most people, the left hemisphere specializes in speech, language and
logical reasoning, while the right hemisphere handles more intuitive tasks,
such as face recognition and the reading of emotional cues. But as scientists
have recently discovered through studies with PET scans and magnetic resonance
imaging, this
pattern changes as we age.
Unlike young adults, who handle most tasks on one side of the brain or the
other, older
ones tend to use both hemispheres.
Duke University neuroscientist Robert Cabeza has dubbed this phenomenon
Hemispheric
Asymmetry Reduction in Older Adults—HAROLD
for short—and his research suggests it is no accident.
In
a 2002 study, Cabeza assigned a set of memory tasks to three groups of people:
one composed of young adults, one of low-performing older adults and one of
high-performing older adults. Like the young people, the low-performing elders
drew mainly on one side of the prefrontal cortex to perform the assigned
tasks. It was the high-scoring elders who used both hemispheres. No one knows
exactly what this all means, but the finding suggests that healthy brains
compensate for the depredations of age by expanding their neural networks
across the bilateral divide. My
own work suggests that, besides keeping us sharp, this
neural
integration
makes
it easier to reconcile our thoughts with our feelings.
When you hear someone saying, "My head tells me to do this, but my heart says
do that," the person is more likely a 20-year-old than a 50-year-old. One of
my patients, a 51-year-old man, remembers how he agonized over decisions
during his 20s, searching in vain for the most logical choice. As he moved
through his 40s and into his 50s, he found himself trusting his gut. "My decisions are more subjective," he
said during one session, "but I'm more
comfortable with many of the choices that
follow."
As
our aging brains grow wiser and more flexible, they also tend toward greater
equanimity. Our emotions are all rooted in a set of neural structures known
collectively as the limbic
system. Some of our strongest negative emotions originate in the
amygdalae, a pair of almond-shaped limbic structures that sit near the center
of the brain, screening sensory data for signs of trouble. At the first hint
of a threat, the amygdalae fire off impulses that can change our behavior
before our conscious, thinking brains have a chance to weigh in. That's why
our hearts pound when strangers approach us on dark sidewalks—and why we often
overreact to slights and annoyances. But the amygdalae seem to mellow with
age. In brain-imaging studies, older adults show less evidence of fear, anger
and hatred than young adults. Psychological studies confirm that impression,
showing that older adults are less impulsive and less likely to dwell on their
negative feelings.
An
editor I know at a New York publishing company provides a case in point. He
was in his 60s, and contemplating retirement, when he realized that he had
finally matured into his job. Despite a sharp intellect and a passion for
excellence, this man had spent much of his career alienating people with
brusque, critical comments and a lack of sensitivity. Now, he told me over
lunch, he was finally beginning to master interpersonal communication. As his
emotional development caught up to his intellectual development, he morphed
from a brilliant but brittle loner into a mentor and a mediator of conflicts.
"I feel like a changed man," he said with a bemused smile. His best work was
still ahead of him.
Clearly,
the aging brain is more resilient, adaptable and capable than we thought. But
that doesn't mean we can sit back and expect good things to happen. Research
has identified several types of activity that can, if practiced regularly,
help boost the power, clarity and subtlety of the aging
brain.
Exercise
physically.
Numerous studies have linked physical exercise to increased brainpower. This
is particularly true when the exercise is aerobic—meaning continuous,
rhythmic exercise that uses large muscle groups.
The positive effects may stem from increased blood flow to the brain, the
production of endorphins, better filtration of waste products from the brain
and increased brain-oxygen levels.
Exercise
mentally.
The brain is like a muscle. Use it and it grows stronger. Let it idle and it
will grow flabby. So choose something appealing and challenging—and don't be
surprised if, once you start, you want to do more. One of the programs I
co-chair, the Creativity
Discovery Corps,
strives to identify unrecognized, talented older adults in the community. A
93-year-old woman we recently interviewed advised us that she might find
scheduling the next interview difficult because she was very busy applying for
a Ph.D. program.
Pick
challenging leisure activities. Getting
a graduate degree isn't the only way to keep your brain fit. An important 2003
study identified five leisure activities that were associated with a lower
risk of dementia and cognitive decline. In order of impact (from highest to
lowest), the winners were dancing,
playing board games, playing musical instruments, doing crossword puzzles and
reading.
Risk
reduction was related to the frequency of participation.
For example, older persons who did crossword puzzles four days a week had a
risk of dementia 47% lower than subjects who did puzzles only once a
week.
Achieve
mastery.
Research on aging has uncovered a key variable in mental health called
"sense
of control."
From middle age onward, people who enjoy a sense of control and mastery stay
healthier than those who don't. The possibilities for mastery are unlimited,
ranging from playing a musical instrument to learning a new language to taking
up painting or embroidery. Besides
improving your outlook, the sense of accomplishment may also strengthen the
immune system.
Establish
strong social networks. Countless
studies have linked active social engagement to better mental and physical
health and lower death rates. People who maintain social relationships during
the second half of life enjoy significantly lower blood pressure, which in
turn reduces the risk of stroke and its resulting brain damage. Social
relationships also reduce stress and its corrosive effects, including anxiety
and depression.
The
brain is like the foundation of a building—it provides the physical substrate
of our minds, our personalities and our sense of self. As we've seen, our
brain hardware is capable of adapting, growing and becoming more complex and
integrated with age. As our brains mature and evolve, so do our knowledge, our
emotions and our expressive abilities. In turn, what we do with those
abilities affects the brain itself, forging the new connections and
constellations needed for further psychological growth. This realization
should embolden anyone entering the later phases of life. If we can move
beyond our stubborn myths about the aging brain, great things are possible.
Successful
aging is not about managing decline. It's about harnessing the enormous
potential that each of us has for growth, love and
happiness.
Cohen
is founding director of the Center on Aging, Health & Humanities at George
Washington University Medical Center. This article is adapted from "The Mature Mind: The Positive Power of the Aging
Brain," published this month by Basic Books, a member of the
Perseus Book Group.
http://www.msnbc.msn.com/id/10753221/site/newsweek/
