Secret Life of the Grown-Up Brain (25 page)

“People have to understand that there is a direct relationship between the physical growth of the brain and how you use it,” Merzenich said, “and as the idea sinks in that we can drive positive changes in the brain, it is empowering.”

At the moment, though, it’s still extremely hard to prove that any of the brain-training programs work outside the lab and carry over into real life. In the study of Merzenich’s system, in fact, there was only a hint that this was true. Those who completed the training said they “perceived” that they were better at remembering phone numbers and names in their actual lives. Those who had simply watched educational DVDs reported no such improvement. Those who completed the training also had higher levels of those helpful growth factors in their blood.

“But we just don’t know,” conceded Zelinski. “We just don’t have good data on how this translates into the real world. You can’t really follow people around and see if they’re forgetting stuff.”

Still, we know enough now to at least get started or think about getting started. Zelinski fervently believes we should get going now—and take the tougher road.

“Crossword puzzles are not enough. You are mostly trying to find words you already know,” she said. “We need to challenge our brains. It should be something hard for you—not so hard that you lose focus—but hard. We need to get out of our comfort zones.”

Concerned herself, Zelinski is doing whatever she can to maintain the power of her fifty-five-year-old brain. She is taking piano lessons.

“My son is eighteen and he’s been playing since he was in third grade and he can read music and beautiful things come out of his fingers. I wanted to be able to do that. I had this longing,” she said. “So when I had a sabbatical, I started taking lessons. It’s very slow and hard and to do it you have to find a teacher who will work with you. But, hey, they work with five-year-olds.”

One small study showed that a group of sixty-year-olds who trained themselves on piano were, after six months, better on cognitive tests. Zelinksi readily admits that such a tiny and “cute” study does not equate with firm evidence. We still have no idea how many sonatas or sound whooshes it takes before our lazy neurons wake up, or if we have to do it in some particular order, or if it will really make a difference in the end.

Still, how can it hurt? Most of us with memory issues are not headed for dementia, but since dementia begins in the brain long before it’s evident, how can we be sure? As Zelinski pointed out, “It will be thirty years until we know,” so we might as well “prepare for the worst and start moving.”

Along the way, we might as well try to enjoy ourselves, too, because our moods are also surprisingly important to our brains. Boxes of studies have found that people who are less grumpy, less lonely, happily married, or otherwise entwined with their fellow human beings or even their pet beagle have a lower risk of developing heart disease or Alzheimer’s, a better chance at staying mentally alert, and a greater likelihood of a long life. One recent study in England found that people in middle age who simply popped down the street to their neighborhood pub on a regular basis had better cognitive skills than their sit-at-home neighbors.

It’s true that many of these mood-brain-health connections have, through the years, also had the classic chicken-and-egg problem. It’s entirely possible that happy, optimistic, pub-hopping sorts are a special breed to begin with, perhaps much more likely to take other steps that improve their health, such as taking their blood pressure pill on time or eating their carrots. It’s also possible that those who are more social are simply healthier overall, with no secret disease cooking away to make them cranky.

Lately, though, more controlled studies have gotten a much better handle on the question. These are true comparison studies that have one group doing something specific, say, joining a choir, and another sitting at home. Then the two groups are compared in a serious, head-to-head way. And those studies, which try to eliminate other possible influences, such as gender, obesity, smoking, and levels of education, now routinely report exactly the same thing that the earlier softer studies found: Being sociable and cheery is good for both body and mind.

One recent study by researchers at Johns Hopkins University, for instance, found that men and women who volunteered to tutor students through a group called the Experience Corps at Baltimore schools had a slower rate of decline in their memories than those who were put in the nonvolunteer control group.

And that was the case even though both groups started out with similar levels of cognitive function. The volunteers also significantly decreased TV watching at home and reported that they felt much stronger physically (the students did better in school, as well).

My own personal favorite of this current rash of “be-social” studies was a recent one by researchers at the medical school at the University of Miami that looked at how architecture might improve the brains of sixteen thousand older residents living on one block in the Little Havana section of Miami. The study found that those who simply lived in houses or apartments with balconies that faced the street and encouraged neighborly chattiness had better cognitive function than those who did not have such architectural benefits.

Even self-image may matter. A study by Becca Levy, a psychologist at Yale University, found that the memories of older people improved after simply seeing positive words about aging. In Levy’s study, the words were flashed too quickly for people to be aware that they had read them, but nevertheless, on some level they had an effect. People did poorly if they first saw negative words, such as
decline, senile, decrepit, dementia,
and
confused.
But memories significantly improved if they were first exposed to positive words about aging, such as
wise, alert, sage,
and
learned.

Similarly, Thomas Hess, the psychologist at North Carolina State University, found that attitudes are self-fulfilling. In his studies, older people did worse on memory tests if they were first told something negative about growing old, such as that the upcoming study was on how aging affects learning and memory. But if they were first told something positive, such as that there was not much of a decline in memory with age, their memories on the tests improved. Another recent study, which keyed in on our competitive natures, found that people in middle age and older did better on cognitive tests if they were told they were being tested with younger rather than older people.

It’s not known precisely how self-image, rich social connections, or peppier moods affect the brain. But there are some good—and fascinating—hints.

One candidate is stress. If social interactions can ease stress—and that means you have to pick your friends carefully, of course—the brain benefits. Unrelenting stress, in particular sustained levels of stress-induced cortisol, kills neurons in the memory-rich hippocampus. Depression, too, has been linked with a smaller hippocampus.

And there’s emerging evidence that our brains are set up from the get-go to cooperate, so they may work better if we do. One brain-scanning study by the National Institute of Neurological Disorders and Stroke found that when participants made a choice to share some money they were given rather than keep it for themselves, the brain’s reward center became active, the same dopamine-releasing area that comes alive with sex, chocolate cake, and cocaine.

And then there are mirror neurons. Over the past few years, neuroscientists have discovered an entire new class of brain cells that appear to exist primarily to help us recognize and feel the joy and pain of others. These mirror neurons may be one of the strongest neurobiological underpinnings of our drive to connect—and yet another reason why we have to be fairly careful with whom we are connecting. Mirror neurons make emotions contagious.

Even the story of the discovery of mirror neurons is fascinating. About twenty years ago, a team of Italian neuroscientists went out for lunch and left a research monkey hooked up to electrodes. When they returned and walked into the lab, one of the researchers lifted an ice cream cone to his mouth. As he did this, bells and lights started going off, indicating that the areas of the monkey’s brain that corresponded with lifting a hand to a mouth to eat something also became active. The monkey was not eating an ice cream cone, but in his brain he was.

From that surprise finding, the field of mirror neurons exploded. It’s now thought that mirror neurons, which are scattered in pockets all over our brains, are what help us understand the motives and actions of others. It is our mirror neurons that make us “feel” the pain of the character in the movie who’s being dumped by his girl-friend or the fear of a kidnap victim with a gun to her head.

“When we watch the movie stars kiss on screen some of the cells firing in our brains are the same ones that fire when we kiss our lovers. . . .” writes Marco Iacoboni, a neurologist at UCLA, in
Mirroring People.

“When we see someone else suffering or in pain, mirror neurons help us to read his or her facial expression and actually make us feel the suffering or the pain of the other person. These moments . . . are the foundation of empathy and possibly of morality, a morality that is deeply rooted in our biology.”

And there’s increasing evidence that being with other humans helps tone our brains’ dendrites as well. Being social is hard and complicated and it taxes the brain.

“People forget how difficult and complex a task social interaction is,” says Denise Park, the neuroscientist in Dallas. “There are a lot of demands just in meeting new people. You have a name and face and you have to integrate that name with that face. And that new person will have personal history they’re telling you. And you will be telling them things about yourself. And the next day when you see them again you have to bring all that back to mind. Social engagement, sustained social engagement, is cognitively very demanding.”

When I spoke with her, Park had just finished the pilot phase of a new study to test this further. In the study, socially isolated middle-aged and older adults come to a center to learn digital photography and quilting. While learning these new skills will help, Park expects that a large part of the benefit will arise from the human interaction itself.

After the initial part of the study, Park will scan the brains of participants to see if there is increased brain volume in areas associated with learning complex tasks such as quilting or photography. But she expects to see the impact of being socially engaged as well.

As we’ve said, the brain as it ages has a tendency to wander, to get distracted. Park believes we need to find ways to keep the brain from slipping into its disengaged default mode. She, too, thinks we have to retrain our brains to get back to younger habits. And it’s possible that simply being socially engaged will help keep that default mode at bay. Something as seemingly simple as chatting with a friend may push a brain out of its daydreaming tendencies and instead activate powerful, focus-tuning frontal regions. Park and a number of others now believe that we need to—and can—find ways to jump-start our brains
out
of that default mode, teaching them to “call in the troops, the frontal lobes, when they need them.”

But we also have to remember that science, try as it might, can’t study everything. No doubt we already do a fair amount of good things for our brains; we just don’t appreciate them enough—or give them their due.

As I mentioned earlier, after a brain science conference in Washington, D.C., I had dinner and then shared a cab with scientists Denise Park and Laura Carstensen. In the cab, Carstensen told a funny story about how she had given her two-year-old grandson a present that she’d bought at a gag store, a duck that laid an egg. She said she had shown him how it worked, squeezing the duck to push out an egg, but he didn’t get it, he was too young. In fact, she said, he was “horrified.” Carstensen’s attempt to amuse her grandson had laid an egg.

It was a silly story, but—well, we’d all had some wine—it made all three of us laugh. And as Carstensen continued to tell the story and we continued to laugh, the cab driver, an elderly man whose gray hair peaked out from under a worn watch cap, turned around and grinned.

“You know,” he said, “you all have the secret of life. Laughing is the secret. You will never get old.”

Wisdom from cab drivers is one of the oldest clichés around, of course. But if we know anything in middle age, it’s that many of the world’s clichés turn out to be true.

Epilogue

A New Place for Better, Longer Lives

So what, then, shall we do with our indefatigable, our inestimable—our newly appreciated—middle-aged brains?

Perhaps it’s time for a middle-age revolution.

After all, we have numbers on our side. For all of our planet’s history, children have outnumbered grown-ups. A huge pile of the young has been the base of a population pyramid that tapered off toward the top, with progressively dwindling numbers of older people.

But that has already changed. More than 500 million people worldwide are sixty-five and older. By 2030, one in every eight people on earth will be middle-aged or older. For the first time in history—and possibly for the rest of human history—people over the age of sixty-five will outnumber those under the age of five.

Not surprisingly, there’s a fair amount of agitated hand wringing about all of this. And it’s not just about keeping Social Security funded. Already some believe that any planet filled with so many older humans is a planet in peril, brimming with brains that have already begun to slide.

But what if that peril can be averted. If we keep pushing down our blood pressure, sidestepping strokes, taking that brisk walk, many of us could remain in one fairly well-oiled piece. With emerging evidence that our middle-aged brains are already considerably better than similar middle-aged brains were twenty years ago, and as education levels and wealth continue to climb, there’s more than a fighting chance that this good-news trajectory will continue.