Boost Your Brain (17 page)

Changing Brain Structure

While Davidson and his team were busy in Wisconsin, a research team led by my colleague at Harvard, neurobiology researcher Sara Lazar, was also at work, studying how meditation affects the structure and size of the brain.

Lazar had long been interested in the effects of mental training on the brain. An avid runner, she’d suffered an injury in 1994 that led her to taking up yoga, which combines physical and meditative exercises. Before long, she realized yoga was far more than mere physical therapy. “It had a profound effect on how I view the world,” she says now. Yoga, Lazar felt, had changed the way her brain operated. “Being a scientist, I thought, how is this working?”

In 2005, Lazar and colleagues added to the small but growing body of research on the topic with their study of the effects of mindfulness meditation on the brain.
⁶
For the study, the team compared the brains of fifteen non-meditators with those of twenty people who practiced insight meditation, which involves focusing attention on internal experiences. These were fairly devoted meditators—on average they meditated for about forty minutes a day, although the length of time they’d been practicing meditation ranged from a year to several decades.

When the research team compared the MRIs of meditators with the control group, they found that those who meditated had a thicker cortex in certain parts of the brain, compared to those who hadn’t meditated. What’s more, meditation appeared to slow the cortical thinning that’s a normal part of aging. Incredibly, in one area of the brain the thickness of the cortex of forty- to fifty-year-old meditators was similar to that of twenty- to thirty-year-olds. In other words, portions of their brains actually looked
decades
younger than expected.

Still, there was the inevitable question: Did meditation lead to a thicker cortex, or was having a thicker cortex part of what drew people to meditation in the first place?

Lazar and colleagues aimed to find out. To do so, they enlisted sixteen healthy adults who were enrolled at the University of Massachusetts Medical School’s Center for Mindfulness in a mindfulness-based stress reduction (MBSR) course.
⁷
None had meditated in the prior six months and all had had no more than ten meditation classes in their lifetimes. In other words, they were novices when it came to meditation. They ranged in age from twenty-five to fifty-five years old.

Participants were given MRIs before beginning a program of mindfulness meditation and again after eight weeks of weekly two-and-a-half-hour meetings plus one full-day class. During these periods of instruction, participants were trained in mindfulness strategies, including awareness of present-moment experiences, a “body scan” during which they sequentially focused their attention on sensations affecting various parts of the body, mindful yoga, and sitting meditation.

They also used forty-five-minute recorded, guided mindfulness exercises to practice daily at home. To integrate mindfulness into their daily lives, participants were even told to practice it informally whenever they could—while walking, washing the dishes, folding laundry. Over the eight-week course, the meditating group reported spending about three hours a week on their homework exercises.

The results, published in 2011, reported that the meditators all saw an increase in the size of their hippocampi, plus increases in the size of the posterior cingulate cortex, the temporoparietal junction, and the cerebellum—areas involved in learning and memory, emotional regulation, self-referential processing, and perspective taking. Changes were significant enough to be detected on MRI with the naked eye. No such brain growth was seen in the control group.

Of course, the study size was small and participants were people actively seeking out stress reduction. It’s also possible that other aspects of the meditation classes helped spur growth in grey matter, say the study authors. The classes, after all, involved social interaction, stress education, general learning, and even gentle stretching exercises.

Lazar’s wasn’t the only study to document changes to the brains of meditators, however. A team of researchers led by UCLA’s Eileen Luders has offered up the results of its study of twenty-two meditators and twenty-two non-meditators.
⁸
Those in the meditating group practiced a variety of styles and had been practicing meditation between five and forty-six years, with an average of twenty-four years. Most meditated daily and many included deep concentration as part of their practice.

MRI imaging showed meditators had “significantly larger volumes” in their hippocampi and increased grey matter in the area of the brain associated with controlling mood and drive. It didn’t seem to matter what style of meditation the volunteers practiced either. No one style of meditation showed a greater effect than another.

Luders and colleagues also looked at the effect of meditation on brain pathways, this time using diffusion tensor imaging (DTI), for a study published in 2011.
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Looking at twenty-seven long-term meditators and twenty-seven non-meditators, the team found significantly greater integrity of white matter—the brain’s highways—throughout the brains of the meditators, indicating stronger connectivity.

You’ll remember from chapter 1 that the integrity of these highways in the brain is vital for optimal brain performance. Keeping the highways running smoothly doesn’t just mean messages will pass quickly; it actually helps to keep the neurons alive and strong, helping to maintain and grow the brain.

Try It at Home

I highly recommend meditating under the guidance of an experienced teacher, at least until you’ve learned a technique. That’s not because meditating is hard, but it does take some getting used to. At my Brain Center, we often find that patients have a hard time clearing their minds of extraneous thoughts at first, but after three or four sessions—and a little help from Dr. Sahin—they find it much easier.

There are many different methods, but the one we use at my Brain Center is performed like this:

Start by sitting on a comfortable chair in a quiet room with the lights dimmed. (You may find it enjoyable to add quiet, gentle music with no lyrics.)

Close your eyes. Try to clear your mind and push away extraneous thoughts. Whenever a stray thought comes to mind during the course of your meditating, just push it gently aside. Remember to count slowly at each step.

Breathe in using abdominal breathing and slowly count to three. Breathe out and count to three.

Focus your attention on your
toes
. Imagine a tingling sensation there. Relax your toes.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your
calves
. Relax your calves.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your
thighs
. Relax your thighs.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your
abdomen
. Relax your abdomen.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your
shoulders
. Relax your shoulders.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your
neck
. Relax your neck.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your
chin
. Relax your chin.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your
cheeks
. Relax your cheeks.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on the spot right between your
eyebrows
. Relax your eyebrows.

Breathe in and count to three. Breathe out and count to three.

Imagine you are in a field with green grass as far as you can see. In the distance is a big, beautiful tree. Imagine yourself walking toward that tree. Sit down under it and relax.

Breathe in and count to three. Breathe out and count to three.

Allow yourself to notice any thoughts, feelings, or sensations that come to mind. Don’t analyze them; just note them. You’re simply paying attention, not thinking of them as good or bad or trying to think more deeply about them. Do this for five minutes.

Breathe in and count to three. Breathe out and count to three.

Imagine yourself standing up and leaving the tree, walking back to where you started.

Breathe in and count to three. Breathe out and count to three.

Focus your attention on your toes. Imagine a tingling sensation there. Relax your toes.

Continue focusing on the parts of your body until you reach the spot between your eyebrows. Once you do, you may either start at your toes again or open your eyes and end your session.

How Much Is Enough?

Davidson, Lazar, Luders, and others are still at work unraveling the mysteries of meditation. One question yet to be answered is just how much—or, rather, how little—meditation we need to experience changes in our brains.

The effect of meditation varies by person—some may experience dramatic improvements while others report more modest gains—but Davidson points to evidence that as little as two weeks of meditation can produce “discernible changes in the brain.”

In my practice, I often find that patients enrolled in our brain fitness program report improvements in as few as two weeks, but the strongest results occur after participation in a twelve-week program that includes weekly meditation sessions.

Often patients start haltingly, taking a few sessions to become comfortable meditators. Once they’ve reached that point, however, they’re much more likely to meditate at home and incorporate mindfulness into their daily lives, increasing the time they spend meditating as the weeks go on. By about week four, I typically recommend that patients meditate thirty minutes a day, four days a week. And although many report improvements in mood, state of mind, and even cognitive function very early in the program, I usually find that it takes twenty to thirty sessions to form a habit of meditating—and to experience the substantial benefits that come with sculpting your brain.

Neurofeedback: Harnessing the Power of Alpha

Once a week a fortysomething patient of mine named Robert settles into a comfortable leather chair in a small room at my Brain Center. In front of him is a large flat-screen computer monitor attached to a standard laptop. On one ear is a sensor similar to those used for EKG in heart monitoring. Sensors about half the size of a penny are also placed on various spots on his scalp.

Robert is about to take part in a session of neurofeedback, a type of biofeedback that uses electroencephalography, or EEG, to capture and display brain activity on a computer monitor, with the ultimate aim of helping him reduce the symptoms of a concussion he suffered in a skiing accident.

The sensors applied to Robert’s scalp record his brain’s activity as he watches a computer display. (The electrode on his ear is merely there to cancel out ambient electrical signals.) When he started the brain fitness program Robert’s EEG showed excessive slow activity (theta waves) in the front of his brain and excessive fast activity (beta waves) toward the back—a pattern that’s attributable to his concussion.

For his neurofeedback session, though, Robert is here to do more than just have his brain activity recorded. Robert is using regular neurofeedback sessions, under the watchful eyes of our EEG brain trainer Nicole Merrill, to retrain his brain and raise his levels of healthy alpha activity. In addition, like an orchestra playing in sync, after training the various parts of Robert’s brain will begin to operate in a harmonious fashion, each playing its own part but in a way that complements the others (a notion author Jim Robbins details in his book
A Symphony in the Brain
¹⁰
). To get there, Robert just needs to practice. With neurofeedback, a passive therapy, he’ll do that without even realizing it.

On the display, Robert will see a scene—in this case a landscape of mountains. Robert must simply look at his scenery. A brain computer interface—his brain connecting with the computer—will do the rest. As he watches the screen, the computer will track his brain waves and produce a quiet beep every time it records alpha activity. That beep is a reward of sorts. It tells Robert’s brain to continue producing alpha waves. Amazingly, his brain will do just that, with no conscious input from him.

The reward reinforces the behavior until eventually Robert’s brain trains itself to operate in the alpha zone even when he’s not attached to sensors. This is the simplest version of brain plasticity at work. And it mimics the way our brains work in our everyday lives: rewards shape our behavior. If someone tells you that you look pretty in your pink sweater, for example, you might find yourself reaching for pink the next time you’re at the mall. Get a kind word or a smile from your spouse when you bring in the newspaper, and you’ll be more inclined to do it again the next day.