How the Body Knows Its Mind_The Surprising Power of the Physical Environment to Influence How You Think and Feel

by Sian Beilock

  Carl Cotman, director of the Institute for Brain Aging and Dementia at the University of California, Irvine, and his colleagues want to know how exercise improves brainpower. One biological mechanism that Cotman believes may be at the root of exercise’s positive effect on mental health is brain-derived neurotropic factor. BDNF and related growth factors are sometimes loosely referred to as “brain fertilizers” because they help support the survival of existing neurons and the growth of new ones. Rats that run on wheels have increased levels of BDNF in their hippocampus, one of the brain areas important for learning and memory. Not only did these rats show increases in BDNF levels, but the more they had, the better they performed on different sorts of cognitive challenges. Likewise BDNF increases after a short bout of exercise in humans.20

  Interestingly, carrying a certain copy (called allele) of the gene encoding BDNF, specifically, the methionine-specifying (Met) allele at amino acid 66 of the BDNF gene, is associated with reduced secretion of BDNF and poorer working memory in healthy adults. Exercise has been found to be particularly beneficial in terms of enhancing working memory for Met carriers. Greater levels of physical activity seem to offset the deleterious effect that the Met version of the gene has on cognitive horsepower.21

  The increase in BDNF levels that exercise affords might benefit folks with dementias such as Alzheimer’s disease, the most common cause of dementia in those sixty-five and older. Because Alzheimer’s is characterized by a reduction in the number of neurons in brain areas such as the hippocampus, and because exercise helps support neurons in this part of the brain, exercise may help to slow the progression of the disease.22 Indeed people with Alzheimer’s who enroll in a twelve-week moderate exercise program show improvements in memory and brain functioning. After exercising, their brain worked more efficiently to do the same memory tasks they had completed before the program.23

  Exercise might even be a successful preventative measure, taken like a vaccine to prevent the onset of Alzheimer’s. Though intense aerobic exercise is particularly effective, you don’t have to run miles on the track to keep your brain healthy; even washing dishes, cleaning, gardening, and cooking are linked to a reduced likelihood of developing Alzheimer’s. Older adults who are physically active are often less likely to develop the dementia than their sedentary counterparts.24

  The aerobic part of exercise seems key for improving mental health. The increase in blood flow that occurs when we swim, run, cycle, walk briskly, or even do household chores at a vigorous pace is an important part of propelling BDNF in the brain. Aerobic exercise is a catalyst for the appearance of the metabolic nutrients necessary to think sharply. Activities such as strength training and stretching don’t result in the production of growth factors in the same way.25 But when exercise is sufficiently aerobic, it actually alters the structure of our brain. The volume of the brain usually shrinks as we get older, and less brain means less power to think, reason, and do pretty much everything we need to do. But exercise slows this shrinkage. Recently neuroscientists found that the size of the hippocampus of older adults who walked for forty minutes around a track three times a week for one year increased by about 2 percent. Those who took part in a stretching routine instead showed the typical age-related decline in size of about 1.5 percent over the course of a year. Even later in life exercise can protect and improve the structure of our brain.26

  Regardless of the specific cellular and molecular cascades created by increased exercise, there is a clear link between exercise and cognition. Mens sana in corpore sano, the ancient Romans wrote, which roughly translates as “A sound mind in a healthy body” and shows that the mind-body connection has been known for thousands of years. Exercise helps grow new connections in the brain and strengthen existing ones; older adults who exercise have the brains of much younger people; young kids who are the most physically fit score highest on important tests of achievement; and people who exercise regularly report worrying less and are less depressed than their sedentary counterparts. Though we are increasingly reliant on technology that keeps us in our seats, the power of movement is clear. The key to a better brain is rooted in the actions of the body.

  Interestingly, it’s not just exercise that alters the structure and functioning of the brain. Being sedentary can also change the makeup of the brain—though not necessarily for the better. In rats, physical inactivity has been linked to alterations in brain areas that are important for regulating the cardiovascular system, which sets up sedentary rats (and, likely, people) for hypertension and an increased risk of cardiovascular disease. Being active affects your brain in positive ways, and being idle affects your brain in unhealthy ways.27

  Your activity not only affects brain functioning; it can also provide a window into how your mind is operating. Take walking. Doctors used to think that signs of slow walking were just a normal part of the aging process. They were wrong. It turns out that slow or unstable walking is often an indicator of subtle cognitive impairments. Many of the same brain circuits that control complex cognitive activities also help us coordinate the complex movements needed to walk down the hall. Using walking to assess cognition represents a real departure from how mental fitness is normally assessed in older adults: while they are sitting down. Many neuroscientists studying the aging mind firmly believe that, when older adults go to the doctor and get their eyes and their blood pressure checked, they should get their walking checked too. Even subtle signs that walking is slowed or impaired may tell doctors that something important is going on in the brain.28

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  Whether or not your goal later in life is to dominate on the track like Olga Kotelko, having a fit body is good for the mind, and it is also good for the pocketbook. Recent estimates suggest that reductions in hospital, nursing home, and home care costs associated with increasing physical activity as we age would save tens if not hundreds of billions of dollars each year.29 Because keeping older adults physically healthy means that they are sharper mentally as well, encouraging structured exercise regimens may be one of the best ways to keep older adults independent longer. The end result would be less burden on their family, the health care system, and taxpayers. In the United States, there seems to be more emphasis on being mentally fit than being physically fit, so perhaps campaigns that emphasize the brainpower benefits of exercise will be more effective than those promising a perfect body. Of course, if an exercise regimen were a mandatory part of health care coverage—or at least provided big reductions in fees for those who participated—the savings could be as impressive as it would be to see Olga Kotelko run the 100-meter dash.

  CHAPTER 10

  Buddha, Alexander, and Perlman

  USING OUR BODY TO CALM OUR MIND

  Meditation from the Neck Down

  Even though I’ve been doing yoga and meditating for the better part of a year, I’m still struggling to master a practice called Ujjayi breath, or cobra breathing. The goal is to breathe in and out through the nose deep into the throat, letting your diaphragm do all the work of controlling the speed and intensity of your breathing. When done right, Ujjayi breath makes a sort of rhythmic swooshing sound that conjures up memories of the ocean or the wind. My Ujjayi breath doesn’t sound much like anything.

  I’ve had countless teachers try to explain cobra breathing to me, and now I am hearing about it yet again. As I sit cross-legged in a simple wood-paneled room tucked into the lush jungle in Puerto Rico, I can’t help but notice that my surroundings are certainly conducive to mastering Ujjayi breath and the calm mind that goes with it. Yet instead of finding a rhythm, I am starting to hyperventilate. My mind is all over the place, first wandering to the question of what I am going to eat for lunch after my meditation lesson and then to worries about all the work I left unfinished back in Chicago.

  My friend and I arrived at the Casa Grande Mountain Retreat the previous night. Home to an old coffee plantation, the retreat has sleeping rooms and a meditation studio perched on stilts on the mountainside
. Folks come from around the globe to take lessons from world-renowned meditation teachers like Jack, who is now coaching me through my breathing. In his late fifties and famous for promoting the idea that having a healthy body is a key to a healthy mind, Jack sees the body as a vehicle for changing the mind. He believes that having a fit body can actually enhance your ability to focus your attention, regulate your emotions, and even improve your memory. Meditative practices hone a connection between body and mind.

  Of course, Jack is not alone in his focus on the body. Eastern cultures have long valued the body as much as the mind in promoting healthy well-being. Philosophers, artists, and playwrights also frequently tout the connection between the brain and the rest of the body. The poet Ovid said, “The mind ill at ease, the body suffers also.” It works the other way around too: when you have trouble reining in your body, your mind tends to run wild.

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  Most of the time, we are thinking about what is not happening. We’re reviewing past events or anticipating what is likely to happen in the future. Indeed this sort of “mind-wandering” is thought to be our brain’s default operating mode. Although being able to think about what isn’t going on around us can help us learn from the past and productively reason about the future, this lack of attention to the present comes at an emotional cost. Simply put, a wandering mind is an unhappy mind. People report being less happy when their mind is jumping all over the place rather than being calmly focused on the now.1

  It turns out that there is something we can do to decrease our mind-wandering: meditation. Experienced meditators report less drifting in their thoughts during meditation practice than people who don’t have a lot of meditation experience, and even when meditators are simply asked to not think of anything in particular, their brain does a better job of keeping them present-focused and in the moment. Meditation also teaches us how to control our body. Mindfulness meditation is a prime example of this body-centered focus.

  Mindfulness plays a central role in many forms of meditation and usually includes two main components: attending to your immediate experience and having an attitude of acceptance toward this experience.2 Critically these experiences are not centered solely in the mind; they also incorporate the body. Take a look at the instructions for two types of mindfulness meditation, concentration and choiceless awareness:

  Concentration: “Please pay attention to the physical sensation of the breath wherever you feel it most strongly in the body. Follow the natural and spontaneous movement of the breath, not trying to change it in any way. Just pay attention to it. If you find that your attention has wandered to something else, gently but firmly bring it back to the physical sensation of the breath.”

  Choiceless Awareness: “Please pay attention to whatever comes into your awareness, whether it is a thought, emotion, or body sensation. Just follow it until something else comes into your awareness, not trying to hold on to it or change it in any way. When something else comes into your awareness, just pay attention to it until the next thing comes along.”

  As you can see, these techniques focus on the body as well as the mind. The idea is that, through a combination of body and mind training, you change both your physical and mental states. And it works, according to a number of studies. In one study, a group of neuroscientists from Yale, Columbia, and the University of Oregon asked several experienced meditators and a group of meditation novices to perform different types of mindfulness meditations while their brain was scanned using fMRI. Brain areas that are commonly active when our mind wanders are quieter in experienced meditators—while they’re meditating and even when they are not. This is interesting because meditators’ brains looked different when they are doing nothing at all. Mediation changes how the brain physically operates all the time.

  At rest, meditators’ brains showed stronger cross-talk between bits of cortex typically involved in mind-wandering and areas involved in self-control, specifically brain networks that help us keep what we want in mind and distracting information out, encompassing areas such as the anterior cingulate cortex and the prefrontal cortex. The brains of the meditators seemed to have developed the ability to automatically set off a warning signal when mind-wandering threatened to take over, allowing for the dampening of thoughts that could have led their attention astray. Meditation had transformed their brain so that even when they are not doing anything at all, their experience resembles a meditative state, a more present-centered state of mind. One key element of these practices is learning how to recognize what’s going on, not just in your mind but in your body too, which trains you to rein in your wandering mind.

  Of course, it’s possible that the meditation experts the neuroscientists studied didn’t learn to curb their wandering mind through meditation. Maybe, instead, these folks were attracted to meditation in the first place because they were endowed from birth with minds that don’t wander as much as yours or mine. But a host of recent work showing the power of meditation—and especially the power of meditative practices involving the body—suggests otherwise. Meditation helps change our mind. For instance, mindfulness meditation can help alleviate anxiety and chronic pain and even reduce symptoms of obsessive-compulsive disorder. Mindfulness helps us to develop a heightened awareness of the present moment. By attending to your body and your thoughts nonjudgmentally, you can learn to think about your feelings as events that will soon pass, which limits the importance you attribute to them. When you don’t get caught up in a cycle of worries, chronic anxiety and depression are lessened and you reduce the chances that you will experience emotional distress.

  Mindfulness changes the brain in ways that lead us to distance ourselves from, well, our self. We all have a capacity for mindfulness to a certain extent. Training this capacity has a quieting effect on brain areas associated with our vigilance toward ourselves and the negative emotional reactions that often arise when we start focusing on events in the past or become wrapped up in the “what ifs” of the future. By considering thoughts and feelings as transitory mental events that can be separated from ourselves, we are less likely to worry, and positive health outcomes follow.

  Given the benefits of meditation, it’s no wonder that such techniques have become widespread, even outside of yoga centers and spas. They are now embraced by politicians, celebrities, and athletes, as well as health-conscious laypeople. When he was coaching Michael Jordan and the Chicago Bulls to several successive championships, Phil Jackson became well known for advocating meditation as a means of enhancing his players’ performance. Successful individuals ranging from leaders of Fortune 500 companies to politicians have also touted the benefits of meditation practices in their everyday and work lives. The Dalai Lama himself has donated time and money to the study of the brain science of meditation; with the neuroscientist Richard Davidson at the University of Wisconsin, he is contributing to the founding of the Center for Investigating Healthy Minds. Davidson, who has practiced meditation for the better part of twenty years, has spent the past several years researching the power of mindfulness in adults and children, teaching meditation that focuses on both the mind and the body to fifth graders, for example.3

  Changes That Last

  A few years ago, researchers set out to document the brain changes associated with several months of juggling practice. That’s right, the art of being able to coordinate multiple flying objects in the air so as to keep them aloft, not falling down at your feet, alters the brain physically. They found that when people devoted several hours a week to learning how to juggle, they showed changes in areas of the cortex involved in tracking motion. These brain areas became more dense with neurons, which generally signals better communication among brain cells. But when people stopped their intensive juggling practice, these motion-understanding brain areas that had grown more lush with practice thinned out again.4

  In contrast, meditation’s effects on the brain are long lasting. Researchers at the University of California, Davis, led by the neuroscientis
t Clifford Saron, recently put the longevity of mediation’s benefits to the test and found that meditation works a lot like a vaccine.5 You just need boosters every so often to reap the positive impact. Saron and his team invited experienced meditators to participate in a three-month residential meditation retreat at the Shambhala Mountain Center in the Colorado Rockies. This was not a part-time meditation study; people who took part in the program got at least five hours of training a day, so the researchers were careful to recruit people who had some meditation experience and knew what they were getting into.

  More than a hundred people applied to take part in the retreat (and to complete the researchers’ concentration tests that went along with it). Volunteers ranged in age from twenty-one to seventy and were from a variety of backgrounds. Thirty were selected to take part in the first retreat; another thirty participated in a second retreat right after the first. It was a clever idea to stage the study this way because it meant that Saron and his team could compare the minds of the first group to those in the second group, people who hadn’t yet participated in the program. The second group, by the way, was flown to Colorado to take part in the concentration testing sessions with the first group in order to make sure that everyone was administered the tests under the same conditions.