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

by Sian Beilock

  Second, students were asked to take a fifty-minute walk through either the Ann Arbor Arboretum or through downtown Ann Arbor. They did not get to choose which walk they went on. Both walks were 2.8 miles long, mapped out ahead of time, and everyone wore a GPS watch to ensure that they followed the prescribed route. The Arboretum is largely tree-lined and secluded from traffic and people. In contrast, those who took the downtown walk were led down traffic-heavy Huron Street, flanked with university and office buildings. After all the students got back to the lab, they performed the computer tasks again.

  Third, a week later, the students returned and repeated the whole procedure, except that they walked in the environment they had not initially walked through. The results were clear. When students walked through the Ann Arbor Arboretum, they scored better on the tests of directed attention after their walk than before. The scores of students after walking through downtown Ann Arbor did not improve. Some environments simply bring out the best in people.

  In fact, you don’t actually have to take a walk in the woods to reap nature’s brainpower benefits. In another study, Kaplan and his colleagues found that simply spending ten minutes (yes, just ten minutes) looking at pictures of Nova Scotia scenery improved people’s concentration compared to when they looked at pictures of cityscapes from Ann Arbor, Detroit, and Chicago. Just as Kuo found that being able to see greenery out your window increases cognitive functioning, gazing at pictures of nature offers many of the same benefits.

  The ability to concentrate is important because it enables people to mentally buckle down and stay on a task long enough to make progress. By mildly engaging our involuntary attention and letting those directed attention skills have a rest, we allow nature to rejuvenate the very cognitive processes that are so important for performing at our best. This new research tells us that nature’s effects aren’t simply peacefulness or quiescence alone. Rather, nature’s ability to modestly capture our involuntary attention and give the rest of our brain a break creates a big impact on how we function.

  Interacting with nature may have the biggest impact for people who are down in the dumps. Walking in nature leads to larger gains in working memory for people with symptoms of depression compared to healthy folks. Mood also improves after a nature walk. Interacting with nature has even been shown to have cognitive benefits for women with breast cancer who are burdened with worries about their cancer, medical treatments, and longevity. The mental fatigue that goes with depression and major illness can be combated by being in a natural, restorative environment.12

  City Living

  Humans evolved in natural environments, and we seem to thrive in them. Yet it’s estimated that by the year 2050, 69 percent of people in the world will live in urban areas. There’s no denying that there are many positive aspects of city living, such as easy access to health care, food, and other services (at least for some), but there are some downsides too. City living tends to be socially stressful; whether it’s competing to get into the best schools and top restaurants or trying to find adequate housing or simply an open parking space, people who live in urban environments constantly battle with others for limited resources.

  Scientists speculate that this battle of city living alters the human mind—and not necessarily for the better. Meta-analyses, in which scientists have aggregated the results of hundreds of studies, show that city dwellers are at a 20 percent increased risk for developing anxiety disorders and a 40 percent increased risk for mood disorders compared with people who live in less populated areas. Even more striking, the incidence of schizophrenia is almost doubled in people born and brought up in cities relative to those who were not. Simply put, on average, people have more mental distress and lower well-being when they live in urban areas with little green space. Of course, a link between urbanization and mental health doesn’t necessarily mean that city living in itself is the problem. There could be some other factors that push people toward an urban lifestyle and also contribute to mental health problems. But scientists like Andreas Meyer-Lindenberg at the University of Heidelberg in Germany think there is good evidence to show that city living itself does the damage. Using schizophrenia as an example, Meyer-Lindenberg points out that there is a large dose-response relationship for the occurrence of this brain disorder, meaning that the longer you live in a city, the more likely you are to develop schizophrenia. It’s hard to explain how the length of time you’ve lived in a city could be systematically related to your chances of developing schizophrenia without implicating the city itself as the driving factor.

  A few years ago, Meyer-Lindenberg and his research team set out to better understand the link between urbanization and the brain.13 The scientists began by inviting volunteers from a variety of backgrounds—some who were born and raised in big cities, others who lived in small towns—to have their brain scanned. During scanning, the volunteers performed a horribly difficult set of math problems, designed to ratchet up the type of stress that often accompanies city living; average scores were between 25 and 40 percent. The volunteers wore headphones in the scanner so they could hear the researchers tell them they were failing miserably.

  Having someone repeatedly point out that you are screwing up is a surefire way to induce social anxiety in most people, and those in the study showed big spikes in their cortisol level after finishing the math problems. More surprising, Meyer-Lindenberg and his colleagues found that people who currently lived in cities showed increased activation in the amygdala (relative to folks who lived in small towns or rural areas) while they were being berated by the researchers. As noted in previous chapters, the amygdala is a major player in our emotions; among its many functions, it signals environmental threat. It has also been implicated in anxiety disorders, depression, and violence—all of which are increased in cities relative to rural areas. Increased amygdala activity often coincides with unpleasant emotional reactions. Simply put, living in an urban environment goes hand in hand with an increased sensitivity to social stress.

  The researchers found that where participants had grown up also mattered in their reactions: the more densely populated the area, the more active their anterior cingulate cortex was during the stressful performance situation. Like the amygdala, the ACC is highly involved in emotional reactions; indeed it works closely with the amygdala to help make sense of our emotions. But the ACC has another function too: when something goes wrong, it emits a neural alarm signal that lets the rest of the brain know that something is amiss. People who had grown up in the city and currently resided there showed the most amygdala and ACC activation in response to induced stress.

  To make sure the results were not a fluke, Meyer-Lindenberg and his colleagues ran the study again with a new group of volunteers. They even ratcheted up the intensity of social stress: the entire time the volunteers were doing the math, they could see a video feed of a disapproving investigator watching them fumble. This time the volunteers didn’t just have to listen to someone comment on their failure; they had to watch him as well, grimacing and frowning every time an answer was wrong. In this second group, too, city living was associated with increased activity in the amygdala and ACC under stress.

  A skeptic might argue that these findings have nothing to do with social stress and everything to do with the fact that people had to perform a demanding cognitive activity—solving math problems—in the scanner. Maybe city folks just show more activation in emotional brain networks when they perform difficult tasks. But the researchers took care of this criticism by scanning volunteers’ brains while they performed the math task alone, without the disapproving experimenter. When there was no social stress, the link between city living and brain activation disappeared.

  Interestingly, the amygdala and ACC aren’t associated just with stress; they also relate to our social network size. The bigger these brain regions, the larger and more complex our social networks are. Because the amygdala and ACC are major players in our emotional reactions, it makes sense that they
would be at the center of a brain network important for socializing, helping us recognize whether somebody is a stranger or an acquaintance, friend or enemy.14

  Perhaps city living and the varied social interactions that come with it furnish city dwellers with bigger brain equipment to deal with the complex situations they face. If so, this would be consistent with something known as the “social brain hypothesis,” the idea that through evolution, living in larger, more complex social groups led to a selection bias for larger brain regions with a greater capacity for performing important social computations, such as learning who is who and remembering many faces and relationships. Across different primate species, those who live in larger social groups tend to have a bigger amygdala relative to those who don’t, even when controlling for overall body and brain size. Of course, people better equipped with the brainpower for socialization might travel to urban environments where social interactions are prevalent. Regardless, with bigger equipment also likely comes an increased risk of malfunctioning. Because city dwellers constantly use this equipment to deal with difficult social situations they frequently encounter, the equipment may stop working the way it should, becoming hypersensitive when even mild forms of stress come its way.

  Our interactions with others not only affect our responses to stressful situations; they can also affect how we feel about our ability to face challenges. As we saw a few chapters back, when we are out of shape, our lack of energy impacts how difficult we think various activities will be to perform. When people are asked to estimate how steep a hill is, they view the incline as more extreme when they are out of shape or wearing a heavy backpack. We get information from our body about how demanding it will be to walk up the hill, and with this information we judge its physical qualities. The same thing happens when we are psychologically depleted—when we have had a stressful interaction, a fight, a heated argument, or just think about someone who has betrayed or disappointed us. Having a friend close by—or just thinking about a supportive friend—can change how difficult we perceive it will be to face a challenge; people judge hills as less steep and difficult to traverse when they are accompanied by a friend. However, this power of friendship depends on the quality of the relationship. The longer you have known the person, the closer you are, and the greater the interpersonal warmth, the more being next to her or just thinking about her lessens the impact of the hill. When you think about someone toward whom you feel ambivalent, you will see the hill as steep and treacherous to climb.15

  Perception of the physical world is not determined solely by the environment itself, such as how steep a hill actually is, but is also shaped by how much energy it would take to negotiate the space or situation. When our physical resources are depleted (due to age, fatigue), hills appear steeper; when we are psychologically taxed, the same thing occurs. When we have friends around, however, the situation changes. Social support changes our mind and eases our judgment about a task’s difficulty. It also reduces our physical reactivity to stress. For instance, the cardiac stress reaction that is often created by challenging mental tests is smaller when you are accompanied by a supportive person than when you are alone.

  This notion that social support can change how we think about physical challenges—that our psychological feelings of inclusion and happiness can seep into and affect how we feel about facing physical challenges—supports the view of depression as an inability to change the physical world. Indeed depression often goes hand in hand with learned helplessness, a phenomenon in which people (and other animals) don’t feel they have control over a particular situation or outcome, so they stop trying to reach a goal. When you feel psychologically helpless, physical challenges, such as getting out of bed, loom larger than they are. Perhaps helping depressed individuals act, to physically move, can help alleviate the depression.

  Changing how the body moves in the world is one way to do this. As we saw in the first chapter, people who have had Botox treatments, who can’t move their face as easily into a frown, show fewer depressive symptoms and are slower at understanding negative information than folks who don’t have this facial paralysis. If depressed individuals can be encouraged to move around and to act in ways that contradict the feeling of a lack of control in their psychological life, they may feel better mentally. When people feel as if they can’t take a step forward to put their life back on track, actually taking steps—putting one foot in front of the other—may be advantageous. Our brain doesn’t always make a distinction between a physical act and a psychological emotion, so experiencing physical control should lead to increased feelings of psychological control.

  Feeling depressed or sad is often described as feeling down or low. Recent research suggests that depressed individuals are more likely to orient their attention downward in visual space compared to people who are not experiencing this negative emotional state. The very act of looking up or standing upright might very well help to lessen depressive symptoms.16

  Encouraging folks who feel down in the dumps to think about how they can physically act differently might help too. A study conducted with Canadian Olympic swimmers who had “choked” at the Olympic trials or on the Olympic stage supports this idea. When Team Canada’s sport psychologist, Hap Davis, and a group of neuroscientists used fMRI to peer inside the brains of these swimmers as they watched videos of their failed races, they found decreased activity in important motor areas of the brain that we use to take action. They also saw a lot of activity in emotional centers of the brain associated with anxiety. But after sport psychologists worked with the athletes to help them have a sense of control over their future swims—to specifically think about what they would do differently with their body in their next big race (a smoother stroke or getting off the blocks faster)—their brain showed less activity in the negative emotion centers and more activity in motor regions the swimmers needed to do their best.17

  Gaining insight into how we are physically going to alter our failure experiences changes our feelings about whether or not we will be able to succeed the next time around.

  * * *

  Our body and our surroundings affect how we think, reason, act, and experience emotions and feelings much more than we ever imagined. From the way we contort our face, to how we move our hands to gesture, these signals don’t just travel in one direction, from the mind to the body. The messages that the body sends to the mind are just as important. In school, in work, and in our relationships, how we act has a big effect on how we think. Whether we are a weekend warrior trying to win a bet with our buddies on the back nine or watching our favorite NBA star dunk the ball during prime time, our brain’s ability to simulate the outcomes of our actions and the actions of those around us makes the difference between being mere observers and feeling as if we are part of the team.

  Our mind is always working to replay, understand, and predict what will happen in the world around us. So it’s easy to see that taking breaks can rejuvenate our brainpower. Indeed, after a week in Italy, roaming through the lush gardens of the villa, ignoring my cell phone and email, and generally not taking part in the hurried pace of urban life, I always feel healthier. Physically and mentally. Up until a few years ago, I didn’t give this mental transformation much thought. Perhaps that’s not surprising, given that most of my training as a scientist has pushed me to think about the disembodied mind. But my thinking has changed. I no longer see mind and body as separate, and I no longer envision our mind as software running on a body of hardware. Now I realize that my thinking extends beyond the cortex and that I can use my body to ensure that my mind functions at its best.

  EPILOGUE

  Using Your Body to Change Your Mind

  The body has a strong influence on the mind. Whether it’s learning in school, creativity in the workplace, or success on the playing field or performance stage, there are countless examples of our physical experiences influencing our thinking. Now we know that the line between mind and body isn’t a one-way street. You ca
n use your body, your actions, and your surroundings to change your mind and the minds of those around you.

  Here is a recap of the striking power of the body.

  Your Body as a Tool to Feel Your Best

  ♦ Your facial expressions affect how you feel inwardly and even how you react to stress. Put another way, your face does more than express how you are feeling inside; it actually affects how emotions are registered in the brain. When smiling, you feel happier and recover from a painful experience faster. Laughter also seems to offer positive psychological benefits. There really is something to the adage “Grin and bear it.”

  ♦ Your body has a direct line to your brain and exerts a powerful influence on your mental health and well-being. That’s one reason why physical ailments affect your interpretation of psychological pain and rejection. The opposite is true too: people who are depressed tend to experience a higher rate of physical ailments than those who are mentally healthy. Even more striking, taking Tylenol not only helps ease physical pain but can ease the psychological pains of loneliness and rejection.

  ♦ How you stand can change your state of mind. Standing in a “power pose,” even for just a minute or so, increases feelings of power. On the flip side, your body postures also give clues to others about how you are feeling. A slumped posture tells others you have failed. Your posture can serve as a tool to help you put your best foot forward.