As the program for playing the tune activates cells from different areas of the brain, those different areas need to be closely connected for the program to run well. We can compare it to a computer, where all the different components need to be connected in order to work. If the connections are bad, the computer won’t run, even if each input works well independently.
AS KIDS, WE’RE ALL LINGUISTIC GENIUSES
The fact that connections between brain cells disappear when we are children has lifelong consequences. A child born in Sweden has all the prerequisites for learning to speak fluently in Japanese without any trace of an accent—provided the child is reared in an environment in which Japanese is spoken. On the other hand, learning to speak fluent Japanese without an accent as an adult is next to impossible for most of us. No matter how much we practice, a native-born Japanese will always be able to detect an accent in our speech.
Spoken language features certain sounds that we have enormous difficulty replicating once we’re adults, and that’s because our prerequisites are missing. The brain connections that handle those sounds begin to disappear during childhood because we never hear those sounds being articulated. Once the connections are gone, we have closed the door to those abilities, neurologically speaking, for the rest of our lives. While we’re kids, however, we are all little linguistic geniuses.
So it’s not the brain with lots of brain cells or many connections between cells that functions best, but rather the one in which the different areas—the frontal lobe and the parietal lobe, for example—are closely interconnected, thus possessing everything that’s required to run effective programs. As you’ve already read in the beginning of this chapter, physical activity can create stronger connections between the different parts of the brain. This connectivity is the basis for a number of positive effects your brain experiences when you move your body, many of which you will read about in this book.
The connections reveal how you live your life
It may sound a bit strange that different areas of the brain can all be, to different degrees, well connected to one another, but research has shown that this could in fact be an important reason why cognitive abilities vary among people. Fascinating findings have recently been uncovered in this specific area of research.
For example, advanced brain testing on hundreds of individuals has revealed that different parts of the brain are closely interconnected in the people with sets of qualities deemed positive, such as good memory function and power of concentration, higher education, and carefulness with alcohol and tobacco. In subjects with “negative” qualities, such as poor anger management and the tendency to abuse alcohol and drugs, an opposite pattern has been observed: these areas of the brain are badly linked to one another.
That many positive qualities leave an identical imprint on the brain, and that negative qualities seem to make the opposite type of mark, implies that there is a “positive-negative axis” along which we could all be placed, depending on how we live. Scientists who have performed this study believe that you can see how a person leads his or her life, roughly, by looking at his or her brain’s connectivity pattern. And is there anything else that’s considered a positive sign
along that positive-negative axis apart from good memory, higher education, and caution with addictive substances? Indeed, there is. It’s being in good physical shape.
It looks like it actually may be possible to see, roughly, what kind of life a person leads by looking at his or her brain’s connections.
Judgmental research?
You might believe that this type of research is judgmental or elitist; after all, the mere fact that we are talking about a “positive-negative axis” suggests a sort of ranking of people. I completely understand how it could be interpreted that way, but I also believe that such an interpretation misses the point. Our inherent qualities are not what primarily affects our brain’s connectivity pattern, nor where we are situated along the positive-negative axis. Instead, it is our lifestyle. Through the choices we make, we can change our brain’s operating mode on a more fundamental level than previously thought. It isn’t only our brain that decides how we think and act; our thoughts and actions can also modify our brain and how it works. It is we who run our brain, not the other way around. From this perspective, it is clear that perhaps the most important thing to improve the connection between the different parts of our brain is regular physical exercise; being in good physical condition produces a positive reading on the positive-negative axis.
THE BRAIN CHANGES THROUGHOUT LIFE—NEUROPLASTICITY
“I wish I had learned to play an instrument as a kid; now it’s too late.” Many of us might have had this thought at one time or another. The truth is the brain is extremely malleable during
childhood, making learning everything, from languages to motor skills, swift and natural. But why is it that a child’s brain can learn so much in such a short time, with little obvious effort?
A young child must quickly learn to navigate in the world. In the brain, this is evident from the cells’ enormous ability to not only create connections with one another, but also to break them off (i.e., pruning). This happens at a rate of speed that, as you’ve noticed, will never come back later in life. However, the brain’s capacity for change, which in scientific parlance is referred to as neuroplasticity, is perhaps its most important quality, because even if its flexibility is never as great as when we were children, it doesn’t vanish entirely. It’s still there—even in adults, even in eighty-year-olds. To see exactly how influenceable and changeable the brain is in an adult, we’re going to look at what happened to Michelle Mack, a forty-two-year-old American woman whose remarkable life story has changed our understanding of what the human brain is truly capable of.
The woman who only had half her brain
Michelle Mack was born in Virginia in November 1973. As early as a few weeks after her birth, her parents noticed that something was not right. Michelle was unable to steady her gaze and couldn’t move her limbs normally, especially her right arm and leg. Her parents brought her to numerous specialists to examine her eyes and to see if she had cerebral palsy, which was not the case. None of the neurologists they consulted could explain Michelle’s symptoms, and neither could an X-ray of her brain. In the early 1970s, our modern technologies (i.e., the CAT scan [Computerized Axial Tomography] and MRI [Magnetic Resonance Imaging]) were still in the early developmental stages. At the age of three, Michelle still wasn’t walking, and she could hardly speak. At this point, her physician recommended that another X-ray be scheduled since medical diagnostic techniques had advanced since her first examination. The result of the CAT scan performed in 1977 shocked Michelle’s parents, as well as her physicians. Michelle Mack was missing the entire left side of her brain. She was living with only half a brain, probably due to something that had happened to her while she was still an embryo.
YOUR LIFESTYLE SHAPES YOUR BRAIN
The debate on whether our genes or our environment shapes us has ebbed and flowed over time, often from one extreme point of view to another more stringent opinion. Today we know that it is, of course, neither our genetic makeup nor our environment that decides our fate exclusively, but a combination of both. We also know that genes and environment are closely interwoven, whereby environment affects our genes—our DNA (Deoxyribonucleic Acid)—through biological mechanisms that are incredibly complex.
A few numbers clearly illustrate that it isn’t only your genetic makeup that decides on its own how your brain will develop and how you will turn out as a human being. You possess approximately 23,000 genes. You also have about 100 billion brain cells that, in turn, have around 100,000 billion connections between them. Your 23,000 genes can’t possibly hold sway over those 100,000 billion connections. Quite simply, the brain is far too complex to be governed by an exact predetermined genetic program that is in charge of the brain’s development throughout life.
Your genes set the stage for how
your brain cells are created and die, and how they connect and disconnect from one another. Exactly how this happens, which characteristics you develop, and how you function mentally will be influenced by your life experiences—by what type of environment you live in and not least by what lifestyle you adopt.
The aspect of our lifestyle that this book is all about—physical exercise—is, naturally, not the only factor in how our brain develops. However, research shows that it plays a pivotal role and is way more important than most of us can fathom.
One possibility is that Michelle had suffered a stroke before birth; another is that her left carotid artery had been blocked, depriving the left side of the brain of blood. No one could provide a definitive answer, but one thing was crystal clear: more than 90 percent of the left side of Michelle’s brain was missing.
The left side of the brain is commonly referred to as the analytical and rational part of the brain—the seat of mathematical and linguistic thinking—while the right side is the artistic and creative part. Even though we now realize that this divvying up is an oversimplification of things, it isn’t too far from reality. Bearing in mind the set of responsibilities held by the left side of the brain, many of Michelle’s difficulties suddenly made sense. Her inability to speak properly could be explained by the missing linguistic part of her brain. And since the left side of the brain is also in charge of the mobility of the right side of the body (and vice versa), it’s no wonder she had trouble moving her right arm and leg.
However, it isn’t Michelle Mack’s first years of life that are fascinating, but rather what happened to her later. She successively developed the abilities she had been lacking, at a rate that her physicians had not dared hope for. She learned to walk, speak, and read and otherwise developed somewhat normally, if a little more slowly, than most of her peers.
Today, Michelle lives a normal life in many ways and works part-time in her parish. Her ability to find words is mostly normal, even though that function is typically found in the part of the brain that’s missing for Michelle. Although mobility in right arm and leg is still limited, she has no problem walking.
Tests have shown that Michelle has some difficulty with abstract thinking, but she is endowed with a phenomenal memory for detail. This comes with a highly unusual skill: she can immediately answer what weekday corresponds to a randomly selected date. For instance, if Michelle is asked what day of the week the 18th of March, 2010, falls on, she’ll answer “Thursday” almost instantly.
The right half of Michelle’s brain has taken over the handling of many tasks that her left brain would normally be dealing with. We know from past studies that this could be done on a smaller scale, but few had speculated that such a massive restructuring of the brain, one that could compensate for a missing half, was possible. The rewiring of Michelle’s brain is so extensive that it actually looks a bit crowded in her brain’s right half. In fact, Michelle has issues with visuospatial orientation (i.e., the ability to judge distance and spatial orientation). Visuospatial orientation is normally found in the right part of the brain (which is intact in Michelle), but it is believed that since her brain’s right side is pulling double duty—handling responsibilities for the right and the missing left side—there just isn’t enough room in there.
It’s also probably no accident that Michelle can immediately match a specific date to its corresponding day of the week. The two halves of our brain work as a kind of “Jante’s Shield” (i.e., a preserver of uniformity) on each other. One side of the brain can’t simply compensate for what the other half lacks; it must also restrain the other half if it grows too strong within a certain area so that we achieve balance in our cerebral abilities. This means that most of us acquire reasonable abilities in many areas instead of becoming extremely adept at some, and very poor at others. If the halves of the brain are unable to communicate, the equilibrium might be lost and certain abilities may blossom, often to the detriment of others.
A human Google
This is exactly what is believed to have happened to Kim Peek, an American man and the inspiration for Dustin Hoffman’s role as Raymond Babbitt in the movie Rain Man. Peek was born with an injury to the corpus callosum, a band of nerve fibers. This band is the part of the brain that forms the most important link between the left and the right sides, and the injury caused a faulty connection. Peek was already four years of age when he learned to walk and was considered so severely mentally disabled that doctors suggested he be institutionalized.
But just like Michelle, Kim Peek recovered and developed in ways no one could have foreseen.
At around five years old, Peek learned to read, and whenever he finished a book he placed it front cover side down. His parents were astonished at the speed with which the house filled up with down-facing books. By then, Peek was also beginning to show a mindboggling memory for detail, perhaps the best-ever documented in a human being. And he could read two pages in a book simultaneously, the left side with his left eye, and the right side with his right eye. It took him ten seconds to read one page; he could go through an entire book in one hour. His favorite pastime was going to the public library, where he would read eight books a day.
Basically, he remembered everything in the approximately twelve thousand books he had read. In his head, he kept an unimaginable amount of facts of varying degrees of importance; from Shakespeare, to facts about the British royal family, to the complete list of American zip codes. If anyone deserves to be called “the human Google,” it’s Kim Peek.
As with Michelle Mack, Peek could also immediately tell which weekday a date corresponded to, be they several decades in the future or in the past. People often walked up to Peek and told him their date of birth and asked him what day it was. Not only did he immediately give them the correct answer—“You were born on a Sunday”—but he could also add, “You will turn eighty on a Friday.”
Kim Peek’s abilities were so unique that he has been called “Kimputer” and “megasavant,” but things were far from simple for him in life. He was very awkward in social situations, and he was hardly able to dress himself. He tested quite a bit below average on IQ tests despite his extraordinary memory. Peek was always generous and volunteered his time whenever neuroscientists asked to conduct studies on him, and his unique case has provided important clues to how memory works. It is now believed that Peek’s outsize memory was a result of his brain’s halves lacking contact and their inability to balance each other out.
THE BRAIN’S PROGRAMS CAN BE REWRITTEN
There are similarities as well as differences between Kim Peek and Michelle Mack. In Michelle’s case, the connection was not absent; half her brain was simply not there. But the missing half of the brain might very well have had the same effect as a bad link between two existing brain halves, allowing certain abilities to grow uncontrollably and giving rise to exceptional qualities.
Kim Peek and Michelle Mack are perhaps the best examples of neuroplasticity—the brain’s superb ability to reorganize itself—and there’s no longer any doubt that the brain’s structure and operating mode is changeable. Not only for Michelle Mack and Kim Peek, but also for you and me.
But why devote so much time to the story above in a book about the effects of exercise and athletic training on the brain? The reason is very simple: it is important to show that the brain can change, because not everyone is aware of this. The next question, then, is what creates this change? This is how we end up on the topic of physical activity and working out.
More like modeling clay than china
In the study of neuroplasticity, it has been shown that there are few things as effective in making the brain changeable—that is, neuroplastic— as being physically active. It also appears that the activity need not last an especially long time. In fact, only twenty to thirty minutes of physical activity are enough to affect neuroplasticity.
One of the mechanisms that converts your running steps to a changeable brain involves an amino acid call
ed gamma-aminobutyric acid (GABA). GABA acts like a brake on the brain, inhibiting activity and making sure nothing changes. But GABA’s influence ebbs when you become physically active, because exercise removes GABA’s block against change, thus making the brain more flexible and better at reorganizing itself. If we consider the brain from a more-like-modeling-clay-than-china perspective, the change in GABA activity makes the clay softer and more malleable.
The brain of a person who exercises becomes more like a child’s, and GABA is involved in that process.
Hopefully, you have now realized how changeable the brain is, and that exercise and training play a big role in this change since they can modify and streamline our brain’s programs. Physical activity produces results in many different areas, and we will now look a bit more closely at those areas, specifically at the impact training has on our mental functions. We’ll start with what afflicts many people today: stress and anxiety.
DO WE ONLY USE 10 PERCENT OF OUR BRAIN?
It’s time to put to rest the myth that we only use 10 percent of our brain. Of course, as you read that last sentence, it’s not entirely unreasonable that you were using only 10 percent of your brain. It’s also not impossible that you may only use 10 percent of your brain when you go for a bike ride (though not necessarily the same 10 percent you use when you’re reading). In actuality, we do work our entire brain—just different parts of it, depending on what we’re up to.
Today, we know that electrical activity and the use of glucose and oxygen—the brain’s main fuels—is a continuous process in the brain. This means it is always active; no area remains idle in a healthy brain. The brain would never allow 90 percent of its capacity to stay dormant. Considering our brain’s phenomenal ability to move different functions around—just think back to Michelle Mack—it would quickly put any quiet area to good use.
The Real Happy Pill Page 2