Boost Your Brain (6 page)

Optimal oxygen flow also aids in bolstering the brain’s highways. Remember the myelin that covers a neuron’s axon, allowing it to pass messages more quickly? That layer of insulation is actually kept intact with the aid of helper cells, which nourish and protect it. And what do those helper cells need to survive? Oxygen! Starve the helper cells and the myelin they’re supporting degrades. The end result is a breakdown of communication between one neuron and the next. In our CogniCity example, you can imagine that happening along the communication highways (fiber bundles) that connect one brain part with another. Limit oxygen flow to the brain and you cause damage to both neighborhoods and highways.

You’ll learn soon enough about factors that help and hinder oxygen flow to the brain. (Hint: They’re the same types of things that keep us heart-healthy.) But for now it’s enough to know that optimal oxygenation is key to boosting your brain.

BDNF

Brain-derived neurotrophic factor (BDNF) is a bit of an emerging rock star in the world of neuroscience. That’s because, though we’ve long known of its existence, in recent years it has become increasingly clear that BDNF—a protein created by neurons—plays a critical role in brain health and growth.

For starters, BDNF is known to be a crucial ingredient in neurogenesis in the hippocampus. As you’ll recall, the hippocampus constantly creates new neurons, perhaps as a sort of backup plan to replace those that are lost. If the fledgling neurons are needed, they grow to maturity; if not, they’ll simply dissolve and dissipate. It is BDNF, though, that helps them grow. Think of it as a particularly effective fertilizer for the brain.

Scientists are in the midst of discovering the many ways we influence our brains’ levels of BDNF, but there’s already clear, compelling evidence that exercise, for one, helps boost our levels of BDNF and promotes neurogenesis.

The hippocampus isn’t the only region that benefits from BDNF either. In the frontal lobes—the area of the brain responsible for abstract thinking and executive decision making—BDNF helps neurons heal and repair in order to stay in peak condition.

Healthy Brain Activity

The concept behind healthy brain activity—an exciting, emerging area of brain science—is simply that by training the brain to operate within an ideal frequency range, we can actually change the structure and function of the brain and enhance its performance.

To help you understand how it works, let me first give you a quick crash course in brain waves. The brain functions, as you know, by way of electrical signals. Those signals in groups of neurons, in turn, produce waves that oscillate at varying frequencies. And just as an orchestra is made up of a variety of instruments, each playing its own part, groups of neurons with a similar firing frequency produce a recognizable “song” or pattern. That song can be detected by sensors placed on the skull, using a technique called electroencephalography (EEG).

Each pattern of EEG is associated with a certain state of mind or level of brain function. For example, delta waves, the brain’s slowest, indicate sluggish activity and are associated with sleep. Theta waves are also on the slow side and indicate either drowsiness or abnormally slow brain activity in a disease process, as seen in patients with traumatic brain injury. Middle-of-the-range alpha waves are associated with focus, calmness, and alertness, as well as creativity. Beta waves—faster than alpha—occur during heightened alertness and critical problem solving, though excessive amounts of beta are associated with anxiety, insomnia, and other problems.

Brain Wave Frequencies

Delta: 1 to 3 hertz

Theta: 4 to 7 hertz

Alpha: 8 to 12 hertz

Beta: greater than 12 hertz

Given the complexity of the brain, it’s no surprise that one part can be motoring along at one frequency while another part can be recording a very different level of activity. If you’re solving a math problem, for example, your left parietal lobe will likely be active, emitting beta waves as you puzzle out an answer, while the part of your brain responsible for orientation—the right parietal lobe—might be emitting slower alpha waves. That’s perfectly normal. But just as you’d be alarmed if your heart raced all the time, a brain that’s revving too high—or too low—without explanation is a sign that something’s wrong.

We’ve long used EEG to measure brain activity—in epileptics, in stroke and coma patients, and for sleep studies—but in recent years a new discipline called quantitative EEG, or brain mapping, has emerged. Several independent groups of experts in the field have put together “normative” data from thousands of healthy individuals as well as hundreds of patients with various brain conditions, such as ADHD, autism, depression, anxiety, and OCD. In brain mapping, we use the available bank of normative data to look for signature patterns that tell us what may be going on in the brains of our patients. And we’ve discovered that we can tell quite a lot.

The normative data have clearly shown that a depressed patient, for example, exhibits excessively slow theta activity on the left side of the brain compared to the right. A person with ADHD typically exhibits slow activity in both frontal lobes, while a person with anxiety might exhibit too much beta activity on the right side of the brain.

Before Brain-Boosting Efforts

A low density of neurons, synapses, BDNF, blood vessels, and fiber bundles in a person whose life is full of brain shrinkers and lacks any brain boosters.

A calm, relaxed brain, on the other hand, exhibits a pattern that is primarily in the alpha zone, with small amounts of theta or beta as well. This is healthy brain activity and, as you’ll soon read, meditation, certain foods, exercise, and other activities promote it.

But how does healthy brain activity grow the brain and enhance cognitive performance? We don’t yet have the extensive studies needed to fully understand how healthy brain activity changes the brain. But we do know that such activity as occurs during meditation is associated with decreased cortisol, which is a major brain shrinker, as you’ll read in
chapter 10
. Healthy brain activity has also been tied to two members of the core four—angiogenesis and bolstering the brain’s highways.

In other words, maintaining a calm and focused mindset actually makes new blood vessels grow and the network of connections between brain regions become stronger.

After Brain-Boosting Efforts

A high density of neurons, synapses, BDNF, blood vessels, and fiber bundles in a person whose life is full of brain growers and low on brain shrinkers.

Big Is a Boon

By now you know that the brain typically shrinks with age. And that the brain’s incredible plasticity means you can not only offset that shrinkage but also enlarge a healthy brain. You know that such growth will help improve your clarity, memory, and creativity, and that it can also reduce your risk for late-life Alzheimer’s disease. But why?

The answer lies in a concept neuroscientists call brain reserve. Brain reserve simply refers to the notion that promoting the core four—increasing the number of synapses in the brain, strengthening the connections across the brain, keeping the brain well nourished with rich blood flow, and growing new neurons—enhances brain performance now and results in a more resilient brain as you age.

You can think of it as a retirement fund, of sorts: pay into it early and often, and you’ll have more to draw on in your later years. There’s ample evidence for this. In one study, for example, people with large hippocampi were less likely to be demented late in life even if they had footprints of Alzheimer’s disease pathology in their brains.
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One significant difference between financial planning and brain-reserve building is that a bigger brain translates to greater clarity, memory, and creativity not just in the future but now as well. Unlike a retirement fund, you don’t have to wait until you clock out for the last time to benefit.

Keep in mind that even the smallest of the brain changes that we’ll talk about in the pages to come—measuring mere fractions of a millimeter—reflect hundreds of thousands of neurons and tens of millions of synapses.

Of course, growth has its limits. As with muscles, once you reach the limit of growth in size, you’ll still see increases in efficiency. After that, your brain will continue to become more efficient, although not larger, in much the same way your biceps muscles max out on size but continue to strengthen.

One good example to illustrate this may be the brain of bona fide brainiac Albert Einstein. Recent studies of Einstein’s brain reveal it contained more intricate folds than the brain of the average person. Researchers are still puzzling out the meaning of this, but it’s possibly an indication that Einstein’s cortex had expanded in size and, in doing so, folded in on itself to a greater degree than most people experience.

Expand Your . . . Intelligence?

When I talk about having a bigger brain, I inevitably get eager nods and then a question along these lines: “But will that make me smarter?”

The answer is no. And yes. Actually, it depends on what you mean by smart.

If you Google the phrase “what is intelligence?” you will get more than six hundred million hits. Within those, you’ll find a wide range of definitions for intelligence. That’s because, despite much study and obvious interest, experts still don’t agree on what, exactly, intelligence is. Still, most definitions include some or all of the following: the ability to engage in abstract thought, understand meaning in words, communicate with others, reason, learn, retain knowledge, plan, and problem solve. One Merriam-Webster definition puts it simply as “the act of understanding.”

The definition I like to use is this: intelligence is the ability to function well in response to obstacles in life. In other words, it is your ability to figure out ways to be successful. This includes having the emotional intelligence—something IQ tests can’t measure—required to interact effectively with others. It includes the ability to process information at a reasonable speed. And, yes, it includes the ability to remember things. But memory is just one component of intelligence. Being able to remember the elements on the periodic table might be helpful to success if your obstacle is a chemistry test, but it won’t mean much when you need to come up with a new idea for the ad campaign that might earn you a promotion.

We’re all born with certain innate abilities when it comes to intelligence, and those abilities vary greatly by person. One person may have a respectable ability to work with numbers, for example, while another may be terrible at math but can movingly convey meaning with words.

But—here’s the beautiful thing—we
can
improve at least some of the components that make up our intelligence. Memory, creativity, mental agility (our ability to respond quickly or “connect the dots”) all can be improved with a bigger brain.

We’re only now beginning to understand how great that improvement can be. In early 2012, researchers at the University of Edinburgh published their findings that genetic factors account for about 24 percent of the change in intelligence that occurs between childhood and old age.
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For the study, published in
Nature,
the research team examined the DNA and intelligence tests of two thousand people. The intelligence tests were conducted when the subjects were children, and again when they were in old age. The largest impact on intelligence, researchers found, seemed to come from environmental rather than genetic factors—what we do rather than what we are given.

To get back to the question—does having a bigger, stronger brain mean you’ll be smarter—I firmly believe it does and that you’ll perform better on tests of intelligence, be they real world or paper and pencil.