Our fascination with the brain seems to come from a longing to make psychology more like a hard science and hence, we assume, more useful. Physics gave us electricity, skyscrapers, and the Internet. Chemistry gave us medicine and more fresh food. Psychology is still taking baby steps, designing empirical tests of unsurprising observations. It may be too much to expect science to reliably save marriages, but how desperately we need the secret to stopping people from burning others alive.
What we do know is, indeed, fascinating. Great Myths of the Brain is a kind of primer that teaches neuroscience by debunking neurononsense, beginning with ancient ideas like “Thought Resides in the Heart.” You’ll learn that much of the neuroscience you hear is trivial or wrong, and also see the useful research threads to follow. The word “brain” isn’t entirely giving us false hope. A neuroscientist-turned-writer, Christian Jarrett is editor of the British Psychological Society’s Research Digest, a blogger, and the father of baby twins. His elegant, enthusiastic prose doesn’t shy from controversy.
Michael Corballis, author of The Wandering Mind, is a New Zealand neuroscientist best known for his thesis that language evolved from gestures. He has the grace and wit of a successful man approaching 80. If you’ve ever heard someone say something such as “So what if I’m spacey? I’m creative,” he would reassuringly agree.
Although The Wandering Mind is a conversational essay, it doesn’t wander. Corballis, like Jarrett, distills to essentials. Memory, thinking about the future, reading other people, storytelling, dreams, hallucinations, and creativity each get a chapter. Each is a function of our “default-mode network,” a large swath of brain not dedicated to perception or responses to the immediate environment. “The brain is a bit like a small town,” he explains, “with people milling around, going about their business. When some big event occurs, such as a football game, the people then flock to the football ground, while the rest of the town grows quiet.” Then we mill around again.
You can get your best ideas washing dishes. There are studies.
Corballis is polite, and it may be his comforting bent that led him to avoid the most troublesome question about wandering minds. Noting that “the Freudian idea that dreams are symbolic disguises of shameful or forbidden thoughts has largely lost favor,” he writes that dreams “may serve . . . to activate the unconscious, to create the internal terrains for later mental meanderings.” I wish he had addressed whether (or how) the unconscious may take the controls, still the core claim of much psychotherapy and a major theme in behavioral finance—which has convinced me that even people who consider themselves financially sophisticated have no idea what they’re doing with their money. In Corballis’s most revelatory chapter, on hallucinations, he suggests that “perception is fundamentally driven from within, with information from the world serving merely to guide what we see, hear and smell.” He adds, characteristically, “Perhaps that’s an exaggeration, but hallucination tells us that there’s more to perception than meets the eye.”
Jarrett addresses aspects of this huge thought as well. Under “Myth #33: The Brain Perceives the World As It Is,” he breaks the news that we’re actually living a self-created “virtual reality experience. . . . The truth is that we catch mere glimpses of physical reality.” Three or four times every second, for example, you close your eyes and see nothing—a mechanism to prevent blurring when you shift your gaze. To compensate, your brain seems to backdate your sense of how long objects have been in their current locations. It takes about a tenth of a second for information to come in, but your brain hides the lag, “constantly predicting how the world probably is now based on how it was a moment ago.”
Although such adjustments may sound minor, the overall illusion creates overconfidence. Jarrett quotes a sobering study that concluded that women with eating disorders who weren’t especially fat or thin were unusually accurate—not less so—about how attractive their bodies would be rated by a panel of strangers. Healthy women, on the other hand, were biased in their own favor. Healthy people also can easily be induced to feel that they have three arms, or that they are floating outside their bodies. You can “hear voices” without being psychotic. The very human idea of I-know-it-like-the-back-of-my-hand is wrong: We tend to see our fingers as shorter and our hands as wider than they are. At last, some good news!
We are overconfident, too, about what passes for popular knowledge, as Jarrett reminds us, pointing out how bad neuroscience sells dubious products and causes. He weighs the research on whether the Internet is making us stupid or lonely, sugar makes kids hyperactive, girls are wired to prefer pink, and left-handed people are more introverted or creative. The answer is no.
Antidepressants are the most consumed medication in the United States, yet the idea behind them—that mood disorders are caused by lack of serotonin or some other chemical imbalance—is unproven, Jarrett and many others say.
One drug that reduces serotonin—a “selective serotonin reuptake enhancer” (Prozac and other SSRIs are reuptake inhibitors)—is an effective antidepressant. Except for the most seriously depressed people, the SSRIs mostly seem to work because of the placebo effect. When I present this argument to my medicated friends, they say, “I’m fine with my placebo effect,” and I’m sympathetic. Advocates for the mentally ill believe that biological explanations make illness more acceptable. But as Jarrett points out, that may be another myth. A growing body of evidence suggests that biological explanations are stigmatizing, possibly because people tend to see such problems as less treatable.
Beyond the placebo effect, the currently popular antidepressants may work because they stimulate neurogenesis, the growth of new neurons. Researchers have stimulated neurogenesis in rats by giving them more exciting environments and challenging learning tasks. Stress and threats diminish neurogenesis in rats. Does this mean that the problem all along was your stifling or precarious job or marriage? There’s also evidence that the balance of microorganisms in your gut affects mood.
Jarrett surprised me most with “Myth #32: The Brain Receives Information from Five Separate Senses.” Was I going to read that there’s really a sixth sense—as in ESP? The idea that we have five senses is usually traced to Aristotle’s De Anima (On the Soul), Jarrett explains. He goes on to list a variety of other senses, such as proprioception (the awareness of where each of our body parts is located in space), signals from within the body (hunger, thirst, the need to empty the bladder or bowel), and the many kinds of tactile sensations (temperature, pressure, pain, and itch). There are more, including one first documented in the 19th century that struck me as utterly bizarre—yet it turns out that you, too, can develop it with practice.
Read the book to find out how.
Temma Ehrenfeld is a writer in New York.
