"Christopher Wanjek uses a take-no-prisoners approach in debunking the outrageous nonsense being heaped on a gullible public in the name of science and medicine. Wanjek writes with clarity, humor, and humanity, and simultaneously informs and entertains."
Dr. Michael Shermer, Publisher, Skeptic magazine; monthly columnist,
Scientific American; author of Why People Believe Weird Things

Prehistoric humans believed cedar ashes and incantations could cure a head injury. Ancient Egyptians believed the heart was the center of thought, the liver produced blood, and the brain cooled the body. The ancient Greek physician Hippocrates was a big fan of bloodletting. Today, we are still plagued by countless medical myths and misconceptions. Bad Medicine sets the record straight by debunking widely held yet incorrect notions of how the body works, from cold cures to vaccination fears.

Clear, accessible, and highly entertaining, Bad Medicine dispels such medical convictions as:

• You only use 10% of your brain: CAT, PET, and MRI scans all prove that there are no inactive regions of the brain . . . not even during sleep.
• Sitting too close to the TV causes nearsightedness: Your mother was wrong. Most likely, an already nearsighted child sits close to see better.
• Eating junk food will make your face break out: Acne is caused by dead skin cells, hormones, and bacteria, not from a pizza with everything on it.
• If you don t dress warmly, you ll catch a cold: Cold viruses are the true and only cause of colds.

Protect yourself and the ones you love from bad medicine the brain you save may be your own.

CHRISTOPHER WANJEK is a frequent contributor to the Washington Post; he has also written for Smithsonian and Forbes, among other publications. He writes jokes for The Tonight Show and Saturday Night Live. Wanjek is also a senior writer for NASA. He has previously worked as an in-house science writer at MIT and the NIH.

Bad Medicine

Misconceptions and Misuses Revealed, from Distance Healing to Vitamin OBy Christopher Wanjek

John Wiley & Sons

ISBN: 0-471-43499-X

Chapter One

10 Percent Misconception, 90 Percent Misdirection: The Brain at Work

Often it is said that we use only 10 percent of our brain. Is the brain really a vast, untapped resource of incomprehensible powers? Absolutely. I've heard countless vapid cell-phone conversations on street corners that attest to this. I remember one young lady giddy over a "brown baby pigeon" that was hopping about her feet while she was talking to her friend. The bird was a sparrow.

Remarkably, she was using nearly 100 percent of her brain in describing the "baby pigeon." Optic nerves were relaying the image of a tiny brown bird to the visual cortex way in the back of her brain via the thalamus, sort of the brain's relay station. Cochlear nerves in her ears were transmitting the electrical impulses of the sound of her friend's inane chatter through the brain stem and thalamus to the auditory cortex, where it was ultimately interpreted as language in her brain's Wernicke's area. Memory is spread widely through the brain, from the hippocampus and amygdala to the cerebral cortex, so it is not clear where the young lady was accessing the incorrect information that small brown birds in the city are baby pigeons and not sparrows. Most certainly, though, her brain stem was relaying motor function from her cerebellum and cerebral cortex to the muscles, enabling her to hold the cell phone, turn her head, unconsciously check out a cute guy, and more or less to stand and breathe. Her brain's hypothalamus was regulating her body temperature. All and all, it was a busy time for her brain.

Our budding ornithologist might not have been using a full 100 percent of her brain on the cell phone all at once. After all, no one exercise utilizes 100 percent of one's muscle system. But she was using far more than 10 percent. More importantly, by the time she woke up in the morning after dreams of baby pigeons and cute guys, she would have used all of her brain. All of the brain's regions and many of its neurons would have gotten a workout.

Now, how you use your brain is your own business. You can read War and Peace or you can watch dating shows on television. While many argue that the latter is a waste of the brain's potential, no one can justifiably say that 90 percent of the brain lies dormant, like some untapped oil well, waiting to gush forth with unrealized brilliance.

The "10 percent" brain myth goes back at least a hundred years, perhaps more if one considers the teachings of transcendental meditation and the concept of maximizing the mind's power. Albert Einstein, whom no one accused of having a lazy brain, may have helped keep the myth alive when he told a reporter, wryly and perhaps sarcastically, that his brilliance came from using more than 10 percent of his brain. But this tale cannot be confirmed. Barry Beyerstein, a neurologist at Simon Fraser University in British Columbia, tried to isolate the origin of this myth in "Whence Cometh the Myth that We Only Use Ten Percent of Our Brain?," a chapter in the book Mind Myths: Exploring Popular Assumptions About the Mind and Brain. Beyerstein finds reference to a "silent cortex" in brain studies from the 1930s, as well as seeds of misconception from the 1800s.

The nineteenth century was a time of remarkable advancements in our understanding of the physical and biological world. The French physiologist Pierre Flourens's groundbreaking work on the brains of rabbits and pigeons in the 1820s and 1830s mapped out regions in the brain responsible for basic movements, memory, and mood. Basically, he removed parts of their brains and took notes on what the animals could no longer do. A few decades later, Pierre Paul Broca, a French physician, isolated the region in the human brain responsible for controlling speech. He performed autopsies on stroke victims who had lost the ability to form words (but could still comprehend language). In the 1870s, Gustav Fritsch and Eduard Hitzig, two German physiologists, improved upon Flourens's work by zapping certain regions in a dog's brain with electricity and seeing which muscles moved.

The electrical zapping continued with greater precision in the 1930s. Researchers found that in all their brain volunteers, from animals to humans, there were certain regions in the brain that did not respond to stimuli. These regions were labeled the "silent cortex," and humans had a lot of them. The name was not meant to imply that the regions were inactive; merely, the electrical stimuli didn't provoke anything obvious, such as twitching. Further research has shown that the "silent cortex" is responsible for the very traits that make us human: language and abstract thought.

How can we be certain that we don't use only 10 percent of the brain? As Beyerstein succinctly says, "The armamentarium of modern neuroscience decisively repudiates this notion." CAT, PET and MRI scans, along with a battery of other tests, show that there are no inactive regions of the brain, even during sleep. Neuroscientists regularly hook up patients to these devices and ask them to do math problems, listen to music, paint, or do whatever they please. Certain regions of the brain fire up with activity depending on what task is performed. The scans catch all this activity; the entire brain has been mapped in this way.

Further debunking the myth is the fact that the brain, like any other body part, must be used to remain healthy. If your leg remains in a cast for a month, it wilts. A 90-percent brain inactivity rate would result in 90 percent of the brain rapidly deteriorating. Unused neurons (brain cells) would shrivel and die. Clearly, this doesn't happen in healthy individuals. In Alzheimer's disease, there is a diffuse 10 percent to 20 percent loss of neurons. This has a devastating effect on memory and consciousness. A person would be comatose if 90 percent of the brain-any 90 percent-were inactive.

The "10 percent" brain myth is silly even from an evolutionary standpoint. The brain is a hungry organ, requiring energy (in the form of oxygen and glucose) all day and all night. This organ, comprising only 5 percent of the body's total weight, consumes 20 per-cent of the oxygen and glucose. Evolution would have never favored a big, useless "high-maintenance" brain if only 10 percent of it were vital for survival. Darwin aside, just use common sense. Never do we hear a doctor say, "Fortunately the bullet wound destroyed the 90 percent of the brain he doesn't use. He's good to go; call me in the morning."

True, there are bizarre brain stories: people impaled by lead pipes and, still functioning, suddenly taking up an interest in yodeling; or people who have up to half their brain removed to control seizures. The brain never truly recovers its full capacity in these situations, but it can learn to adapt-particularly if the patient is young. The brain can reroute its wiring, or neural pathways, to maintain most of its function. Children whose parts of their brain have been damaged or removed can grow up, if treated, to lead productive and seemingly normal lives. Adults with brain damage have far greater difficulty attaining full function. This is because their streets have already been paved, unlike a child who is growing and learning. It is easier to pave a new street around a damaged area than it is to rip up an old street and start anew.

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