The Body Has a Mind Of Its Own

If you want to know more about what makes you what you are, would like to improve your skills, your health and your emotional attitudes, or are curious what the future holds in store for the mind's relationship to the body, this book is for you. This book presents the fascinating story of body maps in the brain: What they are, what they tell us about ourselves, and how an understanding of them can affect our lives.

So first off, what is a "body map"? Just as a road atlas is full of maps that represent real-world locations, your brain if full of maps that represent all aspects of your physical self, inside and out. Your brain is teeming with maps that underlie your ability to touch things, move about, act freely, feel emotion, and interact with others. But unlike road maps, your body maps are dynamic: They grow, shrink, and morph to suit your needs.

Each of your body parts is faithfully mapped based on the touch receptors embedded throughout your skin. This is your primary touch map. You also have a primary motor map, for making movements. Instead of receiving information from your skin, this map sends signals from your brain out to your muscles. Together, these two primary maps are the foundation of your mind-body interface.

Elsewhere in your brain you have maps of the space around your body, out to the end of your fingertips. These personal space maps can extend even further, like an amoeba's pseudopod to include any physical tool you pick up, any item of clothing or sporting equipment you put on, or even any virtual extension of yourself that you control with a mouse or a joystick, into your own bodily self-representation.

Some of your most amazing body maps are made up of special brain cells called mirror neurons. These cells fire when you observe someone doing an action—say, scratching their chin—and when you scratch your own chin. As a result, you may feel a desire to scratch your chin, or even develop a genuine itch there. Mirror neurons map the actions, intentions and emotions of others directly into your own system of body maps, creating as close to a telepathic link as the known laws of nature allow. They allow you to understand and empathize with the minds of others, not through conceptual reasoning, but through direct simulation via your own body maps. They reveal how children learn, why you respond to certain types of sports, dance, music and art, why media and video game violence can be harmful, the appeal of pornography, and may even help explain homophobia.

Your brain also has a set of maps of your internal organs. Present in all mammals, these visceral maps are uniquely super- developed in the human brain. Evolution has extended these maps' functions far beyond their original purpose of just letting you know you are hungry, thirsty, horny, or need air. These maps afford you a level of access to the ebb and flow of your internal sensations unrivaled anywhere else in the animal kingdom, and they are fundamental to the uniquely rich emotional inner life of our species. They are important in empathy, moral judgment, social intercourse, and many aspects of mental and physical health.

All these body maps are profoundly plastic—capable of significant reorganization in response to damage, experience or practice. Concert pianists have enlarged hand maps. Veteran meditators have enlarged visceral maps. Golfers with the yips and musicians with musician's cramp have blurred body maps. Autistic people have scrambled body maps.

The brain's body-mapping system provides a new way of thinking about the mind-body connection. To many people the phrase "mind-body" connotes something mysterious or supernatural. They think life force, qi, healing touch, mindfulness, chakras, faith healing. The not-quite-provable yet not-quite- dismissible ability of the mind to relieve pain, heal the body and calm the soul is taken as an article of faith, and is cast in terms of divine or spiritual forces.

But there is another way to understand the mind-body connection, one that validates at least some of these phenomena as biomedically real and others as psychologically real (that is, experienced as real by the brain for neurally sound reasons). It comes down to the body maps in your brain. As science would have it, the mind is what the brain does. And the brain is intimately connected to the body, as studies of its sprawling network of body maps are revealing in ever greater detail. All your emotions, feelings, and your sense of individual selfhood stem from the interaction of these maps in your brain, the body in your brain, your embodied brain.

There are a number of practical reasons why you should pay attention to the science of body maps.

Consider sports. Mastery of any sport involves long hours of fine-tuning the motor skills involved. As you practice shooting hoops, bowling, or maneuvering your kayak—as you develop any physical expertise—you are re-wiring your sensory and motor body maps. There is now abundant evidence that a form of mental practice called motor imagery, in which you immerse yourself in the imagination of movements, can hone your skills as effectively as the real thing. Physical practice and motor imagery produce similar levels of skill improvement in your brain—under certain conditions. Understanding at what level of skill motor imagery will begin to help—as opposed to wasting time while you should actually be out there practicing—is an important consideration for anyone serious about his or her sport. As such, motor imagery has become an active area of research for sports psychologists.

Stroke patients are also being treated increasingly with motor imagery. By imagining repeatedly that they can move a paralyzed limb it is possible, in some, to restore lost function. Understanding the nature of body maps is an important element of the treatment.

Motor maps can also cross-wire themselves from overuse. Writer's cramp, musician's cramp, and golfer's yips all develop when certain movements are repeated so often and with such fine attention to detail that they begin to scramble, rather than fine-tune, the body maps that encode those skills. Golfers with the yips can no longer putt the ball; their hands fly off in the wrong direction every time they attempt a putt. New treatments for these conditions based on carefully directing the inherent plasticity of normal maps are being developed.

Consider weight loss. Why do you still feel fat after you've successfully shed ten or twenty pounds? Answer: Because there is an important difference between two of your major body-mapping systems—your body schema and your body image. Your body schema derives from the dynamic physical properties of your body while your body image stems from stubbornly held attitudes about your body. Understanding this difference is a key to understanding why many diets fail. If reality can't set in because your body image is locked into an idée fixe, your cannot fully appreciate, or in the worst cases even realize, your progress; and we all know how discouragement can bring us back to the junk food trough.

Abnormal body maps are also implicated in anorexia. Anorexics aren't just being drama queens when they complain that their wasted bodies are "too fat"; as tests reveal, their distorted self-images run deep at the perceptual level. But the insight that body maps play a key role in anorexia is opening new treatment horizons. As you will see, one involves wearing a neoprene body suit, like Catwoman—an outfit that tactilely restores a normal sense of body proportion, leading to weight gain. Other conditions like body dysmorphic disorder, in which people believe a part of their body is deformed or defective and needs radical corrective augmentation, may have similar underpinnings.

If you want to be the life of the party, you can produce parlor tricks that involve body mapping illusions. You can make people's waists "shrink" and their noses "grow."

If you see colored auras around other people, you don't have to attribute them to out-of-this-world explanations. A form of cross-wiring in brain maps, called synesthesia, can tell you why you have that experience. Many phenomena that people attribute to mystical factors are in fact based on how the brain dynamically maps the body. Do you sometimes feel the "presence" of someone behind your back? Have you ever literally been "outside yourself" while meditating? Some say these things are proof of a spirit world beside the physical. But the dynamics of body maps may explain the same experiences within the framework of the known laws of physics.

The neurobiology of body maps is also the neurobiology of cyberspace. The unparalleled flexibility of the human body schema, which originally evolved to make us into tool-wielding savants during the stone age, allows us to extend our embodied selves and the personal space-bubble we carry around ourselves just as readily into virtual realms. This flexibility can clearly be exploited in the design of more fully immersive computer-user interfaces, but so far researchers have barely begun to scratch the surface.

The Body Has a Mind of Its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better