January 31, 2013
Using brain science to explain the mind-body connection.
Today I am pleased to bring you an excerpt from The Body Has a Mind of Its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better.
If you’ve ever wondered how the mind and body communicate, here is an explanation from two talented writers. Sandra Blakeslee is a regular contributor to The New York Times, specializing in the brain sciences, and is the third generation in a family of science writers.
Matthew Blakeslee is a freelance science writer in Los Angeles. He represents the fourth generation of Blakeslee science writers.
So the piece you are about to read has a lot of experience behind it.
What does it mean to have an embodied mind? Can this insight help you in your everyday life?
Absolutely. But to understand how, you need to sit back for a moment and think about how your body and mind communicate. Your body is more than a meat vehicle for your mind to cruise around in. Your mind isn’t like a self-contained puppet master sitting deep inside your brain pulling the marionette strings of your body’s muscles. It may surprise you to learn just how much of a two-way street the mind-body connection really is, and how big a role your body plays in your mind’s health and functioning.
Your body sends two major kinds of input to your brain. One of these information streams arises from receptors in your skin, joints, muscles, tendons and bones. These signals feed into maps of your body which your brain uses to pilot your body through its daily interaction with the outside world.
Your body also bombards your brain with signals from receptors embedded throughout your intestines, heart, lungs and other organs and tissues about temperature, pain, itch, tickle, sensual touch, and other “interoceptive” sensations. These signals feed into a set of visceral maps in a brain region called the insula, a fascinating area which neuroscientists have only begun to explore. One of the insula’s most basic functions is to bring visceral sensation and emotion into your conscious awareness. In so doing, your higher-level cognition exercises some sway over your basic physiological functions such as breathing, arousal, and responses to pain or discomfort.
The two-way mind-body conversation, which the insula mediates, is crucial for achieving, maintaining and restoring balance in the way your body expends or conserves energy (what biologists call homeostasis). These feedback loops keep mind and body attuned. When you are healthy, your mind and body are in equilibrium. But if your mind and body are thrown out of balance, you may be tortured by inexplicable muscle aches, back pain, nausea, bloating, dizziness, fatigue or pain in abdomen, stomach, chest, joints, or pelvis, and a host of other miserable sensations.
Of course sometimes you feel sick because of an objectively verifiable cause. Maybe you caught a virus or bacterial infection. Maybe you tore a tendon or broke an arm. Numerous acute and chronic disease have clearly known causes that Western medicine can combat with drugs, surgery, physical therapy and the like.
But other times you feel sick and there is no explanation as to why. You visit doctor after doctor but no one can find anything wrong with you. You are told you may have fibromyalgia, or chronic fatigue syndrome, or irritable bowel syndrome, but no underlying pathology presents itself. Frustrated, you eventually seek alternative or complementary treatments – healing touch, yoga, acupuncture, hypnosis, reflexology, or any of dozens of other practices. And mercifully, with a little bit of luck and perseverance, you get better.
If you don’t or can’t fully subscribe to the mystical explanations offered by the masters of these traditions, how can you come to terms with the fact that in many cases they do actually, demonstrably, blessedly, work on afflictions about which Western medicine has nothing whatsoever to say beyond labeling it a “syndrome” of some sort and prescribing the proverbial two aspirins?
One reason is that many of these techniques involve bringing conscious attention to bear on breath, heartbeat and internal sensation. Doing this helps restore balance between mind and body by inducing changes, called plasticity, in your body maps. Certain forms of meditation can lead to measurable increases in the thickness and metabolic vigor of the right frontal insula, with concurrent improvements in physiological self-regulation, pain perception, emotional well-being and immune function.
Another reason alternative medical techniques are effective has to do with the power of beliefs. You don’t have to go as far as advocates of The Secret to appreciate the power belief can have. The brain is fundamentally a prediction-generation machine, animated by an almost insatiable drive to seek explanations for everything it perceives and meaning in everything it does. It is a system of staggering complexity in which almost every component is connected to every other component by just one or two removes. Beliefs, opinions and expectations constantly zip up and down the brain’s many layers of processing, which sometimes lead to spectacular misapprehensions and ill-health, but other times lead to amazing insights and healing.
Alternative and complementary medical treatments work extremely well because they relax you and because you believe in them. Unlike the like the external “objective” senses (sight, hearing, touch, etc.), pain is an internal “subjective” sense. Perceiving pain is less like seeing color or feeling a texture and more like an internally generated opinion on the state of the body. Your beliefs, held in mind, can exert powerful effects on your body (and vice versa). In many cases your beliefs can make you well. And they can make you sick.
Beliefs can even kill. In the Caribbean, many people believe in voodoo. When a witch doctor puts them under a curse, they sicken and die.
Hypochondria stems from the fact that people show great variability in how they interpret signals from the body. A small discomfort can be ignored or it can be magnified. It drives physicians crazy. Between a quarter to a half of all patients seeking treatment cannot be helped by conventional medicine.
The so-called somatoform disorders are disorders in the perception of bodily signals. All your body parts send sensory signals to the brain. Most are filtered out at a low level of processing, but sometimes peripheral sensations get through the filter and rise to the level consciousness even though they have no real bearing on your body’s current needs. Again, some people interpret these signal as meaningless and ignore them; but others interpret them as having pathological significance and amplify them through constant attention and worry – like a perverse inversion of the meditation process, perhaps. Through belief itself, free-floating, random, meaningless sensation can be turned into chronic suffering.
In some people, researchers have found that innate immune cells called cytokines – the kind that make you feel sick – can be activated without a pathogen present. Emotions trigger the sickness response instead of disease.
Brain imaging studies reveal that these misinterpreted sensations are not imaginary. Parts of the brain that map the state of the body show real changes in activation to unfiltered information. Pain can alter the body schema. A hypochondriac’s body maps are abnormal.
So-called hysterical conversion disorder is even more dramatic. This is where an emotional conflict or stress mimics neurological disease. People become paralyzed, blind, deaf, mute or have seizures, with no typical injury to the brain. One to three percent of hospital patients have some sort of conversion disorder.
The ancient Greeks in their wisdom believed that such patients had a displaced uterus (“hysterikos”), whence we inherit terms like “hysteria” and “hysterical conversion.” Sigmund Freud pinned conversion to sexual abuse and childhood trauma. But scientists today trace it to genuine changes in how the brain maps the body. For example, the brains of people with hysterical paralysis show underactivity in two brain maps involved in movement. When their symptoms improve naturally over time, the affected regions return to normal.
Beliefs also can make you well. When a person wearing a white coat and a stethoscope hands you a blue pill and tells you it will calm you down, chances are it will, even though the pill is made of an inert substance. Placebos, as such medications are known, can be potent medicine. When people suffering from painful knee arthritis underwent sham surgery – meaning the surgeon cut the skin open but only pretended to scrape the inside of the knee – they got better. When Parkinson’s patients thought they had received brain implants designed to alleviate their symptoms – but instead got a surgical incision but no treatment – they improved. Placebo painkillers and antidepressants are notoriously effective in treating disorders of mind and body.
Acupuncture, on the other hand, alleviates pain better than a placebo. Recent studies show that real acupuncture, using needles, activates the insula and anterior cingulate. Sham acupuncture, in which needles appear to be inserted but are not, works nearly as well as the real thing. This may be because when you expect a medical treatment to work, your body releases painkilling substances and your brain releases extra dopamine, a brain chemical associated with pleasure and reward.
So if you fall ill someday and your physician can find nothing organically wrong with you, sit back for a moment and think about your emotional state. What is worrying you? Then think about the feelings that arise from your body. Can you bring those feelings and emotions into a calm center of your whole body? Can you guide your attention to the state of your body? By doing so, you may induce the kind of healing response described by ancient traditions and that modern science is just starting to understand.
Copyright 2007, Reprinted with permission
For more information on the book, The Body Has a Mind of Its Own: How Body Maps in Your Brain Help You Do (Almost) Everything Better, visit http://www.thebodyhasamindofitsown.com
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