Phantoms in the Brain: Probing the Mysteries of the Human Mind (38 page)

But the cessation of menstruation during depression is common, whereas pseudocyesis is very rare. Perhaps there's something special about the depression of being childless in a child−obsessed culture. If the syndrome occurs only when the depression is associated with fantasies about pregnancy, it raises a fascinating question: How does a highly specific wish or delusion originating in the neocortex get translated by the hypothalamus to induce FSH reduction and prolactin elevation—if that is indeed the cause? And even more puzzling, how do you explain the observation that some patients with pseudocyesis do
not
have an elevated prolactin level or that in many patients labor pains begin at exactly nine months? What triggers the labor contractions if there is no growing fetus?

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Whatever the ultimate answer to these questions, pseudocyesis provides a valuable opportunity for exploring the mysterious no−man's−land between mind and body.

False pregnancy and labor in women are surprising enough, but there are even a few recorded instances of pseudocyesis in men! The whole gamut of changes—including abdominal swelling, lactation, craving for strange foods, nausea, even labor pains—can occur as an isolated syndrome in some men. But more commonly it is seen in men who empathize deeply with their pregnant spouse, producing the so−called sympathetic pregnancy or couvade syndrome. I have often wondered whether the man's emotional empathy with the pregnant woman (or perhaps pheromones from her) somehow releases prolactin—a key pregnancy hormone—in her husband's brain, causing some of these changes to emerge. (This hypothesis is not as outlandish as it seems; male tamarin marmosets develop an elevated prolactin level when in close proximity to nursing mothers, and this may encourage paternal or filial affection and reduce infanticide.) I am tempted to interview men participating in Lamaze classes and to measure prolactin levels in those who experience some of these couvadelike signs.

Pseudocyesis is dramatic. But is it an isolated, exceptional example of mind−body medicine? I think not.

Other stories come to mind, including one I first heard in medical school. A friend said, "Did you know that according to Lewis Thomas you can hypnotize someone and eliminate their warts?"

"Rubbish," I scoffed.

"No, it's true," she said. "There are documented cases.5 You get hypnotized and the warts disappear in a few days or sometimes overnight."

Now on the face of it this sounds very silly, but if it's true, it would have far−reaching implications for modern science. A wart is essentially a tumor (a benign cancer) produced by the papilloma virus. If that can be eliminated by hypnotic suggestion, why not cancer of the cervix, which is also produced by the papilloma virus (albeit a different strain)? I am not claiming that this will work—perhaps nerve pathways influenced by hypnosis reach the skin but not the lining of the cervix—but unless we do the relevant experiment, we will never know.

Assuming, for the sake of argument, that warts can be eliminated by hypnosis, the question arises, How can a person simply "think away" a

tumor? There are at least two possibilities. One involves the autonomic nervous system—the pathways of nerves that help control blood pressure, sweating, heart rate, urine output, erections and other physiological phenomena not under direct control of conscious thought. These nerves form specialized circuits that service distinct functions in various body segments. Thus some nerves control hair standing on end, others cause sweating and some generate the local constriction of blood vessels. Is it possible that the mind, acting through the autonomic nervous system, could literally asphyxiate the wart by constricting blood vessels in its immediate vicinity, making it shrivel up and wither away? This explanation implies an unexpected degree of precise control by the autonomic nervous system and also implies that the hypnotic suggestion can be

"understood" by the autonomic nervous system and transferred to the region of the wart.

The second possibility is that the hypnotic suggestion somehow kick starts the immune system, thereby eliminating the virus. But this would not explain at least one recorded case involving a hypnotized person whose warts vanished on just one side of his body. Why or how the immune system could selectively eliminate warts on one side over another is a mystery that invites further flights of speculation.

A more common example of mind−body interaction involves the interplay between the immune system and perceptual cues from the world around us. Over three decades ago, medical students were often told that an 150

asthmatic attack could be provoked not only by inhaling pollen from a rose but sometimes by merely seeing a rose, even a plastic rose, prompting a so−called conditioned allergic response. In other words, exposure to a real rose and pollen sets up a "learned" association in the brain between the mere visual appearance of a rose and bronchial constriction. How exactly does this conditioning work? How does the message get from the brain's visual areas all the way down to the mast cells lining the bronchi of the lungs? What are the actual pathways involved? Despite three decades of mind−body medicine, we still have no clear answers.

When I was a medical student in the late 1960s, I asked a visiting professor of physiology from Oxford about this conditioning process and whether the conditioned association could be put to clinical use. "If it's possible to provoke an asthmatic attack through conditioning merely by showing a plastic rose to a patient, then theoretically it ought to be possible to abort or neutralize the attack through conditioning as well.

For example, say you suffer from asthma and I give you a bronchodilator such as norepinephrine (or perhaps an antihistamine or a steroid) every time I show you a plastic sunflower. You might begin associating the sunflower image with relief from asthma. After some time you could simply carry around a sunflower in your pocket and pull it out to look at when you felt an attack coming on."

At the time, this professor (who later became my mentor) thought this was an ingenious but silly idea, and we both had a good laugh. It seemed far−fetched and whimsical. Thus chastised, I kept my thoughts to myself, wondering privately whether you really could condition an immune response and, if so, how selective this conditioning process could be. For instance, we know that if you inject a person with denatured tetanus bacilli he will soon develop immunity to tetanus, but to keep the immunity "alive" the person needs booster shots every few years. But what would happen if you rang a bell or flashed a green light every time these booster shots were administered? Would the brain learn the association? Could you eventually dispense with the boosters and simply ring a bell and flash a light to stimulate the selective proliferation of immunologically competent cells, thereby reviving a person's immunity to tetanus? The implications of such a finding for clinical medicine would be enormous.

To this day I curse myself for not trying this experiment. The ideas remained tucked away in my mind until a few years ago, when, as happens so often in science, someone made an accidental discovery, proving that I had missed the boat. Dr. Ralph Ader of McMaster University was exploring food aversion in mice. To induce nausea in the animals, he gave them a nausea−inducing drug, cyclophosphamide, along with saccharin, wondering whether they would display signs of nausea the next time he gave them the saccharin alone. It worked. As expected, the animals did show food aversion, in this case an aversion to saccharin. But surprisingly, the mice also fell seriously ill, developing all sorts of infections. It is known that the drug cyclophosphamide, in addition to producing nausea, profoundly suppresses the immune system, but why should saccharin alone have this effect? Ader reasoned correctly that the mere pairing of the innocuous saccharin with the immunosuppressive drug caused the mouse immune system to "learn" the association.

Once this association is established, every time the mouse encounters the sugar substitute, its immune system will nose−dive, making it vulnerable to infections. Here again is a powerful example of mind affecting body, one that is hailed as a landmark in the history of medicine and immunology.6

I mention these examples for three reasons. First, don't listen to your professors—even if they are from Oxford (or as my colleague Semir Zeki would say,
especially
if they are from Oxford). Second, they illustrate our ignorance and illuminate the need for conducting experiments on topics that most people have ignored for no obvious reason; patients who manifest odd clinical phenomena are only one example. Third, perhaps it's time to recognize that the division between mind and body may be no more than a pedagogic device for instructing medical students—and not a useful construct for understanding human health, disease and behavior. Contrary to what many of my colleagues believe, the message preached by physicians like Deepak Chopra and Andrew Weil is not just New Age psychobabble. It contains important insights into the human organism— ones that deserve serious scientific scrutiny.

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People have become increasingly impatient with Western medicine's sterility and lack of compassion, and this would explain the current resurgence of "alternative medicine." But unfortunately, even though the remedies touted by New Age gurus have a ring of plausibility, they are rarely subjected to rigorous tests.7 We have no idea which ones (if any) work and which ones do not, although even the hardened skeptic would agree that there is probably something interesting going on. If we are to make any headway, we need to test these claims carefully and explore the brain mechanisms that underlie such effects. The general principle of immune conditioning has been clearly established, but can you pair different sensory stimuli with different types of immune responses (for example, a bell with a response to typhoid and a whistle to cholera), or is the phenomenon more diffuse—involving only a general boosting of all your immune functions? Does the conditioning affect the immunity itself or only the subsequent inflammatory response to the provoking agent?

Does hypnosis tap into the same pathway as placebos?8 Until we have clear answers to these questions, Western medicine and alternative medicine will always remain parallel enterprises with no points of contact between them.

So with all this evidence staring them in the face, why do practitioners of Western medicine continue to ignore the many striking examples of direct links between mind and body?

To understand why, it helps to have a feel for how scientific knowledge progresses. Most of the day−to−day progress of science depends on simply adding another brick to the great edifice—a rather humdrum activity that

the late historian Thomas Kuhn called "normal science." This corpus of knowledge, incorporating a number of widely accepted beliefs, is, in each instance, called a "paradigm." Year after year new observations come along and are assimilated into an existing standard model. Most scientists are bricklayers, not architects; they are happy simply adding another stone to the cathedral.

But sometimes the new observation simply doesn't fit. It is an "anomaly," inconsistent with the existing structure. The scientist can then do one of three things. First, he can ignore the anomaly, sweeping it under the carpet—a form of psychological "denial" that is surprisingly common even among eminent researchers.

Second, scientists can make minor adjustments to the paradigm, trying to fit the anomaly into their worldview, and this would still be a form of normal science. Or they can generate ad hoc auxiliary hypotheses that sprout like so many branches from a single tree. But soon these branches become so thick and numerous that they threaten to topple the tree itself.

Finally, they can tear down the edifice and create a completely new one that bears very little resemblance to the original. This is what Kuhn called a "paradigm shift" or scientific revolution.

Now, there are many examples in the history of science of anomalies that were originally ignored as being trivial or even fraudulent but later turned out to be of fundamental importance. This is because the vast majority of scientists are conservative by temperament and when a new fact emerges that threatens to topple the great edifice, the initial reaction is to ignore or deny it. This is not as silly as it seems. Since most anomalies turn out to be false alarms, it is not a bad strategy to play it safe and ignore them. If we tried to accommodate every report of alien abduction or spoon bending into our framework, science would not have evolved into the immensely successful and internally consistent body of beliefs that it is today. Skepticism is as much a vital part of the whole enterprise as the revolutions that make newspaper headlines.

Consider the periodic table of elements, for example. When Mendeleyev arranged elements sequentially according to their atomic weights to create the periodic table, he found that some elements didn't quite

"fit"—their atomic weights seemed wrong. But instead of discarding his model, he chose to ignore the anomalous weights, concluding instead that perhaps they had been measured incorrectly to begin with. And 152

sure enough, it was later discovered that the accepted atomic weights were wrong because the presence of certain isotopes distorted the measurements. There is much truth to Sir Arthur Eddington's famously para−

doxical remark "Don't believe the results of experiments until they're confirmed by theory."

But we must not ignore every anomaly, since some of them have the potential for driving paradigm shifts. Our wisdom lies in being able to tell which anomaly is trivial and which one is a potential gold mine.

Unfortunately, there's no simple formula for distinguishing trivia from gold, but as a rule of thumb, if an odd, inconsistent observation has been lying around for ages and has not been
empirically
confirmed despite repeated honest attempts, then it is probably a trivial one. (I regard telepathy and repeated Elvis sightings as belonging to this category.) On the other hand, if the observation in question has resisted several attempts at disproof and is regarded as an oddity
solely
because it resists explanation in terms of our current conceptual scheme, then you are probably looking at a genuine anomaly.