Phantoms in the Brain: Probing the Mysteries of the Human Mind (39 page)

One famous example is continental drift. Around the turn of this century (1912), the German meteorologist Alfred Wegener noticed that the east coast of South America and the west coast of Africa "fit" neatly together like the pieces of a giant jigsaw puzzle. He also noticed that fossils of a small freshwater reptile "mesosaurus"

were found in only two parts of the earth—in Brazil and in West Africa. How could a freshwater lizard swim across the Atlantic, he wondered? Is it conceivable that in the distant past these two continents were in fact parts of a single large landmass that had subsequently split and drifted apart? Obsessed with this idea, he sought additional evidence and found it in the form of dinosaur fossils scattered in identical rock strata, again in the west coast of Africa and the east coast of Brazil. This was compelling evidence indeed, but surprisingly it was rejected by the entire geological establishment, who argued that the dinosaurs must have walked across an ancient and now submerged land bridge connecting the two continents. As recently as 1974, at St. John's College in Cambridge, England, a professor of geology shook his head when I mentioned Wegener. "A lot of rot," he said with exasperation in his voice.

Yet we now know that Wegener was right. His idea was rejected simply because there was no mechanism that people could conceive of that would cause whole continents to drift. If there's one thing we all regard as axiomatic, it is the stability of terra firma. But once plate tectonics—the study of rigid plates moving about on a hot gooey mantle below—was discovered, Wegener's idea became credible and won universal acceptance.

The moral of this tale is that you should not reject an idea as out−

landish simply because you can't think of a mechanism that explains it. And this argument is valid whether you are talking about continents, heredity, warts or pseudocyesis. After all, Darwin's theory of evolution was proposed and widely accepted long before the mechanisms of heredity were clearly understood.

A second example of a genuine anomaly is multiple personality disorder or MPD, which in my view may turn out to be just as important for medicine as continental drift was for geology. To this day MPD continues to be ignored by the medical community even though it provides a valuable testing ground for the claims of mind−body medicine. In this syndrome—immortalized by Robert Louis Stevenson in
Dr. Jekyll and Mr.

Hyde
—a person can assume two or more distinct personalities, each of which is completely unaware, or only dimly aware, of the others. Again, there have been occasional reports in the clinical literature that one personality can be diabetic while the other is not, or that various vital signs and hormone profiles can be different in the two personalities. There is even a claim that one personality can be allergic to a substance while the other is not and that one might be myopic—or nearsighted— whereas the other has 20/20 vision.9

MPD defies common sense. How can two personalities dwell in one body? In Chapter 7, we learned that the mind is constantly struggling to create a coherent belief system from a multiplicity of life experiences. When there are minor discrepancies, you usually readjust your beliefs or engage in the kinds of denials and 153

rationalizations that Sigmund Freud talked about. But consider what might happen if you held two sets of beliefs—each internally consistent and rational—but these two sets were completely in conflict with one another? The best solution might be to balkanize the beliefs, to wall them off from each other by creating two personalities.

There is of course an element of this "syndrome" in all of us. We talk about whore/madonna fantasies and say things like "I was of two minds," "I'm not feeling myself today" or "He's a different person when you're around." But in some rare instances, it's possible that this schism becomes literal so that you end up with two

"separate minds." Assume that one set of beliefs says, "I am Sue, the sexy woman who lives on 123 Elm Street in Boston, goes to bars at night to pick up studs, drinks straight shots of Wild Turkey and has never bothered to get an AIDS test." Another says, "I am Peggy, the bored housewife who lives on 123 Elm Street in Boston, watches TV at night, drinks nothing stronger than herbal tea and goes to the doctor for every minor ailment." These two

stories are so different that they obviously refer to two different people. But Peggy Sue has a problem: She is both of these people. She occupies one body, indeed one brain! Perhaps the only way for her to avoid internal civil war is to "split" her beliefs into two clusters, like soap bubbles, resulting in the strange phenomenon of multiple personalities.

According to many psychiatrists, some cases of MPD are a consequence of childhood sexual or physical abuse. The child, growing up, finds the abuse so emotionally intolerable that she gradually walls it off into Sue's world, not Peggy's. What is truly remarkable, though, is that to keep the illusion going, she actually invests each personality with different voices, intonations, motivations, mannerisms and even different immune systems—almost two bodies, one is tempted to say. Perhaps she needs such elaborate devices to keep these minds separate and avoid the ever−present danger of having them coalesce and create unbearable internal strife.

I would like to carry out experiments on people like Peggy Sue but have thus far been thwarted by the lack of what I would call a clear−cut case of MPD. When I telephone friends in psychiatry, asking for names of patients, they tell me that they have seen such patients but most of them have several personalities rather than just two. One apparently had nineteen "alters" inside him. Claims of this sort have made me deeply suspicious of the whole phenomenon. Given limited time and resources, a scientist always has to strike a balance between wasting time on tenuous and unrepeatable "effects" (such as cold fusion, poly−water or Kirlian photography) and being open−minded (keeping in mind the lessons from continental drift or asteroid impacts). Perhaps the best strategy is to focus only on claims that are relatively easy to prove or disprove.

If I ever locate an MPD patient with just two personalities, I intend to eliminate doubt by sending the person two bills. If he pays both, I'll know he's for real. If he doesn't, I'll know he's a fake. In either case I can't lose.

On a more serious note, it would be interesting to carry out systematic studies on immune function when the patient is in the two different states by measuring specific aspects of the immune response (such as cytokine production by lymphocytes and monocytes and interleukin production by T cells provoked by mitogens—factors that stimulate cell division). Such experiments may seem tedious and esoteric, but only by doing them can we achieve the right blend of East and West and create a new revolution in medicine. Most of my professors scoffed at ancient "touchy−feely" Hindu practices such as Ayurvedic medicine, Tantra and meditation. Yet ironically, some of the most potent drugs we now use can trace their ancestry to ancient folk remedies such as willow bark (aspirin), digitalis and reserpine. Indeed, it has been estimated that over 30

percent of drugs used in Western medicine are derived from plant products. (If you think of molds—antibiotics—as "herbs," the percentage is even higher. In ancient Chinese medicine, mold was often rubbed into wounds.)

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The moral of all this is not that we should have blind faith in the "wisdom of the East" but that there are sure to be many nuggets of insight in these ancient practices. However, unless we conduct systematic

"Western−style" experiments, we'll never know which ones really work (hypnosis and meditation) and which ones don't (crystal healing). Several laboratories throughout the world are poised to launch such experiments, and the first half of the next century will, in my view, be remembered as a golden age of neurology and mind−body medicine. It will be a time of great euphoria and celebration for novice researchers entering the field.

Do Martians See Red?

All of modern philosophy consists of unlocking, exhuming and recanting what has been said before.

—
V.S. Ramachandran

Why is thought, beinß a secretion of the brain, more wonderful than gravity, a property of matter7.

—
Charles Darwin

In the first half of the next century, science will confront its greatest challenge in trying to answer a question that has been steeped in mysticism and metaphysics for millennia: What is the nature of the self? As someone who was born in India and raised in the Hindu tradition, I was taught that the concept of the self—the "I"

within me that is aloof from the universe and engages in a lofty inspection of the world around me—is an illusion, a veil called
maya.
The search for enlightenment, I was told, consists of lifting this veil and realizing that you are really "One with the cosmos." Ironically, after extensive training in Western medicine and more than fifteen years of research on neurological patients and visual illusions, I have come to realize that there is much truth to this view— that the notion of a single unified self "inhabiting" the brain may indeed be an illusion. Everything I have learned from the intensive study of both normal people and patients who have sustained damage to various parts

of their brains points to an unsettling notion: that you create your own "reality" from mere fragments of information, that what you "see" is a reliable—but not always accurate—representation of what exists in the world, that you are completely unaware of the vast majority of events going on in your brain. Indeed, most of your actions are carried out by a host of unconscious zombies who exist in peaceful harmony along with you (the "person") inside your body! I hope that the stories you have heard so far have helped convince you that the problem of self—far from being a metaphysical riddle—is now ripe for scientific inquiry.

Nevertheless, many people find it disturbing that all the richness of our mental life—all our thoughts, feelings, emotions, even what we regard as our intimate selves—arises entirely from the activity of little wisps of protoplasm in the brain. How is this possible? How could something as deeply mysterious as consciousness emerge from a chunk of meat inside the skull? The problem of mind and matter, substance and spirit, illusion and reality, has been a major preoccupation of both Eastern and Western philosophy for millennia, but very little of lasting value has emerged. As the British psychologist Stuart Sutherland has said, "Consciousness is a fascinating but elusive phenomenon: it is impossible to specify what it is, what it does, or why it evolved.

Nothing worth reading has been written on it."

I won't pretend to have solved these mysteries,1 but I do think there's a new way to study consciousness by treating it not as a philosophical, logical or conceptual issue, but rather as an empirical problem.

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Except for a few eccentrics (called panpsychists) who believe everything in the universe is conscious, including things like anthills, thermostats, and Formica tabletops, most people now agree that consciousness arises in brains and not in spleens, livers, pancreases or any other organ. This is already a good start. But I will narrow the scope of inquiry even further and suggest that consciousness arises not from the whole brain but rather from certain specialized brain circuits that carry out a particular style of computation. To illustrate the nature of these circuits and the special computations they perform, I'll draw from the many examples in perceptual psychology and neurology that we have already considered in this book. These examples will show that the circuitry that embodies the vivid subjective quality of consciousness resides mainly in parts of the temporal lobes (such as the amygdala, septum, hypothalamus and insular cortex) and a single projection zone in the frontal lobes—the cingulate gyrus. And the activity of these structures must fulfill three important criteria, which I call (with apologies to Isaac Newton, who described the three basic laws of physics) the "three laws of qualia" ("qualia" simply means the raw feel of sensations such as the subjective quality of "pain" or "red" or "gnocchi with truffles"). My goal in identifying these three laws and the specialized structures embodying them is to stimulate further inquiry into the biological origin of consciousness.

The central mystery of the cosmos, as far as I'm concerned, is the following: Why are there always two parallel descriptions of the universe—the first−person account ("I see red") and the third−person account ("He says that he sees red when certain pathways in his brain encounter a wavelength of six hundred nanometers")?

How can these two accounts be so utterly different yet complementary? Why isn't there only a third−person account, for according to the objective worldview of the physicist and neuroscientist, that's the only one that really exists? (Scientists who hold this view are called behaviorists.) Indeed, in their scheme of "objective science," the need for a first−person account doesn't even arise—implying that consciousness simply doesn't exist. But we all know perfectly well that can't be right. I'm reminded of the old quip about the behaviorist who, just having made passionate love, looks at his lover and says, "Obviously that was good for you, dear, but was it good for me?" This need to reconcile the first−person and third−person accounts of the universe (the "I" view versus the "he" or "it" view) is the single most important unsolved problem in science. Dissolve this barrier, say the Indian mystics and sages, and you will see that the separation between self and nonself is an illusion—that you are really One with the cosmos.

Philosophers call this conundrum the riddle of
qualia
or subjective sensation. How can the flux of ions and electrical currents in little specks of jelly—the neurons in my brain—generate the whole subjective world of sensations like red, warmth, cold or pain? By what magic is matter transmuted into the invisible fabric of feelings and sensations? This problem is so puzzling that not everyone agrees it is even a problem. I will illustrate this so−called qualia riddle with two simple thought experiments of the kind that philosophers love to make up. Such whimsical pretend experiments are virtually impossible to carry out in real life. My colleague Dr. Francis Crick is deeply suspicious of thought experiments, and I agree with him that they can be very misleading because they often contain hidden question−begging assumptions. But they can be used to clarify logical points, and I will use them here to introduce the problem of qualia in a colorful way.