Phantoms in the Brain: Probing the Mysteries of the Human Mind (24 page)

"dominant" hemisphere because it, like a chauvinist, does all the talking (and maybe much of the internal thinking as well), claiming to be the repository of humanity's highest attribute, language. Unfortunately, the mute right hemisphere can do nothing to protest.

Other obvious specializations involve vision and emotion. The right hemisphere is concerned with holistic aspects of vision such as seeing the

forest for the trees, reading facial expressions and responding with the appropriate emotion to evocative situations. Consequently, after right hemisphere strokes, patients tend to be blissfully unconcerned about their predicament, even mildly euphoric, because without the "emotional right hemisphere" they simply don't comprehend the magnitude of their loss. (This is true even of those patients who are aware of their paralysis.) In addition to these obvious divisions of labor, I want to suggest an even more fundamental difference between the cognitive styles of the two hemispheres,4 one that not only helps explain the amplified defense mechanisms of anosognosia but may also help account for the more mundane forms of denial that people use in daily life—such as when an alcoholic refuses to acknowledge his drinking problem or when you deny your forbidden attraction to a married colleague.

At any given moment in our waking lives, our brains are flooded with a bewildering array of sensory inputs, all of which must be incorporated into a coherent perspective that's based on what stored memories already tell us is true about ourselves and the world. In order to generate coherent actions, the brain must have some way of sifting through this superabundance of detail and of ordering it into a stable and internally consistent

"belief system"—a story that makes sense of the available evidence. Each time a new item of information comes in we fold it seamlessly into our preexisting worldview. I suggest that this is mainly done by the left hemisphere.

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But now suppose something comes along that does not quite fit the plot. What do you do? One option is to tear up the entire script and start from scratch: completely revise your story to create a new model about the world and about yourself. The problem is that if you did this for every little piece of threatening information, your behavior would soon become chaotic and unstable; you would go mad.

What your left hemisphere does instead is either ignore the anomaly completely or distort it to squeeze it into your preexisting framework, to preserve stability. And this, I suggest, is the essential rationale behind all the so−called Freudian defenses—the denials, repressions, confabulations and other forms of self−delusion that govern our daily lives. Far from being maladaptive, such everyday defense mechanisms prevent the brain from being hounded into directionless indecision by the "combinatorial explosion" of possible stories that might be written from the material available to the senses. The penalty, of course, is that you are

"lying" to yourself, but it's a small price to pay for the coherence and stability conferred on the system as a whole.

Imagine, for example, a military general about to wage war on the enemy. It is late at night and he is in the war room planning strategies for the next day. Scouts keep coming into the room to give him information about the lay of the land, terrain, light level and so forth. They also tell him that the enemy has five hundred tanks and that he has six hundred tanks, a fact that prompts the general to decide to wage war. He positions all of his troops in strategic locations and decides to launch battle exactly at 6:00 a.m. with sunrise.

Imagine further that at 5:55 A.M. one little scout comes running into the war room and says, "General! I have bad news." With minutes to go until battle, the general asks, "What is that?" and the scout replies, "I just looked through binoculars and saw that the enemy has seven hundred tanks, not five hundred!"

What does the general—the left hemisphere—do? Time is of the essence and he simply can't afford the luxury of revising all his battle plans. So he orders the scout to shut up and tell no one about what he saw. Denial!

Indeed, he may even shoot the scout and hide the report in a drawer labeled "top secret" (repression). In doing so, he relies on the high probability that the majority opinion—the previous information by all the scouts—was correct and that this single new item of information coming from one source is probably wrong.

So the general sticks to his original position. Not only that, but for fear of mutiny, he might order the scout actually to lie to the other generals and tell them that he only saw five hundred tanks (confabulation). The purpose of all of this is to impose stability on behavior and to prevent vacillation because indeci−siveness doesn't serve any purpose. Any decision, so long as it is
probably
correct, is better than no decision at all. A perpetually fickle general will never win a war!

In this analogy, the general is the left hemisphere5 (Freud's "ego," perhaps?), and his behavior is analogous to the kinds of denials and repressions you see in both healthy people and patients with anosognosia. But why are these defense mechanisms so grossly exaggerated in the patients? Enter the right hemisphere, which I like to call the Devil's Advocate. To see how this works, we need to push the analogy a step further. Supposing the single scout comes running in, and instead of saying the enemy has more tanks, he declares, "General, I just looked through my telescope and the enemy has nuclear weapons." The general would be very foolish indeed to adhere to his original plan. He must

quickly formulate a new one, for if the scout were correct, the consequences would be devastating.

Thus the coping strategies of the two hemispheres are fundamentally different. The left hemisphere's job is to create a belief system or model and to fold new experiences into that belief system. If confronted with some new information that doesn't fit the model, it relies on Freudian defense mechanisms to deny, repress or confabulate—anything to preserve the status quo. The right hemisphere's strategy, on the other hand, is to play

"Devil's Advocate," to question the status quo and look for global inconsistencies. When the anomalous 97

information reaches a certain threshold, the right hemisphere decides that it is time to force a complete revision of the entire model and start from scratch. The right hemisphere thus forces a "Kuhnian paradigm shift" in response to anomalies, whereas the left hemisphere always tries to cling tenaciously to the way things were.

Now consider what happens if the right hemisphere is damaged.6 The left hemisphere is then given free rein to pursue its denials, confabulations and other strategies, as it normally does. It says, "I am Mrs. Dodds, a person with two normal arms that I have commanded to move." But her brain is insensitive to the contrary visual feedback that would ordinarily tell her that her arm is paralyzed and that she's in a wheelchair. Thus Mrs.

Dodds is caught in a delusional cul−de−sac. She cannot revise her model of reality because her right hemisphere, with its mechanisms for detecting discrepancies, is out of order. And in the absence of the counterbalance or "reality check" provided by the right hemisphere, there is literally no limit to how far she will wander along the delusional path. Patients will say, "Yes, I'm touching your nose, Dr. Ramachandran," or

"All of the medical students have been prodding me and that's why I don't want to move my arm." Or even,

"What is my brother's hand doing in my bed, doctor?"

The idea that the right hemisphere is a left−wing revolutionary that generates paradigm shifts, whereas the left hemisphere is a die−hard conservative that clings to the status quo, is almost certainly a gross oversimplification, but, even if it turns out to be wrong, it does suggest new ways of doing experiments and goads us into asking novel questions about the denial syndrome. How deep is the denial? Does the patient really believe he's not paralyzed? What if you were to confront patients directly: Could you then force them to admit the paralysis? Would they deny only their paralysis, or would they deny other aspects of their illness as well? Given that people often think of their car as part of their ex−

tended "body image"(especially here in California), what would happen if the front left fender of their car were damaged? Would they deny that? Anosognosia has been known for almost a century, yet there have been very few attempts to answer these questions. Any light we could shed on this strange syndrome would be clinically important, of course, because the patients' indifference to their predicament not only is an impediment to rehabilitation of the weak arm or leg, but often leads them to unrealistic future goals. (For example, when I asked one man whether he could go back to his old occupation of repairing telephone lines—a job that requires two hands for climbing poles and splicing wires—he said, "Oh, yes, I don't see a problem there.") What I didn't realize, though, when I began these experiments, was that they would take me right into the heart of human nature. For denial is something we do all our lives, whether we are temporarily ignoring the bills accumulating in our "to do" tray or defiantly denying the finality and humiliation of death.

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Talking to denial patients can be an uncanny experience. They bring us face to face with some of the most fundamental questions one can ask as a conscious human being: What is the self? What brings about the unity of my conscious experience? What does it mean to will an action? Neuroscientists tend to shy away from such questions, but anosognosia patients afford a unique opportunity for experimentally approaching these seemingly intractable philosophical riddles.

Relatives are often bewildered by their loved ones' behavior. "Does Mom really believe she's not paralyzed?"

asked one young man. "Surely, there must be some recess of her mind that knows what's happened. Or has she gone totally bonkers?"

Our first and most obvious question, therefore, is, How deeply does the patient believe his own denials or confabulations? Could it be some sort of surface facade or even an attempt at malingering? To answer this question, I devised a simple experiment. Instead of directly confronting the patient by asking him to respond verbally (can you touch my nose with your left hand?), what if I were to "trick" him by asking him to perform 98

a spontaneous motor task that requires two hands—before he has had a chance to think about it. How would he respond?

To find out, I placed a large cocktail tray supporting six plastic glasses half filled with water in front of patients with denial syndrome. Now if I asked you to reach out and grab such a tray, you would place one hand under either side of the tray and proceed to raise it. But if you had one hand tied behind your back, you would naturally go for the middle of the tray—its center of gravity—and lift from there. When I tested stroke patients who were paralyzed on one side of their body but did not suffer from denial, their nonparalyzed hand went straight for the middle of the tray, as expected.

When I tried the same experiment on denial patients, their right hands went straight to the right side of the tray while the left side of the tray remained unsupported. Naturally, when the right hand lifted only the right side of the tray, the glasses toppled, but the patients often attributed this to momentary clumsiness rather than a failure to lift the left side of the tray ("Ooops! How silly of me!"). One woman even denied that she had failed to lift the tray. When I asked her whether she had lifted the tray successfully, she was surprised. "Yes, of course," she replied, her lap all soggy.

The logic of a second experiment was somewhat different. What if one were actually to reward the patient for honesty? To investigate this, I gave our patients a choice between a simple task that can be done with one hand and an equally simple task that requires the use of two hands. Specifically, patients were told that they could earn five dollars if they threaded a light bulb into a bare socket on a heavy table lamp or ten dollars if they could tie a pair of shoelaces. You or I would naturally go for the shoelaces, but most paralyzed stroke patients—who do not suffer from denial—choose the light bulb, knowing their limitations. Obviously five dollars is better than nothing. Remarkably, when we tested four stroke patients who had denial, they opted for the shoelace task every time and spent minutes fiddling with the laces without showing any signs of frustration. Even when the patients were given the same choice ten minutes later they unhesitatingly went for the bimanual task. One woman repeated this bumbling behavior five times in a row, as though she had no memory of her previous failed attempts. A Freudian repression perhaps?

On one occasion, Mrs. Dodds kept on fumbling with the shoelaces using one hand, oblivious to her predicament, until finally I had to pull the shoe away. The next day my student asked her, "Do you remember Dr. Ramachandran?"

She was very pleasant. "Oh, yes, I remember. He's that Indian doctor."

"What did he do?"

"He gave me a child's shoe with blue dots on it and asked me to tie the shoelaces."

"Did you do it?"

"Oh, yes, I tied it successfully with both my hands," she replied.

Something odd was afoot. What normal person would say, "I tied the shoelace
with both my hands?
It was almost as though inside Mrs. Dodds there lurked another human being—a phantom within—who knows perfectly well that she's paralyzed, and her strange remark was an attempt to mask this knowledge. Another intriguing example was a patient who volunteered, while I was examining him, "I can't wait to get back to two−fisted beer drinking." These peculiar remarks are striking examples of what Freud called a "reaction formation"—a subconscious attempt to disguise something that is threatening to your self−esteem by asserting the opposite. The classic illustration of a reaction formation, of course, comes from
Hamlet,
"Methinks the 99

lady doth protest too much." Is not the very vehemence of her protest itself a betrayal of guilt?

Let us return now to the most widely accepted neurological explanation of denial—the idea that it has something to do with neglect, the general indifference that patients often display toward events and objects on the left side of the world. Perhaps when asked to perform an action with her left hand, Mrs. Dodds sends motor commands to the paralyzed arm and copies of these commands are simultaneously sent to her body image centers (in the parietal lobes), where they are monitored and experienced as felt movements. The parietal lobes are thus tipped off about what the intended actions are, but since she's ignoring events on the left side of her body, she also fails to notice that the arm did not obey her command. Although, as I argued earlier, this account is implausible, we did two simple experiments to test the neglect theory of denial directly.7