Thursday, September 28, 2006

Phantoms in the Brain

by

V.S. Ramachandran MD, PHD & Sandra Blakeslee

book review.

I found this book fascinating. Ramachandran is a neurologist who studies people with damaged brains to discover how healthy brains work.

Much of this book is taken up with the persistence of body image. He writes mostly of it in terms of phantom limbs but also with stroke victims who lose the use of something on one side of their body.

It appears that our brains are constantly trying to make things, stories and ourselves ‘whole’. And it’s not above using subterfuge for this. Freud names the following devices:

Denial, Repression, Reaction formation, Rationalization, Humor, Projection

These can be useful ways for our brains to value wholeness over the truth.

The book talks about patients with damage to the right parietal lobe which results in neglect of the left side.

Neglect stories are very popular with medical students. Oliver Sacks tells the strange tale of a woman who, like many left hemineglect patients, ate food only from the right side of her plate. But she knew what was up and realized that if she wanted all her dinner, she had to shift her head, so as to see the food on the left. But given her general indifference to the left and reluctance even to look to the left she adopted a comically ingenious solution. She rolled her wheelchair in a huge circle to the right, traveling 340 degrees or so until finally her eyes would fall on the uneaten food. That consumed, she’d make another rotation, to eat the remaining half of the food on her plate, and so on, round and round, until it was gone. It never occurred to her that she could just turn left—for her—the left simply didn’t exist.

Ramachandran mentions a way to strip one of ones delusions, albeit sometimes only temporarily.

There are people who deny that they are paralyzed. Ramachandran wondered if the truth about their disability was buried somewhere in their brains.

The experiments we discussed earlier suggest that a denial patient is not just trying to save face; the denial is anchored deep in her psyche. But doe this imply that the information about her paralysis is locked away somewhere—repressed? Or does it imply that the information doesn’t exist anywhere in her brain? The latter view seems unlikely. If the knowledge doesn’t exist, why does the patient say things like “I tied my shoelaces with both my hands” or “I can’t wait to get back to two-fisted beer drinking”? And why evasive remarks like “I’m not ambidextrous”? Comments like these imply that “somebody” in there knows she is paralyzed, but that the information is not available to the conscious mind. If so, is there some way to access that forbidden knowledge?

To find out we took advantage of an ingenious experiment preformed in 1987 by an Italian neurologist, Eduardo Bisiach, on a patient with neglect and denial. Bisiach took a syringe filled with ice-cold water and irrigated the patient’s left ear canal—a procedure that tests vestibular nerve function. Within a few seconds the patient’s eyes started to move vigorously in a process called nystagmus. The cold water sets up a convection current in the ear canals, thereby fooling the brain into thinking the head is moving and into making involuntary correctional eye movements that we call nystagmus. When Bisiach then asked the denial patient whether she could use her arms, she calmly replied that she had no use of her left arm! Amazingly, the cold water irrigation of the left ear had brought about a complete (though temporary) remission from the anosognosia.**

I also started wondering about anorexia nervosa. These patients have disturbances in appetite but are also delusional about their body image—claiming actually to “see” that they are fat when looking into a mirror, even though they are grotesquely thin. Is the disorder of appetite (linked to feeding and satiety centers in the hypothalamus) primarily, or does the body image distortion cause the appetite problem?

We know that certain parts of the limbic system such as the insular cortex are connected to the hypothalamic “appetite” centers and also to parts of the parietal lobes concerned with body image. Is it conceivable that how much you eat over a long period of time, your intellectual beliefs about whether you are too fat or thin, your perception of your body image and your appetite are all more closely linked in your brain that you realize—so that a distortion of one of the these systems can lead to a pervasive disturbance in the others as well?

People have become increasingly inpatient 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. 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. …Until we have clear answers, to these questions, Western medicine and alternative medicine will always remain parallel enterprises with no point of contact between them.

So with all this evidence starting 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, incorporated 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.

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 the view—that the notion of a single unified self “inhabiting” the brain may indeed be an illusion. …(as has long been emphasized by Eastern mystical traditions like Hinduism and Zen Buddhism). Once you realize that far from being a spectator, you are in fact part of the eternal ebb and flow of events in the cosmos, this realization is very liberating.

** anosognosia-the inability to perceive that one side of one’s own body is paralyzed

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