Tuesday, November 15, 2005

"Weird Bodies"

Chapter 12 of Up From Dragons: The Evolution of Human Intelligence (Skoyles and Sagan) continues:

"Weird Bodies
We also sense feedback related to our movement as in happens in the space around our body. The brain’s sense of this physically nearby space is made in our parietal cortex, and it is part of our egocentric orientation to the world. Interfere with the working of the parietal cortex – as can happen in migraines or epilepsy – and people experience a distorted sense of embodiment in the outer world. During attacks or seizures people might feel themselves as very small or large. It is called “Alice in Wonderland syndrome” (Rolak 1991; LePlante 1993) after Lewis Carroll’s book. Charles Dodgson (the real Lewis Carroll) suffered from both migraines and epilepsy, so it is likely that Alice’s experiences of growing tiny and huge were based on his own experiences of size change during attacks of migraine or epilepsy, or maybe both. Jonathoan Swift, the eighteenth century satirist, is also thought to have had elpilesy, so size change experiences might have influenced him to write about Lilliputians (miniature people) and Brobdingnagians (mammoth ones) in Gulliver’s Travels (Laplante 1993: 69). Such size change experiences are linked with disruption, particularly to the right posterior parietal lobe.

This suggests not only that neurons create our sense of embodiment but that disturbances to them can change how we feel in our bodies. To take another example: Changes at the neuron level can affect the physical experience of sex. A person with a phantom foot can feel it as an extra “sexual organ” during intercourse. One man reported “that his erotic orgasmic experience ‘actually spread all the way down to the foot instead of remaining confined to the genitals’ – so that the orgasm was ‘much bigger than it used to be…” The reason for this is that the map in our brain for our sexual organs is next to those for our feet. (It is believed to be a developmental “fossil” from the time when the brain laid down body maps in the embryonic stage. During this period the genitals, due to the way the fetus curls up in the womb, are next to the feet (Farah 1998).) Remember the example mentioned in Chapter 3 of people who feel that water dripping on their face is also dripping on their phantom fingers? In such cases, due to neural plasticity, the face map has invaded the hand map. Which, due to the amputation of the hand, is no longer receiving hand input. In the man described here, it seems that for the same reason his genital map has started to invade the nearby one for his missing foot! The scientists who reported this genital-foot link suggested that neuron activation may also spread in those with intact legs; they commented, “It has not escaped our notice that this may provide an explanation for foot fetishes” (Ramachandran 1993: 10417). But do not think of cutting your leg off in order t have more interesting sex. Sexual excitement is not the only thing that spreads to the feet from a person’s genitals. Those with phantom legs also find them stimulated – often painfully so – when they urinate.

Distortion of embodiment can take even weirder and more frightening forms. After suffering multiple strokes, people may claim that they have two left hands, or even three heads and six feet (Weinstein 1954). They may say they have a nestful of fingers under the bed sheets. One man, following a right-hemisphere stroke, when asked about his left hand explained, “My mother has it in a suitcase and there are at least three pairs of fingers in there, and they’re all functional.” “How did that happen?” “We brought them in through customs.” “And where are they now?” “My mother has them. There should be a leg, and there should be three pairs of fingers… from the left side” (Halligan, Marshall, Wade 1995: 178). One woman complained of having an extra hand. Once, in response to a query concerning her left hand, she said, “That’s someone’s hand, someone forgot it – that’s funny, you read in the paper about people losing purses but not a hand” (Weinstein, Kahn, Malitz, Rozanski 1954: 47). She persistently complained about being kept on a neurological ward when her only problem was her hands.

Embodiment can cease to be tied to our bodies. Goethe, after he left his fiancĂ©e, wrote: “I saw myself, not with the eyes of the body but with the eyes of the mind” (Lhermitte 1951: 474). Such a visual body-image delusion is called autoscopy, or out-of-body experience. Hallucinations of the self are not uncommon in near-death situations, such as when our heart stops, or in emotional crises, such as Goethe was going through at the time. Certain people are prone to them. They are characteristic of “schizotopy,” which describes the personality type of those who tend to be reclusive, suspicious, and prone to “magical thinking” and experiencing visual illusions. (Schizotypy is badly named, since although schizophrenics score high on tests for it, so do many other people.)

Embodiment, in spite of being a product of the brain, is felt as totally real. While no necessary link exists between it and our bodies’ real extension, it is still a remarkably powerful “me” experience. After all, we feel that we are our bodies. There is no doubt or hesitation about it: Hurt your hand, and it is “I,” not some scientist’s neural network model, that feels the pain.

Indeed, this feeling turns out to be more fundamental to us than our knowledge that we are extended. Merely knowing that we are attached to a limb does not make it part of us. The neurologist and writer Oliver Sacks tells of a young man who had found a “severed human leg” in his hospital bed. The only way he could explain it was as a “rather monstrous and improper, but very original joke.” “Obviously one of the nurses with a macabre sense of humor had stolen into the Dissecting Room and nabbed a leg, then slipped it under his bedclothes as a joke.” He tried to throw it out of bed – but he was attached to it. It was no good explaining to him that it was a part of him. “A man should know his own body, what’s his and what’s not” (Sacks 1984: 50-52). People in such a confused state will try to attribute the alien limb to the doctor examining it. One American woman in the 1930s, after two strokes, denied that her paralyzed limbs were hers. When asked whose they were, she said, “Yours.” A three-limbed doctor made more sense to her than the idea that that “thing” was part of her body. Shown that her arm merged with her shoulder, she observed: “But my eyes and my feelings don’t agree, and I must believe my feelings. I know they look like mine, but I can feel they are not, and I can’t believe my eyes” (Neilson 1938: 555).

These are other such cases lead us to one conclusion: Our physical sense of being is made by our neurons. It is not just our sense of extension but also the sense of “me” that goes along with it. Here we have come halfway to answering the problem of consciousness. Embodiment may not be consciousness, but the brain, in making it, also makes this inseparable sense of “me.” If our brains can do this for our physical bodies, might they not also be able to create a sense of “me” in a nonconcrete reality? While such a question does not answer the problem of consciousness, it does suggest a new approach.

The approach lies in answering a rather simple but overlooked question: Do our brains give rise to a sense of “me” in more than our physical extension? We have shown above that embodiment arises from our brain’s doing things with or bodies. Are there other things in which the brain might feel we exist that are not physical? If we look, there are several things done by the brain that could be “embodied” with a feeling of “me-ness.” Here, starting with sociability, we shall discuss them, stretching and challenging our quest for an answer to the question, “Who are we?” "

These were all the inner challenges my patients faced as I struggled as a young therapist to do my job, help them regain function, learn to roll over, stand in 4-point kneeling, 2- point kneeling, sit up, stand up, walk.. basic body control in space and gravity. Looking back on those days I think I'm glad I didn't have as much sensitivity then as I do now, or know as much.. but the thought that these people were experiencing shades of what is described above, on their own, with no real understanding or accompaniment from me, still makes me feel sad. At least the information is more accessible to everyone these days, compared to 30 years ago..

More to come.

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