Peter Brugger: Animation and incarnation

When I think about voluntary amputations, I can hardly remember how I felt fifteen years ago. Back then, I was a young neuroscientist studying a rare type of “phantom limb” patient — people who were born without an arm or a leg, but who experienced phantom sensations from the limbs they never had. I wondered why I should care about crazy people who had all their limbs, but wanted one or more chopped off. I empathized with my patients with incomplete bodies, and did not want to waste time thinking about those who desired amputations.

My opinion changed drastically around eight years ago, when I met a man in his forties who told me about his preoccupation with a way to be rid of his legs. He showed me the line on his thighs where he felt there was a border between what was “his body” and what was not. He convinced me that this division was a source of tremendous suffering.

But it was one particular expression of his that changed my mind: he said that his desire to rid himself of parts of his legs had been with him for “as long as I can think of”. A phantom limb patient of mine, who had been born without arms or legs, had used almost exactly the same words. “As long as I can remember” — that’s how she had replied when I asked her how long she had experienced phantom limbs. Could there be a connection between these sensations and the feeling of having “too much of a body”?

I began to think of these two conditions as mirror images. Phantoms of congenitally absent limbs might be a kind of “animation without incarnation” — the brain was trying to animate a body part that had never turned into flesh and bone. On the other hand, experiencing a leg as alien could be seen as “incarnation without animation” — the body part had developed normally in the physical sense, but was not being properly animated by the brain. It was flesh without a soul.

Seen like this, the desire for amputation loses its bizarreness. Can’t you empathize with the wish to have a body part removed that, although developed, has never been incorporated into your sense of self?

Today we know that a network of brain regions is responsible for the “animation” of body parts and the integration of these parts into a unitary bodily self. One of these regions is located in the parietal lobe of the right cerebral hemisphere. In one experiment I conducted, my colleagues and I scanned the brain of the lady who was born without arms and legs while she tried to move one of her phantom hands. A region in her parietal lobe was activated; the same area shows diminished activity when people who desire amputations have their “alien” body parts touched.

Over the past year or so, we have begun to settle on a name for the condition: “xenomelia”, or the syndrome of the “foreign limb”. We have identified some spots on the brain’s surface that are involved and gravitated to one label for a condition that has had several different names (apotemnophilia, Body Integrity Identity Disorder, transableism). But we are in danger of believing that doing so gives us a good grasp of what is going on in the brain.

I agree that much progress has been made. But the boundaries of xenomelia remain unclear, and this lack of uncertainty exposes holes in our knowledge. We don’t know if xenomelia occurs in Asian countries, where people typically hold a less individualized notion of the self. Nor do we know if the condition, should it be added to the diagnostic manuals, should include other forms of body modification. What of the patients who long for paralysis rather than amputation? Or those who desire blindness, deafness or incontinence? (Such cases have been described in the medical literature.) Here the term “xenomelia” requires a stretch: “melia” derives from “melos”, Greek for “limb”. Perhaps only one thing is certain: many scientists are now interested in these conditions, so we will soon learn a great deal more about those who desire to modify their bodies.

Peter Brugger is a neuroscientist at University Hospital Zurich.

To read more about the science behind BIID, and to hear the stories of other BIID patients, read Do No Harm, a story from the new digital publisher MATTER. The story is free to access, but we rely on paid members to support the in-depth journalism we produce — and we’d greatly appreciate your support. Membership costs just 99c per month.


“Xenomelia: a new right parietal lobe syndrome”, McGeoch et al. J. Neurol. Neurosurg. Psychiatry, doi:10.1136/jnnp-2011-300224 (2011).

“Beyond re-membering: Phantom sensations of congenitally absent limbs”, Brugger et al. Proc. Natl. Acad. Sci, v97 p617 (2000).

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