Hallucinations полностью

The body illusions Ehrsson is exploring are very much more than party tricks; they point to the ways in which our body ego, our sense of self, is formed from the coordination of senses—not just touch and vision but proprioception and perhaps vestibular sensation, too. Ehrsson and others favor the idea that there are “multisensory” neurons, perhaps at a number of places in the brain, which serve to coordinate the complex (and usually consistent) sensory information coming into the brain. But if this is interfered with—by nature or experiment—our seemingly unassailable certainties about the body and the self can vanish in an instant.

15

Phantoms, Shadows, and Sensory Ghosts

While hallucinations of sight and sound—“visions” and “voices”—are described in the Bible, in The Iliad and The Odyssey, in all the great epics of the world, none of these so much as mentions the existence of phantom limbs, the hallucinatory feeling that one still has a limb even though it has been amputated. Indeed, there was no term for these before Silas Weir Mitchell gave them their name in the 1870s. And yet they are common—more than a hundred thousand people in the United States have amputations every year, and the vast majority of them experience phantoms after their amputations. The experience of phantom limbs must be as old as amputation itself, and amputations are not new—they were performed thousands of years ago: the Rig Veda tells the story of the warrior queen Vishpla, who went to battle with an iron prosthesis after she lost a leg.

In the sixteenth century, Ambroise Paré, a French military surgeon who was called upon to amputate dozens of injured limbs, wrote, “Long after the amputation is made, patients say that they still feel pain in the amputated part . . . which seems almost incredible to people who have not experienced this.”

Descartes, in his Meditations on First Philosophy, observed that, just as the sense of vision was not always reliable, so “errors in judgment” could occur in the “internal senses” as well. “I have sometimes been informed,” he wrote, “by parties whose arm or leg had been amputated, that they still occasionally seemed to feel pain in that part of the body which they had lost—a circumstance that led me to think that I could not be quite certain even that any one of my members was affected when I felt pain in it.”

But by and large, as the neurologist George Riddoch brought out (in 1941), a curious atmosphere of silence and secrecy seems to surround the subject. “Spontaneous description of phantoms is rarely offered,” he wrote. “Dread of the unusual, of disbelief, or even of the accusation of insanity may be behind this reticence.”

Weir Mitchell himself hesitated for years before writing professionally on the subject; he introduced it first in the form of fiction (he was a writer as well as a physician), in “The Case of George Dedlow,” published anonymously in the Atlantic Monthly in 1866. As a neurologist working at a military hospital in Philadelphia during the Civil War (the place was informally known as the “Stump Hospital”), Mitchell saw dozens of amputees and, driven by his own curiosity and compassion, he encouraged them to describe their experiences. It would take him several years to fully digest what he had seen and heard from his patients, but in 1872, in his classic Injuries of Nerves, he was able to provide a detailed description and discussion of phantom limbs—the first such in the medical literature.⁷⁵

Mitchell devoted the final chapter of his book to phantom limbs, introducing the subject as follows:

No history of the physiology of stumps would be complete without some account of the sensorial delusions to which persons are subject in connection with their lost limbs. These hallucinations are so vivid, so strange, and so little dwelt upon by authors, as to be well worthy of study, while some of them seem to me especially valuable, owing to the light which they cast upon the subject of the long-disputed muscular sense.

Nearly every man who loses a limb carries about with him a constant or inconstant phantom of the missing member, a sensory ghost of that much of himself.

After Mitchell had brought attention to the subject, other neurologists and psychologists were drawn to study phantom limbs. Among them was William James, who sent a questionnaire to eight hundred amputees (he was able to contact them with the help of prosthetic manufacturers), and of these, nearly two hundred answered the questionnaire; a few he was able to interview personally.⁷⁶