Vilayanur S. Ramachandran
Phantoms in the Brain
To my mother, Meenakshi
To my father, Subramanian
To my brother, Ravi
To Diane, Mani and Jayakrishna
To all my former teachers in India and England
To Saraswathy, the goddess of learning, music and wisdom
Foreword
The great neurologists and psychiatrists of the nineteenth and early twentieth centuries were masters of description, and some of their case histories provided an almost novelistic richness of detail. Silas Weir Mitchell — who was a novelist as well as a neurologist — provided unforgettable descriptions of the phantom limbs (or “sensory ghosts”, as he first called them) in soldiers who had been injured on the battlefields of the Civil War. Joseph Babinski, the great French neurologist, described an even more extraordinary syndrome — anosognosia, the inability to perceive that one side of one’s own body is paralyzed and the often-bizarre attribution of the paralyzed side to another person. (Such a patient might say of his or her own left side, “It’s my brother’s” or “It’s yours”. ) Dr. V. S. Ramachandran, one of the most interesting neuroscientists of our time, has done seminal work on the nature and treatment of phantom limbs — those obdurate and sometimes tormenting ghosts of arms and legs lost years or decades before but not forgotten by the brain. A phantom may at first feel like a normal limb, a part of the normal body image; but, cut off from normal sensation or action, it may assume a pathological character, becoming intrusive, “paralyzed”, deformed, or excruciatingly painful — phantom fingers may dig into a phantom palm with an unspeakable, unstoppable intensity.
The fact that the pain and the phantom are “unreal” is of no help, and may indeed make them more difficult to treat, for one may be unable to unclench the seemingly paralyzed phantom. In an attempt to alleviate such phantoms, physicians and their patients have been driven to extreme and desperate measures: making the amputation stump shorter and shorter, cutting pain or sensory tracts in the spinal cord, destroying pain centers in the brain itself. But all too frequently, none of these work; the phantom, and the phantom pain, almost invariably return.
To these seemingly intractable problems, Ramachandran brings a fresh and different approach, which stems from his inquiries as to what phantoms are, and how and where they are generated in the nervous system. It has been classically considered that representations in the brain, including those of body image and phantoms, are fixed. But Ramachandran (and now others) has shown that striking reorganizations in body image occur very rapidly — within forty-eight hours, and possibly much less — following the amputation of a limb.
Phantoms, in his view, are generated by such reorganizations of body image in the sensory cortex and may then be maintained by what he terms a “learned” paralysis. But if there are such rapid changes underlying the genesis of a phantom, if there is such plasticity in the cortex, can the process be reversed? Can the brain be tricked into unlearning a phantom?
