To all outward appearances, Elliot is a perfectly normal middle-aged businessman. Despite an operation a decade ago for removal of a benign brain tumor the size of a small orange, he remains intelligent and seemingly rational, with a wry sense of humor. Yet his behavior makes it clear that there is something very wrong. After years of rock-solid competence, Elliot now has trouble keeping appointments and making decisions. He has squandered much of his life savings on a series of bad investments. And, strangest of all, the very fact that his behavior is self-destructive doesn't seem to bother him-and he keeps on making the same mistakes.
Patient "X" is much more clearly ill. She has suffered a major stroke; her entire left side is paralyzed. It's obvious to everyone that she's severely impaired -- everyone, that is, except her. Ask her how she feels, and she responds, "Just fine." Point out her lifeless left arm, and she seems baffled. She can be convinced, through persistent effort, that the arm doesn't work. But a few minutes later, she has forgotten all about it.
Bill Noonan hasn't suffered any obvious physical damage to his brain. Yet for more than two decades after his return from Vietnam, he has re-experienced the most terrifying event of his life several times a week as a waking dream. "It was a night ambush," he remembers. "The first seven guys to my right were machine-gunned down. My gas mask was shot right off my hip. That was my first fire fight." Bill knew his flashbacks weren't real-but they seemed so real that it made no difference. "I didn't know what was happening," he says. "The biggest fear I had was that I was crazy."
Nothing is more morbidly intriguing, more chillingly compelling than an account of a malfunctioning mind, as medical writers have learned to their great profit. The victims of mental disease or brain damage are fascinating, not simply as exhibits in a neurological sideshow but also as stark demonstrations of how fragile reality can be. Most people agree, within limits, on the objective character of the world around them. Yet while the victims of mental disorders are certainly conscious and aware, their worlds are profoundly different from those of most of us. What can it possibly feel like, we wonder, to live without emotion, to be crippled without realizing it, to re-experience an event from the distant past complete with the fears that originally surrounded it?
As neurologists, psychologists and biologists have zeroed in more and more precisely on the physical causes of mental disorders, they have found themselves addressing a much deeper mystery, a set of interrelated conundrums probably as old as humanity: What, precisely, is the mind, the elusive entity where intelligence, decision making, perception, awareness and sense of self reside? Where is it located? How does it work? Does it arise from purely physical processes-pulses of electricity zapping from brain cell to brain cell, helped along their way by myriad complex chemicals? Or is it something beyond the merely physical-something ethereal that might be close to the spiritual concept of the soul?