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Kochs lab has a slew of more sophisticated versions of these and other experiments, which teach us, he says, that what we see is not a simple mapping of the world out there, but a construction that results from complex neural interactions. In short, I am not a camera but a highly nonlinear processing system. Koch hopes that if he can tease out the neural correlates of visual awareness he will be able to cast light on other aspects of conscious perception including that greatest of all conundrums, self-consciousness.
3. CONSCIOUSNESS REFRAMED
As long ago as the 1890s, William James dreamed about a scientific explanation for consciousness. Yet for much of the past century, the C-word was viewed with nearly as much disdain in scientific circles as the notion of a soul. Over the last decade, however, consciousness has become one of the hottest topics in science a steady stream of books announce the latest theories; two peer-review journals have been formed (Consciousness and Cognition and The Journal of Consciousness Studies); and the field has spawned a slew of conferences, from the strictly academic events of the Society for the Study of Consciousness to the freewheeling hoopla of the Tucson Conferences, where Koch is on the program committee. We get everyone from neurologists to shamanists to people experimenting with drugs, he says.
The emergence of consciousness as a respectable scientific topic is in large part due to the influence of Crick and fellow Nobel Laureate Gerald Edelman. In 1979, in an editorial accompanying a special Scientific American issue on the brain, Crick suggested that the time had come to move forward on this hitherto verboten subject. Fifteen years later, in his controversial book The Astonishing Hypothesis, Crick threw down the gauntlet: A persons mental activities are entirely due to the behavior of nerve cells, glial cells, and the atoms, ions and molecules that make them up. What exactly are those behaviors? Crick advocated focusing on the subproblem of visual consciousness, and he put forward a research program designed to pinpoint the awareness neurons that enable us to see. His ideas have formed the inspiration for Kochs own program, and the two scientists have been working closely together ever since.
On a muggy day this summer, I visit Koch and his mentor at Cricks rambling ranch-style home in La Jolla. Though Crick has lived 30 years in California, where he is based at the Salk Institute, he remains an Englishman through and through. Tall and majestic, he radiates an aura of noblesse oblige, though, uncommonly for a scientist of his iconic stature, there is nothing snobbish about him. At 84, Crick still seems to be sucking in the world with the wonder of a precocious child. Now suffering from advanced cancer, he walks with a stick, but during three hours of conversation he blazes forth with ideas and fiercely held opinions. One gets the feeling that if the inexorable hand of the biological clock were not ticking so loudly, he could live yet another life with just as spectacular results.
Crick has never been one to dream small. Sitting in his study overlooking a lush, rose-filled garden and surrounded by the latest issues of a dozen research journals, he talks about the goals he set himself as a young man in the 1940s. There were two problems that interested him, he says: the borderline between the living and the nonliving, and the nature of consciousness. Amazingly, it took just four years from 1949 to 1953 for him and James Watson to elucidate the structure of DNA, thereby solving the mystery by which living things encode their own blueprint. Fifty years later, Crick still seems awestruck by this discovery. That was a fluke, he tells me. I thought this problem would take me the rest of my life. No one then imagined that the structure of the DNA molecule would turn out to be so critical to genetics: It could have been a very boring structure.
Instead, when he and Watson first divined the double helix, they immediately recognized that, in this twinned spiral, nature had found a miraculous means to store and implement its genetic code. Since each helix carries a complete copy of this code, the double spiral could be unzipped thus one side could be replicated and restored, while the other side is put into action synthesizing proteins. Watson and Cricks astonishing revelation about DNA was that the form of the molecular chain encompassed not only its code but also its function.