By Hillel Aron
By Joseph Tsidulko
By Patrick Range McDonald
By David Futch
By Hillel Aron
By Dennis Romero
By Jill Stewart
By Dennis Romero
Koch’s interest in the mind dates back to his student days in Germany. There he majored in both physics and philosophy, the German scientific-education system being considerably less hostile to the latter discipline than are many of its American counterparts. Koch’s education actually spanned three continents. The son of a diplomat, he was born in Kansas City, Missouri — “I’m as American as apple pie,” he jokes in an accent rippling with Teutonic undercurrent. He spent his high school years in Morocco, where he graduated with a French baccalaureate, then went on to Germany and a doctorate in information processing from the Max Planck Institute for Biological Cybernetics. Before coming to Caltech, he was based at MIT.
More than a few philosophers have expressed the view that, in principle, science cannot provide an explanation for the phenomenon of consciousness. University of Arizona mind-think superstar David Chalmers has suggested that entirely new kinds of laws might be involved; Oxford physicist Roger Penrose believes the solution lies in as-yet-undetected quantum processes; for philosopher Colin McGinn, the problem is simply intractable. Koch is buying none of this. Under the watchful gaze of his phrenology bust, he insists, “It behooves us with science not to say that we can’t do this.” Philosophers can argue forever, he says, but “You can’t solve the problems of mind just by thinking about them. You have to go out and do experiments and see what is actually going on.”
Koch’s lab is dedicated to the proposition that the doors of perception can be subjected to rigorous empirical scrutiny, that the mental state of consciousness must be accompanied by physiological processes that can be studied scientifically. His mission in life is to identify what he and Crick have called these “neurological correlates of consciousness.”
Of the 30 billion neurons in the human brain, most of them are probably not involved in the feeling of conscious awareness. “At any moment, some neuronal processes in your head correlate with consciousness, while others do not — what is the difference between them?” Koch asks. Or as he puts it more formally in his book, “What are the neuronal mechanisms sufficient to cause a specific conscious percept” such as seeing the color red, or hearing a piece of music?
Until recently, there seemed little hope for progress. Now, according to Koch, neuroscientists finally possess appropriate tools. Functional MRI scanners are making it possible to examine human brains in situ, while advances in neural recording are enabling scientists to see the outputs of individual neurons. Researchers at his lab are collaborating with a neurosurgery team at UCLA to investigate the response of neurons in people scheduled for brain surgery. In particular, Koch is interested in the problem of visual consciousness: how and when and under what circumstances we are consciously aware of what we see.
So much of what we see we are not aware of at all. As we sit in Koch’s office, he offers to reveal to me a small portion of my own zombie self. For a moment I am seized by visions of a nasty chemical cocktail, my mind turned to mush, my body rendered into a helpless puppet, but instead of reaching for a syringe, Koch turns on his computer. He brings up an image of an airplane on a runway and tells me that when he presses a key some major feature will disappear. I am to tell him what it is. Koch jabs at the keyboard and the image flashes momentarily, but as far as I can tell everything remains the same. He does it again, several times, but still I see nothing different. Finally Koch tells me it is the aircraft’s fuselage that disappears. Once it’s pointed out, the omission becomes glaringly evident.
If our minds don’t notice things that do occur, they can also invent things that don’t. Koch pulls up another image, a simple black screen speckled with slow-moving blue dots and a couple dozen bright-yellow spots. He asks me to stare at the screen and tell him what happens. After about a minute, some of the yellow spots begin to wink on and off. Wrong, Koch tells me. Nothing happens. All the spots remain on the screen; my mind has just invented the flashing.
Koch’s 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.