Dr. Giulio Tononi has devoted his life’s work to developing a theory of consciousness. A distinguished chair in consciousness science at the University of Wisconsin, Dr. Tononi’s interest in consciousness began when he was a teenager. According to a recent profile published in the New York Times, Dr. Tononi was “initially interested in ethics, but he decided that questions of personal responsibility depended on our consciousness of our own actions. So he would have to figure out consciousness first. ‘I’ve been stuck with this thing for most of my life,’ he said.” Now, after years of research (sometimes even using himself as the test subject), Dr. Tononi hopes to build a system that can measure human consciousness by monitoring the brain’s integrated neuron network. Tononi argues that our brains are systems of information that can be studied in bits—the more active bits there are, the more conscious we are. He and his colleagues have developed an Integrated Information Theory that they claim avoids many of the pitfalls that past models of consciousness have been susceptible to. Though they still have a long way to go, Dr. Tononi’s preliminary results show promise:
Dr. Tononi is now collaborating with Dr. Steven Laureys of the University of Liège in Belgium to test his theory on people in persistent vegetative states. Although he and his colleagues have tested only a small group of subjects, the results are so far falling in line with previous experiments. Dr. Tononi acknowledged, “The theory has to be developed a bit more before I worry about what’s the best consciousness meter you could develop.” But once he has one, he would not limit himself to humans. As long as people have puzzled over consciousness, they have wondered whether animals are conscious as well. Dr. Tononi suspects that it is not a simple yes-or-no answer. Rather, animals will prove to have different levels of consciousness, depending on their integrated information. He and his colleagues are translating the poetry of our conscious experiences into the precise language of mathematics. To do so, they are adapting information theory, a branch of science originally applied to computers and telecommunications. If Dr. Tononi is right, he and his colleagues may be able to build a “consciousness meter” that doctors can use to measure consciousness as easily as they measureand body temperature.
If Dr. Tononi is successful, we’ll be able to measure levels of consciousness in humans who are sleeping, dreaming, awake, meditating, or in vegetative states. What do you think of the idea of developing a system of measuring consciousness?