Roundtable Discussion: Debating the Integrated Information Theory of Consciousness
Integrated Information Theory (IIT) was originally proposed by Giulio Tononi as a quantitative account of consciousness. The theory was updated and expanded in 2004, 2008, and 2012 manuscripts, and most recently in Tononi’s book, φ. Since its inception, IIT has created enormous discussion in various media, including Christof Koch’s recent book, Consciousness: Confessions of a Romantic Reductionist, an online New Yorker piece by Gary Marcus, a book review and critique in The New York Review of Books by John Searle, and a New York Times article by Carl Zimmer. In addition to proposing a new and quantitative measure that can be applied to describing conscious states, IIT could provide important guidelines for the diagnosis of disorders of consciousness and yield epistemic insights into ‘what it is like’ to be in a particular state of consciousness. Recent studies by Dr. Tononi and others indicate that during states associated with absent or reduced consciousness (e.g., NREM sleep, anesthesia, and Unresponsive Wakefulness Syndrome (Vegetative state), thalamocortical networks—widely held, but not yet proven, to be the seat of mammalian consciousness—are less informationally integrated. This debate seeks to assess whether φ is the ‘difference that makes a difference’ for consciousness, addressing both the prowess and the problems of IIT, the questions that remain open, and the difficulties to be solved for extending experimental validation. Put simply, where do we go from here?
Stuart Firestein is the Chair of Columbia University's Department of Biological Sciences where his colleagues and he study the vertebrate olfactory system, possibly the best chemical detector on the face of the planet. Aside from its molecular detection capabilities, the olfactory system serves as a model for investigating general principles and mechanisms of signaling and perception in the brain. His laboratory seeks to answer that fundamental human question: How do I smell? Dedicated to promoting the accessibility of science to a public audience Firestein serves as an advisor for the Alfred P. Sloan Foundation’s program for the Public Understanding of Science, where he reviews scripts for the Ensemble Studio Theatre/Sloan Science and Technology Program, and for the Tribeca and Hamptons International Film Festivals. In 2011 he received the Lenfest Distinguished Columbia Faculty Award for excellence in scholarship and teaching. He became an Alfred P. Sloan Fellow in 2012. Also in 2012 he was elected a Fellow of the AAAS. In 2013 he was awarded a Guggenheim Fellowship for science writing. His book on the workings of science for a general audience, called Ignorance: How it drives Science, was released by Oxford University Press in 2012.
Giulio Tononi is a psychiatrist and neuroscientist in Madison, Wisconsin, whose work focuses on the function of sleep and the nature of consciousness. Together with his collaborators, he has been developing and testing a comprehensive hypothesis on the function of sleep, the synaptic homeostasis hypothesis. Research on consciousness has led to the Integrated Information theory (IIT), which tries to account for what consciousness is, how it can be measured, and how it is realized in the brain.
Gary Marcus, cognitive scientist at NYU, has published numerous articles on language, evolution, and cognitive development, in leading journals such as Science and Nature. He is the author of four books, including Kluge and the New York Times Bestseller, Guitar Zero. Co-editor of the forthcoming book, The Future of the Brain: Essays By The World's Leading Neuroscientists, Marcus frequently blogs on science and artificial intelligence.
Jennifer Goldman is a native Californian pursuing her doctorate at the Montreal Neurological Institute of McGill University, where she is the Colman-Sievers Innovation in Neuroscience Scholar. With a background in the arts and sciences, Jennifer’s research focuses on the cell biology of cerebral cortex, working toward a comprehensive inventory of the mechanisms and molecules by which cortical circuits are established and maintained. Jennifer is extremely honored to take part in this debate and hopes that her unbiased questions will be useful in shedding broader light on the assumptions and implications of IIT, especially with regard to those neural substrates specialized for producing subjective awareness.