UIST 2009 - Monday Keynote
21st UIST @ Monterey, CA










Sponsored by

Generous support also provided by industry.

Monday Oct. 5, 2009
9:15 AM - 10:15 am

Illusions and illusionists:
How to fool the brain with magic and other tricks

Your conscious experience is not a function of the world, it is a function of the neural networks of your brain. Therefore, the biology of the brain and consciousness is as fundamental to understanding the universe, as we know it, as the high-energy physics of subatomic particles. This is especially true for the study of sensory and cognitive illusions, since they represent effects that clearly stand out as not representing the real world. That is, since illusions don’t match reality we can know that by studying illusions we are studying exactly what the brain is actually doing, and not just what we think the brain should be doing. Your brain does a staggering amount of pragmatic self-dealing guesswork and outright confabulation in order to construct the highly imperfect mental simulation of reality known as “consciousness.” This is not to say that objective reality isn’t “out there” in a very real sense – but no one lives there. No one’s ever even been there for a visit. Ironically, the fact that consciousness feels like a solid, robust, fact-rich transcript of reality is just one of the countless illusions your brain creates for itself.

Illusions are not errors of the brain. Far from it. Illusions arise from processes that are critical to our survival. Our brains have developed illusory processes so that we may experience the world in a ready-to-consume manner. Remove the machinery of illusion, and you unwind the entire tapestry of human awareness. Illusions are those perceptual experiences that do not match the physical reality. They are therefore exquisite tools with which to analyze the neural correlates of human perception and consciousness. Neuroscientists have long known that they can only be sure of where they stand, in terms of correlating neural responses to awareness, when they correlate the awareness of an illusion to the brain's response, specifically because of the illusions' mismatch with reality. The study of illusions is therefore of critical importance to the understanding of the basic mechanisms of sensory perception and conscious awareness.

If you’ve ever seen a good magician perform, you know how thrilling it is to watch the impossible happening before your eyes. The laws of physics, probability, psychology and common sense – the four trusty compass points in your mental map of reality – are suddenly turned into liabilities. Objects and people appear, vanish, levitate, transpose, transform, and with all your smarts you can’t imagine how it’s being done. Magicians are the premier artists of attention and awareness, and they manipulate our cognition like clay on a potter's wheel.

And the mechanisms underlying magic perception have implications for our daily lives. The magical arts work because humans have hardwired processes of attention and awareness that are hackable. By understanding how magicians hack our brains, we can better understand how we work.
Speaker Bio

Stephen L. Macknik
Barrow Neurological Institute

Susana Martinez-Conde
Barrow Neurological Institute

Stephen and Susana are laboratory directors at the Barrow Neurological Institute (BNI) in Phoenix, Arizona, where they study various aspects of visual, sensory and cognitive neuroscience. Their research and outreach activities have been written up in hundreds of media stories including many that have appeared in The New York Times, The Wall Street Journal, The Chicago Tribune, The Boston Globe, National Public Radio, Der Spiegel, New Scientist and Wired magazine. Both are monthly columnists for ScientificAmerican.com. Their shared column on the neuroscience of illusions gets hundreds of thousands of hits every month. One of their recent column contributions is the most downloaded article in sciam.com history.

Stephen and Susana are founding board members of the Neural Correlate Society, and Susana serves as its Executive Chair. NCS hosts the annual “Best Visual Illusion of the Year Contest.” The contest’s website maintains an archive of visual illusions and their explanations for a broad audience, and receives almost three million hits per year. They both serve on the board of advisors for Scientific American: Mind and in addition to their column have published several feature articles in Scientific American (circulation > 1,000,000 readers) and several of its family of journals. Their academic publication credits include contributions to Nature, Nature Neuroscience, Neuron, Nature Reviews Neuroscience, and the Proceedings of the National Academy of Science, and they have each authored over 50 academic publications.

Stephen is Director of the Laboratory of Behavioral Neurophysiology at BNI. He received a B.A. in Psychobiology, Psychology, and Biology from the University of California, Santa Cruz, and a Ph.D in Neurobiology at Harvard University. He was a postdoctoral fellow with the Nobel Laureate Prof. David Hubel at Harvard Medical School, and also with Prof. Zach Mainen at Cold Spring Harbor Lab. He led his first independent laboratory at University College London before coming to BNI in 2004.

Susana is Director of the Laboratory of Visual Neuroscience at BNI. She received a B.S. in Experimental Psychology from Universidad Complutense de Madrid and a Ph.D in Medicine and Surgery from the Universidade de Santiago de Compostela. She was a postdoctoral fellow with Nobel Laureate David Hubel at Harvard Medical School, and then an Instructor in Neurobiology at the same institution. She was a Lecturer at University College London from 2001 to 2003 before assuming her directorship at BNI the following year.