Keynote Speaker
Donald Hoffman, Ph.D.
Donald D. Hoffman, Ph.D.
Professor, Department of Cognitive Science

Don Hoffman is a professor at the University of California, Irvine, in the Department of Cognitive Science, with joint appointments in Philosophy, and Information & Computer Science. He received his B.A. in Quantitative Psychology from UCLA, and his Ph.D. in Computational Psychology from MIT. He studies human visual perception using psychophysical experiments and computational modeling. He has received the Distinguished Scientific Award for Early Career Contribution from the American Psychological Association, and the Troland Research Award from the US National Academy of Sciences. He has published more than 50 professional articles, and is author of the book Visual Intelligence: How We Create What We See recently published by W.W. Norton.

While he was an undergraduate at UCLA, Hoffman did research in the laboratory of Professor Edward Carterette, writing programs and running experiments to study visual and auditory perception. This research experience as an undergraduate was pivotal in his choosing to do graduate work at MIT, and in pursuing an academic career. Now as a Professor at UCI, Hoffman enjoys working with undergraduate and graduate student researchers in the study of human vision. In the last year he has worked with ten undergraduate researchers on a variety of topics.

In one recent project he worked with Jason Thornton, a computer science major, to develop a set of Java applets that allow users to interact with remarkable visual illusions. These applets were installed in an exhibit at the Smithsonian in Washington, D.C., last fall, and will be traveling to different museums across the US over the next five years. Jason's picture is prominently posted next to the exhibit. His applets can be seen online using Internet Explorer on a PC (unfortunately Macs don't work). The URL is:
http://aris.ss.uci.edu/cogsci/personnel/hoffman/Applets/index.html.

For the last two academic years, he has also collaborated with Temre Davies, a psychology major, in studies of face perception. Half of the brain's cortex is engaged in visual perception, and a substantial fraction of this cortex is apparently devoted to the perception of faces. At just 30 minutes of age, an infant will look at faces in preference to other visual stimuli of comparable complexity. We seem specially programmed to attend to and interpret faces, and we probably spend more of our lives looking at faces than at anything else. A stroke that damages the face-processing areas of the brain can leave a person with "prosopagnosia:" they can be normal in every respect, except that they are unable to recognize faces, even their own face seen in a mirror.

Temre has used several experimental paradigms to study how human vision attends to faces. It has been previously shown, for instance, that when a person smiles we unconsciously attend to the corners of their eyes. We are unconsciously looking for crinkles at the corners of the eyes that indicate that their smile is genuine. If there are no crinkles, we unconsciously conclude that the smile is simply a social smile. Using a new "change-blindness" paradigm, Temre has shown that human vision does have endogenous strategies for attending to faces, that these strategies often give more attention to the eyes than to the mouth, and that these strategies can be impaired if a face is turned upside down or shown in photographic negative. She is currently confirming her results using a different experimental paradigm based on "visual search." She has also investigated the philosophical implications of her findings. Her philosophical paper has been accepted for publication in the professional Journal of Consciousness Studies. Her paper reporting experimental results of her change-blindness studies of faces is now under review with the professional journal Perception. She is currently writing three other papers for publication in professional journals. As background for writing these papers, she has read and mastered well over 100 scientific journal articles on the subject of face perception. Her first two publications can be seen online at these URLs:

http://aris.ss.uci.edu/cogsci/personnel/hoffman/Face.pdf
http://aris.ss.uci.edu/cogsci/personnel/hoffman/jcs.pdf

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