Chaz Firestone (Psychology) is fascinated by the human mind, and especially how visual perception and cognition interact. His field is cognitive science, which incorporates psychology, neuroscience, computer science, philosophy, linguistics, and anthropology.
“Seeing is the most familiar thing we do, and yet the inner workings of our visual system are completely hidden from us as perceivers,” he says. “Consider your ability to recognize the people and objects you encounter in day-to-day life: You can see that an object is a cup just by looking at it — but how exactly did you accomplish this? From the first-person perspective, the only honest answer is that you have no idea; you just looked at the cup, and then ‘cup’ immediately occurred to you. But, of course, there must be an answer — there must be some process running in your mind that allowed you to do this.”
To investigate one piece of this puzzle, Chaz spent several weekends accosting strangers in New York City’s Times Square. Wearing a Yale sweater, his student ID dangling from a lanyard, he held a tablet computer displaying a simple shape — for example, a triangle or a rectangle — and approached people queuing to buy theater tickets. Advertising “the world’s fastest psychology experiment,” Chaz asked each theater-goer for a simple favor: simply to tap the shape on the tablet, anywhere they’d like.
Most people were happy to comply. “People are dying to have an interesting experience in Times Square, and waiting on a line is boring,” he says.
Why ask people to tap a shape? The answer lies in the pattern of results. After hundreds of people had touched a given shape, Chaz found that in the aggregate, people’s touches formed a pattern known as a “shape skeleton.”
The idea of a shape skeleton originated with research to develop computer software that could recognize shapes. Cognitive scientists are now asking, is this the way people experience shapes?
“In order to recognize an object, your mind needs to compare what you’re seeing right now to some stored representation in memory and determine whether they match. The problem is that the viewing conditions are different just about any time you see an object — for example, the object might be in a different pose, or your viewing angle might be different. The shape skeleton helps to overcome this problem because it remains the same across these differences,” Chaz says. “Just as the bones in your hand remain connected in the same way when you make a fist or wave, the branches of the shape skeleton have the same configuration even if you see the shape from different views.”
One interesting aspect of the shape-tapping pattern is that it seems to arise unconsciously. When a separate group of subjects was asked to predict where the Times Square subjects would touch the shapes, most expected touches in the center or in random locations all over the shape.
“This is par for the course when it comes to perception and cognition,” he says. “The mind is truly exceptional in its ability to find solutions to extremely difficult computational problems. But perhaps even more remarkable is the mind’s ability to hide from us that there are such problems to be solved in the first place.”
The Times Square research was done in collaboration with his adviser, Brian Scholl, and presented at last year’s Object Perception, Attention, and Memory meeting in Minneapolis, where it won the Best Paper Award. It will appear in a forthcoming issue of Psychological Science, a publication of the Association for Psychological Science. It was also presented at the Vision Sciences Society meeting in Florida. Another project with his adviser, “‘Top-down’ effects where none should be found: The El Greco fallacy in perception research,” presented last June to the Society for Philosophy and Psychology, won that organization’s William James Award and was published, in part, in Psychological Science and Perception.
Chaz and his adviser make a good team.
“Brian is the most passionate cognitive scientist I have ever met, and his enthusiasm really animates the entire lab,” Chaz says. “To do cognitive science, you have to constantly remind yourself that all the commonplace mental feats you take for granted — like recognizing an object — are actually incredibly complicated and fascinating to study. Brian is exceptionally good at discovering interesting questions that others might miss.”
A native of Toronto, Chaz majored in cognitive neuroscience and philosophy at Brown, earning bachelor’s and master’s degrees. While there, he wrote science articles for The Atlantic, Nature, Earth, Discover, and other general-audience magazines. As a student-journalist, he was invited by the National Science Foundation to Antarctica with six professional science journalists. The summer before graduate school, Chaz pedaled from Providence to Seattle with Bike and Build, a nonprofit agency that organizes cross-country rides, stopping every few days to work on affordable housing projects. When not studying or conducting research, Chaz hangs out in Yale’s new Center for Engineering Innovation and Design, where he created a real-life model of his own brain by feeding a functional MRI scan into their 3D printer.