Ph.D candidate, Pyschology
Biological Motion Perception - how you perceive body language
by Meredith Dault
“Decisions that you make fairly arbitrarily can come to determine your entire life course,” says Daniel Saunders with a knowing smile. That’s because Saunders, currently in his fifth year of a PhD program in psychology, never expected to be where he is today. Studying computer science as an undergraduate at the University of Waterloo, Saunders says he knew he was interested in psychology, but he never expected it to be the path he’d eventually follow. “I didn’t know any psychologists,” he laughs. “I really thought I would go into something more like A.I (Artificial Intelligence).”
Still, knowing he was interested in cognitive science, Saunders, a native of Victoria, B.C, began to investigate graduate programs and soon landed on one at Queen’s. “It had cognitive science in the name,” he says with an honest shrug, “and that’s what attracted me to it.” Saunders was then invited to visit the lab by Dr. Niko Troje (who would eventually become his supervisor) and immediately found himself feeling right at home. “I got sucked into it,” he says.
Not that he has any regrets. Saunders is clearly passionate about his field and his work. Part of the Department of Psychology’s graduate program in Brain, Behavior and Cognitive Science, which provides training in behavioral neuroscience, cognitive neuroscience, cognition and perception, Saunders studies biological motion perception -- essentially, how it is that we perceive body language. “So if you see your friend across the street, for example, you can still recognize them, just by the way they walk,” he explains. “Or, how walking behind someone you can tell if they are male or female, or you can tell something about their personality. My field tries to figure out how, with only a small bit of information, you can figure out all this detailed stuff about somebody.”
One of the ways his lab tests body movement is through an a test that reduces male and female bodies in motion to a series of dots on space. People are then asked to identify the sex of the respective “bodies.” (You can try it yourself by visiting http://www.biomotionlab.ca/demos.php) “That way we can test hypotheses about what information people are using (to make their selections). So, for instance, is it the movement, or the body structure of a person that they’re looking at to decide on the gender? By controlling the physical stimulus and then measuring people’s responses, we can find those relationships.” Saunders describes this approach, originating in the 19th century, as the birth of scientific psychology -- a way to grapple with the problem of doing science about impressions that seem subjective.
His own thesis project consists of a series of biological motion perception tests which Saunders explains as “an I.Q test for how well you perceive body language. One of the first things that we’re trying to show with (the test) is that there are a lot of different processes at work when you perceive people walking.” He is hoping his research will lead to a better understanding of how people who have perceptual differences can, for example, still read body language and be able to identify someone by their body movements, even if they have trouble perceiving other types of movement. “It’s a seeming paradox,” says Saunders, “that more complicated abilities can be preserved (in the brain) when apparently simpler ones are not.”
With his background in computers, Saunders admits that he took some time to adjust to working with human subjects in his new field. “The mind is a slippery thing to try and measure,” he says. “People never do what you expect them to do in a lab. They often surprise you. It’s a slippery science, but I’m gradually learning how to do it.”
And it’s clear, he’s not looking back. After graduation, Saunders plans to pursue a post-doc in Boston at the Schepens Eye Research Institute, and one day to run his own lab: “I want to do this kind of research for the rest of my life.”