The infants and toddlers resemble cyborgs as they waddle and crawl around the playroom with backpacks carrying wireless transmitters and cameras strapped to their heads. Each has one camera aimed at the right eye and another at the field of view, and both send video to monitors nearby. When the video feeds are combined, the result is a recording in which red cross hairs mark the target of a child’s gaze.
Scientists are using the eye-tracking setup to learn how children look at the world as they figure out how to interact with it. In the lab, children 5 months and older crawl and walk up, down and over an obstacle course of adjustable wooden slopes, cliffs, gaps and steps. And to add to the challenge, the subjects are sometimes outfitted with Teflon-coated shoes or lead-weighted vests.
It may seem like the set for a new reality television show, but there are no prizes, except perhaps for the researchers. They hope to understand what prompts one child to respond to another, how infants coordinate their gaze with their hands and feet to navigate around obstructions or handle objects, and how these very young children adapt to changes, like those brought on by slippery footwear.
The findings provided by these eye-trackers so far (the first light enough for children to wear) suggest that infants may be more capable of understanding and acting on what they see than had been thought. “Quick gazes at obstacles in front of them or at their mothers’ faces may be all they need to get the information they want. They seem to be surprisingly efficient,” said John Franchak, a doctoral candidate in developmental psychology at New York University.
http://www.nytimes.com/2010/08/17/science/17gaze.html?th&emc=th