Kingstone and co-author Tom Foulsham at the University of Essex in Colchester, England, analyzed the eye-tracking data, as they reported Tuesday in Biology Letters. They found that participants first tended to look at the middle of the image, but then tended to fixate on the eyes, regardless of whether the eyes were on the head or elsewhere.
"This paper makes the point explicitly that no, these brain areas are really interested in processing the eyes, not the center of the head," Kingstone says. The human brain's preference for eyes may have evolved as a way for people to communicate quickly and quietly and to convey simple information about a person's age, health, and emotions, he hypothesizes.
"At first blush, these sorts of reactions can seem trivial: OK, so we're slightly more likely to look at the eye region, big deal," says Stephen Shepherd, a neurobiologist at Rockefeller University in New York who was not involved in the research. "But these mechanisms are likely foundational to behaviors like eye contact and gaze following, which humans and other primates use to threaten one another, to flirt, and to share experiences and attitudes," he says.
In addition to answering questions in basic biology, the study's findings may prove useful for children with autism, who often struggle in making eye contact with others. Their therapy includes training that teaches them that skill. Now, researchers may be able to apply the new investigative technique as a first step for clarifying whether children with autism seek out the eyes or whether they focus solely on the head.
However, the study used only two-dimensional images that do not gaze back at the viewer, whereas real-world eye contact is "a much more sophisticated dance," Kingstone notes. "Because there's just so much more going on with the eyes in real life, this would never cut it for teaching natural-looking behavior."
This is adapted from ScienceNOW, the online daily news service of the journal Science. http://news.sciencemag.org