NEW YORK (Reuters Health) - Even when they're as young as two days old, infants can tell whether someone is trying to make eye contact, a new study shows.

The study's lead author, Teresa Farroni, suspects that humans have evolved to be sensitive to direct gaze very early in life as a survival necessity. Farroni is a researcher with the Centre for Brain and Cognitive Development in the School of Psychology at Birkbeck College, University of London.

"Newborns are not able to move, so they need to orient in the direction of faces that care for them--people who can feed and protect them," Farroni said in an interview with Reuters Health. "As we grow up, a face with the averted gaze starts to be considered to be a signal of alarm that tells us something is happening where the other person is looking. And then averted gaze becomes important as well."

Farroni and her colleagues studied 17 healthy newborn infants who were between 2 and 5 days old. For the study, each infant was seated on a researcher's lap in front of a video screen. Two photographs of a woman were projected side-by-side on the screen: one with her gaze directly pointed at the infant and one with her gaze averted.

Researchers initially caught the infants' attention by turning on a tiny blinking light in the center of the screen. Once the infant focused on the screen, the light was turned off.

Farroni and her colleagues videotaped the infants' eyes as they showed them the two photographs.

The babies looked more often toward, and longer at, the images of faces looking directly at them than those with averted eyes, the researchers report in the Proceedings of the National Academy of Sciences Early Edition.

In a second experiment, the researchers fixed electrodes on the scalps of 15 four-month-olds. They then repeated the first experiment with the two photographs, and recorded the babies' brain activity during the test.

When looking at the face that appeared to be gazing directly at them, the infants had more of a certain component of brain electrical activity, known as N170, compared to when they were looking at the face with averted eyes.

This component of brain activity has been shown to be sensitive to face stimuli in previous studies, Farroni explained.

The new research shows that some of the building blocks of social development are hardwired into us, Farroni said. Early sensitivity to the gaze of others facilitates social development, she added.

Farroni and her colleagues believe that the new study could help scientists figure out what goes wrong in children with autism. "Individuals with autism have difficulties with many forms of social communication, and their gaze processing is impaired at various levels, such as eye contact, gaze following, joint attention and understanding gaze," Farroni said. "For this reason, deficits in eye-gaze perception may be symptomatic of, or even contribute to, autism."

It's possible that one of the reasons that autistic children fail to develop properly is that they don't have this hardwired preference for a gaze that is directed towards them, Farroni said.

SOURCE: Proceedings of the National Academy of Sciences 2002;10.1073/pnas.152159999.

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