Three researchers at the University's vision lab have discovered that a baby's ability to see at birth and in the first months of life is crucial for the normal development of face processing skills.

Their findings are published in the April 19 edition of Nature magazine.

Adults are experts at seeing faces — at a glance we can perceive whose face it is, we can tell where the face is looking and we can determine the facial expression.

Earlier research has shown that most people use two types of information to recognize faces: the subtle differences in the shape of features, such as the eyes or mouth (featural processing) and the spacing of the features, such as the distance between the eyes (configural processing). Configural processing seems to underlie adults' expertise at recognizing faces.

This study showed that children who can't see when they are born because they have cataracts in both eyes, never learn to see faces normally. They do learn to see the features (the shape of the eyes and mouth) normally, but never develop expertise at detecting the spacing among features.

“Having visual experience in the first two to three months of life is necessary if you're going to be an expert at recognizing faces,” said Daphne Maurer, the study's principal investigator and a vision scientist and professor in the Department of Psychology.

The study's authors were Maurer, psychology graduate student Rick Le Grand and research associate Cathy Mondloch.
They were surprised by their findings because by the time the patients were tested they had had at least eight years of visual experience with faces following surgery to remove the cataracts.

“Even patients with 20 years of visual experience had difficulty,” said Le Grand, the study's primary author. “The research has given us a better understanding of face processing. It seems that deprivation affects the brain areas that will eventually become specialized for configural processing.”

The researchers studied 14 patients who ranged in age from 9 to 21 years. All of the patients were born with cataracts in both eyes that resulted in blindness.

Ophthalmologist Henry Brent of The Hospital for Sick Children in Toronto fitted each patient with special contact lenses after the cataracts were removed when the patients were between two and six months old. Each patient had at least eight years of visual experience before being tested in the study.

The research team used a picture of a woman they called Jane and using a computer program created eight versions or “sisters” of Jane to show to the study participants and measure their responses.

The next step is to determine which part of the brain is being used in this face processing task.

“We are interested in whether these individuals use the same brain areas for processing faces as individuals with normal vision,” said Le Grand. “To study this we will use fMRI, or functional magnetic resonance imaging, which is a device that identifies the brain areas that are activated during a particular task, such as identifying a face.” That study should begin this summer.

Le Grand and Maurer are presenting their research at a meeting of the Society for Research in Child Development in Minneapolis this week.