Tuesday, December 21, 2010
12/21/2010 08:11:00 PM Publicado por Jorge Franchín
Imagine you’re a school-aged child and this is your reality: You go to school and nobody looks familiar; your classmates are essentially a sea of faces, none of which is recognizable from the day before. A girl walks over to chat and she seems to know a lot about you, but you can’t place the face—and she seems equally perplexed, if not a bit agitated.
Then, at a family gathering, you find out that the strange faces in your house are actually cousins, although you wouldn’t know them from your classmates, whom you wouldn’t know from anyone else on the street.
The condition is known as prosopagnosia, or “face blindness,” and according to U professor Al Yonas, it may affect 1 to 2 percent of the population. The problem is, very few people are aware of it, which makes proper diagnosis problematic. Yonas is hoping to change that reality.
Prosopagnosia is essentially the inability to recognize a face that you’ve seen before and should be able to recall. You can read emotions in a face, but identifying the person is next to impossible without cues like a unique hairstyle or distinctive jewelry. It’s much different, Yonas notes, from being unable to remember somebody’s name, which afflicts all of us from time to time.
There are two types of face blindness—one the result of some sort of brain injury and the other developmental or congenital. Until recently, most of the research has focused on face blindness in adults. Notables with face blindness include primatologist Jane Goodall, artist Chuck Close, and neuroscientist and author Oliver Sacks, who wrote the book The Man Who Mistook His Wife for a Hat, which deals in part with face blindness.
Since 2008, Yonas’s lab in the Institute of Child Development has focused on identifying the condition in children (see video). Yonas and his research assistants have developed a number of tests for face blindness and have collected data from about 200 control subjects—children of various ages who don’t have the condition.
The goal is to make more people aware that face blindness exists, as Yonas suspects many children are misdiagnosed with other cognitive disabilities.
“A lot of people don’t know they have this condition,” he says. “They go through their life with the disability and they don’t know anything is wrong.”
That can lead to uncomfortable and unrewarding social interactions, and it’s not uncommon for sufferers to become withdrawn.
“Children with developmental prosopagnosia really are facing a gigantic obstacle,” says Sherryse Corrow, a doctoral student who works in Yonas’s lab. “You don’t know your father from a different man, your mother from a different woman. So everyone is essentially a stranger.
“For a child this poses a substantial social problem, but also a substantial safety issue. You don’t know which members of your community are safe to you and which ones aren’t.” She adds that in school settings students become stressed “because how do you make friends if everyone is a stranger and you can't distinguish your friends from other classmates?”
Down the road, Yonas hopes that early diagnosis can lead to more effective treatments for the condition. At the very least, it could lead to children recognizing there’s a reason for their difficulties, as happened when people learned more about dyslexia.
“We’re hoping parents will be aware of the problem and contact us if they think their child may have this disability,” he says.
(Photo: Patrick O'Leary and Megan Drabandt)
The University of Minnesota