Health
3:06 pm
Mon December 12, 2011

Losing Face

We all see the world differently. But for people with face-blindness, they see it differently with an added major difference — they can't recognize who you are.

Her whole life, Lee McClain knew something was off. It wasn't that she wasn't smart — she was. She had earned a Ph.D, authored some books, and is a tenured professor. And it wasn't that she wasn't social — because she was. She had friends, and had, for all intents and purposes, found her place in the world. But going into a social situation like a cocktail party was difficult. Remembering people was difficult. Not the people themselves, but their faces.

"It's kind of like if you are looking at a bunch of leaves on a tree, you could study them, but you'd have to work really hard to tell them apart," said McClain. That is how she sees faces. "That part of my brain that most people use to recognize faces instantly doesn't work as well for me."

Making it Work

McClain has congenital prosopagnosia, a brain disorder that makes her "face blind." She can see faces, but when she sees that face again she can't recognize it. Unlike some others, her disorder isn't so severe that she can't recognize herself in the mirror or in a picture. She can recognize her daughter and close friends. And as a professor at Seton Hill University in Greensburg, she can recognize her students.

She works hard at it, giving them assigned seats, actively studying their pictures, paying careful attention to their voices and the way that they dress.

And she goes out of her way to be overly friendly to everyone she sees at her job or in her community — operating under the assumption that she already knows them.

It wasn't until she was in her late 40's that she was diagnosed.

Online research led her to prosopagnosia, a disorder first diagnosed in the 1940s. In Greek, prosopo means 'face' and agnosia means 'without knowledge.' But while the disorder was first found all those years ago, it wasn't until the 1990s, with the advent of advanced MRI scanning and an increased understanding of how the brain works, that researchers have been able to make headway into understanding this little-known disorder, which affects around 2 percent of the population.

Researchers Struggle

Marlene Behrmann, one of the world's leading researchers on the condition, is a psychology and cognitive neuroscience professor at Carnegie Mellon University. Her specialty is in the ways that the brain makes sense of what the eyes see.

"It seems fairly natural to them that this is how the world really is, and only when they're older and they realize that other people can do face recognition so effortlessly and so naturally does it dawn on them that there's something different about their own skills and their own abilities," she said.

In the last decade, there have been numerous scientific peer-reviewed papers on the underlying mechanisms that give rise to face recognition. In Behrman's research on people born with the disorder and regular vision, she has found that the part of the brain that recognizes faces lit up normally when they saw a face. But for them, there are weak links between that part of the brain and other parts of their brain.

Sometimes prosopagnosia doesn't manifest itself until later in life.

When Shawn Muzzey was 18, he was in a car accident that caused numerous injuries. He suffered a severe head injury and several subsequent strokes. Now 37, he has made strides in his recovery, but he has severe face-blindness.

"It's something that is hard to explain. Because when I look at somebody, if I look at you, I feel like if I walked down the street, I would know it's you. But whenever that happens, I realize that that's not the case. One way of explaining it is kind of like holding the picture in front of you and then taking it away. I have no recall of it. I can't take a mental pic of a person's face and store it in my head whenever I see them and match it up with a name," said Muzzey.

Muzzey's disorder is so severe that he can't even recognize his parents. He uses cues like their voices or remembering if they are wearing an unusual item of clothing.

It impacts his entire life.

There is some debate in the literature on the circuits in the brain that cause prosopagnosia. And there are variations in face-blindness. Those with autism sometimes have difficulty telling faces apart. People with some disorders lack emotional face recognition. Those with Alzheimer's also have a variation of face-blindness. But this type is unique, and a bit befuddling to researchers.

Marlene Berhmann said that the research so far is focused on what causes prosopagnosia and understanding it better, with the expectation that if they have a firm understanding of the problem and its neural basis, they might be able to devise better treatment strategies.