[science, psychology] Face Blind
( via blade_bunny)
Face Blind
Joshua Davis
http://wired.com/wired/archive/14.11/blind.html
November 2006
They can see your eyes, your nose, your mouth - and still not recognize your face. Now scientists say people with prosopagnosia may help unlock some of the deepest mysteries of the brain.
BILL CHOISSER WAS 48 when he first recognized himself. He was standing in his bathroom, looking in the mirror when it happened. A strand of hair fell down - he had been growing it out for the first time. The strand draped toward a nose. He understood that it was a nose, but then it hit him forcefully that it was his nose. He looked a little higher, stared into his own eyes, and saw … himself.
For most of his childhood, Choisser thought he was normal. He just assumed that nobody saw faces. But slowly, it dawned on him that he was different. Other people recognized their mothers on the street. He did not. During the 1970s, as a small-town lawyer in the Illinois Ozarks, he struggled to convince clients that he was competent even though he couldn't find them in court. He never greeted the judges when he passed them on the street - everyone looked similarly blank to him - and he developed a reputation for arrogance. His father, also a lawyer, told him to pay more attention. His mother grew distant from him. He felt like he lived in a ghost world. Not being able to see his own face left him feeling hollow.
One day in 1979, he quit, left town, and set out to find a better way of being in the world. At 32, he headed west and landed a job as a number cruncher at a construction firm in San Francisco. The job isolated him - he spent his days staring at formulas - but that was a good thing: He didn't have to talk to people much. With 1,500 miles between him and southern Illinois, he felt a measure of freedom. He started to wear colorful bandannas, and he let his hair grow. When it got long enough, he found that it helped him see himself. Before that, he'd had to deduce his presence: I'm the only one in the room, so that must be me in the mirror. Now that he had long hair and a wild-looking scarf on his head, he could recognize his image. He felt the beginnings of an identity.
It gave him the confidence to start seeing doctors. He wanted to know if there was something wrong with his brain. His vision was fine, they told him - 20/20. One doctor suggested he might have emotional problems and referred him to a psychiatrist. In the medical literature, there were a few reports of head-injury and stroke victims who'd lost their ability to recognize faces. No one, as far as the doctors knew, had ever been born with the condition.
Conventional medicine, in other words, got him nowhere. So Choisser posted a message about his experiences on a Usenet group devoted to people with neurological problems. His subject line was "Trouble Recognizing Faces." After a few months, in late 1996, he received a solitary reply. "Hello, Bill," the email began, "I read what you wrote, and I think I have what you have."
BRAD DUCHAINE WAS SO LOADED, he didn't realize he was plummeting to the ground. It was his 27th birthday party and the handsome Wisconsin native had been trying to have a good time. He'd had more than a few beers, grappled onto the roof to enjoy the beautiful Santa Barbara, California, sky, and fallen asleep. Now, inexplicably, he was falling. He smashed into the concrete driveway and his hip shattered. Luckily, the beer dulled the pain. He clawed his way to the living room and fell asleep among a few other unconscious revelers. Though no one knew it at the time, this guy - passed out, busted up, bleeding on the floor - was going to have a lasting impact on neuroscience.
Duchaine had started out enjoying himself too much as an undergrad and nearly flunked out of two colleges. He tried again at Marquette University in Milwaukee, and this time pulled it together. In the cold, boring Midwest nights, he settled down and did well, graduating summa cum laude in 1995. That got him into the cognitive psychology PhD program at UC Santa Barbara.
But the fall off the roof two years into his PhD coincided with a crack in his confidence. His dissertation was in shambles. He hadn't been able to find a suitable topic and was playing videogames until his thumbs hurt. Did he really think he could succeed as a neuroscientist? His parents were both midlevel managers at a paper company back in Wisconsin. Community college instructor was a more realistic goal.
But when Duchaine's parents visited their son in the summer of 1998, he didn't tell them any of this. The couple had invited an old friend to dinner at the Shoreline Beach Café, a seaside restaurant with tables right on the sand, and it didn't seem like the right time to reveal his doubts. Instead, over appetizers, talk turned to a presentation on unusual neurological cases that Duchaine had given to undergraduates earlier in the day. He was especially fascinated by a study of people who'd been hit on the head and lost their sense of direction or ability to perceive certain objects.
"I know a kid who doesn't recognize faces," the friend said.
"He had a stroke?" Duchaine asked. He knew that in a few rare cases - usually as a result of stroke or trauma - patients reported that they had lost the ability to recognize faces. Oliver Sacks' "man who mistook his wife for a hat" was the most famous example.
"No, he's always been that way," the friend replied.
Duchaine called the teenager's family a few days later. The boy's father told him that if he really wanted to learn more about the condition, he should check out a Yahoo group and Web site maintained by a guy in San Francisco named Bill Choisser. A whole community of these people were chatting online - that's how the teen discovered he wasn't the only one who had a problem with faces. Choisser had even begun to popularize a name for the condition: face blindness. If this were true - if there was a large, previously unidentified population with the condition - it would be a major discovery. Duchaine started to think he might make it as a neuroscientist after all.
IN OCTOBER 1944, as the Russian Red Army advanced into Germany, a single artillery round struck a German command post on the East Prussian front. Everyone inside was ripped apart by shrapnel, but a 36-year-old lieutenant somehow lived. He was evacuated to a field hospital, where a surgeon removed a piece of metal from the back of his head. The external wound healed, but it soon became clear that something strange was going on. The officer reported that he could no longer see faces.
He was sent to a psychiatric hospital near Stuttgart, where a doctor named Joachim Bodamer examined him. There had been reports of face blindness as far back as antiquity, but no one had studied it systematically, so the physician decided to make a detailed analysis.
To assess the extent of the man's impairment, Bodamer dressed the officer's wife of seven years as a nurse and lined her up with four real nurses. Bodamer asked if he noticed anything different about any of the nurses. The man said no. Next, he was told to look in a mirror and report what he saw. "It's strange," he said. "I've looked at myself often, but that's not me anymore, although I know that it's me. But I have a feeling of unfamiliarity."
Bodamer wrote a 47-page report on the case and coined a name for the condition: prosopagnosia (in Greek, prosopo is face and agnosia means without knowledge). He defined it as "the selective disruption of the perception of faces, one's own face as well as those of others, which are seen but not recognized as faces belonging to a particular owner."
While he was producing the report, the world around him was going up in flames. The Allies dropped more than 7,000 tons of bombs on Dresden, incinerating the city. Stuttgart - 13 miles from Bodamer's home - came next. As his work on the paper drew to a close, fundamental questions about human consciousness weighed on him. What might his patient's condition imply about how healthy people experience the world? Maybe there are mental mechanisms for perceiving each aspect of reality - parts of the human mind that render faces, houses, and bombs meaningful. While everything was falling apart, Bodamer had stumbled onto a clue about how things come together in our heads. Perhaps the fluid reality we perceive is just a flimsy construct of individual puzzle pieces, any one of which could suddenly disappear. In nothing else, Bodamer wrote, "does medical fact touch so closely on … the basis of all knowledge."
OVER THE NEXT FIVE DECADES, researchers trying to pursue these questions had one major problem: Not many people get shrapnel shot though their brain and survive. In other words, the pool of potential research subjects was minuscule. Scientists did discover that a small number of stroke victims developed prosopagnosia, but their lesions often continued to grow, preventing reliable comparisons and, in many cases, causing death.
Still, these patients tantalized researchers. "People think of the brain as one seamless intelligence, because that's how it feels to us from the inside," says Nancy Kanwisher, an MIT vision researcher. "But if you look at prosopagnosia, you start to realize that the brain may actually be a grouping of stand-alone computational machines that are wired together."
The question is, how many machines are there and how do they work? On a basic level, we know that there are distinct visual, auditory, memory, and motor systems. But within each of these, are there further specializations? For instance, within the visual cortex, is there a specialized part of the brain devoted to faces? And, if so, are there further specializations within that for gender, skin color, age, and even attractiveness? It's akin to discovering the molecule, only to realize that there may be atoms, electrons, and quarks as well.
As functional MRI came into use in the 1990s, neuroscientists rolled people under the magnets to track blood flow to specific parts of their brain. They learned that a small part of the visual cortex - eventually dubbed the fusiform face area - showed increased blood activity whenever a subject looked at a face. Researchers had discovered what appeared to be a computational machine devoted specifically to processing faces. Stroke or gunshot victims tended to develop prosopagnosia if they sustained injuries to that area. But that was about as much as this relatively crude imaging technique could reveal.
The best that scientists had been able to do was point to a particular part of the brain and say, "That's important." The face-processing system remained a black box.
WHEN ZOË HUNN WAS 14, her three closest friends decided to enter a modeling contest in a London department store. The girls tried to convince Hunn to sign up, too. She thought it was a silly idea; looks didn't matter to her, and she had no idea whether she was pretty. She had never paid much attention to her face - it didn't seem to represent who she was.
Though she didn't know it, Hunn was severely face blind. Her father had the same problem. Both just assumed that they were bad with faces, in the same way some people are bad with names. They developed elaborate coping strategies, like focusing on voices and searching for clues in a conversation. Inevitably, they embarrassed themselves.
Since all her friends were entering the contest, Hunn decided to go along. To her surprise, she ended up winning the top prize: an offer from a modeling agency. In 2002, she was signed by Models 1 in London, the same agency that represents Stephanie Seymour and Linda Evangelista. She appeared in Vogue and Elle and in fashion ads across Europe, earning as much as $1,500 a day. But she could never spot herself in any of the photos. She might recognize the clothes and deduce her presence in the picture, but she was never sure.
Hunn decided to see a doctor. She explained to him that she was a rapidly rising model - this should be the time of her life. It wasn't. She was completely unable to appreciate her beauty, which had now become the centerpiece of her young life. When she should have been going out to parties and having fun, she chose to stay home. "Everyone looks the same," she told the doctor, "so it's hard to connect emotionally with anyone." The doctor checked her eyes, made sure she didn't have a tumor, and then recommended counseling for shyness.
In the summer of 2003, she traveled to Edinburgh, Scotland, for the annual theater festival. On the third night, she saw a performer who was unusually memorable. He was a tall mime with white hair and vivid black eyebrows. She stared at him. He was the first person she felt she'd ever really seen.
Later that night, the unimaginable happened: Hunn recognized him in a bar. It was like being thrown a lifeline. She mustered the courage to introduce herself and told him that his performance made her laugh. He smiled and thanked her. She learned his name was Mick, and that was all she needed. She was in love. It didn't matter that he was a 44-year-old mime trying to make ends meet. She could see him.
Mick, for his part, was captivated not by her beauty but by the way she watched him as if her whole world depended on the sight of him. It was a performer's dream, and Mick melted in the intensity of it. Despite the protests of her parents, they moved in together within a few months.
One day in their new home, she read a short article in a British magazine about a man named Brad Duchaine and his work on something called face blindness. It described her symptoms: inability to recognize faces, leading to social embarrassment and a sense of isolation. She felt a tumult of emotion, like someone exonerated from a crime. It seemed to explain so much about who she was.
TO CONDUCT HIS FIRST INTERVIEW with Bill Choisser, Duchaine had to drive his red 1988 Camry 300 miles north to San Francisco. It wasn't easy for him. He'd been playing too much V8, a car combat videogame, and driving on a real freeway now gave him panic attacks. He'd pull over to calm himself down. It took a long time to get there.
When he did arrive, Choisser was clearly uncomfortable. Duchaine asked if everything was OK, and Choisser said he couldn't read Duchaine's expressions. It would help if he had a beard - facial hair made faces easier to comprehend.
So three weeks before each of his next eight road trips to San Francisco, Duchaine stopped shaving. He also cut back on playing V8, decreasing his freeway anxiety. He'd show up at Choisser's door with a scruffy beard and a newfound confidence, ready to run his subject through face-recognition tests, some of which he'd just invented. Once back in Santa Barbara, he would run the tests on dozens of grad students and faculty to generate averages for a representative sample. When the numbers came in, it was clear that Choisser's facial-recognition system was severely impaired.
Next, Duchaine tested Choisser on his ability to recognize small differences between the same type of objects. In one exam, Choisser was asked to memorize the details of a particular house. Duchaine then showed him 150 pictures of other houses and randomly threw in images of the original. Choisser consistently identified it. He did the same in similar tests that used shoes, horses, cars, and natural landscapes. It was strong evidence that the brain's system for processing faces is separate from its system for discerning other objects.
The finding was controversial. "People love to carve up the brain and say, 'There's a hand area, there's a face area, and there's a love area,'" says Michael Tarr, a Brown University vision researcher who is one of the leading proponents of an alternative theory. Tarr believes that the fusiform face area is part of a generalized recognition system that gets switched on when someone develops enough expertise to distinguish between two very similar things.
"The discovery of otherwise healthy people living with prosopagnosia is the most exciting development in the field in a long time," Tarr says. "But we can't rely on neuropsychology to figure out what's going on, because you're just asking people questions. You're not getting in there and finding the damage."
The problem is that scientists aren't able to cut open someone's head, plug in electrodes, and test every neuron in the fusiform face area. But as Duchaine's work progressed, fMRI testing indicated that developmental prosopagnosics - those, like Choisser, who were born with the condition - had a smaller face area than normal. One study found that the neural pathways leading out of the face area might be damaged. But none of the tests explained the structure of the face-processing system itself. The best that could be done was to develop visual tests that narrowed down the nature of the impairment and then try to deduce what was going on inside the brain.
Using Choisser's group, now hosted on Yahoo, as a resource, Duchaine contacted and tested other developmental prosopagnosics and began piling up evidence that, with a bit of practice, they could distinguish between very similar objects. In other words, they could learn how to differentiate objects but not faces. The implication: Facial recognition was a hardwired aptitude that did not depend on learning.
As he found more prosopagnosics through Yahoo, Duchaine began to see that this previously unknown population offered a new way of exploring the brain's face-processing system. First of all, the patients were healthy and young, unlike gunshot or stroke victims. Their condition was stable, and the unobstructed blood flow in their brains allowed for clear imaging. They could also be studied over time. Duchaine had discovered an untapped well of subjects, and he was sure that a key to understanding how our brains are organized lay inside their heads.
FOR KEN NAKAYAMA, a leading vision researcher at Harvard, Duchaine's dissertation on Choisser was a turning point. He had heard of developmental prosopagnosia - he had even seen it mentioned in the academic literature. But Duchaine's work with Choisser was so thorough and persuasive, it convinced Nakayama that the condition merited serious attention. "Brad did more than anybody else had done, by far," he says. "As soon as I saw his dissertation, I knew that this was what my lab needed to be studying."
Nakayama quickly offered Duchaine a job, and together they formed the Harvard Prosopagnosia Research Center. Though Duchaine still wore jeans, sneakers, and faded T-shirts to work, he was now a rising star in cognitive neuroscience. It suited him well - he stopped playing videogames, and the panic attacks subsided. In his free time, he pored over research papers on vision. If he stayed up late, it was to correspond with prosopagnosics in other parts of the world and to think about new ways to figure out what was going on in their heads. When particularly conclusive test results came in from a new subject, he would exclaim, "That guy's really bad with faces." It gave him a thrill. It was as if he'd spent his whole life waiting to stumble across this condition. Now that he'd found it, he had a prestigious job and a stable income. In exchange for shining a light on the disorder, prosopagnosia had made him an adult.
But research on face blindness was still in its infancy. Duchaine wanted to find out how our brains process faces and how that influences who we are. He and others hypothesize that one part of the face-processing system might be designed specifically for processing gender, another for skin attributes, and a third for reading emotional expression. To test the theory, he had to find double dissociations: a subject who could look at a face and perceive, say, skin color but not gender, and a second subject who had the opposite condition. That would provide evidence that skin color and gender perception were separate brain mechanisms.
The key was to find many different combinations of deficits. It would require lots of subjects, which is exactly what the discovery of developmental prosopagnosia promised. Before that, a scientist might have waited a lifetime to come across a stroke victim who had just one set of problems. Now, thanks to Choisser and the Internet, Duchaine could locate hundreds - even thousands - of subjects. "A whole new world of questions can now be asked," he says. "We're moving inside the black box."
Duchaine's questions touch on some fundamental social and cultural issues. For instance, what would it mean if there were a particular part of the brain devoted to recognizing gender? Bill Choisser reports that he has more trouble perceiving women's faces, and that could be one of the reasons he's gay. Another prosopagnosic says that his inability to distinguish between men and women explains his bisexuality. Is it possible that our sexuality is influenced by the wiring in the face-processing system?
TOM UGLOW, A GRAPHIC DESIGNER in London, didn't have a problem perceiving that it was a girl watching him across the bar. Her blond hair had a nice sheen. She seemed pretty. Uglow ordered another beer, downed it, and walked her way. He was about to introduce himself when she cut him off.
"Hi, Tom," she said, no longer smiling. "Why were you making eyes at me?"
"Damn," he thought. "This isn't going as planned."
Her voice sounded familiar. He searched her face but couldn't place her. This happened more than he liked to admit.
"How've you been?" he asked, casually trying to fish for a clue as to who she was.
"Better now that we're broken up."
Ah! It was his ex-girlfriend. Once he'd had a moment to process her voice, he was able to place her. They had dated for a year. Definitely not a good person to be hitting on. It was a problem: Every time he saw a face, it felt like it was for the first time.
Uglow tried to work around it. Everyone looked equally unfamiliar, but rather than treat unfamiliar faces as strangers, he acted like everyone was his best pal. "Generally, I'll be very smiley, friendly, and nice, even though I have no idea who I'm talking to," he says. "But at least that person would come away liking me." He'd rather live in a world populated with friends than with strangers.
It never occurred to Uglow that his inability to see the world as others did would stand in the way of becoming an artist. Ever since he was a kid, he had loved drawing and made endless sketches of friends and family in his journals. They almost never had faces. For Tom, that wasn't a big deal. He felt he could convey personality with his brushstrokes or a particularly adept representation of someone's posture.
Every year, he made a pilgrimage to London's National Portrait Gallery. The museum hosts an annual contest to select the best emerging portrait artists, and Uglow likes to keep up with the latest techniques. This year, the winning portrait was a photorealistic depiction of an elderly woman, her face wrinkled and blotchy. Uglow loved it, though not because of the three-quarters-crazy look in the woman's eyes or her haunted expression. He loved it because the technique was so precise, so exact. To him, it spoke of the struggle against chaos, decay, and death. It was an attempt to impose order on what couldn't be controlled. In his own way, he had grasped the essence of the painting.
By day, Uglow makes a living designing logos, but someday he'd like to see his portraits hang in the gallery. The fact that they don't have faces doesn't seem to be an impediment. "Faces aren't that important in the contemporary art world," he observes. And yet, despite the missing faces - or maybe because of them - his paintings and sketches are evocative. In one sketch, a young girl holds an umbrella in a field. The umbrella has a densely patterned green and purple canopy, and individual blades of grass are visible. The girl's scarf is sharply defined, but she has no face. In another drawing, newlyweds stand beside a wedding cake; the bride has no head, but the fringe of her dress is elaborately delineated. It's a view into another reality.
IN 2004, UNIVERSITY COLLEGE in London wooed Duchaine with the offer to run his own lab. He took the opportunity but continued to collaborate with Harvard's Nakayama. In 2005, the two conducted a study to determine the extent of prosopagnosia in the general population. They assessed 1,600 people online, running them through a face-recognition test the researchers had invented, and found that 32 had severely impaired face recognition. At the same time, a German researcher tested 680 high school and college students and identified 17 prosopagnosics. Both studies suggested a prevalence of roughly 2 percent. If the ratio held, it would mean that nearly 6 million people in the US are face blind.
Duchaine says the implications are far-reaching. He believes, for example, that the Transportation Safety Administration should administer tests to make sure all airport passenger screeners can match faces with IDs. And the reliability of eyewitness identification should be reconsidered in the courtroom. "You'd want to know if the witness was drunk, right?" Duchaine says. "Well, we should also know if they're face blind."
Baseline testing should be done at a young age so prosopagnosic children don't develop feelings of isolation and depression. There is no cure, but as with dyslexia or autism, once parents know a kid has the condition, they can make accommodations. It can be hard emotionally, particularly if a child doesn't recognize his parents. But it's worse if parents chastise a kid for something that can't be controlled. And, for the children of prosopagnosics, it can be comforting to know why their parent can sometimes seem oblivious to them.
MORDECHAI HOUSMAN, A GENIAL, portly Hasidic Jew, is playing Minesweeper on his computer at home in Brooklyn. One of his three young sons sits next to him - though Housman isn't sure which.
"Who are you?" Housman finally asks with a smile.
"I'm Abraham, Dad," Abraham says. The 6-year-old has heard this question before and thinks his father is just kidding. It's like a family joke. He doesn't understand that his dad really can't tell him apart from other kids on the street.
The Hasidic men in the neighborhood - clad uniformly in black pants, white shirt, black jacket, and black hat - are even harder to distinguish. But this doesn't bother Housman. He considers it a blessing of sorts. "In my culture," he says, "we de-emphasize material things and appearances. Our focus should be on God. For me, I've been given a head start."
Nonetheless, even the religious have to make a living. Housman found work as a swing-shift building manager for a Hasidic college in Borough Park, Brooklyn. Most nights, he sits behind a small window near the entrance, answers questions, and is supposed to keep an eye on who is coming and going.
Housman doesn't think he's ill-suited for the task; he has developed other ways to recognize people. On a recent Monday night, he peers out of his small window, chews on a pen while beads of sweat gather on his forehead, and watches people walk past. He recognizes one student by his "intense, inwardly focused attitude." He greets a professor he thinks he recognizes by the type of yarmulke he is wearing, though it turns out to be the wrong guy. A young man darts past, but Housman knows him. "I recognize him by his soul," he says.
For Housman, as for most prosopagnosics, the Internet is changing everything. He learned about his condition when his wife stumbled across Choisser's Web site one night. She thought it explained a lot about her husband, and she showed the site to him. Housman stayed up until five in the morning reading Choisser's online memoir and following links to other prosopagnosia Web sites. For Hasidics, Housman says, "it's considered arrogant if you make a big deal out of something or call attention to yourself. So I didn't really talk about my problems until I sent my first email to Brad Duchaine."
FOR THE PAST FIVE YEARS, Duchaine has been hungrily collecting profiles of developmental prosopagnosics though his Web site, Faceblind.org. It's a war chest assembled to search for double dissociations. There is the Caucasian man who upset a colleague by telling him a racial joke, not recognizing that the listener was black. There is the woman who waved to someone in a hotel, only to discover that it was a mirror. There is the man who takes emotional cues from the way a person's pants crease and bunch.
Now Duchaine is trying to prove that the condition is inherited. He plans to spend this New Year's in Las Vegas at a reunion of a family full of prosopagnosics. Three generations will be there. By sequencing DNA samples from every attendee and looking at the differences between those who do and don't have the condition, Duchaine hopes to pinpoint a particular gene or set of genes that code for face perception. It's unlikely to lead to a cure, but it could illuminate how the brain builds specialized abilities.
Developmental prosopagnosia came to light in large part because of Internet groups. Before that, most people born with the condition assumed they were just bad with faces. It's not the type of thing most would go to a doctor about, and even if they did, their physician probably couldn't help, because many doctors are unaware of it. In many ways, this is a neurological condition discovered by Yahoo.
Which makes Duchaine wonder if other groups of people with perception problems will start to coalesce online. It would certainly help him if new groups formed with names like Trouble Recognizing Gender or Trouble Recognizing Myself. Among the millions of Internet users, there are sure to be some who consider themselves normal save for one troubling quirk. They may hold the key to a deeper understanding of the way we assemble reality.
Face Blind
Joshua Davis
http://wired.com/wired/archive/14.11/blind.html
November 2006
They can see your eyes, your nose, your mouth - and still not recognize your face. Now scientists say people with prosopagnosia may help unlock some of the deepest mysteries of the brain.
BILL CHOISSER WAS 48 when he first recognized himself. He was standing in his bathroom, looking in the mirror when it happened. A strand of hair fell down - he had been growing it out for the first time. The strand draped toward a nose. He understood that it was a nose, but then it hit him forcefully that it was his nose. He looked a little higher, stared into his own eyes, and saw … himself.
For most of his childhood, Choisser thought he was normal. He just assumed that nobody saw faces. But slowly, it dawned on him that he was different. Other people recognized their mothers on the street. He did not. During the 1970s, as a small-town lawyer in the Illinois Ozarks, he struggled to convince clients that he was competent even though he couldn't find them in court. He never greeted the judges when he passed them on the street - everyone looked similarly blank to him - and he developed a reputation for arrogance. His father, also a lawyer, told him to pay more attention. His mother grew distant from him. He felt like he lived in a ghost world. Not being able to see his own face left him feeling hollow.
One day in 1979, he quit, left town, and set out to find a better way of being in the world. At 32, he headed west and landed a job as a number cruncher at a construction firm in San Francisco. The job isolated him - he spent his days staring at formulas - but that was a good thing: He didn't have to talk to people much. With 1,500 miles between him and southern Illinois, he felt a measure of freedom. He started to wear colorful bandannas, and he let his hair grow. When it got long enough, he found that it helped him see himself. Before that, he'd had to deduce his presence: I'm the only one in the room, so that must be me in the mirror. Now that he had long hair and a wild-looking scarf on his head, he could recognize his image. He felt the beginnings of an identity.
It gave him the confidence to start seeing doctors. He wanted to know if there was something wrong with his brain. His vision was fine, they told him - 20/20. One doctor suggested he might have emotional problems and referred him to a psychiatrist. In the medical literature, there were a few reports of head-injury and stroke victims who'd lost their ability to recognize faces. No one, as far as the doctors knew, had ever been born with the condition.
Conventional medicine, in other words, got him nowhere. So Choisser posted a message about his experiences on a Usenet group devoted to people with neurological problems. His subject line was "Trouble Recognizing Faces." After a few months, in late 1996, he received a solitary reply. "Hello, Bill," the email began, "I read what you wrote, and I think I have what you have."
BRAD DUCHAINE WAS SO LOADED, he didn't realize he was plummeting to the ground. It was his 27th birthday party and the handsome Wisconsin native had been trying to have a good time. He'd had more than a few beers, grappled onto the roof to enjoy the beautiful Santa Barbara, California, sky, and fallen asleep. Now, inexplicably, he was falling. He smashed into the concrete driveway and his hip shattered. Luckily, the beer dulled the pain. He clawed his way to the living room and fell asleep among a few other unconscious revelers. Though no one knew it at the time, this guy - passed out, busted up, bleeding on the floor - was going to have a lasting impact on neuroscience.
Duchaine had started out enjoying himself too much as an undergrad and nearly flunked out of two colleges. He tried again at Marquette University in Milwaukee, and this time pulled it together. In the cold, boring Midwest nights, he settled down and did well, graduating summa cum laude in 1995. That got him into the cognitive psychology PhD program at UC Santa Barbara.
But the fall off the roof two years into his PhD coincided with a crack in his confidence. His dissertation was in shambles. He hadn't been able to find a suitable topic and was playing videogames until his thumbs hurt. Did he really think he could succeed as a neuroscientist? His parents were both midlevel managers at a paper company back in Wisconsin. Community college instructor was a more realistic goal.
But when Duchaine's parents visited their son in the summer of 1998, he didn't tell them any of this. The couple had invited an old friend to dinner at the Shoreline Beach Café, a seaside restaurant with tables right on the sand, and it didn't seem like the right time to reveal his doubts. Instead, over appetizers, talk turned to a presentation on unusual neurological cases that Duchaine had given to undergraduates earlier in the day. He was especially fascinated by a study of people who'd been hit on the head and lost their sense of direction or ability to perceive certain objects.
"I know a kid who doesn't recognize faces," the friend said.
"He had a stroke?" Duchaine asked. He knew that in a few rare cases - usually as a result of stroke or trauma - patients reported that they had lost the ability to recognize faces. Oliver Sacks' "man who mistook his wife for a hat" was the most famous example.
"No, he's always been that way," the friend replied.
Duchaine called the teenager's family a few days later. The boy's father told him that if he really wanted to learn more about the condition, he should check out a Yahoo group and Web site maintained by a guy in San Francisco named Bill Choisser. A whole community of these people were chatting online - that's how the teen discovered he wasn't the only one who had a problem with faces. Choisser had even begun to popularize a name for the condition: face blindness. If this were true - if there was a large, previously unidentified population with the condition - it would be a major discovery. Duchaine started to think he might make it as a neuroscientist after all.
IN OCTOBER 1944, as the Russian Red Army advanced into Germany, a single artillery round struck a German command post on the East Prussian front. Everyone inside was ripped apart by shrapnel, but a 36-year-old lieutenant somehow lived. He was evacuated to a field hospital, where a surgeon removed a piece of metal from the back of his head. The external wound healed, but it soon became clear that something strange was going on. The officer reported that he could no longer see faces.
He was sent to a psychiatric hospital near Stuttgart, where a doctor named Joachim Bodamer examined him. There had been reports of face blindness as far back as antiquity, but no one had studied it systematically, so the physician decided to make a detailed analysis.
To assess the extent of the man's impairment, Bodamer dressed the officer's wife of seven years as a nurse and lined her up with four real nurses. Bodamer asked if he noticed anything different about any of the nurses. The man said no. Next, he was told to look in a mirror and report what he saw. "It's strange," he said. "I've looked at myself often, but that's not me anymore, although I know that it's me. But I have a feeling of unfamiliarity."
Bodamer wrote a 47-page report on the case and coined a name for the condition: prosopagnosia (in Greek, prosopo is face and agnosia means without knowledge). He defined it as "the selective disruption of the perception of faces, one's own face as well as those of others, which are seen but not recognized as faces belonging to a particular owner."
While he was producing the report, the world around him was going up in flames. The Allies dropped more than 7,000 tons of bombs on Dresden, incinerating the city. Stuttgart - 13 miles from Bodamer's home - came next. As his work on the paper drew to a close, fundamental questions about human consciousness weighed on him. What might his patient's condition imply about how healthy people experience the world? Maybe there are mental mechanisms for perceiving each aspect of reality - parts of the human mind that render faces, houses, and bombs meaningful. While everything was falling apart, Bodamer had stumbled onto a clue about how things come together in our heads. Perhaps the fluid reality we perceive is just a flimsy construct of individual puzzle pieces, any one of which could suddenly disappear. In nothing else, Bodamer wrote, "does medical fact touch so closely on … the basis of all knowledge."
OVER THE NEXT FIVE DECADES, researchers trying to pursue these questions had one major problem: Not many people get shrapnel shot though their brain and survive. In other words, the pool of potential research subjects was minuscule. Scientists did discover that a small number of stroke victims developed prosopagnosia, but their lesions often continued to grow, preventing reliable comparisons and, in many cases, causing death.
Still, these patients tantalized researchers. "People think of the brain as one seamless intelligence, because that's how it feels to us from the inside," says Nancy Kanwisher, an MIT vision researcher. "But if you look at prosopagnosia, you start to realize that the brain may actually be a grouping of stand-alone computational machines that are wired together."
The question is, how many machines are there and how do they work? On a basic level, we know that there are distinct visual, auditory, memory, and motor systems. But within each of these, are there further specializations? For instance, within the visual cortex, is there a specialized part of the brain devoted to faces? And, if so, are there further specializations within that for gender, skin color, age, and even attractiveness? It's akin to discovering the molecule, only to realize that there may be atoms, electrons, and quarks as well.
As functional MRI came into use in the 1990s, neuroscientists rolled people under the magnets to track blood flow to specific parts of their brain. They learned that a small part of the visual cortex - eventually dubbed the fusiform face area - showed increased blood activity whenever a subject looked at a face. Researchers had discovered what appeared to be a computational machine devoted specifically to processing faces. Stroke or gunshot victims tended to develop prosopagnosia if they sustained injuries to that area. But that was about as much as this relatively crude imaging technique could reveal.
The best that scientists had been able to do was point to a particular part of the brain and say, "That's important." The face-processing system remained a black box.
WHEN ZOË HUNN WAS 14, her three closest friends decided to enter a modeling contest in a London department store. The girls tried to convince Hunn to sign up, too. She thought it was a silly idea; looks didn't matter to her, and she had no idea whether she was pretty. She had never paid much attention to her face - it didn't seem to represent who she was.
Though she didn't know it, Hunn was severely face blind. Her father had the same problem. Both just assumed that they were bad with faces, in the same way some people are bad with names. They developed elaborate coping strategies, like focusing on voices and searching for clues in a conversation. Inevitably, they embarrassed themselves.
Since all her friends were entering the contest, Hunn decided to go along. To her surprise, she ended up winning the top prize: an offer from a modeling agency. In 2002, she was signed by Models 1 in London, the same agency that represents Stephanie Seymour and Linda Evangelista. She appeared in Vogue and Elle and in fashion ads across Europe, earning as much as $1,500 a day. But she could never spot herself in any of the photos. She might recognize the clothes and deduce her presence in the picture, but she was never sure.
Hunn decided to see a doctor. She explained to him that she was a rapidly rising model - this should be the time of her life. It wasn't. She was completely unable to appreciate her beauty, which had now become the centerpiece of her young life. When she should have been going out to parties and having fun, she chose to stay home. "Everyone looks the same," she told the doctor, "so it's hard to connect emotionally with anyone." The doctor checked her eyes, made sure she didn't have a tumor, and then recommended counseling for shyness.
In the summer of 2003, she traveled to Edinburgh, Scotland, for the annual theater festival. On the third night, she saw a performer who was unusually memorable. He was a tall mime with white hair and vivid black eyebrows. She stared at him. He was the first person she felt she'd ever really seen.
Later that night, the unimaginable happened: Hunn recognized him in a bar. It was like being thrown a lifeline. She mustered the courage to introduce herself and told him that his performance made her laugh. He smiled and thanked her. She learned his name was Mick, and that was all she needed. She was in love. It didn't matter that he was a 44-year-old mime trying to make ends meet. She could see him.
Mick, for his part, was captivated not by her beauty but by the way she watched him as if her whole world depended on the sight of him. It was a performer's dream, and Mick melted in the intensity of it. Despite the protests of her parents, they moved in together within a few months.
One day in their new home, she read a short article in a British magazine about a man named Brad Duchaine and his work on something called face blindness. It described her symptoms: inability to recognize faces, leading to social embarrassment and a sense of isolation. She felt a tumult of emotion, like someone exonerated from a crime. It seemed to explain so much about who she was.
TO CONDUCT HIS FIRST INTERVIEW with Bill Choisser, Duchaine had to drive his red 1988 Camry 300 miles north to San Francisco. It wasn't easy for him. He'd been playing too much V8, a car combat videogame, and driving on a real freeway now gave him panic attacks. He'd pull over to calm himself down. It took a long time to get there.
When he did arrive, Choisser was clearly uncomfortable. Duchaine asked if everything was OK, and Choisser said he couldn't read Duchaine's expressions. It would help if he had a beard - facial hair made faces easier to comprehend.
So three weeks before each of his next eight road trips to San Francisco, Duchaine stopped shaving. He also cut back on playing V8, decreasing his freeway anxiety. He'd show up at Choisser's door with a scruffy beard and a newfound confidence, ready to run his subject through face-recognition tests, some of which he'd just invented. Once back in Santa Barbara, he would run the tests on dozens of grad students and faculty to generate averages for a representative sample. When the numbers came in, it was clear that Choisser's facial-recognition system was severely impaired.
Next, Duchaine tested Choisser on his ability to recognize small differences between the same type of objects. In one exam, Choisser was asked to memorize the details of a particular house. Duchaine then showed him 150 pictures of other houses and randomly threw in images of the original. Choisser consistently identified it. He did the same in similar tests that used shoes, horses, cars, and natural landscapes. It was strong evidence that the brain's system for processing faces is separate from its system for discerning other objects.
The finding was controversial. "People love to carve up the brain and say, 'There's a hand area, there's a face area, and there's a love area,'" says Michael Tarr, a Brown University vision researcher who is one of the leading proponents of an alternative theory. Tarr believes that the fusiform face area is part of a generalized recognition system that gets switched on when someone develops enough expertise to distinguish between two very similar things.
"The discovery of otherwise healthy people living with prosopagnosia is the most exciting development in the field in a long time," Tarr says. "But we can't rely on neuropsychology to figure out what's going on, because you're just asking people questions. You're not getting in there and finding the damage."
The problem is that scientists aren't able to cut open someone's head, plug in electrodes, and test every neuron in the fusiform face area. But as Duchaine's work progressed, fMRI testing indicated that developmental prosopagnosics - those, like Choisser, who were born with the condition - had a smaller face area than normal. One study found that the neural pathways leading out of the face area might be damaged. But none of the tests explained the structure of the face-processing system itself. The best that could be done was to develop visual tests that narrowed down the nature of the impairment and then try to deduce what was going on inside the brain.
Using Choisser's group, now hosted on Yahoo, as a resource, Duchaine contacted and tested other developmental prosopagnosics and began piling up evidence that, with a bit of practice, they could distinguish between very similar objects. In other words, they could learn how to differentiate objects but not faces. The implication: Facial recognition was a hardwired aptitude that did not depend on learning.
As he found more prosopagnosics through Yahoo, Duchaine began to see that this previously unknown population offered a new way of exploring the brain's face-processing system. First of all, the patients were healthy and young, unlike gunshot or stroke victims. Their condition was stable, and the unobstructed blood flow in their brains allowed for clear imaging. They could also be studied over time. Duchaine had discovered an untapped well of subjects, and he was sure that a key to understanding how our brains are organized lay inside their heads.
FOR KEN NAKAYAMA, a leading vision researcher at Harvard, Duchaine's dissertation on Choisser was a turning point. He had heard of developmental prosopagnosia - he had even seen it mentioned in the academic literature. But Duchaine's work with Choisser was so thorough and persuasive, it convinced Nakayama that the condition merited serious attention. "Brad did more than anybody else had done, by far," he says. "As soon as I saw his dissertation, I knew that this was what my lab needed to be studying."
Nakayama quickly offered Duchaine a job, and together they formed the Harvard Prosopagnosia Research Center. Though Duchaine still wore jeans, sneakers, and faded T-shirts to work, he was now a rising star in cognitive neuroscience. It suited him well - he stopped playing videogames, and the panic attacks subsided. In his free time, he pored over research papers on vision. If he stayed up late, it was to correspond with prosopagnosics in other parts of the world and to think about new ways to figure out what was going on in their heads. When particularly conclusive test results came in from a new subject, he would exclaim, "That guy's really bad with faces." It gave him a thrill. It was as if he'd spent his whole life waiting to stumble across this condition. Now that he'd found it, he had a prestigious job and a stable income. In exchange for shining a light on the disorder, prosopagnosia had made him an adult.
But research on face blindness was still in its infancy. Duchaine wanted to find out how our brains process faces and how that influences who we are. He and others hypothesize that one part of the face-processing system might be designed specifically for processing gender, another for skin attributes, and a third for reading emotional expression. To test the theory, he had to find double dissociations: a subject who could look at a face and perceive, say, skin color but not gender, and a second subject who had the opposite condition. That would provide evidence that skin color and gender perception were separate brain mechanisms.
The key was to find many different combinations of deficits. It would require lots of subjects, which is exactly what the discovery of developmental prosopagnosia promised. Before that, a scientist might have waited a lifetime to come across a stroke victim who had just one set of problems. Now, thanks to Choisser and the Internet, Duchaine could locate hundreds - even thousands - of subjects. "A whole new world of questions can now be asked," he says. "We're moving inside the black box."
Duchaine's questions touch on some fundamental social and cultural issues. For instance, what would it mean if there were a particular part of the brain devoted to recognizing gender? Bill Choisser reports that he has more trouble perceiving women's faces, and that could be one of the reasons he's gay. Another prosopagnosic says that his inability to distinguish between men and women explains his bisexuality. Is it possible that our sexuality is influenced by the wiring in the face-processing system?
TOM UGLOW, A GRAPHIC DESIGNER in London, didn't have a problem perceiving that it was a girl watching him across the bar. Her blond hair had a nice sheen. She seemed pretty. Uglow ordered another beer, downed it, and walked her way. He was about to introduce himself when she cut him off.
"Hi, Tom," she said, no longer smiling. "Why were you making eyes at me?"
"Damn," he thought. "This isn't going as planned."
Her voice sounded familiar. He searched her face but couldn't place her. This happened more than he liked to admit.
"How've you been?" he asked, casually trying to fish for a clue as to who she was.
"Better now that we're broken up."
Ah! It was his ex-girlfriend. Once he'd had a moment to process her voice, he was able to place her. They had dated for a year. Definitely not a good person to be hitting on. It was a problem: Every time he saw a face, it felt like it was for the first time.
Uglow tried to work around it. Everyone looked equally unfamiliar, but rather than treat unfamiliar faces as strangers, he acted like everyone was his best pal. "Generally, I'll be very smiley, friendly, and nice, even though I have no idea who I'm talking to," he says. "But at least that person would come away liking me." He'd rather live in a world populated with friends than with strangers.
It never occurred to Uglow that his inability to see the world as others did would stand in the way of becoming an artist. Ever since he was a kid, he had loved drawing and made endless sketches of friends and family in his journals. They almost never had faces. For Tom, that wasn't a big deal. He felt he could convey personality with his brushstrokes or a particularly adept representation of someone's posture.
Every year, he made a pilgrimage to London's National Portrait Gallery. The museum hosts an annual contest to select the best emerging portrait artists, and Uglow likes to keep up with the latest techniques. This year, the winning portrait was a photorealistic depiction of an elderly woman, her face wrinkled and blotchy. Uglow loved it, though not because of the three-quarters-crazy look in the woman's eyes or her haunted expression. He loved it because the technique was so precise, so exact. To him, it spoke of the struggle against chaos, decay, and death. It was an attempt to impose order on what couldn't be controlled. In his own way, he had grasped the essence of the painting.
By day, Uglow makes a living designing logos, but someday he'd like to see his portraits hang in the gallery. The fact that they don't have faces doesn't seem to be an impediment. "Faces aren't that important in the contemporary art world," he observes. And yet, despite the missing faces - or maybe because of them - his paintings and sketches are evocative. In one sketch, a young girl holds an umbrella in a field. The umbrella has a densely patterned green and purple canopy, and individual blades of grass are visible. The girl's scarf is sharply defined, but she has no face. In another drawing, newlyweds stand beside a wedding cake; the bride has no head, but the fringe of her dress is elaborately delineated. It's a view into another reality.
IN 2004, UNIVERSITY COLLEGE in London wooed Duchaine with the offer to run his own lab. He took the opportunity but continued to collaborate with Harvard's Nakayama. In 2005, the two conducted a study to determine the extent of prosopagnosia in the general population. They assessed 1,600 people online, running them through a face-recognition test the researchers had invented, and found that 32 had severely impaired face recognition. At the same time, a German researcher tested 680 high school and college students and identified 17 prosopagnosics. Both studies suggested a prevalence of roughly 2 percent. If the ratio held, it would mean that nearly 6 million people in the US are face blind.
Duchaine says the implications are far-reaching. He believes, for example, that the Transportation Safety Administration should administer tests to make sure all airport passenger screeners can match faces with IDs. And the reliability of eyewitness identification should be reconsidered in the courtroom. "You'd want to know if the witness was drunk, right?" Duchaine says. "Well, we should also know if they're face blind."
Baseline testing should be done at a young age so prosopagnosic children don't develop feelings of isolation and depression. There is no cure, but as with dyslexia or autism, once parents know a kid has the condition, they can make accommodations. It can be hard emotionally, particularly if a child doesn't recognize his parents. But it's worse if parents chastise a kid for something that can't be controlled. And, for the children of prosopagnosics, it can be comforting to know why their parent can sometimes seem oblivious to them.
MORDECHAI HOUSMAN, A GENIAL, portly Hasidic Jew, is playing Minesweeper on his computer at home in Brooklyn. One of his three young sons sits next to him - though Housman isn't sure which.
"Who are you?" Housman finally asks with a smile.
"I'm Abraham, Dad," Abraham says. The 6-year-old has heard this question before and thinks his father is just kidding. It's like a family joke. He doesn't understand that his dad really can't tell him apart from other kids on the street.
The Hasidic men in the neighborhood - clad uniformly in black pants, white shirt, black jacket, and black hat - are even harder to distinguish. But this doesn't bother Housman. He considers it a blessing of sorts. "In my culture," he says, "we de-emphasize material things and appearances. Our focus should be on God. For me, I've been given a head start."
Nonetheless, even the religious have to make a living. Housman found work as a swing-shift building manager for a Hasidic college in Borough Park, Brooklyn. Most nights, he sits behind a small window near the entrance, answers questions, and is supposed to keep an eye on who is coming and going.
Housman doesn't think he's ill-suited for the task; he has developed other ways to recognize people. On a recent Monday night, he peers out of his small window, chews on a pen while beads of sweat gather on his forehead, and watches people walk past. He recognizes one student by his "intense, inwardly focused attitude." He greets a professor he thinks he recognizes by the type of yarmulke he is wearing, though it turns out to be the wrong guy. A young man darts past, but Housman knows him. "I recognize him by his soul," he says.
For Housman, as for most prosopagnosics, the Internet is changing everything. He learned about his condition when his wife stumbled across Choisser's Web site one night. She thought it explained a lot about her husband, and she showed the site to him. Housman stayed up until five in the morning reading Choisser's online memoir and following links to other prosopagnosia Web sites. For Hasidics, Housman says, "it's considered arrogant if you make a big deal out of something or call attention to yourself. So I didn't really talk about my problems until I sent my first email to Brad Duchaine."
FOR THE PAST FIVE YEARS, Duchaine has been hungrily collecting profiles of developmental prosopagnosics though his Web site, Faceblind.org. It's a war chest assembled to search for double dissociations. There is the Caucasian man who upset a colleague by telling him a racial joke, not recognizing that the listener was black. There is the woman who waved to someone in a hotel, only to discover that it was a mirror. There is the man who takes emotional cues from the way a person's pants crease and bunch.
Now Duchaine is trying to prove that the condition is inherited. He plans to spend this New Year's in Las Vegas at a reunion of a family full of prosopagnosics. Three generations will be there. By sequencing DNA samples from every attendee and looking at the differences between those who do and don't have the condition, Duchaine hopes to pinpoint a particular gene or set of genes that code for face perception. It's unlikely to lead to a cure, but it could illuminate how the brain builds specialized abilities.
Developmental prosopagnosia came to light in large part because of Internet groups. Before that, most people born with the condition assumed they were just bad with faces. It's not the type of thing most would go to a doctor about, and even if they did, their physician probably couldn't help, because many doctors are unaware of it. In many ways, this is a neurological condition discovered by Yahoo.
Which makes Duchaine wonder if other groups of people with perception problems will start to coalesce online. It would certainly help him if new groups formed with names like Trouble Recognizing Gender or Trouble Recognizing Myself. Among the millions of Internet users, there are sure to be some who consider themselves normal save for one troubling quirk. They may hold the key to a deeper understanding of the way we assemble reality.