March 06, 2023
Gerd Altmann/Pixabay
Prosopagnosia is a neurological condition in which the brain can’t recognize faces or facial expressions. People with this condition have normal vision, but the brain has difficulty processing sensory information.
The ability to instantly recognize the face of family members, friends and co-workers is one that most people take for granted. But for some people, facial recognition is a real challenge.
A new study suggests more than 10 million Americans likely suffer from prosopagnosia, a neurological condition in which the brain can't recognize faces or facial expressions. That's more than the 2.5% cited by previous studies. And because the severity of condition varies, many of them may not realize it.
People with prosopagnosia, better known as face blindness, have normal vision, but the brain has difficulty processing sensory information. It can be caused by brain damage from strokes, infections, head injuries, tumors and neurodegenerative diseases, like Alzheimer's.
But people also can be born with it, too. Because prosopagnosia can run in families, scientists say there may be a genetic component.
Blogger Glenn Alperin, who has had prosopagnosia since birth and once failed to recognize that he was shaking hands with Jimmy Carter, has used a metaphor to describe the way his brain works.
"Imagine that every person has a camera inside their head," Alperin told Nature.com in 2013. "Every time they meet somebody for the first time, they take a picture with their camera, develop the picture, and file it away for future use. ... For me, I take a picture with my camera, but I never store it away."
People with prosopagnosia rely on various strategies to connect the face before them with the person they have known, maybe for years. These include recognizing the person's voice, hairstyle, a distinguishing facial feature, or the style of dress. Other times, they rely on a family member to provide prompts when someone they know approaches. Or, they take on a listening role at the start of a conversation so they have more time to identify the person.
Sometimes, connecting people to certain locations can help – like remembering the people one commonly interacts with at work. But those cues aren't any help when bumping into a co-worker at the supermarket, or when a co-worker gets a new haircut. To avoid awkward situations, some people with face blindness avoid social situations as much as possible. But this can make them appear aloof or absentminded, and it can hamper their relationships. It can be very isolating and lead to depression.
Sheila Pagliaro, 74, of Richboro, Bucks County, said she often feels embarrassed by her inability to recognize people she previously met, particularly if she has been in their company more than once.
Pagliaro self-diagnosed herself with prosopagnosia about two years ago after finding it difficult to remember faces and researching her symptoms. She has never been diagnosed by a doctor.
"I don't have a severe case, but it is enough that I have been embarrassed," Pagliaro said. "I try to study a face to find a distinguishing feature."
The latest research on face blindness, conducted by researchers at Harvard Medical School and the Veterans Affairs health care system in Boston, suggests as many as 1 in 33 people meet the criteria for face blindness, with 1 in 108 having a severe case, and 1 in 47 having a mild one. The condition also can present differently from person to person.
The ability to recognize faces and facial cues depends on specific regions of the brain, particularly the fusiform face area, and certain perceptual processes, such as the ability to see a face as an integrated whole and the ability to associate faces with prior knowledge, researcher Joseph DeGutis told Harvard Medical News.
He stressed that prosopagnosia is important to study because it can be socially debilitating and limit job opportunities.
"For example, networking is extremely difficult for people with prosopagnosia and can cause social distress and embarrassment," DeGutis said. "Recognizing someone is a social signal, indicating that 'you are important to me.'"
DeGutis explained that face blindness can also affect people with autism and that it may also be worsened by age-related cognitive decline.
"In a world where social isolation is on the rise, especially in teens and young adults, fostering and maintaining social bonds and good face-to-face interactions are more important than ever," he said.
Sadie Dingfelder, a freelance writer, has described her life with severe prosopagnosia as "living in a world full of strangers."
In a story for The Washington Post, Dingfelder recounted the time she went up to a stranger at the supermarket and questioned him about the brand of peanut butter he was grabbing. She had mistaken him for her husband, Steve.
"Steve jumped away from me, his eyes wide with fear and surprise," she wrote. "It was an expression unlike anything I'd seen cross my husband's face before — because, I belatedly realized, this man was not my husband.
"I dropped the peanut butter jar and sprinted off — leaving this poor stranger utterly perplexed. When I found Steve in the frozen-food aisle, I told him what had happened. 'It's because you have the same coat,' I explained. 'Good thing you have different cars, or I might have gone home with him.'"
She added, "The fact that some of these people are acquaintances and even friends is no solace. It's actually a source of constant anxiety. One face-blind man I read about walked around with his eyes downcast to avoid chance encounters with people he knew but couldn't recognize. This earned him a reputation for being aloof, which made it even harder for him to make friends."
In an opinion video for The New York Times, filmmaker James Robinson talked to Paul Kram who said prosopagnosia has affected his ability to connect to people. "Some people in my life just developed a serious dislike of me," Kram said. "'Oh this guy is such a jerk. We've talked several times and he never acknowledges me.'"
But when people are smiling at him, Kram said he is never sure whether it is because they recognize him or they are being friendly. So, he is not sure if he should approach them.
"There's a certain amount of fear that somebody's going to come back and say what kind of idiot are you?" he said.
Diagnosing prosopagnosia generally involves undergoing a neurological exam, diagnostic imaging and sensory, memory and face recognition tests in which the patient is asked to identify pictures of famous people or specific facial expressions.
But diagnosing prosopagnosia can be difficult because the tests physicians use aren't always reliable. One study found that irregular test scores did not necessarily indicate prosopagnosia. Plus, scientists have more information on congenital prosopagnosia than the acquired form.
"The majority of researchers have used overly strict diagnostic criteria and many individuals with significant face- recognition problems in daily life have been wrongly told they do not have prosopagnosia," DeGutis told Harvard Medical News. "Expanding the diagnosis is important because knowing that you have real objective evidence of prosopagnosia, even a mild form, can help you take steps to reduce its negative impacts on daily life, such as telling consequential coworkers, or seeking treatment.
Though there is no cure for face blindness, cognitive training can help improve sensory perception. Other programs are designed to improve face associations.
If face blindness is caused by an underlying condition, doctors generally first try to treat that condition with medications or surgery before offering therapy and rehabilitation programs that help people adapt.
In his lab, DeGutis works with people with prosopagnosia to improve their facial recognition. While a graduate student at the University of California, Berkeley, he created a training program that teaches people with face blindness to use the spacing of facial features as a cue.
"Recent evidence suggests that people with milder forms of face blindness may benefit more from certain treatments than people with more severe forms of the condition," DeGutis said. "These treatments might include cognitive training to enhance perceptual abilities or training aimed directly at improving face associations."
People who notice that they suddenly can't recognize people they have known for years are advised to call a health care provider. Fast onset may be caused by a tumor. If people also have symptoms of a stroke or a brain injury, they should be taken directly to an emergency department. Symptoms of a stroke include weakness, numbness or paralysis on one side of the body, confusion, difficulties with concentration and memory, sudden severe headache and trouble swallowing.
