“Prosopagnosia,” from the Greek prosōpon “face” + agnōsia “ignorance” — or “face blindness” — is “a very specific neurological symptom … [in which] a person loses the ability to recognize people’s faces but retains the ability to recognize that person by the sound of their voice” or other means, says Karen Postal, a clinical instructor in neuropsychology at Harvard Medical School.
Studies suggest up to 2.5 percent of the population has “developmental prosopagnosia” — that is, they’ve had it since birth, Postal says. Acquired prosopagnosia is rarer and “can arise in a variety of neurological conditions, including stroke, tumor, and degenerative dementia.”
Face recognition is a highly complex cognitive process involving a dedicated network of brain regions. Prosopagnosia may present as degrees of impairment — some people are mildly affected, others might not recognize their own reflection.
My Life With Face Blindness
The onset of prosopagnosia, Postal says, depends on what caused it. With a stroke, it’s sudden: A patient wakes up in the hospital and recognizes the person keeping vigil at their bedside only when they speak. For those with dementia, there might be a slow decline in the ability to recognize faces.
Some days the symptoms might be more prominent, “the next less so, but the trajectory is for increasing problems over time,” Postal says. “In the case of developmental prosopagnosia, it is usually a parent’s dawning realization that a child cannot distinguish one face from another.”
Faceblind.org co-founder Brad Duchaine says it can be difficult for people with prosopagnosia to get a diagnosis.
“Most physicians and many neurologists will not have experience with it,” says Duchaine, whose laboratory explores the mechanisms underlying prosopagnosia and the different forms in which it presents. There are tests, but older ones (the Warrington Recognition Memory for Faces and the Benton Facial Recognition Test) aren’t perfect, he adds.
“Impaired scores on these tests are good evidence of difficulties with face recognition, but scores in the normal range should be treated cautiously; some participants are able to score in the normal range on these when facial features are covered,” Duchaine says. “The hair and clothing provides an alternative way to recognize the people in the tests.”
They never forget a face. Research delves into how ‘super-recognizers’ can do this.
Duchaine created the Cambridge Face Memory Test, the newest and now most commonly used assessment. The best way to get a diagnosis, he says, “is to register with a lab that does research on prosopagnosia and participate in their studies.” Faceblind.org is recruiting for such a study, he adds.
A handful of treatments are available for face blindness, some that target fixing the impairment, while others provide ways to work around it, says Joseph DeGutis, a collaborator at Faceblind.org and director of the Boston Attention and Learning Lab.
He say his lab and others have “focused on improving face perception abilities, for example, by enhancing matching internal facial features or improving holistic processing abilities: the ability to integrate all the parts of the face into a single representation.”
The lab has developed a training approach focused on memory to improve “face encoding strategies to enhance face recollection,” DeGutis says, because those with prosopagnosia typically lack “the ability to automatically recall semantic and contextual details when they see a face, although they may have a vague feeling of knowing.”
Jean Gilbert, whose memoir, “The Picasso Mirror,” describes her experience of the condition, doesn’t recognize herself in the mirror. She was born with prosopagnosia but didn’t know anything was wrong with her until she watched a TV program about face blindness in her 20s.
“It was shocking for me to learn I had a brain disorder, and at the same time, a relief. It explained much about my behavior,” Gilbert says.
Covid-19 in seniors linked to increased Alzheimer’s risk, study finds
But how did Gilbert manage before she was diagnosed?
Gilbert, who doesn’t recognize her family members’ faces, focuses on visual cues and looks for distinguishing features, a tattoo, a scar, a mole. “But what’s more important,” she says, “is a person’s posture, the inflection in their voice, their smile. That’s how I function. It is as natural to me as breathing. I don’t need to ‘see’ a face.”
What about when Gilbert looks at herself in the mirror?
“Logic dictates the face looking back belongs to me. But I feel no connection to it. It’s just a face, forgotten as soon as I look away. I know I have hazel eyes and auburn hair, so I expect to see those. It doesn’t mean anything to me. It’s like asking a blind person what they see when they look at a colorful painting.
“I wear makeup and do my hair because I understand that my face represents me, and I want to present a normal appearance to the world even though I’m far from feeling normal on the inside,” she says.
Prosopagnosia sufferers deal with significant practical and social difficulties. Some are dismissed as “snobs” or unfriendly, and Gilbert says the condition means she sometimes struggles to understand deep emotion.
“It’s not that I don’t care about the people in my life, but when I’m not with them, they are no longer in my head. I have no face to remember, nothing to attach an emotion to,” she said. “Imagine going on vacation by yourself. You can recall the places you visited, the food you ate and the things you did, but there are no people in the memories. That’s been my life from the time I was born. It can be lonely.”
Experts agree, however, that most prosopagnosics develop strategies to compensate.
Says Postal: “Whenever we visually process an object or a face, there are two pathways being processed simultaneously. One involves the visual aspect, and the other involves an emotional sense of familiarity.”
Gilbert says she is upfront about her condition now: “I come right out and say, ‘Have we met before? I have face blindness and can’t recognize people, not even myself.’ My real friends come up to me and say their names and remind me what we last did together. I call those my memory prompts. I may not have the person in my memory, but I can recall an event or conversation.”