Oliver Sacks opens a window, personally, on the condition of "face-blindness"

Neurologist Oliver Sacks has had a personal route to, and a personal stake in, understanding face-blindness.

"It is with our faces that we face the world, from the moment of birth to the moment of death. Our age and our gender are printed on our faces. Our emotions, the open and instinctive emotions that Darwin wrote about, as well as the hidden or repressed ones that Freud wrote about, are displayed on our faces, along with out thoughts and intentions. . . . Crucially, it is by our faces that we can be recognized as individuals."

-- Oliver Sacks, in "Face-Blind," in the August 30 New Yorker

by Ken

It was just recently that I read for the first time about "face-blindness," or prosopagnosia, and at first it seemed not just an arcane but a vaguely comical and minor affliction. Clearly, the first objective of Oliver Sacks (author of such books as Awakenings, The Man Who Mistook His Wife for a Hat, and Musicophilia: Tales of Music and the Brain) in this new New Yorker piece is to communicate its nature and seriousness.

At two and a half months, babies respond to smiling back. "As the child smiles," Everett Ellinwood writes, "it usually engages the adult human to interact with him -- to smile, to talk, to hold -- in other words, to initiate the processes of socialization. . . . The reciprocal understanding mother-child relationship is possible only because of the continual dialogue between faces." The face, psychoanalysts consider, is the first object to acquire visual meaning and significance.

But there's another storyline here. It's used as way of ushering us into the world of prosopagnosia, and the question of what other kinds of memory either are functionally identical or work similarly enough to be considered with it. However, it's also a revelation on the part of this gentle guide to so many of the brain's malfunctions. It's news to me, anyway, that the British-born Sacks, resident in this country since 1965 (and now a much-honored professor of neurology and psychiatry at Columbia University Medical School), is himself a lifelong sufferer from prosopagnosia.

I have had difficulty recognizing faces for as long as I can remember. I did not think too much about this as a child, but by the time I was a teen-ager, in a new school, it was often a cause of embarrassment. My frequent inability to recognize schoolmates would cause bewilderment, and sometimes offense -- it did not occur to them (why should it?) that I had a perceptual problem. I usually recognized close friends without much difficulty, especially my two best friends, Eric Korn and Jonathan Miller. But this was partly because I identified particular features: Eric had heavy eyebrows and thick spectacles, and Jonathan was tall and gangly, with a mop of red hair. Jonathan was a keen observer of postures, gestures, and facial expressions, and seemingly never forgot a face. A decade later, when we were looking at school photographs, he still recognized literally hundreds of our schoolmates, while I could not identify a single one.

It was not just faces. When I went for a walk or a bicycle ride, I would have to follow exactly the same route, knowing that if I deviated even slightly I would be instantly and hopelessly lost. I wanted to be adventurous, to go to exotic places -- but I could do this only if I bicycled with a friend.

And at 77, Sacks writes, "despite a lifetime of trying to compensate, I have no less trouble with faces and places." What recognition he is able to manage depends overwhelmingly on the combination of pronounced identifying characteristics like those he mentions above and, crucially a context in which he can connect them. What's lacking is a whole system of brain function that extends from recognition and identification of kinds of visual detail to an ability to store and then retrieve and connect those details. As so often happens in brain functions that we take for granted, it's vastly more complex than we realize until we really break it down and examine it -- and the potential for dysfunction is correspondingly wider.

The revolution of recent decades in understanding of which parts of the brain are involved in which activities, and which functions can be replicated elsewhere in the brain, has led to an overwhelming appreciation of how few functions are accomplished in single places in the brain. This is good news in that many functions can be farmed out to other locations in the event of disability in one; the not-so-good news, apart from the fact that many functions don't appear to be capable of such outsourcing, all those functions that involve multiple areas of the brain also require large quantities of coordination. To put it another way, in my strictly lay understanding, the more complex brain function turns out to be, the more vulnerable it is to breakdown.

Above all, the recognition of faces depends not only on the ability to parse the visual aspects of a face -- its particular features and their over-all configuration -- and compare them with others but also on the ability to summon the memories, experiences, and feelings associated with that face. . . .

Recognition is based on knowledge and familiarity is based on feeling, but neither entails the other. The two have different neural bases and can be dissociated; thus, although both are lost in tandem with prosopagnosia, one can have familiarity without familiarity in other conditions

And the opposite occurs too, Sacks notes -- "in people with Capgras syndrome, for whom faces, though recognized, no longer generate a sense of emotional familiarity."

Sacks explains that a key to understanding that he wasn't just "very bad at recognizing faces, as my friend Jonathan was very good at it," came when he traveled to Australia to visit his older brother Marcus, whom he hadn't seen in 35 years, "and discovered that he, too, had exactly the same difficulties recognizing faces and places," and "it dawned on me that this was something beyond normal variation, that we both had a specific trait, a so-called prosopagnosia, probably with a distinctive genetic basis."

He not only became more aware of the dimensions of his own situation but collected case histories of other sufferers.

As I continued to receive more and more letters from people with prosopagnosia or topographical agnosia [the apparently related difficulty recognizing places], it became clear to me that "my" visual problem was not uncommon and must affect many people around the world.

Face recognition is crucially important for humans, and the vast majority of us are able to identify thousands of faces individually, or to easily pick out familiar faces in a crowd. A special expertise is needed to make such distinctions, and this expertise is nearly universal, not only in humans but in other primates. How, then, do people with prosopagnosia manage?

In the past few decades, we have become very conscious of the brain's plasticity -- how one part or system of the brain may take over the functions of a defective or damaged one. But this does not seem to occur with prosopagnosia or topographical agnosia -- they are usually lifelong onditions that do not lessen as one grows older. People with prosopagnosia, therefore, need to be resourceful and inventive in finding strategies for circumventing their deficits: recognizing people by an unusual nose or beard, for example, or by their spectacles or a certain type of clothing.

This may mean features like "voice, posture, or gait," and as noted, context is crucial. Sacks offers examples such as neighbors he is able to recognize when they're with their distinctive dogs; without the dogs, the women are visual strangers. Between his own experiences and those of an assortment of fellow sufferers who have described theirs, it's a window to an understanding of an area of brain function that most of us probably have never been aware of. The good doctor also makes clear how much he has depended on his longtime assistant, Kate. With some amusement, for example, he recalls spending weeks in 1988 with the "memory artist" Franco Magnani and writing a piece about him for The New Yorker, only to have then-editor-in-chief Robert Gottlieb reply --

"Very nice, fascinating -- but what does he look like? Can you add some description?" I parried this awkward (and, to me, unanswerable) question by saying, "Who cares what he looks like?"

"Our readers will want to know," Bob said. "They need to picture him."

"I will have to ask Kate," I said. Bob gave me a peculiar look.

For anyone with any curiosity about the mysterious if not actually preposterous workings of our brain (such a bizarre apparatus that, as a number of scientists have pointed out, it's hard to imagine as the product of an especially intelligent "intelligent designer"), the piece is indispensable. For anyone with any appreciation of the job Oliver Sacks has done in guiding us through some of those mysteries, it's also a deeply moving read.

THERE IS AN AUDIO LINK --

which can be played online or downloaded, in which Dr. Sacks talks to newyorker.com editor Blake Eskin about prosopagnosia. He estimates that two to three percent of the population suffers from a serious version of it, and talks about how their plight can be eased by society, as that of dyslexics has been, starting with simple recognition of the condition.

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