Transcript for Oliver Sacks on Facial Blindness

Jim Fleming: But first, we turn to Oliver Sacks, the celebrated doctor who writes about some of the brains strangest disorders. His many books include Awakenings, The Island of The Colorblind, and The Man Who Mistook His Wife For A Hat. His latest book, The Mind’s Eye, is a study of rare visual impairments caused by neurological disorders. It is an unusually personal book for Sacks, because it reveals his own struggle with a disorder called "Facial Blindness". Steve Paulson sat down with Sacks recently to talk about some case histories.


Steve Paulson: You start your book with the story of a woman who lost her ability to read music, and then much else as well. Can you explain what happened?


Oliver Sacks: Yeah, this was a, um, a fine concert pianist. To her great surprise, when there was a sudden switch in a concert from one Mozart piano concerto to another, and she wanted to just take a glance at the scroll, she found it unintelligible. She saw the notes, the clefts, the markings, but none conveyed any meaning for her. Later, this problem extended to reading ordinary print, although she could still write perfectly well.


Paulson: And she could still play the piano..


Sacks: And she could still play the piano very beautifully, continued to give concerts and to teach, although now she could not increase her repertoire by reading score. She had to do everything by ear.


Paulson: So, neurologically, what was going on?


Sacks: Well, she seemed to have a, a slowly progressive problem which started with music, spread to print, and from there to all sorts of common objects and people and faces, which she could no longer recognize. But all of which, she saw perfectly clearly. So, neurologists call this an agnosia, these are percepts which have been stripped of meaning, and agnosias go with damage to part of the visual cortex of the back of the brain. They may come on suddenly with a head injury or a stroke, or slowly because people have a degenerative brain disease, as Lilian had.


Paulson: So her eyes were perfectly fine, her vision was fine, but it was her brain..could not make sense of what she was looking at.


Sacks: Yes, absolutely, and in her first letter to me she commented that she could see the smallest letters on the eye chart, but nonetheless couldn't make sense of them.


Paulson: So, how did she compensate? How did she manage to get through her daily routines?


Sacks: Well, I was very puzzled when I saw her and tested her in the clinic. I couldn't imagine how, and so I made a house call, as I like to do. I think it's very important to see people in their own surroundings, and I found that she had really reorganized everything in the apartment by color, by size, by position, by association. She developed a system for finding her way around, and identifying objects, although none of them were identified in the usual way.


Paulson: Now, you tell another story of a different patient, who lost his ability to read after a stroke. Actually a writer, and somehow managed to continue to write, but could no longer read. Can you tell me about him?


Sacks: Well, with him it was quite sudden, he came down one morning, had breakfast, had no intimation of anything the matter, but then went outside to get his daily paper, which at a distance looked normal, but when he looked closer, seemed to be full of some unintelligible peculiar-looking script, which he said was like Korean or Surilic or Serbo-Croat. And like the first patient, like Lilian, he found he could write perfectly well, although he couldn't read what he had written. And initially, he was in despair about this, he thought it would be the end of him as a creative writer. He could write, but he wouldn't be able to revise or reread what he'd written, but then to his own surprise and bewilderment, reading started to become easier and at first he thought this was due to neurological recovery, to healing, but then it became apparent that some new mechanisms, or strategies, were operating for him. And inadvertently, he would often copy what his eyes saw with his finger and in this way as it were, turn what he saw into writing, into finger writing, and then this moved up to his tongue. And so he would copy what he was reading on the back of his teeth, or the roof of his mouth.  Basically, this way he was reading by writing with his tongue. This was not something which he consciously devised, but it happened. And I think it's an example of the extraordinary, sort of ingenuity, the nervous system often provides.


Paulson: That's..that's astonishing. *laughs* The story of somehow maintaining this ability to read, with the help of your tongue!


Sacks: Um, he did mention to me, this was a letter I got just a few months ago that he'd bitten the end of his tongue accidentally, and it was so sore he couldn't move it, and that he had become functionally illiterate while the tongue was out of action.


Paulson: Now you seem to be particularly interested in these cases of, uh, of people with rare visual impairments, and the ways they've learned to compensate for their difficulties. Why are you so interested in sort of this connection between the brain and how we see?


Sacks:  Well, ah, we take seeing for granted. We think that we're given the world full of color and movement and texture and meaning and I think one would have no idea of how this all worked if not for strange disorders, which can suddenly make reading impossible, or suddenly make one totally colorblind, or totally unable to perceive movement. Sometimes it can occur briefly with a migraine. I once had it, myself for five minutes with a migraine, and I, I couldn't read the street signs, I thought they were in phoenician. And sometimes, even as a child, I would find that half the world disappeared, or lost its color. And so I had a very precocious introduction to how necessary the brain was for seeing.


Paulson: And you, you write about how you've had some of your own visual challenges. For instance, you have a great deal of difficulty recognizing peoples faces.


Sacks: Yes, this has been life-long, and it has cause offense and embarrassment and bewilderment and I would have to apologize to people every day for forgetting them all. I thought I was, I think, inattentive or careless, and it was only later that I began to realize, especially when I met an older brother whom I hadn't seen for decades and he had exactly the same problem, that this might be some odd family thing, and if we had it in our family, it might be common elsewhere. And when my Man Who Mistook His Wife For A Hat book came out in 1986, I recieved, in fact I continue to recieve, dozens of letters from people who spoke of lifelong difficulties recognizing faces.


Paulson: And it turns out that this is a surprisingly common problem, this face blindness. I mean, aren't there estimates that are something like two percent of the population has some form of face blindness?


Sacks: Yes, yes, absolutely. And this estimate is based on large samples/ Some of it pretty mild, and people are hardly aware of it unless they're specially tested, but sometimes so severe that they don't recognize their wives or husbands or children, or for that matter, themselves.


Paulson: So what causes this?


Sacks: Well, this again, is part of the, what's called the visual association cortex, part of the visual system being knocked out or failing to develop. Again, I think it wouldn't occur to one that there is a special system for recognizing faces, if it were not for this extraordinary specific business of face blindness. But here, unlike reading, which is only a redeployment of systems developed long ago by evolution, I think there's much evidence to suggest that face recognition appeared in monkeys about twenty-five or thirty million years ago. Perhaps, along with full color vision, because at that point monkeys became bare-faced, they lost their hair, and it became crucially important to recognize their faces and see what their emotions were. And so, we all have to become expert at face recognition.


Paulson: Hmm, makes me wonder if my dog can recognize my face, I guess I've always assumed he can, but maybe I should not assume that. Maybe he recognizes me through other means.


Sacks: Well, it may be by your movement or your shape or your sound or your smell, in somewhat the same way as face blind people find other ways of recognizing human beings.


Paulson:So has, has this been a big part of your life? I mean, sort of this inability to recognized other people, have you constructed your life in ways to compensate?


Sacks: Well, I, I think I've probably done so automatically without much thought, but it's probably contributed to my avoiding of large gatherings and usually having someone with me who will act as a recognizer.



Paulson: Have you found yourself relying on other senses more acutely because you have certain visual impairments?


Sacks: I think so, but also in other aspects of visual sense, I think I'm extremely sensitive to visual movement and motor style and posture. The way people walk, the way they hold their limbs, I often pay conscious attention to the way they dress, but the voices is quite crucial. Again and again, I don't recognize someone until they speak, and then the first syllable lets me recognize them. I have to say, although I don't usually make too much of a point to this, that I have a very keen nose, and sometimes various people I recognize by smell.


Paulson: Really? What do you smell in them? Do people have different sents, sort of a personal smell?


Sacks: Oh, absolutely. I mean, ask any dog. *Both laugh* But no, I feel a little bit like a dog this way.


Paulson: And yu say in fact there are times when you look in the mirror, and you don't actually realize it's you you're looking at.


Sacks: Yeah, it tends to occur in unexpected context. When I suddenly feel I'm about to bump into a large man with a grey beard and I start to apologize, to then realize it's a mirror or shop window or something like this, and I've occasionally had the corollary of this, sitting outside at a table at a restauraunt and starting to comb my beard in the window, and realizing my reflection isn't doing that. But there's a bearded man on the other side who wonders why I'm preening myself in front of him.


Paulson: You seem to have a remarkable ability to laugh at these kinds of embarrassing situations.


Sacks: Well, I can laugh later but some of them are not laughing matters initally. Although laughter is one adaptations. If one can laugh at something then you can defuse offense.


Narrator: The neurologist and best selling writer, Oliver Sacks. He talked to Steve Paulson about his book, The Mind’s Eye.

Comments for this interview

Don't Know If Dogs Recognize Human Faces, But Seagulls Do (Steve MacIntyre, 02/26/2012 - 3:58pm)

I don't know if my dogs recognize my face, but do know that birds can recognize human faces. At least seagulls can, a phenomenon which has been scientifically studied and established.

An article about this appeared in Natural History magazine many years ago detailing the methodology and the result. I don't keep my back issues nearly long enough to lay my hands on it, but I do recall the colorful way in which the scientist went about his experimentation: He was stationed at some remote location and with the help of a colleague and the use of masks they would behave in different ways toward the birds — generously, threateningly, etc. — in different dress, guises with faces covered or uncovered and so forth and were able to establish that the birds were able to recognize who was who on the basis of facial recognition alone.