Monday, September 6, 2010

Face Blindness

In The New Yorker, Aug 30 issue is a piece by Dr. Oliver Sacks about prosopagnosia, the inability to recognize faces.   I was interested, since I have a mild case of this problem.  My problem is just severe enough to be annoying, but not debilitating.  Dr. Sacks has the same problem, but much worse.  He wrote of an incident where he had spent an hour with his psychiatrist, and then took the elevator down to the lobby.  The psychiatrist had taken another elevator and arrived there first, and had taken off his white coat.  Dr. Sacks walked right past him without recognizing him.   Dr. Sacks has been classified as autistic, but does not believe that he is.  He thinks that his inability to recognize faces merely makes him appear autistic.
            But prosopagnosia affects not only faces, but also our ability to classify visual images of any kind.  I had planned to take up fishing as a hobby when I retired.  But I realized that this would not work unless I took someone else along to examine each fish I caught and tell me what species it was and whether I could legally keep it.  When I tried to explain this to my friends, they said, “Oh no.  When you buy a license, they give you a little folder which shows pictures of each species.”  I said, “Unless it was a catfish or a sturgeon, I don’t think that would help."  When I visit the DNR aquarium in Guttenberg, they have every game species in the tank, and on the wall they have beautiful drawings and descriptions of each.  But I have never been able to completely match one with the other.  Whenever my wife and I drive somewhere, I’m content to let her navigate.  Unless I have driven the same route several times, I have no memory of it. I always assumed that these problems were related to my face blindness.  Turns out I was right.
            Dr. Sacks says that once he walked around his neighborhood in the rain for two hours, looking for his house.  He walked past his own house 3 times before a kindly neighbor told him where he was.  While Dr. Sacks has a more serious case than mine, some of his patients are still worse.  He writes of patients who cannot recognize their own children.  And of course, his most famous patient was “the man who mistook his wife for a hat.”
            The particular area of the brain involved is a long narrow area in the underside of the right occipital lobe, extending from the visual cortex to the pre-frontal.  And there may be a gradient of functions from one end to the other.   The functions may range from identifying shapes, to classifying faces versus objects, to remembering whose face it is, or to reading the emotional content of faces.  Dr. Sacks says that there is a bell curve distribution of these abilities.  And for every person born with poorer than average face recognition abilities, there is probably one with greater than average.  He mentioned people who can recognize the face of every person they have ever met. 
            I know of such a case, and the person involved used this facility to his advantage.  When I worked at the John Deere tractor works in the late 1950s, the manager, Harley Walden, had a legendary ability to remember faces.  Once a year, he would walk slowly through the plant, walk down every aisle, and stop and introduce himself to every worker, and speak with them a few minutes.   It took him a few days to do this, because there were 8,000 workers there.  The next year, he would do it again, and he remembered them—all 8,000 of them.   He’d walk up and say something like, “Well, how’s it going Jim?  Is your boy still wrestling for East High this year?"  People were astounded.  But most workers interpreted this to mean that Harley Walden had taken an interest in them personally.  This bought him a lot of respect and loyalty.  But the strange thing about prosopagnosia is that if this part of the brain is ever damaged, no adjacent area ever takes over this function.  When you have face blindness, you have it. 

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