Sacks himself has a condition called prosopagnosia, or "face blindness." It's a difficulty or inability to recognize or distinguish human faces. That type of agnosia can be congenital or acquired, and can be mild or severe. Sacks has the severe form; he can meet a patient or friend in his office, then encounter the same person fifteen minutes later in the hallway and not recognize them.
Jane Goodall also has a certain degree of prosopagnosia. Her problems extend to recognizing chimpanzees as well as people - thus, she says, she is often unable to distinguish individual chimps by their faces... "I have huge problems with people with 'average' faces.... I have to search for a mole or something. I find it very embarrassing! I can be all day with someone and not know them the next day."Disorders of face perception can be traced to specific loci in the brain, and understanding the disorder helps understand why Caucasians may consider all Oriental faces the same (and vice versa). Sometimes a person can retain the "familiarity" of a person or place, but lose the identification of it - thus resulting in a "deja vu" experience. The opposite is the Capgras syndrome, where the face is recognized, but the association and emotional connections are lost, and the person perceives the other person as an imposter or alien.
She adds that she, too, has difficulties in recognizing places: "I just don't know where I am until I am very familiar with the route. I have to turn and look at landmarks so I can find my way back. This was a problem in the forest, and I often got lost."
Finally, there can be "hyperfunction" of the locus, resulting in "superrecognition" - the ability never to forget a face.
There are other interesting sections of the book, notably on depth perception and stereoscopy, which I'll try to touch on re Islamic art in a separate post. I've not listed the book in my recommended books list, not because it's too dense, but rather because it's a bit too wordy and could have been edited much more tightly. But it's a nice read for those interested in human biology, and especially if anyone has (or has friends/family with) difficulties in remembering faces and people, this is a valuable resource for understanding the condition.
Yeah, I have rather mild prosopagnosia. I depend really heavily on context (I can't recognize horse people in the grocery store, for instance) and nonfacial clues like hair styles. I cope really well, overall, but I've never understood how those "have you seen me" flyers work.
ReplyDeleteWasn't aware of Sacks' new book - thanks for the heads up!
Typo -- should be "and not know them the next day."
ReplyDeleteI think if any Sacks book is a 'must read,' it's this one. He's one of his own cases this time. It's incredibly moving and sad, especially listening to him on the audiobook. He lost one of his favorite abilities and managed to write about his own circumstance with the same blend of kind humor, fascinating science, and amazement at the world around him with which he presents the trials of others.
ReplyDelete(...just wish more of his books were available in audio form, since reading is somewhat difficult for me)
A second glance reminded me of something I saw on tv a while ago. Infants have been found to be able to recognize the faces of individuals of different primate species, but we lose this ability by around 9 months. They tested this by showing photos of different lemurs to babies under and over 9 months old. The younger infants looked at each photo as if it was novel, indicating that they see differences in the lemurs' faces. The older babies stared at the first photo briefly, but quickly lost interest, showing their boredom with 'just another lemur'. I forget if this is mentioned in this book, but it does relate to the 'blindness' we develop for people outside our general experience, i.e. other races.
ReplyDeleteI've personally had an amount of difficulty with faces. I manage fairly well using other indicators; context, hair, gender, height, age, coloring, etc...though this has tripped me up many times. More than once I've failed to notice a friend or relative right in front of me when I didn't expect them, especially if I was working. (Or confused a total stranger with a passing resemblance to them.) A haircut or dye job will throw me for a while too. I've even been momentarily startled by my own reflection if I've drastically changed my hair or I'm wearing heavy makeup and don't expect a mirror. ...though I've never made Sacks' error of thinking someone on the other side of a window was me. I'm not *that* impaired.
Thanks, Peter. I missed that one.
ReplyDeleteI have face blindness but strangely enough, I never gotten lost in forests. I suppose it's because I've learned to do as Jane Goodall did and learned to recognize people by facial landmarks - glasses, scars, and hair colors and I do the exact same thing in the woods: I look for unique trees, variations in the undergrowth, moss-covered rocks. I don't really understand why Dr. Goodall wasn't able to do the same.
ReplyDeleteI've often been mystified by my wife's inability to "retrace her footsteps", even for just a short distance. For years I've just put it down to her not paying attention to her surroundings, but now I wonder if she might not have a mild form of this condition. She's not so great with faces either!
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