Sunday, September 05, 2010

The Capgras Delusion

Oliver Sachs wrote a thought provoking article in the New Yorker about prosopagnosia - the inability to recognize faces, a problem with which he has personally suffered his whole life. Up to 2% of people it is speculated may be afflicted this to some degree. Acute cases don't even recognize the faces of their loved ones; or the face of someone they were with 5 minutes ago.

I got interested in neurological oddities when I met a synesthetic in the course of my flavor work. He experienced flavor in terms of color. When he tasted something he would say, "This is purple" or "blue green". He had to learn to correlate his color perceptions of flavor with the "normal" person's taste perception. I was fascinated having always felt that we live in our own separate sensory worlds. Do you experience the same sensations as me when we listen to music or taste a peppermint? 

Now that my own brain is handicapped in several ways, I'm more conscious (pardon the pun) of it's function - it's success and failure. I have to jolt it frequently when it goes on strike, abandoning me in the middle of a sentence, leaving me alone, mouth open with no word to say.  

But imagine how you would cope if you couldn't recognize faces? Oliver Sacks says he will recognize a caricature more readily than a face because a facial feature may be exaggerated - "large nose", "big teeth", "curly hair" and he associates that feature with a voice. This problems extends to some degree to "mapping" locations and he is frequently lost because of the same inability to recognize the "face" of a certain location.

And while I'm being thankful I don't have prosopagnosia and only minor neurological misfirings, how about the bizarre Capgras Delusion? It's described in wikipedia as:
"the reverse of prosopagnosia. In this condition people report conscious recognition of people from faces, but show no emotional response, perhaps leading to the delusional belief that their relative or spouse has been replaced by an impostor."
A 2006  National Book Award winner for fiction, titled The Echo Maker, by Richard Power uses the Capgras Delusion as a central theme. I've added it to my reading list. 



  1. I have always been interested in synesthesia. Both Eric Clapton and Jerry Garcia have discussed experiencing the phenomenon while they were playing, creating paintings with musical notes. The Capgras and initial dysfunction you describe would be awful, but perhaps not as awful as to the condition said to afflict meth users, the inability to ever feel joy. The meth burns out the circuitry and they can never manufacture natural dopamine - now that would be real torture. Did you know that there is another man in Fallbrook who ran the food tasting division for Hunt Wesson? - he visited me some months ago - said that he would only hire women because they had more taste buds per square inch on their tongue.

  2. Sorry I missed the meeting last week - I've been reading and immensely enjoying your blog for about a year. I had no idea meth was so devestating. I do not know about the Hunt Wesson person living in Fallbrook - I suspect I might know him as we all belonged to an thrilling association known as IFT, Institute of Food Technologists.

    More women than men are "supertasters" - those with more buds. Because they are not typical of most consumers we tended to be very careful using them for normal taste tests. They can be trained and be very useful for discerning faults at lower levels than regular tasters might perceive - in particular bitterness. Because flavor is taste combined with aroma, aroma being the most informative sense, supertasters are not better at judging overall flavor. Non-tasters, at the other end of the scale (fewer buds) are just as good at overall flavor.

    I'll drop in next time I'm in town and your light is on.