Mind Hacks: When faces fade

This post originated from www.MindHacks.com. Specific post link in title.

A March 2005 article in New Scientist reports on a study on a type of inherited prosopagnosia, suggesting a genetic basis for face recognition.

The research was an international effort, led by husband and wife team, geneticists Thomas and Martina Grüter. Notably, Thomas has a particular interest in this area, as he has prosopagnosia himself.

Mind Hacks spoke to two members of the research team about this intriguing study: Thomas on his own experience of prosopagnosia and the genetics of face recognition, and neuropsychologist Hadyn Ellis on the implications for the developing field of 'cognitive genetics'. Follow the title links for the entire interviews.

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Thomas and Martina are part of a team of geneticists from the Institute of Human Genetics in Münster, Germany. They became interested in how Thomas' condition seemed to run in families and decided to study it in more detail. They recruited neuropsychologists from Cardiff University, initiating an international effort to examine the genetic basis of face perception.

The main finding of the study was that prosopagnosia seemed to be inherited in an autosomal dominant fashion, meaning only a single gene from one parent is needed to cause the condition.

Could it really be the case that the development of face recognition relies on a single gene ? We tackled Thomas on this controversial interpretation, but first we wanted to know, what it is like having prosopagnosia? * * *

How did you first realise you were unable to recognise faces as well as other people?

When I didn't recognize my teachers in the street. Some didn't care, but others were not amused. Most of the time, I wasn't even aware that I had overlooked them, if so, they didn't say a word.

What is it like having prosopagnosia ? For example, do faces seem strange or distorted to you?

Faces look perfectly normal, they just fade in my memory very quickly. I can recognize emotions as well as other people, maybe better.

To most people, not being able to recognise faces would seem a great disability. Why do you think most people with hereditary prosopagnosia are not significantly impaired by their condition ?

They have had all of their life to cope with the problem. They have learned to recognize people by other features like gait [walking style] or voice. And, of course, like colorblind people, they cannot imagine how it feels to remember faces normally.

Face blindness is a common hereditary disorder

This article on recent research into the hereditary type of prosopagnosia (HPA), which came out last summer. There are some statements I noted in bold type.

Face blindness is a common hereditary disorder: "Face blindness is a common hereditary disorder

"In the first study to examine whether the inability to recognize faces can be inherited, researchers found that it is in fact a common disorder that runs in families and is one of the most frequent disorders apparently controlled by a defect in a single gene. The study was published online June 30, 2006 in American Journal of Medical Genetics Part A, and is available via Wiley InterScience.

Prosopagnosia (PA) or face blindness is characterized by the inability to differentiate faces, except for the most familiar ones such as members of one's family. It can be caused by brain injury, but cases where the disorder appears to run in families have also been reported. In the first systematic study of hereditary prosopagnosia (HPA), researchers led by Ingo Kennerknecht, M.D. of the Institute of Human Genetics at the University of Muenster in Germany, recruited 689 subjects from local secondary schools and a medical school and administered a questionnaire to identify those with suspected HPA. They found 17 cases of the disorder, and of the 14 subjects who consented to further interfamilial testing, all of them had at least one first degree relative who also had it."

"Nearly all affected persons report a problem in deciding immediately whether a face is known," the authors state. Subjects report uncertainty in social situations and the inability to visualize the faces of close relatives or recall mental images of trees, leaves, or birds. They generally have difficulty following TV programs or movies because they cannot tell similar actors apart. All of the PA subjects revealed that they used up to three different strategies for overcoming the disorder. In the compensation strategy, subjects attempt to recognize people by other characteristics such as voice, gait, clothing or hair color. In the explanation strategy, subjects have a ready set of excuses as to why they can't recognize someone, such as being deep in thought or needing new glasses. In the avoidance strategy, subjects try to avoid situations where they might be unable to recognize faces, such as large functions or crowded places.

Inability to recall images of trees, leaves, or birds? Hmmm, I've never heard that before. I would say I'm not affected in this way, but then its not something I have ever focused on. I've heard many prosopagnosics (PA's) have trouble recognizing cars, but I've tested on this and seem to do ok.

The summary hits the nail on the head regarding the 3 coping strategies. One of the reasons I finally decided to "come out" about PA (albeit slowly) was that I noticed I was lying ALL the time, trying to cover up for my lapses, and make sure people did not feel that I took them lightly. My most frequent excuse was probably "I didn't recognize you because I was in my own little world.", implying I was daydreaming, and, of course, I never do that.