You may not be able to see fear, but you can still be afraid

Take a look at these two faces.

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One of these women can't recognize that the other is afraid, but when asked to express fear, is still able to produce a fearful expression. Can you tell which is which?

We know the amygdala is associated with identifying scary music; we know the amygdala helps us generate a fear response, but what about producing a fear response?

S.P. are the initials of a 54-year-old woman who had surgery to remove her right amygdala to alleviate the symptoms of epilepsy. During the surgery, it was found that her left amygdala was damaged as well, and so she effectively lost the function of the entire amygdala. The amygdala is primarily associated with processing the emotion of fear, so it was to be expected that S.P. would not be able to recognize fearful facial expressions. What had not been previously studied, however, is whether she would be able to produce the same expressions.

Adam Anderson and Elizabeth Phelps showed S.P. faces corresponding to each of six different emotions: happy, surprised, afraid, angry, disgusted, and sad. She rated each face on a scale of 1 to 6 for how well the face expressed each of the six emotions. A group of 20 normal volunteers also rated the same faces. Here's how the responses broke down for the all-important fear rating:

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S.P.'s ratings weren't significantly different from normal individuales except in one case: when the face depicted fear. Then her ratings were significantly lower than the others. One month later, the experimenters asked S.P. to perform another task: they had her think of a situation which inspired each of the six emotions. Then she was asked to show what the facial expression for that emotion would look like. (The normal volunteers did this task immediately after performing the emotion identification task.) Finally, a set of three judges rated photos of all the participants for how well they expressed the intended emotion. Here are the results:

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For each of the intended emotions, S.P. was able to express them at least as well as the normal volunteers, and for the key emotion of fear, S.P. was in the 85th percentile.

Anderson and Phelps conclude that while the amygdala may be responsible for the perception of fear, the production of fearful facial expressions must be produced elsewhere in the brain. Further tests showed that S.P. was capable of understanding the situations which may produce fear -- her primary impairment was simply the recognition of fearful facial expressions.

So, can you guess which of the faces depicted above was S.P.'s? Let us know in the comments.

Anderson, A.K., & Phelps, E.A. (2000). Expression without recognition: Contributions of the human amygdala to emotional communication. Psychological Science, 11(2), 106-110.

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I am guessing the left because it is the more genuine expression of fear and we know that S.P. did well on expressing fear.

By Mark Frank (not verified) on 18 Apr 2006 #permalink

When I read only the part of this post "above the fold," I guessed that the face on the right was that of the person who was unable to recognize fear in others (assuming that the person unable to recognize fear would be less able to make a fearful face).

Having read the entire article, and knowing that S.P. was judged better than average at making a fearful face, I'm guessing that the left face is S.P.'s.

Or, to be less wordy, I think the face on the left expresses fear better than the one on the right.

(I have written this comment before looking at any other comments on this post.)

I didn't know they could cut fear out of the brain. That sounds pretty handy.

I'm guessing the right for purely disingenious reasons - the face on the left I've previously seen in cognitive textbooks, so I'm guessing it's a stock photo of some sort.. it was even in Ramachandran's "Phantom's" book.

Boronx: not handy at all; you often get something akin to Klüver-Bucy syndrome, which includes increased oral behavior (a tendency to examine things with your mouth, like an infant), overeating, increased sexuality with "inappropriate" objects of focus.

And fear is a pretty handy thing, really. Ãhman (I think it was; don't quote me on it) has described how chimpanzees with bilateral lesions can pick up a live snake (normally a feared animal) and taste it to examine it. You really don't want to be fearless.

What an interesting question! I decided on my response before reading the other comments. I assumed S.P. to be on the left, because for me that fear expression seemed "less expressive", or "less real", more like that produced by a poor actor. Reading the commentaries, this is interestingly the opposite of Qoheleth's perception. That textbook recollection, however, probably clinches it. We'll see ;-).

Fascinating. Yes, S.P. is on the right. I agree that the face on the left looks familiar from textbooks -- too bad we couldn't find a better counter-example. You have to agree, though, both faces are pretty good examples of fear.

Hmmm....SP cannot imitate fear, since she can't recognise it in others...so presumably her "fear face" is genuine...she was asked not to simply "act scared" but to think of a scary situation and show how she feels.
If the other picture is a stock photo, it might well be of somone just "acting scared" i.e. imitating a scared person.
So...the real SP is the most genuine looking picture...which, for me, is the one on the left (although I've done these "what's the emotion tests?" before and scored lowly!)

By Shane Horan (not verified) on 19 Apr 2006 #permalink

The face on the left is from Ekman and Friesen's Pictures of Facial Affect. That face is one of several that are often reprinted in textbooks.

By Michael Anes (not verified) on 23 Apr 2006 #permalink