Here’s a buzz — and strange conclusions based on neuroimaging data.
A forthcoming article in Psychological Science by Lasana Harris and Susan Fiske is studying how people react when they are shown images of people from social out-groups. What they find is that people react with disgust (rather than the socially correct fellow humanity). Subjects were shown images of people from different social groups, and other non-human and hoh-animal objects (from the Stereotype Content Model). The perception of a picture’s “warmth” was judged by friendliness, competence by capability. The two emotional extremes were pride and disgust; pride elicited high warmth and high perception of competence, and disgust elicited low warmth and low perception of competence.
The article is not available yet. However, from EurekAlert we can read that:
Medial prefrontal cortex (MPFC) brain imaging determined if the students accurately chose the correct emotion illustrated by the picture (according to pretest results in which a different group of students determined the emotion that best fit each photograph). The MPFC is only activated when a person thinks about him- or her-self or another human. When viewing a picture representing disgust, however, no significant MPFC brain activity was recorded,
Well, that’s interesting. If you see a picture of a person whom you have rated as less favourable (i.e. “disgusting” (huh?)), the activity of your medial prefrontal cortex is less activated. According to EurekAlert, these results indicate that the subjects:
(…) did not perceive members of social out-groups as human. The area was only activated when viewing photographs that elicited pride, envy, and pity. (However, other brain regions — the amygdala and insula — were activated when viewing photographs of “disgusting” people and nonhuman objects.)
Furthermore, citing the researchers themselves, it is claimed that “members of some social groups seem to be dehumanized.”
I have not read the article yet, but I can’t see how the results warrant this kind of conclusion. To put the argument very simple:
- area X is activated when we look at people (of our own kin)
- area X is not activated when we look at non-kin people
- ergo: we don’t look at non-kin people as being human
That’s just plain bad logics to me. Did these guys ever look at other areas that are known to involve face perception? An obvious example would the fusiform gyrus, so often found to activate when we see HUMAN faces? I guess that this area would be showing activation to non-kin faces, too. That’s just a guess. I need to read the article. But there is a hint that “other brain regions — the amygdala and insula — were activated when viewing photographs of “disgusting” people and nonhuman objects”. So if we find fusiform activation, that indicates that at least part of these people’s brain (be it conscious or unconscious perception) show that they perceive these faces as human.
So the lacking medial PfC activation should probably be viewed in a different light. Maybe it rather reflects how people judge other people as in-group or out-group (or, kin vs. non-kin)? To me, that sounds much more favourable. If your medial PfC activates, you have identified a kin member. If not, and it is still a face you’re looking at, you perceive it as a human non-kin.
I guess I’ll have to wait until the article comes out. Just as everybody else. Buzz-buzz-buzz.
-Thomas
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