Prosopagnosia

The assignment: Find an article "popular psychology" magazine and explore how the article deals with the science underlying the topic.

Eliyahu N Kassorla

Behavioral Neuroscience

Forgetting Faces

I. The article Forgetting Faces is about a phenomenon called “prosopagnosia”. Prosopagnosia is a deficit, or series of deficits, related to the inability of identifying either faces or facial expressions. For people with prosopagnosia, the author notes, facial features hold no interest.

Prosopagnosia, the author contends, can be genetic and runs in families. He posits, based on his recent work, that a single gene may be implicated in congenital prosopagnosia. Further, in cases of traumatic brain injury, similar regions affected by the faulty gene may cause these deficits.

The author makes note of one hypothesis concerning prosopagnosia. Functional magnetic resonance imaging has revealed several key areas that are implicated in intact facial recognition. These areas are the fusiform face area in the temporal lobe, and the occipital facial area. Further, the superior temporal sulcus in the temporal lobe has shown activation in response to changes in “a person’s expression or viewing angle” (Grueter, 2007, 71). Once the areas of normal functioning are identified, inferences about the deficiencies can be made.

There are many tactics people with prosopagnosia use to deal with their deficit. “Some prosopagnostics attempt to avoid casual encounters in public places […]” (Grueter, 2007, 70). Others may “glean emotional and other cues from faces” (Grueter, 2007, 70). In children, prosopagnosia may manifest itself as a child who is excessively “clingy” to their parents, because they may not recognize their parents’ faces and are excessively concerned about losing their parents if detached (Grueter, 2007, p. 73). The author suggests that in critical periods, when children are trying to encode those other features, that appearances of those around the child should remain as stable as possible.

The author, a physician at the University of Muenster in Germany, has done a survey of prosopagnosia in his area using a convenience sample of secondary school children and medical students at his university. His results showed that, in his area, 2.5% of his subjects, or 17 out of 689, met his criteria for prosopagnosia. Further inquiry revealed that 14 of the 17 students had at least one other family member who also met his criteria for prosopagnosia. The author describes his clinical perspective by describing the importance of research into prosopagnosia because of its implications in children and adults, and finding ways to cope. Although there is no cure for prosopagnosia, the affected can use other methods of discerning identity. More research into prosopagnosia, the author concludes, can reveal more about normal functioning in facial recognition, as well as providing early intervention programs for children.

II. The textbook “Discovering Biological Psychology” has a brief description of what prosopagnosia is, partially confusing this disorder with the more extreme Capgras syndrome. The book defines prosopagnosia as a disorder where familiar faces are not recognized, retaining facial the ability to discriminate faces. Martha Farah, however, describes prosopagnosia as pertaining to all faces, despite “intact intellectual functioning,” and the article’s tone concurs with this definition (Farah, 1990, p. 68).

While the article does introduce data that can be considered empirical support, the author’s sample statistic felt artificial because of its nature as a convenience sample. Further studies would be needed to replicate his statistic before it can be taken as fact. The articles main attraction is the clinical application to ongoing research in neuropsychology and its implications to those afflicted by prosopagnosia. Further, the claim that a defect in a single genet can “cause” prosopagnosia is not referenced, and therefore unverified.

However, from what I’ve already read with regard to prosopagnosia, this article did not cover enough. The author oversimplifies prosopagnosia, losing a lot of its defining characteristics. Prosopagnosia is in fact a graded disorder, marked by either deficits in or the absence of facial recognition. Further, patients with prosopagnosia may in some cases retain discrimination of faces, the ability to discriminate samples from different angles or facial expressions. Research by Benton and Van Allen, cited in Farah, have shown that recognition and perception can be a double dissociation, that “’perception of both the whole and parts of a facial stimulus is intact… prospagnostic patients are generally able to perform complex perceptual tasks’” (Allen in Farah, 1990, p. 75). There exists a case where a birdwatcher, as noted by Farah, loses the ability to discriminate different birds (Farah, 1990, p. 73). I think that certain familiar stimuli can be encoded as a face, hijacking the FFA to encode what makes things different. All humans have two arms, two legs, and a torso; aside from semantic details about height and hair color, the part of a person that uniquely identifies (before biometrics) is their face. In an evolutionary context, if you needed to be able to discriminate between various stimuli, it would have been adaptive to encode it in an area that provides emotion before conscious recognition. I think the role of the FFA in cognitive categorization needs to be explored, and the FFA may possible be better names as the fusiform familiar area.

References

Farah, Martha J. (1990). Visual agnosia. Cambridge, MA: The MIT Press.

Grueter, Thomas. (2007). Forgetting faces. Scientific American Mind, Aug./Sep. 2007, 69-73.

Ramachandran, V. S. & Blakeslee, Sandra. (1998). Phantoms in the brain. New York: William Morrow and Company, Inc.