Can perceptual expertise account for the own-race bias in face recognition? A split-brain study.

Gazzaniga, M.S., Handy, T.C., & Turk, D.J. (2005). Can perceptual expertise account for the

Own-Race Bias in face recognition? A split-brain study. Cognitive Neuropsychology,

22(7), 877-883. doi: 10.1080/02643290442000383

The ability to recognize faces takes place in both hemispheres of the brain. The way faces from each race are encoded in the brain produce a cross race deficit or own race bias (ORB). But what happens to the facial recognition abilities in a split brain patient? Chapter 15 defines split brain as the surgical dissconnection of the two hemispheres in which the corpus callosum is cut. Because this connection has been severed the split brain patient is expected to better recognize faces that are of there own race than those of other races. Researchers think this is where perceptual expertise, the ability to process configural or coordinate representations, is vital. Since this has been linked to the lateralized processes of the right hemisphere researchers expect a split brain patient to perform well at this task.

JW a 51 year old split brain patient was used for the experiment. He was shown twelve pairs of photographs, on a computer, of male caucasian and japanese faces. After being shown a target area and face the photographs were presented alone and as a pair to see which one was more recognized and by what hemisphere of the brain. The results showed that the right hemisphere performs better than the left in facial recognition tasks, especially for faces that are similar to one’s own race. The right hemisphere seems to handle the short term processing and the left hemisphere handles the long term memory of faces. Since the corpus callosum is severed the faces of different races does not go to the left side to be encoded for later retrieval. Researchers concluded that the Own-Race bias for facial recognition is lateralized to the right hemisphere of the brain with the help of perceptual expertise.