Walsh & Hoyt: Other Disorders of Face Perception

The use of unfamiliar face-matching tests has generated some interesting data on hemispheric processing of stimuli. One of the interesting observations has been that deficits in unfamiliar face matching can occur in subjects without prosopagnosia. This too tends to be associated with right hemispheric lesions. Since some prosopagnosic patients can match unfamiliar faces, though with some effort and increased test time, this raises the possibility of a double dissociation. However, a later study of 34 patients found that most subjects were impaired with both familiar face recognition and unfamiliar face matching. Also, in the two patients with preserved accuracy scores on one test but not the other, the reaction times were prolonged on the test with the normal accuracy score. The authors concluded that the processes for familiar and unfamiliar face identity were not independent.