Abstract
This research examines the effects of prosopagnosia on the processing of featural and configural information in faces. Featural and configural information was manipulated in a face matching task by incrementally varying the size and distance of the eyes and mouth features respectively. In a control study with visually normal adults, the featural and configural conditions for the eye and mouth regions were equated for their overall perceptual discriminability. Using the same task, we assessed featural and configural processing in two cases of acquired prosopagnosia: LR and HH. Compared to age-matched controls, both prosopagnosic patients performed normally in their ability to discern differences in the size and spacing of the mouth feature. In contrast, the two patients were selectively impaired in their ability to detect featural and configural differences in the eye region. The same pattern of results was found whether the stimulus faces were presented sequentially or simultaneously. The findings indicate that brain-damage does not necessarily result in a global impairment of face processing ability. Although LR and HH showed an impaired ability to detect differences in the eye region, they were spared in their ability to discriminate differences in the mouth region. Interestingly, the face processing deficits identified in the patients did not correspond to impairment in sensitivity to featural or configural information.
Supported by the James S. McDonnell Foundation, and the Natural Science and Engineering Research Council of Canada