Electrodermal Discrimination of Familiar and Unfamiliar Faces: A Methodology

A study is reported which establishes a methodology for investigating the hypothesis that prosopagnosic patients, who have lost the ability to recognize faces, may nonetheless demonstrate electrodermal discrimination of familiar versus unfamiliar facial stimuli. Skin conductance response (SCR) data were recorded while neurologically-intact, college-aged subjects viewed slides of 8 famous, highly familiar faces and 42 unfamiliar faces. The results showed that the familiar faces elicited, on the average, much larger SCRs than the unfamiliar faces. In addition, a second group of subjects rated the familiar faces as more “significant” than the unfamiliar ones, and it is concluded that highly familiar faces are potential signal stimuli. Also, because the paradigm involves few instructions and no overt behavioral response by the subject, this methodology could be readily adapted to investigations of prosopagnosic and other brain-damaged populations in which there is severe amnesia, aphasia, or apraxia.