REDUCED AUTONOMIC RESPONSES TO FACES IN CAPGRAS DELUSION

People experiencing the Capgras delusion claim that others, usually th ose quite close emotionally, have been replaced by near-identical impo stors. Ellis & Young suggested in 1990 that the Capgras delusion resul ts from damage to a neurological system involved in orienting response s to seen faces based on their personal significance. This hypothesis predicts that people suffering the Capgras delusion will be hyporespon sive to familiar faces. We tested this prediction in five people with Capgras delusion. Comparison data were obtained from five middle-aged members of the general public, and a psychiatric control group of five patients taking similar anti-psychotic medication. Capgras delusion p atients did not reveal autonomic discrimination between familiar and u nfamiliar faces, but orienting responses to auditory tones were normal in magnitude and rate of initial habituation, showing that the hypore sponsiveness is circumscribed.