Autonomic recognition of names and faces in prosopagnosia: a neuropsychological application of the Guilty Knowledge Test.

A prosopagnosic was shown two sets of faces, one comprised of famous personalities, the other of family members. After he was allowed to visually inspect each face, he was given five names, one of which was correct. Skin conductance was continuously recorded. He could not identify any of the faces spontaneously, and performed at chance level when given multiple choice names. However, electrodermal responses indicated far more accurate discrimination between correct and incorrect names, suggesting that the patient "recognized" facial identity at the psychophysiological level. Neuropsychological mechanisms for this phenomenon, which in this case involve multiple visual-limbic interrelationships, are postulated. The method appears useful for studying islands of spared recognition ability in associative agnosia.