The Capgras delusion (or Capgras syndrome) is a disorder in which a person holds a delusion that a friend, spouse, parent, or other close family member has been replaced by an identical-looking impostor. The Capgras delusion is classified as a delusional misidentification syndrome, a class of delusional beliefs that involves the misidentification of people, places, or objects (usually not in conjunction). It can occur in acute, transient, or chronic forms. Cases in which patients hold the belief that time has been “warped” or “substituted” have also been reported.
It is generally agreed that the Capgras delusion has a more complex and organic basis, and can be better understood by examining neuroanatomical damage associated with the syndrome.
Some of the first clues to the possible causes of the Capgras delusion were suggested by the study of brain-injured patients who had developed prosopagnosia. In this condition, patients are unable to recognize faces consciously, despite being able to recognize other types of visual objects. However, a 1984 study by Bauer showed that even though conscious face recognition was impaired, patients with the condition showed autonomic arousal to familiar faces, suggesting that there are two pathways to face recognition—one conscious and one unconscious.
