Capgras Delusion

First described by Jean Marie Joseph Capgras and Jean Reboul-Lachaux in 1923, the Capgras delusion is one of several rare psychiatric disorders whose symptoms share a common theme—delusional misidentification. It is a universal condition that affects both sexes, and strikes at all ages from adolescence upward. A typical belief held by a Capgras patient is that at least one close family member or friend (some significant other) has been replaced by a physical duplicate—an impostor. This entry presents a brief overview of some of the key features and explanations of the Capgras delusion, including early psychoanalytic and more recent neurological and phenomenological accounts.

Within the Capgras patient, there occurs a conflict of recognition: a seeming paradox in which the significant other is and yet is not recognized by the patient. Physically, including all mannerisms and voice patterns, the impostor is said to be just like the real person yet is not recognized as being that person. The specificity of the delusion is a central feature of the condition and a key aspect to be explained. Early psychoanalytical accounts posited the patient's putative ambivalence toward the significant other as an underlying cause of the delusion. To cope with this ambivalence, the patient splits the significant other into real and impostor personas. The “real” person symbolizes the ideal—the way the patient should feel toward the other. The “impostor,” on the other hand, provides the patient with a target he or she can safely direct feelings of hostility toward. The delusion is therefore a way of resolving the love-hate conflict underlying the patient's relationship with the significant other.

In contrast, early theorists proffering a neurological basis for the delusional state noted the prevalence of brain disease or head trauma among the patient group. However, it was initially difficult to understand how organic disease or trauma could account for the high degree of selectivity evident in these delusions. To illustrate, consider Broca's aphasia, which affects the production of language and is caused by damage to a specific region of the left hemisphere (Broca's area). How strange it would be if difficulty in language production were directed solely at a select few, with speech occurring normally at all other times and toward all other people.

In 1990, Hayden Ellis and Andrew Young published their mirror-image model that, they claimed, was able to account for the selectivity of the Capgras delusion while positing a neurological rather than psychoanalytic basis for the condition. Ellis and Young argued that the neurological dysfunction underlying prosopagnosia (the inability to recognize faces) is mirror reversed in the Capgras delusion. Research has demonstrated that patients suffering from prosopagnosia, despite failing to consciously recognize familiar faces, nevertheless exhibit increased autonomic arousal when the face is presented. The increase in autonomic arousal is interpreted as unconscious recognition. In contrast, the neurological pathway responsible for conscious recognition, which is damaged in the prosopagnosia patient, is intact in the Capgras patient, and the pathway responsible for unconscious recognition is [Page 128]damaged. As such, when presented with a familiar face, despite consciously recognizing it, the patient exhibits no increase in autonomic arousal.

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