Capgras syndrome: a novel probe for understanding the neural representation of the identity and familiarity of persons

Abstract

SUMMARYPatients with Capgras syndrome regard people whom they know well such as their parents or siblings as imposters. Here we describe a case (DS) of this syndrome who presents several novel features. DS was unusual in that his delusion was modality-specific : he claimed that his parents were imposters when he was looking at them but not when speaking to them on the telephone. Unlike normals, DS's skin conductance responses to photographs of familiar people, including his parents, were not larger in magnitude than his responses to photographs of unfamiliar people. We suggest that in this patient connections from face-processing areas in the temporal lobe to the limbic system have been damaged, a loss which may explain why he calls his parents imposters. In addition, DS was very poor at judging gaze direction. Finally, when presented with a sequence of photographs of the same model's face looking in different directions, DS asserted that they were ' different women who looked just like each other '. In the absence of limbic activation, DS creates separate memory ' files ' of the same person, apparently because he is unable to extract and link the common denominator of successive episodic memories. Thus, far from being a medical curiosity, Capgras syndrome may help us to explore the formation of new memories caught in flagrante delicto.

Brain activation during eye gaze discrimination in stable schizophrenia

“…For persons with schizophrenia and poor eye contact, this communicatory effect of gaze may differ from the effect in healthy persons and may contribute to misinterpretation of the target emotion or even non-emotional faces, relating to paranoia and ideas of reference. This concept is partly supported by findings in a person with Capgras syndrome, characterized by misidentification of familiar persons as imposters, where failure to identify gaze was associated with failed recognition of the face (Hirstein and Ramachandran 1997). While our study did not examine the possible relationship between gaze discrimination and clinical symptoms, direct eye contact may relate to positive symptoms of schizophrenia, such as ideas of reference and paranoia.…”

Psychiatric Disorders of Face Recognition

“…In the case of patients with Capgras delusion, the Ellis and Young hypothesis was confirmed with the observation of a deficit in emotional reactivity while the conscious awareness of recognition is preserved (Hirstein & Ramachandran, 1997). The patient physically recognizes his relative's face but doesn't have the affective confirmation of this recognition.…”

Az arcfelismerési zavarok osztályozása a kialakulás oka, az idegtudományi, valamint a viselkedéses eredmények tükrében

“…A tudatos felismerésből (ez a személy az anyám) és a normális esetben ilyenkor kiváltódó érzelmek hiányából (és szeretnem kellene) adódó összeférhetetlenségnek köszönhetően, bizonyos esetekben kialakulhat a Capgrastéveszme (a 3. ábrán a 3-assal jelölt sérüléshez köthető zavar) (ELLIS és LEWIS, 2001). Capgras-téveszme esetén a kapcsolat jellegétől függően (ismerős arc vs. ismeretlen) a GBR-ben nem mérhető semmilyen különbség (HIRSTEIN és RAMACHANDRAN, 1997). Az esetek áttekintésével kirajzolódik egy újabb deficit, a multimodális személyfelismerési zavar.…”