Reduced autonomic responses to faces in Capgras delusion

Abstract

SUMMARYPeople experiencing the Capgras delusion claim that others, usually those quite close emotionally, have been replaced by near-identical impostors. Ellis & Young suggested in 1990 that the Capgras delusion results from damage to a neurological system involved in orienting responses to seen faces based on their personal significance. This hypothesis predicts that people suffering the Capgras delusion will be hyporesponsive 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 patients did not reveal autonomic discrimination between familiar and unfamiliar faces, but orienting responses to auditory tones were normal in magnitude and rate of initial habituation, showing that the hyporesponsiveness is circumscribed.

Lost in dissociation: The main paradigms in unconscious cognition

“…Nevertheless, today evidence abounds, including on double dissociations, that these individuals produce significant SCRs when presented photos of the faces of people who are close to them (e.g., Damásio et al, 1990;Tranel et al, 1995). One of these double dissociations is particularly interesting in that it suggests a "mirror image" condition of prosopagnosia: in the Capgras delusion, it is precisely the autonomic, covert recognition of people that is impaired (SCRs are absent), leaving the patients with the distressing experience of consciously recognizing persons close to them and yet claiming that they are impostors (e.g., Ellis & Young, 1990;Ellis et al, 1997). It is possible that these two conditions reflect a double dissociation that can be mapped into a limbic dual visual system, a hypothesis first conceived by Bauer (1984): in the one case, prosopagnosia, only the neuroanatomical pathway of covert processing of emotional content, to wit, the "dorsal visual-limbic pathway" (DVLP), is unimpaired, with deficit occurring in the "ventral visual-limbic pathway" (VVLP); in the mirror case, the Capgras delusion, the unconscious, covert emotional processing is believed to be greatly or entirely compromised due to damage to the DVLP, whereas the overt recognition in the VVLP is preserved (see Ellis & Lewis, 2001, for neuroanatomical details).…”

Upon Type, Frequency and Some Clinical Aspects of Psychotic Symptoms in Alzheimer’s Disease

“…Unlike hallucinations, misidentifications are misperceptions of external stimuli and can be defined as misperceptions with an associated belief that is held with delusional intensity. Ellis et al (1997) proposed that Capgras patients interpret the loss of affective response for familiar people in a paranoid suspicious way (11). In some instances anger or violence can be provoked towards perceived impostor.…”

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

“…Bizonyos prosopagnosiás személyek is mutatják a rejtett felismerés jeleit, azaz például nem tudják, hogy kit látnak, de vegetatív válaszaik szelektívek ismerős/ismeretlen arcokra, ami a tudatos és a nem tudatos arcfelismerés disszociációjára utal (J. PAUW, 1997). 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).…”