Capgras syndromebecomes an example of underpersonalizedmisidentiﬁcation, and Fre´golisyndrome represents overpersonalizedmisidentiﬁcation
Benton Test: Subjects presented with a target face on top of six test faces, they have to match the target face with the same face, which is mixed in the test faces. http://visionlab.harvard.edu/members/ken/Ken%20papers%20for%20web%20page/130NeurologyDuchaine04.pdf
Delusional Misidentification Syndromes Inability to register the identity of something: an object, event, place or person. Due to malfunctioned familiarity processing during information processing
Capgras delusionDelusional belief that a friend, family member,etc. has been replaced by a twin impostorMost commonWhile they may look and act just like the realperson, some essence of the person is missing,almost as though "the soul of the person isntin there,“ ( Being John Malkovich)
Capgras delusionVisual route (visual cortex) and affective route (limbic system) face recognitionMaladaptive function of the hypersensitive amygdala:creates a feeling too strongly suspicious to be rejected
Case of Sylvie G.•Believed that her husband was transformed before her eyes into different people•Continually felt as though people she knew were replaced by other people•Sylvie looked at the shoes and feet of those she suspected were fakes, and woulduse that as an indicator.•She also thought her hens were replaced by older ones; she even struggled withbelieving her coat was the same one she’d always had. Courbon and Tusques (French neuropsychiatrists)
Prosopagnosia•Inability to recognize familiar faces•Cannot match the face to the person it belongs to•Individuals know the face, but elicits no emotionalresponse.•Dysfunction in the fusiform gyrus of the brain, thepart where color and facial recognition is centered
Reduplicative Paramnesia An individual believes a place or location has been duplicated, existing in two or more places simultaneously
Reduplicative Paramnesia• RS, a 71 year old man, no previous brain damage or history of schizophrenia• Insisted his home was not his "real" house, yet recognized his family• Noticed similarities, but still believed the house was fake• Remarked on how striking it was that the owners of this house had the sameornaments as he had in "his" house and on what a coincidence it was that there weresimilar items beside the bed as there were in "his" house.• At interviews, RS continued to insist that there were two "Riverside Avenues“• A few days later he believed he returned to his ‘real home’
IntermetamorphosisWhen a patient confuses the identities of familiar people or feels that they are being mistaken for someone else.Courbon and Tusques coined the term to describe the illusion where things/people suddenly change into something or someone else.
Fregoli delusion• A delusional belief that different people are in fact a singleperson (well known to the victim) who changes appearance oris in disguise• Interior of the person is different• Form of persecution (Courbon and Fail)
History The condition is named after the Italian actor Leopoldo Fregoli who was renowned for his ability to make quickchanges of appearance during his stage act. Famous for his impersonations.
Fregoli Case• 35 year old woman, divorced, unemployed•Diagnosed with chronic paranoid schizophrenia, stopped medication•Suffered grandiose delusions of actors who she thought were herfriends•Believed she was the girlfriend of a famous actor Erik Estrada whowas always visiting her home, disguised as other people•Scored borderline impaired on the Benton Test
Mirrored-self misidentification Belief that ones reflection in a mirror is some other person who is following them around
Patient FE• 87 year old male, married with 2 children, no history of schizophrenia• Began having nocturnal hallucinations• He started not being able to recognize himself in the mirror• He thought the mirror image was a stranger• Had knowledge about mirrors and understood what reflections were.• Later on, he was unable to recognize his wife’s reflection, said: “I have met the stranger’s wife, seen her. I don’t think she talks, either”
Syndrome of subjective doubles • Delusion that person has a double or doppelgänger •Same appearance, but usually with different character traits and leading a life of its own. •Sometimes the patient has the idea that there is more than one double
Reverse subjective doubles•When one believes an impostor is taking over their body•Misidentification of the self•In the process of being replaced
Cotard delusiona disorder where the individual believes• They are dead(either figuratively or literally)• Do not exist• Are putrefying• Have lost their blood or internal organs• Delusions of immortality• Feelings of unreality
Cotard Delusion• Named after Jules Cotard, a French neurologist who firstdescribed the condition• Mostly occurs from brain damage to the right cerebralhemisphere, which deals with the expression ofvisual, facial, and verbal emotion as well as body-image.• Usually accompanied by other delusions
RB Case• 61 year old man with a schizophrenic wife• Became depressed and overdosed, following surgery• Believed he had been dead for a week• Said he wasn’t on earth but was somewhere between heaven and hell• “Anxious agitation”• He was deeply distressed, unable to lie or sit for a long time• Electro-convulsive therapy was used, and his beliefs ceased
Somatoparaphrenia• When an individual denies ownership of a limb, or part oftheir body• Sometimes believes that the limb belongs to someone else• Related to body integrity identity disorder (BIID)• May cause the person to desire amputation
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