Capgras delusion
Encyclopedia
The Capgras delusion theory (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that a friend, spouse, parent, or other close family member has been replaced by an identical-looking impostor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. It can occur in acute, transient, or chronic
forms.
The delusion is most common in patients diagnosed with schizophrenia
, although it can occur in connection with a number of conditions, including brain injury
and dementia
. It occurs more frequently in females, with a female:male ratio of 3:2. Although the Capgras delusion is commonly called a syndrome
, because it can occur as part of, or alongside, various other disorders and conditions, some researchers have argued that it should be considered a symptom, rather than a syndrome or classification in its own right.
(1873–1950), a French
psychiatrist
who first described the disorder in 1923 in his paper co-authored by Reboul-Lachaux, on the case of a French woman who complained that corresponding "doubles" had taken the places of her husband and other people she knew.
Their term l'illusion des « sosies »...—which can be literally translated as "the illusion of 'doubles'..."—finds some modern professional use in French (e.g. "L’illusion des sosies de Capgras est...", which however its authors render in English as "Capgras’ syndrome is ..."). But the distinction between illusion
and delusion
is important in modern technical English, and the Capgras syndrome is clearly a delusional condition.
of epilepsy; magnetic resonance imaging revealed bilateral subcortical lesions in occipitotemporal and frontal regions. These findings have implications for the postulated association between Capgras' syndrome and neuropsychological deficits, in particular 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 (measured by a galvanic skin response
measure) to familiar faces, suggesting that there are two pathways to face recognition—one conscious and one unconscious.
In a 1990 paper published in the British Journal of Psychiatry
, psychologists Hadyn Ellis and Andy Young hypothesized that patients with Capgras delusion may have a "mirror image" of prosopagnosia, in that their conscious ability to recognize faces was intact, but they might have damage to the system that produces the automatic emotional arousal to familiar faces. This might lead to the experience of recognizing someone while feeling something was not "quite right" about them.
In 1997, Hadyn Ellis and his colleagues published a study of five patients with Capgras delusion (all diagnosed with schizophrenia) and confirmed that although they could consciously recognize the faces, they did not show the normal automatic emotional arousal response.
In 1997, William Hirstein
and Vilayanur S. Ramachandran
reported similar findings in a paper published on a single case of a patient with Capgras delusion after brain injury. Ramachandran also portrays this case in his book Phantoms in the Brain. Ramachandran also gave a talk about it at TED
2007 video can be found here Since the patient was capable of feeling emotions and recognizing faces but could not feel emotions when recognizing familiar faces, Ramachandran hypothesizes that the origin of Capgras syndrome is a disconnection between the temporal cortex
, where faces are usually recognized (see temporal lobe
), and the limbic system
, involved in emotion
s. Because the patient could not put together memories and feelings, he believed objects in a photograph were new on every viewing, even though they normally should have evoked feelings (e.g., a person close to him, a familiar object, or even himself). Ramachandran therefore believed there was a relationship between Capgras syndrome and a more general difficulty in linking successive episodic memories, since it is believed that emotion is critical for creating memories.
Most likely, more than an impairment of the automatic emotional arousal response is necessary to form Capgras delusion, as the same pattern has been reported in patients showing no signs of delusions. Ellis and colleagues suggested that a second factor explains why this unusual experience is transformed into a delusional belief; this second factor is thought to be an impairment in reasoning, although no definitive impairment has been found to explain all cases.
Delusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
that a friend, spouse, parent, or other close family member has been replaced by an identical-looking impostor
Impostor
An impostor or imposter is a person who pretends to be somebody else, often to try to gain financial or social advantages through social engineering, but just as often for purposes of espionage or law enforcement....
. The Capgras delusion is classified as a delusional misidentification syndrome
Delusional misidentification syndrome
Delusional misidentification syndrome is an umbrella term, introduced by Christodoulou for a group of delusional disorders that occur in the context of mental or neurological illness. They all involve a belief that the identity of a person, object or place has somehow changed or has been altered...
, a class of delusional beliefs that involves the misidentification of people, places, or objects. It can occur in acute, transient, or chronic
Chronic (medicine)
A chronic disease is a disease or other human health condition that is persistent or long-lasting in nature. The term chronic is usually applied when the course of the disease lasts for more than three months. Common chronic diseases include asthma, cancer, diabetes and HIV/AIDS.In medicine, the...
forms.
The delusion is most common in patients diagnosed with schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
, although it can occur in connection with a number of conditions, including brain injury
Acquired brain injury
An acquired brain injury is brain damage caused by events after birth, rather than as part of a genetic or congenital disorder such as fetal alcohol syndrome, perinatal illness or perinatal hypoxia. ABI can result in cognitive, physical, emotional, or behavioural impairments that lead to permanent...
and dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
. It occurs more frequently in females, with a female:male ratio of 3:2. Although the Capgras delusion is commonly called a syndrome
Syndrome
In medicine and psychology, a syndrome is the association of several clinically recognizable features, signs , symptoms , phenomena or characteristics that often occur together, so that the presence of one or more features alerts the physician to the possible presence of the others...
, because it can occur as part of, or alongside, various other disorders and conditions, some researchers have argued that it should be considered a symptom, rather than a syndrome or classification in its own right.
History
The Capgras delusion is named after Joseph CapgrasJoseph Capgras
Jean Marie Joseph Capgras was a French psychiatrist who is best known for the Capgras delusion, a disorder named after him....
(1873–1950), a French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
psychiatrist
Psychiatry
Psychiatry is the medical specialty devoted to the study and treatment of mental disorders. These mental disorders include various affective, behavioural, cognitive and perceptual abnormalities...
who first described the disorder in 1923 in his paper co-authored by Reboul-Lachaux, on the case of a French woman who complained that corresponding "doubles" had taken the places of her husband and other people she knew.
Their term l'illusion des « sosies »...—which can be literally translated as "the illusion of 'doubles'..."—finds some modern professional use in French (e.g. "L’illusion des sosies de Capgras est...", which however its authors render in English as "Capgras’ syndrome is ..."). But the distinction between illusion
Illusion
An illusion is a distortion of the senses, revealing how the brain normally organizes and interprets sensory stimulation. While illusions distort reality, they are generally shared by most people....
and delusion
Delusion
A delusion is a false belief held with absolute conviction despite superior evidence. Unlike hallucinations, delusions are always pathological...
is important in modern technical English, and the Capgras syndrome is clearly a delusional condition.
Brain Imaging
A patient that has developed Capgras' syndrome would be a part of an interictal psychosisPsychosis
Psychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...
of epilepsy; magnetic resonance imaging revealed bilateral subcortical lesions in occipitotemporal and frontal regions. These findings have implications for the postulated association between Capgras' syndrome and neuropsychological deficits, in particular prosopagnosia.
Presentation
This case is taken from a 1991 report by Passer and Warnock:Causes
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 prosopagnosiaProsopagnosia
Prosopagnosia is a disorder of face perception where the ability to recognize faces is impaired, while the ability to recognize other objects may be relatively intact...
. In this condition, patients are unable to recognize faces consciously
Face perception
Face perception is the process by which the brain and mind understand and interpret the face, particularly the human face.The human face's proportions and expressions are important to identify origin, emotional tendencies, health qualities, and some social information. From birth, faces are...
, 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
Autonomic nervous system
The autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
arousal (measured by a galvanic skin response
Galvanic skin response
Skin conductance, also known as galvanic skin response , electrodermal response , psychogalvanic reflex , skin conductance response or skin conductance level , is a method of measuring the electrical conductance of the skin, which varies with its moisture level...
measure) to familiar faces, suggesting that there are two pathways to face recognition—one conscious and one unconscious.
In a 1990 paper published in the British Journal of Psychiatry
British Journal of Psychiatry
The British Journal of Psychiatry is a peer-reviewed medical journal published monthly by the Royal College of Psychiatrists containing original research, systematic reviews, commentaries on contentious articles, short reports, a comprehensive book review section, and a correspondence column...
, psychologists Hadyn Ellis and Andy Young hypothesized that patients with Capgras delusion may have a "mirror image" of prosopagnosia, in that their conscious ability to recognize faces was intact, but they might have damage to the system that produces the automatic emotional arousal to familiar faces. This might lead to the experience of recognizing someone while feeling something was not "quite right" about them.
In 1997, Hadyn Ellis and his colleagues published a study of five patients with Capgras delusion (all diagnosed with schizophrenia) and confirmed that although they could consciously recognize the faces, they did not show the normal automatic emotional arousal response.
In 1997, William Hirstein
William Hirstein
William Hirstein is an American philosopher primarily interested in philosophy of mind, philosophy of language, metaphysics, cognitive science, and analytic philosophy. He is a professor of philosophy, director of the Cognitive Science Lab, and the current chair of the Philosophy Department at...
and Vilayanur S. Ramachandran
Vilayanur S. Ramachandran
Vilayanur Subramanian "Rama" Ramachandran, born 1951, is a neuroscientist known for his work in the fields of behavioral neurology and visual psychophysics...
reported similar findings in a paper published on a single case of a patient with Capgras delusion after brain injury. Ramachandran also portrays this case in his book Phantoms in the Brain. Ramachandran also gave a talk about it at TED
TED
TED may refer to:* TED , an annual multidisciplinary conference* TED spread, the yield spread between U.S...
2007 video can be found here Since the patient was capable of feeling emotions and recognizing faces but could not feel emotions when recognizing familiar faces, Ramachandran hypothesizes that the origin of Capgras syndrome is a disconnection between the temporal cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
, where faces are usually recognized (see temporal lobe
Temporal lobe
The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both cerebral hemispheres of the mammalian brain....
), and the limbic system
Limbic system
The limbic system is a set of brain structures including the hippocampus, amygdala, anterior thalamic nuclei, septum, limbic cortex and fornix, which seemingly support a variety of functions including emotion, behavior, long term memory, and olfaction. The term "limbic" comes from the Latin...
, involved in emotion
Emotion
Emotion is a complex psychophysiological experience of an individual's state of mind as interacting with biochemical and environmental influences. In humans, emotion fundamentally involves "physiological arousal, expressive behaviors, and conscious experience." Emotion is associated with mood,...
s. Because the patient could not put together memories and feelings, he believed objects in a photograph were new on every viewing, even though they normally should have evoked feelings (e.g., a person close to him, a familiar object, or even himself). Ramachandran therefore believed there was a relationship between Capgras syndrome and a more general difficulty in linking successive episodic memories, since it is believed that emotion is critical for creating memories.
Most likely, more than an impairment of the automatic emotional arousal response is necessary to form Capgras delusion, as the same pattern has been reported in patients showing no signs of delusions. Ellis and colleagues suggested that a second factor explains why this unusual experience is transformed into a delusional belief; this second factor is thought to be an impairment in reasoning, although no definitive impairment has been found to explain all cases.
See also
- ChangelingChangelingA changeling is a creature found in Western European folklore and folk religion. It is typically described as being the offspring of a fairy, troll, elf or other legendary creature that has been secretly left in the place of a human child. Sometimes the term is also used to refer to the child who...
- Cognitive neuropsychiatryCognitive neuropsychiatryCognitive neuropsychiatry is a sub-discipline of psychology and psychiatry that aims to understand mental illness and psychopathology in terms of models of normal psychological function. It is also a way of uncovering normal psychological processes by studying the effects of their change or...
- DoppelgängerDoppelgängerIn fiction and folklore, a doppelgänger is a paranormal double of a living person, typically representing evil or misfortune...
- Face perceptionFace perceptionFace perception is the process by which the brain and mind understand and interpret the face, particularly the human face.The human face's proportions and expressions are important to identify origin, emotional tendencies, health qualities, and some social information. From birth, faces are...
- Fregoli delusionFregoli delusionThe Fregoli delusion or the delusion of doubles is a rare disorder in which a person holds a delusional belief that different people are in fact a single person who changes appearance or is in disguise...
- Monothematic delusionMonothematic delusionA monothematic delusion is a delusional state that only concerns one particular topic. This is contrasted by what is sometimes called multi-thematic or polythematic delusions where the person has a range of delusions...
External links
- An Impostor in the Family on damninteresting.com
- Trial of former SCTV/SNL comic Tony Rosato, with Capgras lit review
- When a "Duplicate" Family Moves In—Article in The New York Times Magazine by Carol W. Berman, MD.
- Vilayanur Ramachandran touches on Capgras at TED