Capgras delusionCapgras delusion or Capgras syndrome is a psychiatric disorder in which a person holds a delusion that a friend, spouse, parent, another close family member, or pet has been replaced by an identical impostor. It is named after Joseph Capgras (1873–1950), the French psychiatrist who first described the disorder. The Capgras delusion is classified as a delusional misidentification syndrome, a class of delusional beliefs that involves the misidentification of people, places, or objects.
Delusional misidentification syndromeDelusional misidentification syndrome is an umbrella term, introduced by Christodoulou (in his book The Delusional Misidentification Syndromes, Karger, Basel, 1986) for a group of delusional disorders that occur in the context of mental and neurological illness. They all involve a belief that the identity of a person, object, or place has somehow changed or has been altered. As these delusions typically only concern one particular topic, they also fall under the category called monothematic delusions.
Monothematic delusionA monothematic delusion is a delusional state that concerns only one particular topic. This is contrasted by what is sometimes called multi-thematic or polythematic delusions where the person has a range of delusions (typically the case of schizophrenia). These disorders can occur within the context of schizophrenia or dementia or they can occur without any other signs of mental illness. When these disorders are found outside the context of mental illness, they are often caused by organic dysfunction as a result of traumatic brain injury, stroke, or neurological illness.
Mirrored-self misidentificationMirrored-self misidentification is the delusional belief that one's reflection in the mirror is another person – typically a younger or second version of one's self, a stranger, or a relative. This delusion occurs most frequently in patients with dementia and an affected patient maintains the ability to recognize others' reflections in the mirror. It is caused by right hemisphere cranial dysfunction that results from traumatic brain injury, stroke, or general neurological illness.
Face perceptionFacial perception is an individual's understanding and interpretation of the face. Here, perception implies the presence of consciousness and hence excludes automated facial recognition systems. Although facial recognition is found in other species, this article focuses on facial perception in humans. The perception of facial features is an important part of social cognition. Information gathered from the face helps people understand each other's identity, what they are thinking and feeling, anticipate their actions, recognize their emotions, build connections, and communicate through body language.
Cognitive neuropsychologyCognitive neuropsychology is a branch of cognitive psychology that aims to understand how the structure and function of the brain relates to specific psychological processes. Cognitive psychology is the science that looks at how mental processes are responsible for the cognitive abilities to store and produce new memories, produce language, recognize people and objects, as well as our ability to reason and problem solve.
Cotard's syndromeCotard's syndrome, also known as Cotard's delusion or walking corpse syndrome, is a rare mental disorder in which the affected person holds the delusional belief that they are dead, do not exist, are putrefying, or have lost their blood or internal organs. Statistical analysis of a hundred-patient cohort indicated that denial of self-existence is present in 45% of the cases of Cotard's syndrome; the other 55% of the patients presented with delusions of immortality.
ProsopagnosiaProsopagnosia (from Greek prósōpon, meaning "face", and agnōsía, meaning "non-knowledge"), also known as face blindness, is a cognitive disorder of face perception in which the ability to recognize familiar faces, including one's own face (self-recognition), is impaired, while other aspects of visual processing (e.g., object discrimination) and intellectual functioning (e.g., decision-making) remain intact. The term originally referred to a condition following acute brain damage (acquired prosopagnosia), but a congenital or developmental form of the disorder also exists, with a prevalence of 2.
Cognitive neuropsychiatryCognitive neuropsychiatry is a growing multidisciplinary field arising out of cognitive psychology and neuropsychiatry that aims to understand mental illness and psychopathology in terms of models of normal psychological function. A concern with the neural substrates of impaired cognitive mechanisms links cognitive neuropsychiatry to the basic neuroscience. Alternatively, CNP provides a way of uncovering normal psychological processes by studying the effects of their change or impairment.
DelusionA delusion is a false fixed belief that is not amenable to change in light of conflicting evidence. As a pathology, it is distinct from a belief based on false or incomplete information, confabulation, dogma, illusion, hallucination, or some other misleading effects of perception, as individuals with those beliefs are able to change or readjust their beliefs upon reviewing the evidence.
