Prosopagnosia (sometimes known as face blindness) is disorder of face perception where the ability to recognize faces is impaired, while the ability to recognize objects may be relatively intact. Face perception is the process by which the brain and mind understand and interpret the face, particularly the human face. ... Image:X:uikfhduishnei. ...

The cause of the disease is not widely agreed upon, but some researchers believe it is related to the fusiform gyrus, which is generally accepted as playing a role in face recognition.^[1] Grays Fig. ...

Few successful therapies have so far been developed for affected people, although individuals often learn to use 'piecemeal' or 'feature by feature' recognition strategies. This may involve secondary clues such as clothing, hair color, body shape, and voice. Because the face seems to function as an important identifying feature in memory, it can also be difficult for people with this condition to keep track of information about people, and socialize normally with others. For other uses, see Memory (disambiguation). ...

Some people also use the term prosophenosia, which refers to the inability to recognize faces following extensive damage of both occipital and temporal lobes.^[2][3] The occipital lobe is the visual processing center of the mammalian brain. ... The temporal lobes are part of the cerebrum. ...

Overview

Selective inabilities to recognize faces were reported throughout the 19th century, and included case studies by Hughlings Jackson and Charcot. However, it was not named until the term prosopagnosia was first used in 1947 by Joachim Bodamer, a German neurologist. He described three cases, including a 24-year old man who suffered a bullet wound to the head and lost his ability to recognise his friends, family, and even his own face. However, he was able to recognize and identify them through other sensory modalities such as auditory, tactile, and even other visual stimuli patterns (such as gait and other physical mannerisms). Bodamer gave his paper the title Die Prosop-Agnosie, derived from classical Greek πρόσωπον (prosopon) meaning "face" and αγνωσία (agnosia) meaning "non-knowledge". Alternative meaning: Nineteenth Century (periodical) (18th century — 19th century — 20th century — more centuries) As a means of recording the passage of time, the 19th century was that century which lasted from 1801-1900 in the sense of the Gregorian calendar. ... John Hughlings Jackson (1835–1911), was an English neurologist; born at Providence, Green Hammerton, Yorkshire. ... Professor Charcot was well-known for showing, during his lessons at the Salpêtrière hospital, hysterical woman patients – here, his favorite patient, Blanche (Marie) Wittman, supported by Joseph Babinsky. ... Year 1947 (MCMXLVII) was a common year starting on Wednesday (the link is to a full 1947 calendar). ... Neurology is the branch of medicine that deals with the nervous system and disorders affecting it. ... This article or section does not cite its references or sources. ... Agnosia (a-gnosis, non-knowledge) is a loss of ability to recognize objects, persons, sounds, shapes or smells while the specific sense is not defective nor is there any significant memory loss. ...

The study of prosopagnosia has been crucial in the development of theories of face perception. Because prosopagnosia is not a unitary disorder (i.e., different people may show different types and levels of impairment) it has been argued that face perception involves a number of stages, each of which can be separately damaged.^[4] This is reflected not just in the amount of impairment displayed but also in the qualitative differences in impairment that a person with prosopagnosia may present with. Face perception is the process by which the brain and mind understand and interpret the face, particularly the human face. ...

This sort of evidence has been crucial in supporting the theory that there may be a specific face perception system in the brain. This is counter-intuitive to many people as we do not experience faces as 'special' or perceived in a different way from the rest of the world.

There is some debate about the specificity of both face perception and prosopagnosia and some people have argued that it is just a subtype of visual agnosia. Whilst prosopagnosia is often accompanied by problems with recognising visual objects, cases have been reported where perception for faces seems to be selectively impaired.^[5] Agnosia (a-gnosis, non-knowledge) is a loss of ability to recognize objects, persons, sounds, shapes or smells while the specific sense is not defective nor is there any significant memory loss. ...

It has also been argued that prosopagnosia may be a general impairment in understanding how individual perceptual components make up the structure or gestalt of an object. Psychologist Martha Farah has been particularly associated with this view. Gestalt psychology (also Gestalt theory of the Berlin School) is a theory of mind and brain that proposes that the operational principle of the brain is holistic, parallel, and analog, with self-organizing tendencies. ... Martha Farah has been trying to understand the mechanisms of vision, memory, and executive function in the human brain. ...

Until early in the 21st century, prosopagnosia was thought to be quite rare and solely associated with brain injury or neurological illness affecting specific areas of the brain. However, some evidence suggests that there may be a form of congenital prosopagnosia in which people are born with a selective impairment in recognising and perceiving faces. The cases that have been reported suggest that this form of the disorder may be highly variable and some newer research suggests that it may be heritable and much more common that previously thought (about 2% of the population may be affected).^[6][7] It has been suggested that very mild cases of face blindness are much more common, perhaps affecting 10% of the population, although there have not been any studies confirming this.^[1] Brain damage or brain injury is the destruction or degeneration of brain cells. ... Neurology is a branch of medicine dealing with disorders of the central and peripheral nervous systems. ...

Subtypes of prosopagnosia

• Apperceptive prosopagnosia is thought to be a disorder of some of the earliest processes in the face perception system. People with this disorder cannot make any sense of faces and are unable to make same-different judgements when they are presented with pictures of different faces. They may also be unable to work out attributes such as age or gender from a face. However, they may be able to recognise people based on non-face clues such as their clothing, hairstyle or voice.
• Associative prosopagnosia is thought to be an impairment to the links between early face perception processes and the semantic information we hold about people in our memories. People with this form of the disorder may be able to say whether photos of people's faces are the same or different and derive the age and gender from a face (suggesting they can make sense of some face information) but may not be able to subsequently identify the person or provide any information about them such as their name, occupation or when they were last encountered. They may be able to recognise and produce such information based on non-face information such as voice, hair, or even particularly distinctive facial features (such as a distinctive moustache) that does not require the structure of the face to be understood. Typically such people do not report that 'faces make no sense' but simply that they do not look distinctive in any way.
• Developmental prosopagnosia is thought to be a form of 'congenital prosopagnosia', and that some people are born with a selective impairment in recognising and perceiving faces. The cases that have been reported suggest that this form of the disorder may be highly variable and there is some suggestion that it may be heriditary.

Developmental disorders such as autism and Williams syndrome are known to also involve differences in face perception, but the mechanism by which these effects take place is largely unknown. Developmental disorders are disorders that occur at some stage in a childs development, often retarding the development. ... Autism is classified by the World Health Organization and American Psychological Association as a developmental disability that results from a disorder of the human central nervous system. ... Williams syndrome (also Williams-Beuren syndrome, sometimes called Pixieism) is a rare genetic disorder, occurring in fewer than 1 in 7,500 live births. ...

Unconscious face recognition

One particularly interesting feature of prosopagnosia is that it suggests both a conscious and unconscious aspect to face recognition. Experiments have shown that when presented with a mixture of familiar and unfamiliar faces, people with prosopagnosia may be unable to successfully identify the people in the pictures, or even make a simple familiarity judgement ("this person seems familiar / unfamiliar"). However, when a measure of emotional response is taken (typically a measure of skin conductance) there tends to be an emotional response to familiar people even though no conscious recognition takes place^[8] Consciousness is a quality of the mind generally regarded to comprise qualities such as subjectivity, self-awareness, sentience, sapience, and the ability to perceive the relationship between oneself and ones environment. ... This article may contain original research or unverified claims. ...

This suggests emotion plays a significant role in face recognition, perhaps unsurprising when basic survival (particularly security) relies on identifying the people around you.

It is thought that Capgras delusion may be the reverse of prosopagnosia. In this condition people report conscious recognition of people from faces, but show no emotional response, perhaps leading to the delusional belief that their relative or spouse has been replaced by an impostor. The Capgras delusion or Capgras syndrome is a rare disorder in which a person holds a delusional belief that an acquaintance, usually a close family member or spouse, has been replaced by an identical looking imposter. ... A delusion is commonly defined as a fixed false belief and is used in everyday language to describe a belief that is either false, fanciful or derived from deception. ...

See also

Look up prosopagnosia in
Wiktionary, the free dictionary.

• Cognitive neuropsychology
• Recognition of human individuals
• Thatcher effect
• Temporal lobe epilepsy

Wikipedia does not have an article with this exact name. ... Wiktionary is a multilingual, Web-based project to create a free content dictionary, available in over 150 languages. ... == ISABEL IS COOL AND SHE LOVES COGNITIVE NEUROPSYCHOLOGY!!!!!!!!! == Cognitive neuropsychology is a branch of neuropsychology that aims to understand how the structure and function of the brain relates to specific psychological processes. ... Recognition of acquaintances From nearby, a human individual is mainly recognized by his or her face. ... The Thatcher effect or Thatcher illusion is a phenomenon where it becomes difficult to detect local feature changes in an upside down face, despite identical changes being obvious in an upright face. ... Temporal lobe epilepsy is a form of epilepsy, a chronic neurological condition characterized by recurrent seizures. ...

References

Further reading

• Bruce, V. and Young, A. (2000) In the Eye of the Beholder: The Science of Face Perception. Oxford: Oxford University Press. ISBN 0-19-852439-0
• Farah, M.J. (1990) Visual agnosia: Disorders of object recognition and what they tell us about normal vision. MIT: MIT Press. ISBN 0-262-06238-0
• (December 2 2004) "About face". Economist. 
• (October 19 2006) "Your mother's smile". Economist.  Evidence mounts that making, and perhaps recognising, expressions is inherited
• Abedin, Shahreen (February 5 2007). "Face blindness not just skin deep". CNN.com. 

External links

• Additional information on face blindness may be obtained from http://www.faceblind.org/ , a site sponsored by Harvard University in conjunction with University College London.
• A book by Bill Choisser, who is face-blind from birth, may be downloaded free of charge from http://www.choisser.com/faceblind/
• Implications of face-blindness in daily functioning and some coping mechanisms are aptly described by Cecilia Berman on her site at http://www.prosopagnosia.com/main/stones/index.asp
• Face-blindness as a result of temporal lobe injury is described by Dr. Daniel Amen in his book, Healing ADD, with includes case histories.
• Many finer points of the degree of temporal lobe impairment, the site of the source of face-blindness, are covered on the website eMedicine at http://www.emedicine.com/NEURO/topic365.htm
• The Sunday Times: Identity crisis Article published 17 December 2006
• New Scientist: Face blindness runs in families
• Cecilia Burman's Prosopagnosia Pages - information about prosopagnosia from someone with the condition.
• Bill Choisser's Faceblind!, a book published online
• Glenn Alperin's Prosopagnosia: My Favorite Word FAQ An informal lighthearted introduction to prosopagnosia from someone with the condition
• Face Blind Prosopagnosia Research Centers at Harvard and University College London
• Face Recognition Tests - online tests for self-assessment of face recognition abilities.
• What’s in a face? - transcript of a show from ABC Radio National's All in the Mind program from February 2006
• Have We Met? - ScienceNOW Daily News article published June 2006
• Do I Know You? - Time magazine article published July 2006
• [1] - Congenital prosopagnosia is hereditary and very common
• Gladwin Medical Blog
• "Face Blind" - Wired article