Prosopagnosia (sometimes known as
face blindness) is a disorder of
face 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. Faces are from birth...
where the ability to recognize
faceThe term face refers to the central sense organ complex, for those animals that have one, normally on the ventral surface of the head, and can depending on the definition in the human case, include the hair, forehead, eyebrow, eyes, nose, ears, cheeks, mouth, lips, philtrum, teeth, skin, and chin....
s is impaired, while the ability to recognize other objects may be relatively intact. The term originally referred to a condition following acute
brain damageBrain damage, or acquired brain injury, is the destruction or degeneration of brain cells.-Causes:Brain damage may occur due to a wide range of conditions, illnesses, injuries, and as a result of iatrogenesis...
, but recently a
congenitalCongenital disorder involves defects in or damage to a developing fetus. It may be the result of genetic abnormalities, the intrauterine environment, errors of morphogenesis, or a chromosomal abnormality. The outcome of the disorder will further depend on complex interactions between the pre-natal...
form of the disorder has been identified, which is inherited by about 2.5% of the population. The specific brain area usually associated with prosopagnosia is the
fusiform gyrusThe fusiform gyrus is part of the temporal lobe. It is also known as the occipitotemporal gyrus. Other sources have the fusiform gyrus above the occipitotemporal gyrus and underneath the parahippocampal gyrus.-Function:...
.
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
memoryIn psychology, memory is an organism's mental ability to store, retain, and recall information. Traditional studies of memory began in the fields of philosophy, including techniques of artificially enhancing the memory....
, it can also be difficult for people with this condition to keep track of information about people, and socialize normally with others.
Some also use the term
prosophenosia, which refers to the inability to recognize faces following extensive damage of both
occipitalThe occipital lobe is the visual processing center of the mammalian brain containing most of the anatomical region of the visual cortex. The primary visual cortex is Brodmann area 17, commonly called V1...
and
temporal lobeThe temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both the left and right hemispheres of the brain....
s.
Overview
Selective inabilities to recognize faces were reported throughout the 19th century, and included case studies by
Hughlings JacksonJohn Hughlings Jackson, FRS , was an English neurologist; born at Providence Green, Green Hammerton, near Harrogate, Yorkshire.- Biography :...
and Charcot. However, it was not named until the term
prosopagnosia was first used in 1947 by Joachim Bodamer, a
GermanGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
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
gaitHuman gait is the way locomotion is achieved using human limbs. For this article different gaits do not require changes in the geometry of motion, but rather, changes in the contact with the surface .-Walks:...
and other physical mannerisms). Bodamer gave his paper the title
Die Prosop-Agnosie, derived from classical
GreekGreek , an independent branch of the Indo-European family of languages, is the language of the Greeks. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. In its ancient form, it is the language of classical...
πρόσωπον (prosopon) meaning "face" and
αγνωσία (
agnosiaAgnosia 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...
) meaning "non-knowledge".
The study of prosopagnosia has been crucial in the development of theories of
face 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. Faces are from birth...
. 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. 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.
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
agnosiaAgnosia 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...
. While prosopagnosia is often accompanied by problems with recognising visual objects, cases have been reported where perception for faces seems to be selectively impaired.
A recent case report described a closely related condition called
prosopamnesiaProsopamnesia is a rare neuropsychological deficit defined by an inability to remember faces. It can be subdivided into two different types, including a 'congenital' and 'acquired' version....
, in which the subject, from birth, could perceive faces normally but had a severely impaired ability to remember them.
It has also been argued that prosopagnosia may be a general impairment in understanding how individual perceptual components make up the structure or
gestaltGestalt psychology or gestaltism of the Berlin School is a theory of mind and brain positing that the operational principle of the brain is holistic, parallel, and analog, with self-organizing tendencies, or that the whole is different from the sum of its parts...
of an object. Psychologist
Martha FarahMartha Farah is a cognitive neuroscience researcher at the University of Pennsylvania. She has worked on an unusually wide range of topics; the citation for her lifetime achievement award from the Association for Psychological Science states that “Her studies on the topics of mental imagery, face...
has been particularly associated with this view.
Until early in the 21st century, prosopagnosia was thought to be quite rare and solely associated with
brain injuryAn acquired brain injury is damage to the brain acquired after birth. It usually affects cognitive, physical, emotional, social or independent functioning and can result from traumatic brain injury and nontraumatic brain injury...
or neurological illness affecting specific areas of the brain. However, recently a form of congenital prosopagnosia has been identified, 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 than previously thought (about 2.5% of the population may be affected). 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. The inability to keep track of the identity of characters in movies is a common complaint.
A classic case of a prosopagnosia is presented by "Dr P" in
Oliver SacksOliver Wolf Sacks, CBE, FRCP , is a British neurologist residing in New York City. Sacks is the author of several bestselling books, including several collections of case studies of people with neurological disorders...
' 1985 book
The Man Who Mistook His Wife for a HatThe Man Who Mistook His Wife for a Hat and Other Clinical Tales is a 1985 book by neurologist Oliver Sacks describing the case histories of some of his patients. The title of the book comes from the case study of a man with visual agnosia...
. Although Dr P could not recognize his wife from her face, he was able to recognize her by her voice. His recognition of pictures of his family and friends appeared to be based on highly specific features, such as his brother's chipped tooth.
Apperceptive 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
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
Developmental prosopagnosia is thought to be a form of 'congenital prosopagnosia', and that some people are born with a selective impairment in recognizing 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 hereditary.
- It is known that there are many Developmental disorder
Developmental disorders are disorders that occur at some stage in a child's development, often retarding the development. These may include psychological or physical disorders.-See also:* Developmental disability* Mental retardation* Learning disability...
s that incorporate within themselves an increased likelihood that the person will have differences in face perception, of which the person may or may not be aware. That is to say, the person may or may not have insightInsight can be used with several related meanings:*a piece of information*the act or result of apprehending the inner nature of things or of seeing intuitively in Greek called noesis*an introspection...
in the clinical sense of the word. However, the mechanism by which these effects take place is largely unknown. A partial list of some disorders that often have prosopagnosiac components would include nonverbal learning disorderNonverbal learning disorder or nonverbal learning disability is a proposed condition characterized by a significant discrepancy between high verbal and lower performance scores on an IQ test, with deficits in motor, visual-spatial, and social skills...
, Williams syndromeWilliams syndrome is a rare neurodevelopmental disorder caused by a deletion of about 26 genes from the long arm of chromosome 7...
, and Autism spectrum disorders in general. However, these types of disorders are very complicated, so arbitrary assumptions should be avoided.
Unconscious face recognition
One particularly interesting feature of prosopagnosia is that it suggests both a conscious and
unconsciousThe unconscious mind is a term invented by the 18th century German romantic philosopher Ser Christopher Riegel and later introduced into English by the poet and essayist Samuel Taylor Coleridge...
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 conductanceGalvanic skin response , also known as electrodermal response , psychogalvanic reflex , or skin conductance response , is a method of measuring the electrical resistance of the skin...
), there tends to be an emotional response to familiar people even though no conscious recognition takes place
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 delusionThe Capgras delusion is a disorder in which a person holds a delusional belief that a friend, spouse or other close family member, has been replaced by an identical-looking impostor. The Capgras delusion is classed as a delusional misidentification syndrome, a class of delusional beliefs that...
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
delusionA delusion, in everyday language, is a fixed belief that is either false, fanciful, or derived from deception. Psychiatry defines the term more specifically as a belief that is pathological...
al belief that their relative or spouse has been replaced by an impostor.
Popular culture
The 2007 short romantic drama movie
In Vivid Detail, written and directed by Dara Bratt, is a love story between a young woman, played by
Piper PeraboPiper Lisa Perabo is an American stage, film and television actress.-Early life:Perabo was born in Dallas, Texas and grew up in Toms River, New Jersey, the daughter of Mary Charlotte , a physical therapist, and George William Perabo, the Dean of English & Literature at Ocean County College. She is...
, and a man suffering from prosopagnosia, played by
John VentimigliaJohn Ventimiglia is an American actor, most famous for his role as Artie Bucco on the HBO television series The Sopranos. He has had parts in feature films such as Cop Land, Jesus' Son, and Mickey Blue Eyes and has appeared in numerous television shows including Law & Order and NYPD Blue...
.
In the
Ally McBealAlly McBeal is an American television series which ran on the Fox network from 1997 to 2002. The series was created by David E. Kelley, who also served as the executive producer, along with Bill D'Elia...
episode "A Kick in the Head", a defendant has symptoms similar to prosopagnosia when he mistakes his wife's head for a soccer ball.
An episode of
Picket FencesPicket Fences is a 60-minute American television drama centering around the residents of the fictional community of Rome, Wisconsin. The show initially ran from September 1, 1992, to June 26, 1996, on the CBS television network in the United States. Picket Fences was created by producer David E....
dealt with a man suffering from prosopagnosia who shot his brother, claiming he believed him to be an intruder.
The short story "Liking What You See: A Documentary" by science fiction writer
Ted ChiangTed Chiang is an American speculative fiction writer. He was born in Port Jefferson, New York and graduated from Brown University with a Computer Science degree. He currently works as a technical writer in the software industry and resides in Bellevue, near Seattle, Washington...
proposed an intentionally-induced form of prosopagnosia.
In the Michael Cordy novel "The Venus Conspiracy", Isabella Bacci is studying prosopagnosia.
Science fiction author
Alastair ReynoldsAlastair Preston Reynolds is a British science fiction author. He specialises in dark hard science fiction and space opera. He spent his early years in Cornwall, moved back to Wales before going to Newcastle, where he read physics and astronomy. Afterwards, he earned a PhD from St Andrews, Scotland...
created a character suffering from prosopagnosia named Felka who features in several novels and short stories of his
Revelation Space universeThe Revelation Space universe is a fictional universe which was created by Alastair Reynolds and used as the setting for a number of his novels and stories...
.
Humpty DumptyHumpty Dumpty is a character in a nursery rhyme typically portrayed as an egg. Most English-speaking children are familiar with the rhyme. It has a Roud Folk Song Index number of 13026.-The rhyme:The most common text is:-Origins:...
in
Lewis Carroll Charles Lutwidge Dodgson , better known by the pen name Lewis Carroll , was an English author, mathematician, logician, Anglican deacon and photographer...
's novel
Through the Looking-GlassThrough the Looking-Glass, and What Alice Found There is a work of children's literature by Lewis Carroll , generally categorized as literary nonsense. It is the sequel to Alice's Adventures in Wonderland...
makes a statement suggesting prosopagnosia.
`` `The face is what one goes by, generally', Alice remarked in a thoughtful tone. `That's just what I complain of ', said Humpty Dumpty. `Your face is the same as everybody has--the two eyes, so--' (marking their places in the air with his thumb) `nose in the
middle, mouth under. It's always the same. Now if you had the two eyes on the same side of the nose, for instance--or the mouth at the top-- that would be some help'.
See also
- Cognitive neuropsychology
Cognitive neuropsychology is a branch of cognitive psychology that aims to understand how the structure and function of the brain relates to specific psychological processes. It places a particular emphasis on studying the cognitive effects of brain injury or neurological illness with a view to...
- Recognition of human individuals
- Thatcher effect
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. It is named after British former Prime Minister Margaret Thatcher on whose photograph the effect...
- Temporal lobe epilepsy
Temporal lobe epilepsy is a form of focal epilepsy, a chronic neurological condition characterized by recurrent seizures. Over 40 types of epilepsies are known. They fall into two main categories: partial-onset epilepsies and generalized-onset epilepsies...
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 Evidence mounts that making, and perhaps recognising, expressions is inherited
External links
- Further information on Prosopagnosia, from Dr Sarah Bate, University of Exeter.
- Online screening for Prosopagnosia, from Dr Sarah Bate, University of Exeter.
- Additional information on face blindness, from Harvard University
Harvard University is a private university located in Cambridge, Massachusetts and a member of the Ivy League. Founded in 1636 by the colonial Massachusetts legislature, Harvard is the oldest institution of higher learning in the United States and currently comprises ten separate academic units...
and University College LondonUniversity College London is a British university institution and a constituent college of the University of London, based primarily in Bloomsbury, London...
.
- Detailed information on temporal lobe impairment, the site of the source of face-blindness
- The Sunday Times: Identity crisis Article published 17 December 2006
- New Scientist: Face blindness runs in families
- 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
Radio National is an Australia-wide non-commercial radio network run by the Australian Broadcasting Corporation.Radio National broadcasts national programming in areas that include news and current affairs, the arts, social issues, science, drama and comedy...
's All in the Mind program from February 2006
- Do I Know You? - Time magazine article published July 2006
- Information in several languages
- "Face Blind" - Wired
Wired is a full-color monthly American magazine and on-line periodical, published since March 1993, that reports on how technology affects culture, the economy, and politics...
article
- Prosopagnosia information at Wikiversity
Wikiversity is a Wikimedia Foundation project, which supports learning communities, their learning materials, and resulting activities. It differs from more structured projects such as Wikipedia in that it instead offers a series of tutorials, or courses, for the fostering of learning, rather than...
.
- Congenital Prosopagnosia-Visual Perception Lab, ,Ben Gurion University of the Negev, Israel.
- Face Blind!, Bill Choisser, 2002.
- The Guardian: I don't recognise my own face Article published 22 November 2008
Further reading
- Face-blindness as a result of temporal lobe
The temporal lobe is a region of the cerebral cortex that is located beneath the Sylvian fissure on both the left and right hemispheres of the brain....
injury is described by Dr. Daniel Amen in his book, Healing ADD, with includes case histories.