Savant syndrome

Savant syndrome is a rare condition in which someone with significant mental disabilities demonstrates certain abilities far in excess of average.[1][2] The skills that savants excel at are generally related to memory.[1] This may include rapid calculation, artistic ability, map making, or musical ability.[1] Usually, only one exceptional skill is present.[1]

"Savant" redirects here. For other uses, see Savant (disambiguation).
Savant syndrome
Other namesAutistic savant, idiot savant (historical)[1]
Kim Peek, the savant who was the inspiration for the main character in the movie Rain Man
SpecialtyPsychiatry, Neurology
SymptomsGeneral mental disability with certain abilities far in excess of average[1][2]
TypesCongenital, acquired[3]
CausesNeurodevelopmental disorder such as autism spectrum disorder, brain injury[1]
Frequencyc. 1 in a million people[4]

Those with the condition generally have a neurodevelopmental disorder such as autism spectrum disorder or have a brain injury.[1] About half of cases are associated with autism, and these individuals may be known as "autistic savants".[1] While the condition usually becomes apparent in childhood, some cases develop later in life.[1] It is not recognized as a mental disorder within the DSM-5.[5]

Savant syndrome is estimated to affect around one in a million people.[4] The condition affects more males than females, at a ratio of 6:1.[1] The first medical account of the condition was in 1783.[1] Among those with autism, 1 in 10 to 1 in 200 have savant syndrome to some degree.[1] It is estimated that there are fewer than a hundred savants with extraordinary skills currently living.[1]

Signs and symptoms
Venice by British artistic savant Stephen Wiltshire

Savant skills are usually found in one or more of five major areas: art, memory, arithmetic, musical abilities, and spatial skills.[1] The most common kinds of savants are calendrical savants,[6][7] "human calendars" who can calculate the day of the week for any given date with speed and accuracy, or recall personal memories from any given date. Advanced memory is the key "superpower" in savant abilities.[6]

Approximately half of savants are autistic; the other half often have some form of central nervous system injury or disease.[1] It is estimated that up to 10% of those with autism have some form of savant abilities.[1][8][9]

Calendrical savants

A calendrical savant (or calendar savant) is someone who – despite having an intellectual disability – can name the day of the week of a date, or vice versa, on a limited range of decades or certain millennia.[7][10] The rarity of human calendar calculators is possibly due to the lack of motivation to develop such skills among the general population, although mathematicians have developed formulas that allow them to obtain similar skills.[10] Calendrical savants, on the other hand, may not be prone to invest in socially engaging skills.[11]

Mechanism

Psychological

No widely accepted cognitive theory explains savants' combination of talent and deficit.[12] It has been suggested that individuals with autism are biased towards detail-focused processing and that this cognitive style predisposes individuals either with or without autism to savant talents.[13] Another hypothesis is that savants hyper-systemize, thereby giving an impression of talent. Hyper-systemizing is an extreme state in the empathizing–systemizing theory that classifies people based on their skills in empathizing with others versus systemizing facts about the external world.[14] Also, the attention to detail of savants is a consequence of enhanced perception or sensory hypersensitivity in these unique individuals.[14][15] It has also been confirmed that some savants operate by directly accessing low-level, less-processed information that exists in all human brains that is not normally available to conscious awareness.[16]

Neurological

In some cases, savant syndrome can be induced following severe head trauma to the left anterior temporal lobe.[1] Savant syndrome has been artificially replicated using transcranial magnetic stimulation to temporarily disable this area of the brain.[17]

Epidemiology
See also: Epidemiology of autism

There are no objectively definitive statistics about how many people have savant skills. The estimates range from "exceedingly rare"[18] to one in ten people with autism having savant skills in varying degrees.[1] A 2009 British study of 137 parents of autistic children found that 28% believe their children met the criteria for a savant skill, defined as a skill or power "at a level that would be unusual even for 'normal' people".[19] As many as 50 cases of sudden or acquired savant syndrome have been reported.[20][21]

Males with savant syndrome outnumber females by roughly 6:1 (in Finland),[22] slightly higher than the sex ratio disparity for autism spectrum disorders of 4.3:1.[23]

History

The term idiot savant (French for "learned idiot") was first used to describe the condition in 1887 by John Langdon Down, who is known for his description of Down syndrome. The term idiot savant was later described as a misnomer because not all reported cases fit the definition of idiot, originally used for a person with a very severe intellectual disability. The term autistic savant was also used as a description of the disorder. Like idiot savant, the term came to be considered a misnomer because only half of those who were diagnosed with savant syndrome were autistic. Upon realization of the need for accuracy of diagnosis and dignity towards the individual, the term savant syndrome became widely accepted terminology.[1][18]

Society and culture

Notable cases

Fictional cases

See also

References
  1. Treffert DA (May 2009). "The savant syndrome: an extraordinary condition. A synopsis: past, present, future". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1351–7. doi:10.1098/rstb.2008.0326. PMC 2677584. PMID 19528017.
  2. Miller LK (January 1999). "The savant syndrome: intellectual impairment and exceptional skill". Psychological Bulletin. 125 (1): 31–46. doi:10.1037/0033-2909.125.1.31. PMID 9990844.
  3. Hughes JR (2012). "The savant syndrome and its possible relationship to epilepsy". Advances in Experimental Medicine and Biology. 724: 332–43. doi:10.1007/978-1-4614-0653-2_25. ISBN 978-1-4614-0652-5. PMID 22411254.
  4. Hyltenstam, Kenneth (2016). Advanced Proficiency and Exceptional Ability in Second Languages. Walter de Gruyter GmbH & Co KG. p. 258. ISBN 9781614515173.
  5. Sperry, Len (2015). Mental Health and Mental Disorders: An Encyclopedia of Conditions, Treatments, and Well-Being [3 volumes]: An Encyclopedia of Conditions, Treatments, and Well-Being. ABC-CLIO. p. 969. ISBN 9781440803833.
  6. Saloviita T, Ruusila L, Ruusila U (August 2000). "Incidence of Savant Syndrome in Finland". Perceptual and Motor Skills. 91 (1): 120–2. doi:10.2466/pms.2000.91.1.120. PMID 11011882. S2CID 20306664.
  7. Kennedy DP, Squire LR (August 2007). "An analysis of calendar performance in two autistic calendar savants". Learning & Memory. 14 (8): 533–8. doi:10.1101/lm.653607. PMC 1951792. PMID 17686947.
  8. Treffert DA. "The Autistic Savant". Wisconsin Medical Society.
  9. "Savant Syndrome Statistics". Health Research Funding. 2014-07-12.
  10. Conway, Richard; Carney, Daniel P. J. (June 2006). "Calendrical savants: Exceptionality and Practice". Cognition. 100 (2): B1–B9. doi:10.1016/j.cognition.2005.08.001. PMID 16157326. S2CID 34912923. Retrieved 9 October 2020.
  11. Cowan R, Frith C (May 2009). "Do calendrical savants use calculation to answer date questions? A functional magnetic resonance imaging study". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1417–24. doi:10.1098/rstb.2008.0323. PMC 2677581. PMID 19528025.
  12. Pring, Linda (2005). "Savant talent" (PDF). Developmental Medicine & Child Neurology. 47 (7): 500–503. doi:10.1017/S0012162205000976. PMID 15991873.
  13. Happé F, Vital P (May 2009). "What aspects of autism predispose to talent?". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1369–75. doi:10.1098/rstb.2008.0332. PMC 2677590. PMID 19528019. Lay summary – The Economist (April 16, 2009).
  14. Baron-Cohen S, Ashwin E, Ashwin C, Tavassoli T, Chakrabarti B (May 2009). "Talent in autism: hyper-systemizing, hyper-attention to detail and sensory hypersensitivity". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1377–83. doi:10.1098/rstb.2008.0337. PMC 2677592. PMID 19528020.
  15. Mottron L, Dawson M, Soulières I (May 2009). "Enhanced perception in savant syndrome: patterns, structure and creativity". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1385–91. doi:10.1098/rstb.2008.0333. PMC 2677591. PMID 19528021.
  16. Snyder A (May 2009). "Explaining and inducing savant skills: privileged access to lower level, less-processed information". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1399–405. doi:10.1098/rstb.2008.0290. PMC 2677578. PMID 19528023. Lay summary – The Economist (April 16, 2009).
  17. Snyder A (May 2009). "Explaining and inducing savant skills: privileged access to lower level, less-processed information". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1399–405. doi:10.1098/rstb.2008.0290. PMC 2677578. PMID 19528023.
  18. "Archived copy". Archived from the original on 2012-10-25. Retrieved 2012-10-06.CS1 maint: archived copy as title (link)
  19. Howlin P, Goode S, Hutton J, Rutter M (May 2009). "Savant skills in autism: psychometric approaches and parental reports". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 364 (1522): 1359–67. doi:10.1098/rstb.2008.0328. PMC 2677586. PMID 19528018. Lay summary – The Economist (April 16, 2009).
  20. Yant-Kinney M (2012-08-20). "An artist is born after car crash". The Inquirer. Philadelphia. Retrieved 2012-11-24.
  21. "'A ski accident left me with advanced mental abilities': US woman tells her extraordinary story". Daily Telegraph. 17 April 2015.
  22. Treffert, Darold. A Visual Feast
  23. Newschaffer CJ, Croen LA, Daniels J, Giarelli E, Grether JK, Levy SE, Mandell DS, Miller LA, Pinto-Martin J, Reaven J, Reynolds AM, Rice CE, Schendel D, Windham GC (2007). "The epidemiology of autism spectrum disorders". Annual Review of Public Health. 28: 235–58. doi:10.1146/annurev.publhealth.28.021406.144007. PMID 17367287.
  24. McGowan, Kat (March 13, 2013). Exploring Temple Grandin's Brain. Discover Magazine (April 2013). Retrieved June 20, 2018.
  25. Badcock, Christopher (2009). The Imprinted Brain: How Genes Set the Balance Between Autism and Psychosis. London: Jessica Kingsley. p. 29. ISBN 9781849050234.
Classification
External resources
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