—sometimes abbreviated as savantism
—is not a recognized medical diagnosis, but researcher Darold Treffert defines it as a rare condition in which persons with developmental disorders
(including autism spectrum
disorders) have one or more areas of expertise, ability or brilliance that are in contrast with the individual's overall limitations. Treffert says the condition can be genetic
, but can also be acquired, and coexists with other developmental disabilities "such as mental retardation or brain injury or disease that occurs before (pre-natal) during (peri-natal) or after birth (post-natal), or even later in childhood or adult life."
Individuals with the syndrome are often simply called savants. This can be a source of confusion since savant can also mean a person of learning, especially one of great knowledge in a particular subject. The terms idiot savant or autistic savant are also used. "Idiot" was used by the medical profession in the late 19th and early 20th century to refer to a person whose IQ was less than 20, although that usage has now given way to "profound mental retardation"; the term idiot savant is no longer regarded as a valid medical term.
According to Treffert, about half of persons with savant syndrome have autistic disorder, while the other half have another developmental disability, mental retardation, brain injury or disease. He says, "... not all savants are autistic, and not all autistic persons are savants." Other researchers state that autistic traits and savant skills may be linked, or have challenged some earlier conclusions about savant syndrome as "hearsay, uncorroborated by independent scrutiny".
According to Treffert, something that almost all savants have in common is a remarkable memory: a memory that he describes as "exceedingly deep but very, very narrow".
Savant-like skills may be latent in everyone. Allan Snyder attempted to simulate savant impairment in normal controls by "directing low-frequency magnetic pulses into the left fronto-temporal lobe" of the brain (believed to be a method of temporarily inactivating the region and allowing for more direct processing of the extremely rapid counting task). Differences were observed in four of 11 subjects.
An autistic savant (historically described as an idiot savant) is a person with both autism and savant skills. Autistic savants may have mental abilities called splinter skills. Why autistic savants are capable of these astonishing feats is not quite clear. Some savants have obvious neurological abnormalities (such as the lack of corpus callosum in Kim Peek's brain). Many savants are known to have abnormalities in the left hemisphere of the brain.
Causes and pathophysiology
The Savant Syndrome is poorly understood. There is no cognitive theory that explains the combination of talent and deficit found in savants
Savant syndrome is four to six times more frequent in males than females, and this delta is not entirely explained by the preponderance of males in the autistic population . This has led to suggestions that the Geschwind-Galaburda Hypothesis applies to savant syndrome where both the brain injury and savantism appear to be congenital.
According to Treffert:
- 10% of people on the autistic spectrum have savant skills
- Less than 1% of persons with other developmental disabilities have savant skills
- 50% of savants are autistic; the other 50% have different disabilities, mental retardation, brain injury or a brain disease
- Male savants outnumber female savants by four to six times.
Between 0.5 and 1% of people on the autistic spectrum have savant skills according to the UK National Autistic Society.
According to Treffert, the term idiot savant
was first used to describe the condition in 1887 by Dr. John Langdon Down
, who is known for his description of Down Syndrome
Society and culture
Kim Peek was the basis for the 1988 fictional film Rain Man, although his diagnosis is no longer autism.
A prodigious savant is someone whose skill level would qualify him or her as a prodigy, or exceptional talent, even in the absence of a cognitive disability. Prodigious savants are those individuals whose abilities would be considered phenomenal or genius even in a person without any limitations or special diagnosis of impairment. The most common trait of these prodigious savants is their seemingly limitless memonic skills, with many having eidetic or photographic memories. Indeed, prodigious savants are extremely rare, with fewer than one hundred noted in more than a century of literature on the subject. Darold Treffert, the leading researcher in the study of savant syndrome, estimates that fewer than fifty or so such individuals are believed to be alive in the world today. The website of the Wisconsin Medical Society lists 29 savant profiles . Darold Treffert is past-president of the society. There are only about 100 recognized prodigious savants in the world.
- Alonzo Clemons, American clay sculptor.
- Tony DeBlois, blind American musician.
- Leslie Lemke, blind American musician.
- Jonathan Lerman, American artist.
- Thristan Mendoza, Filipino marimba prodigy.
- Derek Paravicini, blind British musician.
- Kim Peek
- Gilles Tréhin
- James Henry Pullen, gifted British carpenter.
- Matt Savage, U.S. autistic jazz prodigy.
- Henriett Seth-F., Hungarian autistic savant, poet, writer and artist.
- Daniel Tammet, British high-functioning autistic savant (mathematical synesthaesia, language absorption, and memory).
- Stephen Wiltshire, British architectural artist.
- Richard Wawro, Scottish artist.
- Heaton P, Wallace GL (2004). "Annotation: The savant syndrome." Journal of Child Psychology & Psychiatry (journal)|Journal of Child Psychology & Psychiatry 45 (5): 899–911. PMID PMID 15225334
- Hou C, Miller BL, Cummings JL et al. (2000). "Artistic savants". Neuropsychiatry Neuropsychol Behav Neurol 13 (1): 29–38.
- Miller LK (1998). "Defining the Savant Syndrome". Journal of Developmental and Physical Disabilities 10 (1): 73–85.
- Miller LK (1999). "The savant syndrome: intellectual impairment and exceptional skill". Psychol Bull 125 (1): 31–46.
- Nettelbeck T, Young R (1996). "Intelligence and savant syndrome: Is the whole greater than the sum of the fragments?". Intelligence 22 (1): 49–68.
- Ockelford A, Pring L (2005). "Learning and creativity in a prodigious musical savant". Int Congr Ser 1282 903–7.
- O'Connor N, Cowan R, Samella K (2000). "Calendric Calculation and Intelligence." Intelligence 28, 31–48.
- Pearce JC (1992). Evolution's End: Claiming the Potential of Our Intelligence, HarperSanFrancisco, San Francisco.
- Pring L (2005). "Savant talent". Dev Med Child Neurol 47 (7): 500–3.
- Saloviita T, Ruusila L, Ruusila U (2000). "Incidence of savant syndrome in Finland". Percept Mot Skills 91 (1): 120–2.
- Snyder AW, Mulcahy E, Taylor JL, Mitchell DJ, Sachdev P, Gandevia SC (2003). "Savant-like skills exposed in normal people by suppressing the left fronto-temporal lobe". J. Integr. Neurosci. 2 (2): 149–58.
- Snyder AW (2001) "Paradox of the savant mind." Nature 413, 251–252.
- Snyder AW, Mitchell DJ (1999). "Is integer arithmetic fundamental to mental processing?: the mind's secret arithmetic". Proc. Biol. Sci. 266 (1419): 587–92.
- Tammet Daniel (2006). Born On A Blue Day, Hodder & Stoughton, London.
- Treffert DA, Christensen DD (2005). "Inside the mind of a savant". Sci Am 293 (6): 108–13.
- Treffert DA (2000). Extraordinary People, Bantam Press, London. ISBN 0593016734
- Treffert DA (1988). "The idiot savant: a review of the syndrome". Am J Psychiatry 145 (5): 563–72.
- Treffert DA Savant Syndrome: Recent Research, Results and Resources (1999). Wisconsin Medical Society. Retrieved on 2008-03-27..
- Young R (2005). Neurobiology of Exceptionality.