Not everybody on the Autistic Spectrum has what is known as Savant skills, which are usually found in one or more of five major areas: art, musical abilities, calendar calculation, mathematics and spatial skills. It is believed that around 50% of savants are on the Autistic Spectrum; the other 50% often have some other forms of central nervous system injury or disease. Still, the myth persists, even to this day, that if you have Autism, you are like Raymond Babbit, the central character in the 1988 film "Rainman" or like Stephen Wiltshire, the Autistic savant who can draw a building identical to how it appears after just viewing it for a few seconds.
Savant skills exist over a spectrum of abilities. The most common savant abilities are called splinter skills. These include behaviours such as obsessive preoccupation with, and memorization of, music and sports trivia, license plate numbers, maps, historical facts, or obscure items such as vacuum cleaner motor sounds, for example. Talented savants are those persons in whom musical, artistic, mathematical or other special skills are more prominent and highly honed, usually within an area of single expertise, and are very conspicuous when viewed against their overall handicap. The term prodigious savant is reserved for those very rare persons in this already uncommon condition where the special skill or ability is so outstanding that it would be spectacular even if it were to occur in a non-handicapped person.
Savant syndrome occurs four to six times more frequently in males than females.
While a number of theories have been put forth to date, no single theory can explain all savants. Some of those theories have included eidetic imagery or the related but separate phenomenon generally called photographic memory; inherited skills; sensory deprivation and sensory isolation with overcompensation in isolated skills, compensation, ritualistic practice and reinforcement of very narrow skills to offset and compensate for lack of more general capacity or intelligence; and phenomenal memorizing ability. There are problems with each of those theories.
Even beyond that, however, research by Geschwind and Galaburda, demonstrated in the developing human fetus the left hemisphere of the brain always completes its development later than the right hemisphere. Therefore the left hemisphere of the brain is exposed for a longer period of time than the right to brain insult or injury of any kind. One such type of neuronal damage can be produced by circulating testosterone, which in the male fetus, reaches very high levels and can be, in some instances, neurotoxic. This same testosterone mediated developmental injury, causing left hemisphere brain damage before birth in males may account for the same highly disproportionate male:female ratio seen in some other forms of CNS injury such as stuttering, dyslexia, hyperactivity, other learning disabilities and autistic disorder itself.
For example formal testing shows the presence of eidetic imagery in some, but not all, savants. Two studies, one of 25 savants and another of 51 savants showed relatives with special skills or abilities in some, but not all cases; another study of 23 savants found only one family member with special skills.
In addition to left brain injury and right brain compensation, in the savant, it is postulated that there is damage to the higher level cognitive or semantic memory circuitry, with enhanced compensatory function in the lower level, more primitive, habit or procedural memory circuitry. This results in reliance on the characteristic
The first ever written account of Savant syndrome appeared in a German Psychology journal, Gnothi Sauton, in 1783. It described a man named Jerediah Buxton who was a lightning calculator with "An extraordinary memory". Six years later, in 1789, Benjamin Rush, who has been dubbed the "father of American psychiatry", as he was the first to believe that mental illness is a disease of the mind and not a "possession of demons", provided reports of Thomas Fuller, a lightning calculator. Fuller, according to Rush, could scarcely comprehend anything else, either theoretical or practical. However, when asked how many seconds a man had lived who was 70 years, 17 days and 12 days old, he gave the correct answer of 2,210, 500, 800 in 90 seconds, even allowing for the 17 leap years that had occurred.
John Langdon Down is best known for being the first person in the medical profession to describe the set of symptoms, both physical and neurodevelopmental, that came to be known as Down's Syndrome. What Down is less well known for is being the first person to coin the term "Idiot Savant". In 1887, almost 100 years after Rush had described the abilities of Thomas Fuller, Down presented at a lecture at Earlswood Hospital, reflecting on his 30 years as a physician there, cases of ten different individuals with special faculties. One had memorised "The rise and fall of the Roman Empire" verbatim and could recite it off by heart, backwards or forwards. Other children Langdon Down mentioned drew with remarkable ease and skill, in incredible detail, but had showed a comparative blank in other areas. He called the individuals he described "Idiot Savants" because of the seemingly contradictory abilities and skills that they showed.
In 1887 "Idiot" was an acceptable classification for a person with severe learning disabilities, in both society and the medical profession. Both would use the term freely for many more years, before it gained circulation as an insult amongst the wider population. The French word "Savoir" means to know. As a result, Down joined the words together.
Tredgold in 1914, also from Earlswood Hospital, wrote a very comprehensive account of savant syndrome in a chapter in his well-known textbook, Mental deficiency. This classic chapter, which was carried for many years into subsequent editions, described over 20 additional cases from a variety of clinicians. Hill (1978), provided a review of the literature between 1890 and 1978, including 60 reports involving over 100 savants.
Then, on Wednesday 25th February 1987, the BBC's QED series broadcast an episode called "The Foolish Wise Ones". It showed Stephen Wiltshire, then almost 13 years old, producing from memory drawings of London buildings, in incredible, remarkable and fantastic detail. Other savants were feature. This was probably the first time savants had been featured on Television live, in such detail.
