THE popular 1988 film, Rain Man, stars Dustin Hoffman as an autistic savant, and Tom Cruise as Hoffman's younger, materialistic and cynical brother. Both actors give great performances in an excellent film, particularly Hoffman in what must have been a most difficult role.
The savant syndrome is the term now used for a condition originally called the idiot savant syndrome. It was first described in 1789 by a physician named Benjamin Rush, a signatory of the American Declaration of Independence. Rush was amazed by the lightning calculations of a 79 year old slave called Thomas Fuller. Fuller, who understood little that was more complicated than counting, could answer questions, after a minute's reflection like how many seconds a man had lived who was 70 years, 17 days and 12 hours old. When told that his answer - 2,210,500,800 - was slightly incorrect, Fuller replied: "Massa, you forget de leap year." He was perfectly right.
A typical example of the savant syndrome is a person of low intelligence who nevertheless shows spectacular ability in a narrowly defined area. These abilities generally fall into one of the following categories - an aspect of musical ability, an aspect of artistic capacity, ability to perform lightning mathematical calculations, lightning calendar calculations and prodigious feats of memory.
The original term idiot savant has passed out of usage for two reasons. One is to do with modern sensibility and the other reason is that the original term is technically incorrect. The term idiot is a classical psychiatric one (no longer used) and technically means having an IQ lower than 25. Almost all savants who have been tested for intelligence have registered scores greater than 40. An IQ score of 90-109 is average, 80-89 is low average, 70-79 is border line handicapped, 55-69 is mild mental handicap, 40-54 is moderate mental handicap, 25-39 is severe mental handicap, and less than 25 is profound handicap (idiot). Most savants (85 per cent) are male and many are autistic.
The first detailed description of the savant syndrome was given by J. Langdon Down in 1887. Down was superintendent of the Earlswood Asylum in England. He came across several retarded children who exhibited odd Hashes of brilliant ability - lightning calculators, musical prodigy, and memory feats such as the boy who read Edward Gibbon's History of the Decline and Fall of the Roman Empire and then recited it perfectly.
A recent celebrated case of the savant syndrome is Leslie Lemke. Leslie was born in Wisconsin in 1953. He was given up at birth and lived in a children's home until he passed into the care of May Lemke at the age of six months. By this time his eyes had been surgically removed because of a congenital condition.
As he developed, it became apparent not only that he was spastic, but that he was incapable of holding the simplest conversation. He could, however, parrot what he heard, a condition known as echolalia, and he could repeat perfectly every word he heard during the course of a day. He could also accurately mimic every speaker.
HE showed an innate sense of rhythm and his prompted his oster mother to buy him a piano. By the age of 10 he had mastered the piano and several other musical instruments as well. He was, however, unable to dress himself or to eat with a knife and fork.
One evening the Lemke family retired to bed after watching a film on television May Lemke was awakened during the night by the sound of loud piano music. Thinking she had left the television on, she went into the living room to switch it off. She found Leslie there playing Tchaikovsky's Piano Concerto No. 1. This was the theme music of the film they had seen. Leslie had only heard the music once, but he could flawlessly reproduce it, note for note.
Leslie Lemke is mentally retarded and virtually incapable of abstract reasoning. He has a verbal IQ of 58, which classifies him as mildly retarded. When asked to fit shaped wooden blocks into appropriate cutouts on a wooden board, he is completely incapable of performing the task. Nevertheless, he has expertly mastered the 88 keys of the piano.
Lemke became an accomplished concert performer, playing a wide variety of compositions on the piano on cue from his minder. He sings songs in several languages and mimics singers such as Louis Armstrong, Nelson Eddy etc.
TWO calendar calculators, Charles and George, known as "The Twins" in medical circles, were very popular in the 1960s when they regularly performed an act on stage and television. They would ask the audience to call out any date in the past or the future 40,000 years and then, without hesitation, would announce the correct day of the week for that date. In addition, both could recall the weather, key news items and even the most mundane events from their own lives for every day back to the age of about four years.
They had an amazing recall for figures and could repeat a string of digits hundreds long with total ease. For their private amusement they would exchange prime numbers (a number divisible only by itself and by one). George would call out, for example, a 10 digit prime number. Charles would think for a minute and then flash back a prime number of 15 or 20 digits long. Prime numbers of this magnitude normally can be calculated only with the aid of a computer.
Charles and George each have an IQ of 60 and lack the ability to perform simple addition or subtraction.
There is as yet no satisfactory explanation as to how or why savants develop their special powers. It appears that the circuitry in the brains of savants develops somewhat differently to normal circuitry and this effect is usually mediated by the male sex hormone, testosterone.
In some cases, efforts to improve the general level of performance of savants results in a drastic or total diminution of their special powers. This happened in the case of the calendar calculating twins, who were separated 20 years ago to live apart in halfway houses. They could now do menial jobs under careful supervision. However, they seemed to lose their strange power with numbers and with that the chief joy in their lives.
This does not always happen, however. In other cases, an enhancement of artistic talents occurs in concert with successful efforts to broaden their language and social skills. This happened with Leslie Lemke, whose language improved greatly and who can now dress and eat with little assistance. His musical talent became richer over the years and he has experienced great personal growth. Darold A. Treffert, a psychiatrist who has worked with Lemke, has written of the savant syndrome in a book, Extraordinary People, published by Harper and Row (1988).