What autism tells us about development of savant skills

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http://www.irishtimes.com/newspaper/sciencetoday/2009/0702/1224249896390.html

Thursday, July 2, 2009

What autism tells us about development of savant skills

WILLIAM REVILLE

UNDER THE MICROSCOPE: ALTHOUGH SAVANT syndrome is not an officially recognised

medical diagnosis, Darold Treffert, an American research psychiatrist, who was a

consultant for the film Rain Man , defines the savant syndrome as " a rare

condition in which persons with developmental disorders have one or more areas

of expertise, ability or brilliance that are in contrast with the individual's

overall limitations " .

Langdon Down (1828-1896) was the first to describe the savant syndrome (he

is also known for his description of Down syndrome). Down used the term " idiot

savant " to describe the condition and this terminology was used until well into

the 20th century. Back then, the term " idiot " was accepted within the scientific

community to describe a person with an IQ below 20. That term is now

unacceptable because it offends personal dignity, but it is also technically

incorrect, since almost all cases of savant syndrome have IQs above 40.

About half those diagnosed with savant syndrome are autistic and the term

" autistic savant " was also used in the past, but no longer. About 10 per cent of

autistic people have savant skills. Also, male savants are six times more common

than female savants. Although it is extremely rare, some savants show no

evidence of abnormalities accompanying their unique abilities.

Paravicini is a typical example of savant syndrome (described by Celeste

Biever in New Scientist , Issue 2711, June 2009). He is a 29-year-old musical

savant. has severe general learning difficulties and needs everyday

support. Yet he can play on the piano any musical piece you request, entirely

from memory and with considerable technical skill. He doesn't simply regurgitate

music he has heard, but constantly improvises the pieces.

Many readers will have seen the 1988 film Rain Man, starring Tom Cruise and

Hoffman. Hoffman plays autistic savant Babbit, who can remember

everything he reads and do lightening-fast calculations in his head. The

character was based on real-life Kim Peek who lives in Salt Lake City. Peek is a

savant who is not autistic. He probably suffers from Opitz-Kaveggia syndrome, a

genetic syndrome linked to the X chromosome that causes developmental delays and

physical anomalies. Peek has a photographic memory. He reads a book in about an

hour and remembers almost everything he reads. He can recall the content of more

than 12,000 books.

Savant syndrome is poorly understood. The latest research is published in the

Philosophical Transactions of the Royal Society B, Vol 364, 2009. It used be

thought that the amazing talents displayed by savants emerge fully formed, but

it is now believed that such skills are more common than previously thought and

may even arise from traits found in the general population. Furthermore, savant

skills may develop only after years of obsessive practice.

Since half of all savants are autistic, autism must hold some clues to the

origins of the special talents. One study has identified the capacity of

" remembering details that other people miss " as the biggest indicator of special

talent in autistic children. This eye for detail seems to give one a " foothold

into talent " . Biever speculates that, in the case of musical savants such as

Paravicini, a bias towards noticing small details could lead their developing

brains to home in on the exact notes more than the overall melody, encouraging

outstanding musical memory and perfect pitch. In general, people with autism are

hypersensitive to sensory information.

Biever describes studies that have shown that savant brains are physically

somewhat different from average brains. These differences may not be innate,

rather they may develop with practice. Some London taxi drivers have an

encyclopaedic knowledge of the layout of 25,000 streets and thousands of places

of interest. Studies have shown differences between their brain structures and

the brains of adults who do not drive taxis. These differences become less

pronounced after the drivers retire. It seems that they start out with typical

brains that then develop with training and practice to accommodate the special

skill.

Many things no doubt make essential contributions to the development of savant

skills. It seems that one of these things, overlooked in the past, is

motivation. Autistic savants obsessively practice their skills. Adam Ockelford

(quoted by Biever), a professor of music, has watched Paravicini's talent

develop since the age of four. At first, Paravicini was entirely self-taught and

bashed at a plastic keyboard with fists and elbows to reproduce the sounds he

heard. His technical skills developed only after years of practice. But he was

motivated far beyond the average music student and practised " as if his life

depended on it " . Hard work seems to play an essential part in the development of

savant skills.

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Reville is associate professor of biochemistry and public awareness of

science officer at University College Cork – http://understandingscience.ucc.ie