Tuesday, April 22, 2008

Autistic savant

Autism is a puzzling disorder characterised by developmental delays. A person with autism often has problems understanding the meaning and purpose of body language and the spoken and written word. They find social interaction difficult, confusing and scary.

'Autistic savant' means a person with autism who has a special skill. 'Savant' comes from the French word for 'knowing' and means 'a learned person'. A person with this condition was once known as an 'idiot savant', since 'idiot' was an acceptable word for mental retardation in the late 19th century, when the phenomenon was first medically investigated. Around 10 per cent of people with autism show special or even remarkable skills. For example, a person with autism, who may be intellectually disabled in most ways, could have an exceptional memory for numbers.

Savant skills are occasionally found in people with other types of intellectual disability and in the non-disabled population, so most researchers use the term 'savant syndrome' instead of autistic savant.

A range of savant abilities
Around 10 per cent of people with autism show special or even remarkable skills. The skills range includes:

* Splinter skills - the most common type. The person, like an obsessive hobbyist, commits certain things to memory, such as sports trivia.
* Talented skills - the person has a more highly developed and specialised skill. For example, they may be artistic and paint beautiful pictures, or have a memory that allows them to work out difficult mathematical calculations in their head.
* Prodigious skills - the rarest type. It is thought that there are only about 25 autistic savants in the world who show prodigious skills. These skills could include, for example, the ability to play an entire concerto on the piano after hearing it only once.

Specialised skill
In all cases of savant syndrome, the skill is specific, limited and most often reliant on memory. Generally, savant skills include:

* Music - the piano is the most popular instrument. For example, the skill may be the ability to play the piano without being taught.
* Art - such as the ability to draw, paint or sculpt to high standards. For example, Richard Wawro is an autistic savant who is also blind, but his crayon drawings command up to $10,000 each.
* Mathematics - for example, the ability to work out complicated sums in their head, or to calendar calculate (for example, work out what day it was on 1 June1732).
* Language - in rare cases, the person may be unusually gifted in languages.
* Other skills - such as knowing the time without seeing a clock, untaught mechanical skills, having an unfailing sense of direction or the ability to commit maps to memory.

The brain's right hemisphere
Autistic savant behaviour is so far unexplained. However, researchers think it might have something to do with the right hemisphere of the brain.

The brain is divided into two hemispheres, left and right, bridged by a thick band of nerve fibres called the corpus callosum. While left hemisphere skills are involved with symbolism and interpretation (such as understanding words and body language), the skills of the right hemisphere are much more concrete and direct (such as memory).

CT and MRI scans of the brains of autistic savants suggest that the right hemisphere is compensating for damage in the left hemisphere. It seems that the right hemisphere of an autistic savant focuses its attention on one of the five senses - for example, if it concentrates on hearing, then the autistic savant may have a special skill in music. Research is ongoing.

Their skills may be reinforced
It is thought that habitual memory centres of the brain take over from higher memory centres, which helps to explain why some autistic savants are like obsessive hobbyists who do the same thing over and over. Apart from habitual memory, other factors that may help an autistic savant to hone their special skill could include:

* The ability to focus and concentrate
* The desire to practise endlessly
* Positive reinforcement by family, friends and caregivers.

Every brain may have untapped savant skills
San Franciscan neurologist Dr Bruce Miller recently discovered new savant skills in some of his patients who were undergoing a certain type of dementia. These patients had a type of dementia that affected the left temporal region of their brains (located over the left ear).

When the patients were given brain function tests, their results were similar to those of a young autistic savant. Researchers from the Flinders University in Adelaide were able to provoke new savant skills in volunteers by using transcranial magnetic stimulation to temporarily 'disable' the frontal temporal lobe. (Transcranial magnetic stimulation is a type of treatment for depression.) During the test, five of the 17 volunteers showed new and remarkable skills like calendar calculation. These studies suggest that amazing savant abilities may be lying dormant in all of us.

Where to get help

* Your doctor
* Austism Infoline Tel. 1300 308 699 or email info@autismvictoria.org.au
* Autism Victoria Tel. (03) 9885 0533
* The Centre for Developmental Disability Health Victoria (CDDHV) Tel. (03) 9564 7511

Things to remember

* Autistic savant means a person with autism who has a special skill.
* Around 10 per cent of people with autism show special or even remarkable skills.
* Savant skills can be occasionally found in people with other types of intellectual disability and in the non-disabled population.

1 comment:

sietselogger said...

I agree. Fascinating subject. I saw bits of the Australian research on the National Geographic Channel recently, and it's stunning.