Using functional magnetic resonance imaging technology (fMRI) the Florey scientists have shown that children with autism have less activation in the deep parts of the brain responsible for executive function (attention, reasoning and problem solving).
Research leader Dr Ross Cunnington said autism was known to have a biological cause, but this neuroimaging research clearly showed the dysfunction in the brain that accounted for why children with autism have problems with their executive function.
"Discovering why children with autism have impaired executive function may help develop better therapies to improve their ability to pay attention and solve problems," Dr Cunnington said.
Specifically, we found that activity in the caudate nucleus, a critical part of circuits that link the prefrontal cortex of the brain, is reduced in boys with autism."
"These findings have important implications, since prefrontal brain circuits play a critical role in maintaining and focusing attention, planning and setting goals, and keeping goals in memory during problem-solving and decision-making."
"Our neuroimaging findings showing dysfunction in these prefrontal brain circuits now explain why children with autism have problems with learning and problem-solving," he said.
Dr Cunnington along with PhD student, Tim Silk, have also been studying children with attention deficit hyperactivity disorder (ADHD) and have found similarities in the impairment of specific executive function in children with ADHD and autism.
The autism study was conducted with boys aged 11 to 18 years who had autism or Asperger's disorder, as well teenage boys without the condition.
Autism affects one in 100 Australians and is lifelong condition that affects the way a person communicates and relates to other people. People affected by autism typically display major impairments in social interaction, communication and behaviour (restricted interests and repetitive behaviours).
The majority of people with autism also have an intellectual disability. Those with Asperger's disorder are typically of average or above average intelligence and may have relatively good communication skills but specific learning difficulties.
The Florey scientists collaborated with scientists from Monash University, the Brain Research Institute and Texas Tech University in the USA. The results of this research are soon to be published in American Journal of Psychiatry.