Brain scan using EEG
Credit: Wikimedia
WASHINGTON, D.C.: Unusual patterns in brain activity have been found in individuals with autism spectrum disorders, Australian researchers said.
The findings suggest that an EEG scan could be an effective, non-invasive aid for early detection of the disorder in children, and that brain scans could be a useful tool in behavioural therapies.
"The aim of this study was to test whether low- and high-scoring individuals on the AQ (autism spectrum quotient) scale differed on measures of local and global processing and visual pathway integrity," said David Crewther from Swinburne University of Technology in Melbourne, Australia, lead author of the study, published in the journal Brain.
Scans compared to 'Autism quotient scale'
The autism spectrum quotient is a series of questions regarding social and behavioral tendencies. Answers to these questions determine whether an individual has traits of an autism spectrum disorder.
Scores range from about 15 in normal people to above 30 in high functioning autistics and those with Asperger's Syndrome, a condition on the autistic spectrum.
The researchers looked at the AQ scores taken from test subjects and compared them to the results of their electroencephalographies (EEGs), which are recordings of the brain's electrical activity.
One brain pathway slower
The brain perceives objects via two pathways, which function independently. The first is the magnocellular pathway, which detects objects and their boundaries and helps to govern depth perception and motion. The other is the parvocellular pathway, which is responsible for the perception of color and detail.
According to Crewther, scientists found that those with high AQ scores (or a higher autistic tendency) were more likely to rely on the visual pathway known as the parvocellular system because of a delay in magnocellular firing in their brains, which is reflected in their brain scan.
"This is a wonderful study that changes how we think about autism spectrum disorders," said Robert Froemke, a neuroscientist at the University of California, Berkeley.
