Neuromarker for autistic tendency revealed

A potential tool in the diagnosis of autism spectrum disorders has been revealed with Swinburne researchers demonstrating that markers for autistic tendency can be seen in an electroencephalogram (EEG).

In a study published in the prestigious neuroscientific journal Brain, Alexandra Sutherland and Dr David Crewther suggest that this tendency can be predicted through physiological recording of visual activation of the brain.

"Everyone has some degree of autistic tendency, expressed in terms of socialisation preference, scope of imagination, level of rigidity in opinion and whether or not we are fascinated by patterns, numbers and so on," Crewther said.

"This can be measured by the Autism Spectrum Quotient (AQ). However few would expect that scores based on behavioural questions such as whether you are good at social chit chat could be predicted by physiological recording from the brain.

"The aim of this study was to test whether low- and high-scoring individuals on the AQ scale differed on measures of local and global processing and visual pathway integrity."

The results showed abnormal processing of the fast visual stream – the magnocellular pathway, which transmits information about movement and transient attention – in those with a high AQ score (range 20–34) compared to those with a low AQ score (range 4–11).

"Tiny electrical responses recorded from the brains of high scoring individuals showed a delay in completion of magnocellular firing, suggesting that object recognition is dominated by the slower parvocellular stream," Crewther said.

"The data obtained showed a striking ability to predict high or low AQ score," Crewther said.

"This is particularly remarkable as the AQ scale is purely social/behavioural in nature and studies indicate that several factors are involved in the explanation for autism."

Crewther added that further research is being undertaken to determine whether these neurological markers can be recorded in children and infants.

(Source: Swinburne University of Technology: Brain: July 2010)