Washington: In what could turn out to be
a potential tool in the diagnosis of autism, scientists claim
to have discovered that a person`s performance on autism test
can be predicted from an EEG.
An international team has demonstrated that markers
for autistic tendency could be seen in an electroencephalogram
(EEG) and 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.
"This can be measured by the Autism Spectrum Quotient.
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,"
lead scientist Dr David Crewther of Swinburne University said.
Their study 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. The data showed
a striking ability to predict high or low AQ score.
"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 said, adding that further research is needed to find
out whether these neurological markers can be recorded in
children and infants.
The findings have been published in the latest edition
of the `Brain` journal.