Test to spot autism in babies at six months
Signs of autism can be detected in six-month-old babies by measuring their brain activity, research has shown.
Scientists say the test could help identify infants most at risk of developing the disorder later in life. Currently autism is not officially diagnosed until after the age of two.
Many experts believe affected children would benefit if therapy could be started at an even younger age.
Autism is a lifelong developmental disability that impairs a person's ability to connect socially and communicate.
The new research focused on six- to 10-month-old babies believed to be at increased risk of autism because they had an older brother or sister with the disorder.
Sensors placed on the babies' scalps measured brain activity while the infants were shown faces that switched between looking at them or away from them.
An association was seen between the responses and later diagnoses of autism.
The study suggests that the "autistic brain" processes social information differently right at the start of life.
Study leader Professor Mark Johnson, from Birkbeck College, University of London, said: "Our findings demonstrate for the first time that direct measures of brain functioning during the first year of life associate with a later diagnosis of autism -- well before the emergence of behavioural symptoms.
"Differences in the use of eye gaze to regulate social interaction are already a well-recognised early feature in many children with autism from the second year of life and at present it is these increasingly well-documented 'first signs' that will alert parents and professionals to possible differences.
"Future studies will be required to determine whether measurements of brain function such as those used in our study might one day play a role in helping to identify children at an even earlier age."
The findings are published today in the journal Current Biology.
Prof Johnson stressed that the observed trend did not apply in all cases. Some babies that showed the unusual responses in brain activity were not later diagnosed with autism, and vice-versa.
He said: "The method would require further refinement."