Signs of autism may be traced all the way back to early infancy, according to a study that found a link between autism and a steady decline in babies' attention to others' eyes within the first two to six months of life.
"Autism isn't usually diagnosed until after age 2, when delays in a child's social behavior and language skills become apparent. This study shows that children exhibit clear signs of autism at a much younger age," said Thomas Insel, director of the National Institute of Mental Health "The sooner we are able to identify early markers for autism, the more effective our treatment interventions can be."
Researchers used eye-tracking equipment to measure the eye movements of infants divided into two groups based on their risk for developing autism. Each child was tested 10 different times between two and 24 months of age.
After some of the children, nearly all from the high-risk group, were diagnosed with autism spectrum disorder, the researchers were able to review the results from their eye-tracking tests in order to detect in any differences between them and the other children.
In doing so, they detected a clear decline in the amount the babies looked at eyes that began between two and six months, and continued throughout the study.
The discovery was surprising to the researchers based on the evidence that social behaviors, once believed to be entirely absent in those with autism, were present for a short time after birth.
"This insight, the preservation of some early eye-looking, is important," Jones said. "In the future, if we were able to use similar technologies to identify early signs of social disability, we could then consider interventions to build on that early eye-looking and help reduce some of the associated disabilities that often accompany autism."