Autism Evident in Early Infancy by Tracking Eye Movements

Identifying autism early can make all of the difference in a child's life. Parents can begin treatment far earlier which could greatly improve the child's quality of life. Now, scientists have discovered that eye contact during early infancy may be a key to this early identification. They've shown the earliest sign of developing autism ever observed--a steady decline in attention to others' eyes within the first two to six months of life.

"Autism isn't usually diagnosed until after age two, when delays in a child's social behavior and language skill become apparent," said Thomas R. Insel, one of the researchers, in a news release. "This study shows that children exhibit clear signs of autism at a much younger age. The sooner we are able to identify early markers for autism, the more effective our treatment interventions can be."

Children with autism do not exhibit an interest in eye-looking. In fact, a lack of eye contact is one of the diagnostic features of this disorder. In order to find out how this deficit emerges, though, the researchers followed infants from birth to the age of three. They divided the infants into two groups based on their risk for developing an autism spectrum disorder--those in the high risk group already had an older sibling diagnosed with autism.

In order to watch for this lack of eye contact, the researchers employed eye-tracking equipment. This allowed them to measure each child's eye movements as they watched video scenes of a caregiver. The scientists then calculated the percentage of time each child fixated on the caregiver's eyes, mouth and body, as well as the non-human spaces in the images. The children were tested 10 different times between 2 and 24 months of age.

 "In infants later diagnosed with autism, we see a steady decline in how much they look at mom's eyes," said Warren Jones, one of the researchers, in a news release.

The researchers found that the drop in eye-looking began between two and six months and continued throughout the course of the study. By 24 months, the children later diagnosed with autism focused on the caregiver's eyes only about half as long as their peers. This finding in particular was somewhat surprising, since it reveals that social engagement skills are still intact shortly after birth in children with autism.

"This insight, the preservation of some early eye-looking, is important," said Jones in a news release. "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."

The findings are published in the journal Nature.