Baby’s gaze may signal autism, study finds
Researchers focused on babies’ ability to make eye contact with caregivers, since lack of eye contact is one of the hallmarks of the developmental disorder.
Los Angeles Times
LOS ANGELES — Children with autism spectrum disorders usually aren’t diagnosed until they are at least 2, but a new study finds that signs of the condition are apparent as early as two months after birth.
Researchers focused on babies’ ability to make eye contact with caregivers, since lack of eye contact is one of the hallmarks of autism. Among typical children, interest in the eyes increased steadily with age.
But for those with autism, interest in the eyes waned starting between 2 and 6 months of age.
By the time the children reached their second birthdays, levels of eye fixation were only half as high as levels seen in typically developing children, according to a report published Wednesday in the journal Nature.
Although researchers expected to see a difference between the two groups, they were surprised that the infants later diagnosed with autism started out developing just like their peers. That suggests “some social adaptive behaviors may initially be intact” in babies’ brains, which would “offer a remarkable opportunity for treatment,” the researchers wrote.
Warren Jones and Ami Klin of the Marcus Autism Center at Emory University School of Medicine in Atlanta recruited 110 infants for their study. Among them, 59 had a sibling with an autism spectrum disorder and thus were considered at high risk for the condition.
An additional 51 infants who had no first-, second- or third-degree relatives with autism were considered low-risk, and they served as controls.
The infants were shown “scenes of naturalistic caregiver interaction” while the researchers used eye-tracking technology to monitor where the babies focused their gazes. They measured the proportion of time spent paying attention to a woman’s eyes, mouth, body (including neck, shoulders and hair) and nearby inanimate objects.
The subjects were tested 10 times over the course of the study, when they were 2, 3, 4, 5, 6, 9, 12, 15, 18 and 20 months old.
By the time the toddlers were 3 years old, 13 were formally diagnosed with an autism spectrum disorder — 10 boys and two girls from the high-risk group and one boy from the control group. For the sake of simplicity, the analysis focused on boys: 11 with autism and 25 without.
The data showed that distinct differences in eye interest became apparent when the babies were between 2 and 6 months old. The boys in the control group spent more time focused on the caregiver’s eyes than the mouth, body or object regions. But for the boys with autism, interest in the caregiver’s eyes steadily declined after the 2-month test.
The researchers also found that steeper declines in eye interest tended to be linked to more severe cases of social disability.
If the results are confirmed and doctors are able to identify children with autism as early as 2 months of age, therapists could intervene earlier and perhaps get better results.
“The sooner we are able to identify early markers for autism, the more effective our treatment interventions can be,” said Dr. Thomas Insel, director of the National Institute of Mental Health, which paid for the study.