Autism spectrum disorders (ASD) is the name for a range of developmental disturbances leading to difficulties with social interaction, communication, and repetitive, restricted patterns of behavior. In the United States, there are 10 times as many diagnoses of autism as there were 40 years ago, with one in 88 American children now being diagnosed with ASD.
ASD can typically be recognized before a child’s third birthday, and some signs can appear in the child’s first or second year of life. Presently, however, a reliable diagnosis can only be made when a child
turns about two, though screening tests can point to possible signs of the disorder in children 18 months or younger.
Studies with younger siblings of children diagnosed with ASD have made some progress in identifying signs of autism earlier. This is because if one child has autism, the child’s siblings have 35 times the average risk of developing the disorder.
A study by Yale University, published online in the January 2013 edition of the journal Biological Psychiatry, used this increased risk in siblings of autistic children, to detect signs of ASD in six-month-old infants.
The researchers followed a group of infants from age three months to three years. They were assessed at three years of age, when some were found to have ASD. Among the baby siblings of these three-year-olds, 67 babies were deemed at high risk for ASD because their older siblings had autism, and 50 were at low risk, because no one in their family had autism.
The babies were shown a three-minute video where an actress performed routine tasks, such as making a sandwich and playing with some toys. The woman would also periodically try to engage the babies’ attention by looking at the camera, and making comments like “How are you, baby?” or “You are so cute!”
The babies were allowed to look at whatever was of greatest interest to them. Researchers used eye-tracking technology, to measure how often the babies looked at the scene in the video, the toys, the woman, her eyes and her mouth.
The study tried to determine whether children who later develop ASD showed a comparable level of interest in other humans as babies who are developing normally.
Compared to the control groups, infants who were later diagnosed with ASD showed less interest in the complex social scene portrayed in the video. They also spent less time looking at the woman actress and her face. However, they did not look longer at the toys shown in the video.
According to the researchers, these findings suggest that difficulty in paying attention to people might come before the excessive interest in objects that older children with ASD often display.
Before this study, it was not clear whether this precursory symptom of autism, decreased attention to other humans, was present during a child’s first year of life.
The study indicates that it may be possible to identify signs in babies, related to diminished visual attention, which could be used to determine which infants are at greater risk for ASD. This could in turn make earlier intervention and treatment possible.
By Lisa Pecos