What is Autism?Tracing the Beginnings of ASD
The Latest Research is Redefining Autism
Research groups around the world have mounted an intensive effort to understand the early development of infants who later go on to be diagnosed with ASD. Their goal is to learn about early factors that may distinguish “ASD infants” from typically developing children.
Researchers compare the development of younger siblings of ASD diagnosed children, who themselves go on to be diagnosed, to those that do not, as well as to a ‘low risk’ comparison group. Infants are recruited in the first months of life and followed until the time when a diagnosis can be made. In other studies, researchers ask parents to provide videotapes of the early months of life of children who have already been diagnosed with ASD (for example their first birthday party). These videos are then compared to video clips provided by parents of a matched group of typically-developing children.
Failure to Find Early Differences
Researchers have found that many ASD infants, when observed at 6-7 months-of-age gaze at their mothers, smile and vocalize in ways that are similar to their typically-developing peers. Autism expert Dr. Helen Tager Flusberg noted:
“During the earliest months there are no clear differences between infants who later meet criteria for ASD and other infants. These babies show social interest and engagement, they smile at other people, the follow eye gaze, vocalize and have good eye contact during face-to-face interactions.”
Divergence During the Second Year
In contrast to their similarities at 6-7 months, the same groups of ASD infants over the course of their second year are exhibiting a dramatic divergence from typically-developing peers. Both retrospective and prospective studies report consistent group differences, differentiating children with ASD from Typically Developing comparison groups, as well as those infants who go on to have other developmental disabilities, starting at around one year and becoming quite dramatic by 18 months of age.
Based on these findings, many scientists believe that in the vast majority of future ASD infants, something critical takes place during infancy resulting in this divergence. While a great deal of study is now being directed to this issue, what exactly happens during this period is still somewhat of a mystery to researchers.