Autism prodrome 7 of 89
technologies it was possible to start conducting large scale prospective studies
regarding the development of children with ASDs and children at risk for ASDs.
What can we learn about the prodrome of ASDs from home video
studies?
Evidence for developmental difficulties in infants who are later diagnosed
with ASDs is provided by investigators who analyzed home movies made available
by parents. These retrospective studies offer an opportunity to explore the early
behavioral characteristics of children with ASDs, with the advantage of enabling
unbiased, trained observers who are blind to later diagnoses to examine the child's
behavior over time and across different situations as well as in a natural context.
Although this methodology has some advantages in that natural occurring behavior
prior to diagnosis is evaluated, home videos also suffer from some limitations as the
data is not standardized and parents may chose to videotape their children when the
children are at their best and not necessarily while manifesting some of the behaviors
which may be of most interest to researchers studying the early emergence of ASDs.
Studies vary in the use of comparison groups (e.g. typically developing children vs.
children with an intellectual disability but not an ASD), the types of behavior coded,
and the time window in which video captured materials were available (See Table 1;
for a summary of studies).
Losche (1990) was the first to analyze home videos of children who were later
diagnosed with ASDs in comparison to a group of typically developing children (age
ranged from 4 to 42 months). Impairments in sensorimotor development, joint social
activities, and symbolic play were evident in the ASD group compared to the typically
developing group. Adrien et al. (1993; 1991) examined home movies of infants (birth
to 24 months) and found that early symptoms prior to age of 12 months that were