Dynamic Allocation of Visual Resources In the First 6 Months

Background: From birth, infants actively shape the environment in which they interact and learn by specifically directing their attention to content they perceive to be salient. For example, longitudinal studies of eye-tracking data suggest that infants who are later diagnosed with autism spectrum disorders (ASD) decrease the amount of time they spend looking at the eyes during their first 6 months of life, which, in turn, shapes the information they have access to. While this method of quantifying attention provides a summary of individual viewing, it does not show how viewing changes dynamically from one moment to the next. A novel method for quantifying visual attention continuously assesses group agreement in the allocation of visual resources within a certain context. This method provides a dynamic measure of group tendency as well as a measure of individual deviation from group norms. Previous research using this method has demonstrated that older children with ASD often fail to attend to content that is highly salient to typically developing peers. This research suggests that dynamic measures of visual attention may be useful as an early indicator of ASD.

Objectives: This study aims to identify the earliest age at which measures of dynamic visual attention indicate a child’s risk for developing autism. Specifically, this research will 1) provide information about aspects of the environment that are salient to typically developing infants, and 2) investigate the process by which children with ASD construct alternative schemas of salience during infancy.

Methods: Data were collected prospectively and longitudinally from cohorts of infants at high- or low-risk for ASD (infant sibling study design), and conventional diagnostic evaluations at 24 months defined two groups: typically-developing children (TD, N = 25), and children with confirmed ASD diagnosis (ASD, N = 11).  Eye-tracking data were collected during viewing of naturalistic movie scenes. Allocation of visual resources was quantified by kernel density analysis at each moment in time in typically developing children to create a continuously changing map of normative visual salience in relation to movie-content. This process was repeated using infant eye-tracking data from children with ASD, and differential landscapes of salience for this group were constructed and compared to salience data from the typically developing group.

Results: Preliminary results suggest that children with ASD begin to exhibit unique strategies for allocating attention as early as 4 months of age. During the first 6 months of life, typically developing infants diminish their attention to physically salient stimuli in favor of more socially relevant content. In addition, results indicate that individual measures of deviance from typical viewing patterns increase over time for children with ASD.

Conclusions: Overall, this research demonstrates that dynamic measures of visual attention reveal early indicators of risk for ASD in the first 6 months of life. Furthermore, because of the importance of attention for learning, this study suggests that intervention programs may capitalize on early development in ASD through better measures and improved understanding of what is or is not inherently salient to infants with ASD.