Comparison of Social Motivation and Sticky Attention Models of Early Development in ASD
Objectives: This study compared these two developmental models, Social Motivation and Attention theories, in a community-based sample of infants who screened positive on an autism screening inventory and were followed into early childhood.
Methods: Participants included 43 children identified at high-risk for a later diagnosis of ASD based on the First Year Inventory (FYI) community screening at 12 months of age. Toddlers were evaluated at 13 (Time 1) and 22 months (Time 2). A third evaluation was conducted during early childhood (age 3-5 years) to determine diagnostic outcome using the Autism Diagnostic Observation Scale, parent interview, and clinical judgment. Thirteen children were diagnosed with ASD and 30 children did not meet criteria for ASD at Time 3.
Video coding for social motivation (looking at people) and “sticky” attention (shifting of attention and RRBs) was completed using the Communication and Symbolic Behavior Scales (CSBS) at 13 and 22 months. Social motivation was defined as the proportion of time the child spent clearly looking at a person. An attention shift was identified when children disengaged their attention from a stimulus, shifted their gaze, and immediately re-engaged their attention with another stimulus. RRBs were measured using the CSBS RSM scale (Wetherby & Morgan, 2007). Group means are displayed in Table 1.
Results: Path analyses were conducted to evaluate the direct and indirect effects of measures of looking at people, attention shifting, and RRBs at Time 1 and 2 on ASD symptom severity as measured by the ADOS-2 comparison score after controlling for cognitive abilities at Time 1. Direct effects are shown in Figure 1. Results indicated a significant indirect effect from decreased looking at people at Time 1 to decreased attention shifting at Time 2 to increased ASD symptom severity during early childhood (β=-.36, p=.02). Further analyses indicated that this indirect effect remained when only examining social-specific shifting (i.e., attention shifting including a person) but was not present when only including non-social shifting (i.e., shifting attention between objects).
Conclusions: Using this longitudinal sample provides an opportunity to disentangle the role of social motivation and attention shifting. Results from this study better support the Social Motivation theory of ASD. Looking at people at 13 months predicted ASD symptoms during early childhood as mediated by attention shifting at 22 months. While impairments in attention clearly play an integral role in later diagnosis of ASD, attention shifting that included social information appears to play a larger role than attention shifting to non-social information. Future studies can examine trajectories starting earlier in development to better evaluate the developmental processes in ASD.