Developmental Trajectories of Attention to Social and Nonsocial Events As a Function of Chronological and Mental Age in Children with Autism and Typical Development

Background: Compared to typically developing (TD) children, children with autism (ASD) show impairments in intersensory processing and in maintaining and disengaging attention to social events (see Bahrick & Todd, 2011). Because symptoms of ASD increase across development, and children with ASD show wide variability in cognitive functioning, it is critical to assess which attention skills are maintained vs. become increasingly impaired across development, whether mental age (MA) is a better predictor of change, and how trajectories differ as a function of diagnostic group. These questions can be addressed using the Multisensory Attention Assessment Protocol (MAAP; Bahrick & Todd, 2011; Newell et al., 2007), a comprehensive, nonverbal test of attention to dynamic audiovisual social and nonsocial events that assesses four fundamental indices of attention.

Objectives: We assessed developmental trajectories for attention disengagement, orienting, maintenance, and intersensory processing for social and nonsocial events across 2-5 years of age in children with ASD and TD. We evaluated whether skills increased, decreased, or were maintained across chronological age (CA) and whether MA was a better predictor and resulted in different trajectories compared to CA.

Methods: Children with ASD (N=18; M=4.19 yrs, SD=.87, range: 2.50 to 5.58 yrs), who passed cutoff on the ADOS, and TD children (N=26; M=3.15 yrs, SD=1.15, range: 1.75 to 5.75 yrs) participated. Mullen adjusted MA was calculated (ASD: M=2.30, SD=1.23; TD: M=3.44, SD=1.22). In the MAAP, trials of a central visual event followed 3 s later by two side-by-side peripheral events (10s) with the natural soundtrack synchronized with one of the events, were presented. Trials of social (woman speaking), and nonsocial events (objects striking a surface) were presented. Intersensory matching (looking to sound-synchronous events), attention maintenance, disengagement (RT to shift from the competing central event), and orienting (RT to shift without the competing central event) were assessed.

Results: Regression analyses revealed that with increasing CA, TD children showed increased attention maintenance and intersensory processing for social events (ps<.01). In contrast, children with ASD showed no significant changes across CA for any measure. MA was a better predictor of performance than CA in both groups (average R² increase=.11). As MA increased, TD children showed increased attention maintenance and intersensory processing for social events (ps<.05), whereas children with ASD showed increased attention maintenance and decreased latencies to disengage to social events (ps<.04), but no change in intersensory processing. No changes in orienting nor in attention to nonsocial events emerged for either group as a function of CA or MA.

Conclusions: Although TD children showed significant increases across CA in attention and intersensory processing of social events, children with ASD showed no significant change, indicating that they lose ground compared to TD children across 2-5 years of age. In contrast, ASDs showed increases as a function of MA in attention maintenance to social events (as did TDs) and faster attention shifting to social events. These findings indicated that MA is a significant predictor of social attention in ASD and with increasing MA, children with ASD show more typical attention patterns to social events.