Social Attention As a Baseline Measure of Social Motivation in Toddlers with Autism Spectrum Disorder

Background:  Diminished social attention is a well-established early-emerging feature of autism spectrum disorder (ASD). Decreased eye contact is among the earliest observable behaviors in toddlers and children with ASD and eye-tracking technology has captured decreased attention to social stimuli as one of the earliest behavioral indicators of ASD in infancy (Chawarska, Macari, & Shic, 2013; Jones & Klin, 2013). It is suggested that these patterns of attenuated social attention are indicative of reduced social reward sensitivity and reduced social motivation, a core feature of ASD (Chevallier et al., 2012). A greater understanding of how social motivation is related to the behavioral manifestation of autism symptoms could elucidate developmental pathways contributing to social-communicative skills and reveal behavioral profiles that uniquely predict differential treatment outcome.

Objectives:   The current study presents baseline data from an early intervention study in which eye-tracking was used as a behavioral indicator of social motivation prior to onset of treatment in a group of 24-48-month-old toddlers with ASD. Baseline levels of social motivation were measured and compared to performance of age-matched typically developing toddlers. Social attention was then compared to behavioral performance on standardized measures and parent-child interactions. 

Methods:   Participants were 24-48-month-old toddlers with ASD and age-matched typically developing (TD) toddlers. All participants were presented with a social preference paradigm modeled after the social preference task created by Pierce et al. (2011). Six 5 s videos depicted clips of children engaging in high-motion behaviors presented side-by-side with clips of non-social high-motion geometric patterns. Social preference ratios across the six videos were calculated for each participant and compared both between and within groups. Within-group analyses for participants with ASD included correlations between social preference ratios and standardized measures (ADOS, Mullen Scales of Early Learning, and Vineland Adaptive Behavior Scales) and social-communication during naturalistic parent-child interactions.

Results:   Results were consistent with Pierce et al. (2011) demonstrating a significantly lower mean social preference ratio for the ASD group (M=.57; SD = .08) compared to the TD group (M=.70; SD=.12). Additionally, social preference ratios were negatively correlated with parent-reported socialization and positively correlated with frequency of undirected vocalizations during naturalistic parent-child interactions. Finally, total attention to any part of the screen during this task was moderately associated with nonverbal developmental quotient, expressive language, and fewer autism symptoms. 

Conclusions:  These results extend previous findings and suggest that toddlers with ASD have significantly lower baseline levels of social motivation than TD toddlers measured through a simple social preference task. Additionally, it provides evidence for hypotheses that increased social motivation may serve as a protective factor associated with more advanced social-communicative skills and decreased autism symptomology that may lead to enhanced treatment effectiveness. Results also suggest that overall attention may be associated with autism severity and therefore could play a mediating role in tasks attempting to capture social motivation in this population. Additional post-intervention data will enhance these findings and reveal how social motivation may be a prognostic indicator for treatment outcome for toddlers with ASD.