Parent responsiveness mediates the association between hyporeactivity at age 1 year and communication at age 2 years in children at elevated likelihood of ASD.

Studies suggest that higher parent responsiveness is associated with higher child language abilities. Infants and toddlers later diagnosed with autism spectrum disorder (ASD) often display hyporeactivity to sensory stimuli, which has also been associated with lower child communication abilities and lower parent responsiveness. Yet, whether parent responsiveness mediates the relationship between child hyporeactivity and later communication outcomes remains unexplored. This study is a secondary data analysis which includes children (n = 83; 56 males) identified as at elevated likelihood of later ASD. Children completed an observational measure of sensory reactivity and a standard developmental assessment at 14 (Time 1) and 23 months old (Time 2). At each time point, parents reported on the child's adaptive communication behaviors and sensory behaviors, and Parent Verbal Responsiveness (AvgPVR) was coded from parent-child free-play videos. Results indicated that the association between child sensory hyporeactivity at Time 1 (observed and parent-reported) and communication at Time 2 (observed and parent reported) was significantly mediated by AvgPVR. Although child hyporeactivity predicts poorer communication outcomes, increased parent verbal responsiveness may attenuate this negative impact. Parent responsiveness, a focus of many parent-mediated interventions, may be an important mechanism of treatment response that should be directly tested in future research. LAY SUMMARY: Toddlers at elevated likelihood of autism spectrum disorder (ASD) are often under-reactive (hyporeactive) to sensory stimuli. This hyporeactivity slows learning of communication skills and provides parents with fewer opportunities to respond to their children. In this study, children with hyporeactivity at 14 months generally had poorer communication at 23 months; however, the more responsive their parents were, the weaker the relationship between early hyporeactivity and later communication. Thus, increasing parent responsiveness may lead to better communication outcomes for toddlers with the early ASD symptom of hyporeactivity.