Date of Award

Summer 2023

Document Type

Open Access Dissertation


Communication Sciences and Disorders

First Advisor

Jessica Klusek


Social communication difficulties are a core feature of autism and are associated with a range of long-term consequences, including persistent deficits in pragmatic language and fewer and poorer quality friendships. High-quality synchronous interactions between parents and their children play a crucial role in children’s social functioning. The theory of biobehavioral synchrony suggests that the dyadic coordination of behavioral and physiological processes is essential to maximally benefit from a communicative exchange. Respiratory sinus arrhythmia (RSA) serves as an indicator of physiological regulation and is reduced in those with autism; thus, dyadic coordination of RSA may also be impacted and could play a role in social communication differences in this population. The examination of synchrony across physiological and behavioral modalities in the context of autism is limited, and accounting for both behavioral and physiological coordination of the parent-child dyad is critical to understand how these exchanges can be optimized to better support social functioning in autism. Therefore, this dissertation included three studies that aimed to better understand the relationship between dyadic synchrony and social functioning using a biobehavioral approach.

Given the considerable variation in methodological approaches to studying biobehavioral synchrony, a scoping review of the existing biobehavioral synchrony research was conducted in Study 1 to determine the most common and appropriate methods used to study both behavioral and physiological synchrony in autism. Study 2 investigated RSA synchrony in 40 mothers (M age = 40 years) and their school-aged autistic children (M age = 8 years) during a collaborative, goal-oriented task. Additionally, this study examined the moderating effect of behavioral synchrony on RSA synchrony. Results of Study 2 demonstrated evidence of negative RSA synchrony in mothers and their children with autism, such that when one partner displayed an increase in RSA, the other partner showed a decrease in RSA. Behavioral synchrony did not moderate the concordance of mother-child RSA, challenging the assumption that physiological and behavioral synchrony are dependent on one another, at least in the context of autism. Using the same sample from Study 2, Study 3 examined whether mother-child RSA synchrony and its interface with behavioral synchrony is associated with pragmatic language abilities and friendship quality in autistic children. While results from this study did not show a relationship between either modality of synchrony and child friendship quality, negative RSA synchrony was associated with better child pragmatic language abilities in mother-child dyads who displayed high levels of behavioral synchrony. The results from Study 3 emphasize the importance of both physiological and behavioral synchrony as a potential foundation for pragmatic language skills that extend beyond the caregiver context.


© 2023, Carly Glenn Moser

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