The Role of Infant Physiology on Dyadic Coordination and Social Communication in the Emergence of ASD

PROJECT SUMMARY Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized in part by difficulties with social communication. Social impairments are evidenced across the lifespan in ASD and often become more apparent throughout early childhood. Interestingly, robust behavioral indicators of ASD prior to 12 months of age have yet to be uncovered. This may be due to a focus on core social features that have not fully emerged within the first year. To gain a mechanistic understanding of ASD that can inform detection and intervention before 12 months, researchers must look beyond social behaviors. The contributions of infant physiology to social-interactive behaviors have been well-documented in typical development, but the role of this developmental context for predicting social-communication outcomes, including those associated with ASD, is understudied. Infant physiological regulation, indexed by respiratory sinus arrythmia (RSA), is predictive of in-the-moment parent- infant dyadic coordination and later social communication. Dyadic coordination directly relates to the emergence of the infant’s capacity for more complex and reciprocal social interactions around 6- to 9-months of age. This transition marks the emergence of social communication skills, thereby providing evidence for a cascade wherein physiology supports coordination which begets social communication. While understudied, evidence suggests that this dynamic developmental context is disrupted in ASD. By leveraging data from the first-ever study to utilize head-mounted eye tracking to capture the dynamics of social interactions in infants at elevated likelihood for ASD, the current proposal will therefore examine the longitudinal associations between these factors in a group of infants at elevated and low likelihood for ASD. Specifically, the study aims are to (1) compare dyadic coordination using dynamic systems modeling at 4- and 8-months-old, (2) to identify the role of infant physiology on dyadic coordination, and (3) to examine relationships between RSA and dyadic coordination on 18-month social communication. Results have the potential to elucidate a novel mechanistic understanding of the early development of social communication skills. This research will be implemented within the outstanding training environment at the University of South Carolina with full support from the primary mentor, Dr. Jessica Bradshaw, and an exceptional interdisciplinary team of Co-Sponsors. The proposed training plan focuses on (1) advanced training in translational and clinical research in the infant period in ASD, (2) development of dynamic systems modeling skills that can be applied to both behavioral and physiological data, (3) developing expertise in validating and disseminating a novel RSA tool, and (4) refining essential professional development skills to support the transition into a tenure-track research career. The proposed research and related training experiences will provide the fellow the necessary skillset to develop a programmatic line of translational research that is focused on identifying both social and physiological mechanisms underlying the development of ASD that can inform novel methods for diagnosis and intervention.