Does Dyadic Synchrony and Responsiveness in the First Year Inform Later Autism Diagnoses?

Background:  Within dyadic play interactions, infants and their partners create temporal responsiveness and synchrony (Feldman, 2007). In the first year of life, the ability to engage in sustained synchronous interactions develops as infants learn to match play partner behaviors and sequentially regulate their behaviors in response to others (Feldman, 2007; Fogel, 1993; Tronick, 1989). Difficulty developing competence in these early social building blocks can inform later difficulties with language, joint attention, and emotion regulation (e.g., Granat et al., 2016). For children at elevated risk for autism (i.e., infant siblings of children with autism), it is unclear if early synchrony could inform later autism diagnoses and/or developmental progress/concerns.

Objectives:  The present study explored if dyadic synchrony and responsiveness observed within the first year could inform autism diagnoses and other developmental progress/concerns at 36 months of age.

Methods:  As part of a prospective study, 151 infants and their mothers (high-risk group n = 105, low-risk group n = 46) completed a standardized mother-infant play task when infants were 6, 9, and 12 months of age. These interactions were recorded and micro-coded for infant and mother gaze, affect, and vocalizations. Using these micro-codes, we created theory-driven composites for dyadic synchrony, responsiveness, and responsiveness timing (Table 1). At 36 months, infants/toddlers completed an assessment that included developmental functioning (via the Mullen Scales of Early Learning; MSEL) and were assigned diagnostic outcome classifications (i.e., autism, other developmental concerns, or typical development).

Results:  Using linear and multinomial regression models, we assessed each composite at 6, 9, and 12 months as predictors of 36-month diagnostic outcomes and MSEL scores (with terms for infant sex, maternal education, and family income). Overall, the tested synchrony and responsiveness composites did not predict which children received an autism diagnosis. However, these composites did inform 36-month language development for all assessed infants, particularly when considering synchrony and responsiveness at 12 months of age (Table 1). For children who received an autism diagnosis, dyads coded as more synchronous and responsive in the first year had higher language scores at 36 months (Table 2). However, this finding was not consistent across the 6-, 9-, and 12-month assessments.

Conclusions:  Dyadic synchrony and responsiveness, within the first year of life, did not inform which children would receive an autism diagnosis at 36 months. However, consistent with previous research (Northrup & Iverson, 2015), dyadic behaviors during the first year informed language progress for children with and without autism. The findings of the present study highlight mother-infant synchrony and responsiveness as a mechanism through which interventions may promote optimal development in children at elevated risk for autism.