Maternal Gestures and Infant Responses in High- and Low-Risk for Autism Spectrum Disorder Dyads

Background: Language, including gestural communication, is delayed in infant siblings of children with autism spectrum disorder (ASD), who are at high risk for the disorder (high-risk; HRA). Factors such as parental communication influence infant language development. In typically developing infant-mother dyads, maternal gestures tend to remain stable over time (Iverson et al. 1999), but this has not been extensively studied in mothers of HRA children. Talbott et al. (2015) found that mothers of HRA 12-month infants not diagnosed and later diagnosed with ASD produced similar rates of total gestures. The responsivity of infants during communication may relate to parental communicative actions (Goodman et al. 2005) or to future ASD diagnosis (Wan et al. 2013). However, it remains unclear whether infants and their mothers respond contingently to each other’s gestures. Here, we specifically examined maternal gestures and their infants’ responses as the initial step toward a better understanding of the nature of maternal gestures and bi-directionality of communicative synchrony.

Objectives: To investigate whether: (1) mothers of high- and low-risk (LRC) infants change over time in gesture production at 12, 18, and 24 months of infant age; (2) infant responsivity to maternal gestures differs between diagnostic groups at the three age groups.

Methods: 70 mother-child dyads were videotaped in the lab during a 10-minute free-play interaction at 12, 18, and 24 months. The ADOS and best clinical estimate at 18-36 months were used to determine ASD diagnosis (+) or lack thereof (-) and classify infants into outcome groups: HRA+: n = 17; HRA-: n = 25; LRC: n = 29. Gestures were reliably coded and further classified into two categories following Özçalışkan and Goldin-Meadow (2009): gestures produced alone (e.g., pointing to a dog) or with speech (e.g., “look at the dog!” + pointing to a dog). Infant responses to maternal gestures were coded and defined as verbal or nonverbal behaviors that occurred within one utterance of each gesture.

Results: (1) Mothers of HRA+, HRA-, and LRC infants produced similar rates of gestures, with or without speech, at 12, 18, and 24 months (Kruskal-Wallis; Figure 1). (2) Infants produced significantly more overall responses to maternal gestures over time, and the groups did not differ in their responses (repeated measures ANOVA). Infants responded differently to maternal gestures produced with or without speech (Figure 2). Visual inspection suggests that infants responded proportionally more to gestures alone than to gesture-speech combinations. In addition, while infants remained stable in their responses to gestures produced alone over time, they significantly increased responses to gestures produced with speech between 12-24 months.

Conclusions: In our sample, HRA+, HRA-, and LRC mothers and their infants demonstrated comparable gestural input and responses, respectively. Infants – regardless of group – responded differentially to maternal gestures depending on whether the mother produced the gesture with speech or if the mother gestured without speech. These findings can guide further research and inform our understanding of infant and maternal behavior in the development of infants’ communication.