Emergence of Social Engagement in Infants at High and Low Risk for ASD As Indexed By Cry

Background: Early infant cry is reflexive in nature, and initially reflects the internal condition of the infant. Yet as the infant develops within the first months of life, cry gradually evolves into a volitional prelinguistic vocalization used to negotiate social interactions, and begins to reflect the emergence of socialization. Previous work has demonstrated that acoustic and durational features of cries in early infancy determine the nature of parental perception of cry and latency of response to cry, in typical development and in developmental disorders other than autism. As studies have shown that cry of infants at high genetic risk for ASD and toddlers with ASD have atypical cry characteristics, it is important to understand whether these atypicalities affect the quality of emergent social engagement between infants at risk for ASD and their caregivers.

Objectives: The focus of this study was to determine whether the function of cry is disordered in infants at high genetic risk for ASD, relative to those at low genetic risk for ASD, before signs of deficits in social communication apparent in speech may emerge. As cry becomes an infant’s means of initiating and responding to social interaction in infancy, the goal of the project was to investigate the efficacy of cry in negotiating social interactions in these high-risk infants. We explore the hypothesis that high-risk infant cries evoke maternal responses that less effectively capitalize on the social value of cry, compared to cries of low-risk infants.  

Methods: As part of a larger ongoing NIH Autism Center of Excellence, tracking vocal development in 230 high-risk infants (with older siblings already diagnosed with autism) and 100 low-risk infants (with no family history of autism), digital audio recording devices (LENA Foundation) were sent to families’ homes monthly, beginning at 1-2 months, for the purpose of making day-long, naturalistic recordings of infants’ vocalizations. In this study, we focused on an exhaustive analysis of 2 high-risk infants and 2 low-risk infants, at three time points between 1 and 6 months. We labeled and segmented cries and the corresponding maternal response to these cries using a customized coding scheme. We then evaluated the nature of infant cry and maternal response to cry. 

Results: The quality of response to cry differed perceptually between the high-risk and low-risk infants. Maternal response to high-risk infant cry was less sustained and less varied than response to low-risk infant cry. Further, while cry was a definite means of communication for several of the low-risk infants by 6 months, one of the high-risk infants hardly cried at all throughout the 2-month recording and systematically failed to evoke differential maternal responses. 

Conclusions: Systematic atypicalities in cry at different stages of development are likely to provoke sustained changes in interactional style between parent and child. The adaptive function of cry to serve as a platform for social engagement between infant and caretaker may be weakened in interactions between mothers and their high-risk infants.