Trajectories of Attention, Regulation, and Motor Organization from Birth to 6-Months for Infants at Risk for ASD

Background: Although autism is believed to be a congenital disorder, little is known about its course in the neonatal and early infancy period. Yet from the first days of life, rich social interactions are present, facilitated by requisite neonatal neurological and behavioral organization. While neonatal neurobehavior (e.g., attention, regulation, and motor organization) sets the stage for the earliest forms of social interaction, these measures have rarely been used to understand the emergence of social-communication and ASD. The very early period between birth and 6-months spans key neurodevelopmental transitions wherein disruptions may, in part, determine the emergence of social and communication impairments.

Objectives: This study aims to 1) quantify neonatal and early infant trajectories of attention in infants at risk for ASD, 2) quantify trajectories of self-regulation and motor control that may be associated with attention, and 3) determine whether early patterns of attention are associated with later social-communication skills.

Methods: Participants included 42 high-risk infant siblings of children with ASD and 38 low-risk infants with no family history of ASD. Infants were administered the NICU Network Neurobehavioral Scale (NNNS) monthly from 1-week to 6-months, and the Communication and Symbolic Behavior Scales (CSBS) at 12-months. The NNNS is a reliable, standardized, measure that uses direct assessment to quantify neurological integrity, which forms the requisite basis for social interactive capacities. The attention item of the NNNS captures the infant’s ability to orient to animate (faces) and inanimate (objects) stimuli that are presented in auditory-only, visual-only, and combined auditory-visual modalities. Generalized linear mixed effect models were used to compare trajectories of attention, self-regulation, and motor control between high-risk and low-risk infants. Because the relationship between age and attention was non-linear, splines functions were used to model the effect of age. Spearman correlations were used to assess the association between very early attention and later social-communication.

Results: High-risk and low-risk infants exhibited significantly different trajectories of attention from birth to 6-months [F(12,179)=25.88;p<0.001], with pronounced significant differences occurring between 1½ to 3-months (see Fig. 1). Investigation of the six items that make up the attention score revealed that differences were driven by attention to inanimate stimuli. High-risk infants also scored significantly lower on items of self-regulation and head/trunk motor control during this same period between 1½-3 months. Finally, we observed significant associations between social-communication at 12-months and attention at 2-months (r_s=0.36, p<0.05) and 3-months (r_s=0.45, p<0.01).

Conclusions: Infants at high risk for ASD exhibit divergent trajectories of attention beginning as early as the second month of life. We hypothesize that these differences reflect deficits in attention shifting, decreased sensitivity to social cues, and/or delayed emergence of socially adaptive, cortically-mediated behavior. Further, differences in attention for high-risk infants were accompanied by less efficient self-regulation strategies and motor control. These results provide evidence for a potential cascade of attentional and neurological abnormalities that culminate in social-communication deficits. Understanding how these behaviors are interconnected can help to develop viable early detection methods and bridge the gap between neonatal neurobehavior and complex social development.