Sensory Hypersensitivity Predicts Enhanced Attention Capture By Faces in the Early Development of ASD

Background: Sensory symptoms are highly prevalent in young children with ASD, but their relation to the canonical social communication symptomatology is unclear. Recently, sensory hypersensitivities have been linked to increased allocation of attention to low-level sensory stimuli within the neural salience network (Green et al., 2016). Since people possess many salient low-level features that drive attention capture in early development (e.g. motion, audio-visual synchrony, and relative unpredictability), we reasoned that greater levels of hypersensitivity should predict greater early attentional responses to social stimuli. Further, since social attention is thought to promote more optimal social development, we predicted that greater early attentional responses to social stimuli should predict greater social approach within a group of children with ASD.

Objectives: In two longitudinal samples, we tested whether early sensory hypersensitivity predicts later enhanced attention capture by faces, and whether this in turn predicts better social approach within groups of children with ASD.

Methods: We used questionnaire measures to assess sensory hypersensitivity (the perceptual sensitivity subscale of the Infant Behavioral Questionnaire and a composite measure of sensory hypersensitivity from the Sensory Profile) in two cohorts respectively: n=88 infants at low and high familial risk for ASD tested at 6, 12 and 18 months; and n=48 toddlers with ASD tested at 2, 3 and 4 years. Neural attention capture by faces was measured using event-related potential responses to faces and objects. We also examined behavioral attention capture by faces and objects using a habituation paradigm.

Results: In Experiment 1, greater sensory hypersensitivities (lower scores) at 2 years in toddlers with ASD (n=48) predicted larger amplitude ERP responses to faces (P1, P400 and Nc) at 4-years (Fig 1), and this in turn was related to greater social approach (interest and interaction). In Experiment 2, greater perceptual sensitivity at 6 months predicted larger P1 amplitude to faces at 18 months in infants at low (n=45) and high (n=43) familial risk for ASD.

Conclusions: In this study, we provide the first demonstration that early sensory sensitivities predict greater attention capture by faces, and this mediates improved social approach behaviors in the early development of ASD. Our findings are consistent with a theoretical model in which early hypersensitivities are associated with increased attention capture by stimuli with salient sensory features; and that because people tend to have salient sensory features in naturalistic environments (e.g. motion, audiovisual synchrony and unpredictability) attention capture to faces becomes stronger. In the context of a supportive environment, heightened sensory hypersensitivity may support social development for children with ASD. This information may be critical to consider when designing therapeutic strategies or trying to predict individual outcomes for children with ASD.