Sensory Features in Autism Spectrum Disorder: A Systematic Review of Measurement Quality and Empirical Investigation of Sensory Responsivity in Children at High and Low Familial Risk for Autism

Abstract

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with heterogenous presentation and varying outcomes for children impacted by the condition. The etiology and bio-mechanisms of autism are not well understood. For decades research has focused on the social, communication, and cognitive symptoms associated with ASD. However, sensory symptoms were added to the diagnostic criteria for ASD in 2013 and continue to gain research attention. Historically, sensory symptoms were thought to emerge as secondary consequences of social-cognitive deficits. However, recent empirical work suggests that sensory symptoms manifest early in development and may contribute to the heterogeneity of ASD. For this dissertation, I systematically reviewed the literature to appraise the quality of proxy report sensory measurement tools used to assess sensory features in ASD. Furthermore, in a sample of children with a high and low familial likelihood for developing ASD, I characterized sensory responsivity in social and non-social contexts early in life and investigated the development of sensory responsivity throughout childhood with considerations for variables that may relate to developmental changes and their association with later adaptive behavior. Results from the current studies indicate that proxy report sensory questionnaires attempt to quantify sensory features in ASD via vastly different dimensions with little attention given to either construct or structural validity. Moreover, results show that sensory responsivity behaviors emerged across social and non-social contextual domains early in life and relate to restricted and repetitive behavior and adaptive behavior later in toddlerhood. Compared to children without ASD, children with ASD tend to demonstrate more early sensory responsivity behaviors that increase in a curvilinear relation to chronological age with specific trajectory differences across responsivity behavior patterns (hyperresponsivity, hyporesponsivity, sensory seeking). Additionally, heightened hyporesponsivity in the first year of life predicts lower adaptive behavior later in childhood. Specifically, results suggest that sensory features emerge prior to the consolidation of broad ASD symptoms and relate to adaptive outcomes. However, construct dimensions including the un-agreed upon multidimensionality of sensory features has important implications for future understanding and clinical practice.