Modelling gesture use and early language development in autism spectrum disorder

Background: Nonverbal communication abilities, including gesture use, are impaired in autism spectrum disorder (ASD). However, little is known about how common gestures may influence or be influenced by other areas of development. Aims: To examine the relationships between gesture, fine motor and language in young children with ASD compared with a comparison group using multiple measures and methods in a structural equation modelling framework. Methods & Procedures: Participants included 110 children with ASD and a non-ASD comparison group of 87 children (that included children with developmental delays (DD) or typical development (TD)), from 12 to 48 months of age. A construct of gesture use as measured by the Communication and Symbolic Behavior ScalesDevelopmental Profile Caregiver Questionnaire (CQ) and the Autism Diagnostic Observation Schedule (ADOS), as well as fine motor from the Mullen Scales of Early Learning and Vineland Adaptive Behavior ScalesII (VABS-II) was examined using second-order confirmatory factor analysis (CFA). A series of structural equation models then examined concurrent relationships between the aforementioned latent gesture construct and expressive and receptive language. A series of hierarchical regression analyses was run in a subsample of 36 children with ASD with longitudinal data to determine how gesture factor scores predicted later language outcomes. Outcomes & Results: Across study groups, the gesture CFA model with indicators of gesture use from both the CQ (parent-reported) and ADOS (direct observation), and measures of fine motor provided good fit with all indicators significantly and strongly loading onto one gesture factor. This model of gesture use, controlling for age, was found to correlate strongly with concurrent expressive and receptive language. The correlations between gestures and concurrent language were similar in magnitude in both the ASD and non-ASD groups. In the longitudinal subsample of children with ASD, gestures at time 1 predicted later receptive (but not expressive) language outcomes on the VABS-II, after controlling for nonverbal cognition, ASD severity, age and time 1 language. Conclusions & Implications: This study extends research on the relationship between nonverbal communication and language by supporting the idea of an underlying construct of gesture use that includes fine motor ability and relates to language in young children with ASD. This further supports theories espousing developmental influences of motor and nonverbal communication strategies as important in early language learning.