Characterization and Profiling of the Tactile Sensory Behavior in Children with Autism Spectrum Disorders

Background: Children with autism spectrum disorders (ASD) exhibit atypical sensory responses including under- and over-sensitivity to audio, visual and tactile perception. Previous reports have noted these behaviors, but little systematic research has been done to characterize typical and atypical tactile sensory behavior in children with ASD. Prior research by this lab observed increased variability between children with ASD in comparison to typically-developing (TD) children when interfacing with a novel device measuring haptic interactions between two individuals. That study led to observations of tactile selectivity with the hand and forearm during interaction with the measurement device.  This selectivity was observed in children with ASD but not in TD children, leading to the present study of characterizing and profiling the tactile sensory behavior in children with ASD.

Objectives: The goal of the present study is to measure the tactile selectivity of the hand and forearm in school-age children with ASD in comparison with age- and IQ-matched TD children. We will also test the extent to which these measures relate to IQ, handedness, fine/gross motor scores and level of autistic symptomology (via ADOS scores).

Methods: A novel device was designed and built to allow a school-aged child to freely spin two independent rollers along the lateral axis for the left and right hands. Adhered to the surface of the rollers are pressure sensors that output not only the pressure applied to the roller, but also a pressure profile at that moment of contact (measured at 75Hz). These discretized pressure profiles were overlaid onto a reference of the child’s hand to measure selectivity in hand use and preferred tactile stimulation. These profiles were then correlated with metrics of cognitive function and social/communicative competence.

Results: Preliminary results reveal differences in hand use in a subset of children with ASD compared to TD children. Measures also indicate increased variability within the group of children with ASD, and the hand profiles indicate clear areas of preferential selectivity among the children with ASD.

Conclusions: These results quantify altered sensitivity and response to tactile stimulation in individuals with ASD. These results serve as a platform for future investigations of the development of haptic development: how TD children, beginning in infancy, develop selectivity in tactile perception and its effects on social/communicative processes. This will be an important part of understanding atypical behavioral and neural specialization in individuals with ASD.