Sensory-Motor Control in Autism

Background:  

Despite being typically characterized as a social deficit, research has repeatedly highlighted the presence of measurable motor problems associated with Autism Spectrum Disorders (ASD) (Fournier et al, 2010). In particular, performance comparisons imply distinct difficulties in the areas of manual dexterity and ball skills (e.g. Green et al., 2010; Whyatt & Craig, 2012). However, the nature and thus potential root of these difficulties remains unclear. 

Objectives:  

This research aimed to further profile motor control in children diagnosed with ASD. Specifically, levels of spatial and temporal control were assessed during a manual dexterity task, measuring the ability for participants to use external sensory information to prospectively control and guide action. Moreover, we aimed to provide insight into underlying cognitive-motor interaction, by using two distinctive control groups, independently matched for verbal and non-verbal IQ. These refined comparisons allowed problems specific to autism to be identified. 

Methods:  

Building on preliminary assessment using the Movement Assessment Battery for Children (Whyatt & Craig, 2012), this study explicitly assessed levels of performance on a controlled manual dexterity trace task. Participants were asked to successfully 'draw' through a maze presented on a touch screen tablet. Three levels of task difficulty were presented, allowing in-depth assessment of underlying spatial and temporal control. Comparisons of performance were made between children diagnosed with ASD (aged 9-11) and two distinct, age-matched control groups.

Results:  

Preliminary assessment of spatial performance implied a significant impairment in the ASD group in relation to both the non-verbal (p<. 05) and receptive language (p<. 05) control groups. Kinematic assessment revealed similarities between the ASD and receptive language group, with specific difficulties tailoring temporal characteristics of the movement to maximize spatial accuracy. However, more complex levels of precise temporal control, including the use of corrective sub movements and deceleration into corner sections of the maze, successfully differentiated between the ASD and both control groups (p<.05). 

Conclusions:  

This study has demonstrated that poor levels of manual dexterity in ASD are potentially due to fundamental problems with perception-action coupling leading to difficulties with both prospective and online control. Moreover, results demonstrated similarities between children diagnosed with ASD and typically developing children matched on age and receptive language, highlighting the importance of independently controlling for facets of IQ.

Fournier, K.A., Hass, C.J., Naik, S.K., Lodha, N., & Cauraugh, J. H. (2010). Motor coordination in Autism Spectrum Disorders: A synthesis and meta-analysis. Journal of Autism and Developmental Disorders, 40, 12227-1240.

Green, D., Charman, T., Pickles, A., Chandler, S., Loucas, T., Simonoff, E., & Baird, G. (2010). Impairment in movement skills of children with autistic spectrum disorder. Developmental Medicine and Child Neurology, 51,311-316.

Whyatt, C. & Craig, C.M. (2012). Motor Skills in Children aged 7-10 years, diagnosed with Autism Spectrum Disorder. Journal of Autism and Developmental Disorders, 42(9), 1799-1809.