Attentional and sensory contributions to postural sway in children with autism spectrum disorder

Postural control is known to depend on sensory and cognitive factors. Little is known about how children with autism spectrum disorder (ASD) regulate static balance, and to what extent vision and cognition contribute to the regulation of balance in this group. We compared a group of children with mild ASD and a group of age- and gender-matched controls on various postural tasks, standing on a Wii Balance Board. We tested a sensory disturbance (closing the eyes) and a cognitive disturbance (word memorization) on the control of quiet standing. Analysis of center-of-pressure excursions revealed moderate effects of cognitive load, but clear effects of vision. We found a greater destabilizing effect of closing the eyes (greater postural excursions in the medio-lateral direction) for the ASD group than for controls. No group differences were found on word recall and on a standardized balance test (Movement Assessment Battery for Children; M-ABC2). We suggest that the postural effects reflect tighter coupling between vision and motor adjustments in ASD than in controls, which is consistent with recent suggestions of greater reliance on vision in this group.