Abstract
The aim of this study was to investigate visuo-motor control in children with developmental coordination disorder (DCD). Children with DCD show impairments in a wide range of basic movement skills. This includes the ability to utilise partial (but not complete) advance information to speed up their movement times in a reach-to-grasp paradigm. We hypothesised that children with DCD are impaired in their ability to use visual information in order to rapidly adjust on-going movements (i.e. they lack ‘on-line’ visual control). To test this hypothesis we studied 10 children with DCD with a control group matched on age, and another control group matched on motor ability, on a perturbation paradigm. The task required the children to move a hand held stylus 25cm from a starting location to a target 2cm in diameter on a computer screen. The starting location and the computer screen were embedded within a flat horizontal surface. The experimental task involved the children making simple aiming movements when they knew that the target would not alter position (baseline condition). Following the baseline trials, the children made aiming movements after being told that the target would ‘jump’ on some trials. On the ‘jumping’ trials, the target changed position by jumping either 10cm to the left or 10cm to the right 10ms following the movement commencement. Electromagnetic tracking equipment was used to monitor the reaction times and movement accuracy including the speed with which children could respond to the change of target location. We will discuss the findings in the context of assessing children with DCD and distinguishing between neurodevelopmental disorders.