Visual information and the control of reaching in children: A comparison between children with and without developmental coordination disorder

Three experiments were performed on reach and gasp in 9- to 10-year-old chi ldren (8 controls and 8 with developmental coordination disorder [DCD]). In normal reaching, children in the DCD group were less responsive to the acc uracy demands of the task in controlling the transport component of prehens ion and spent less time in the deceleration phase of hand transport. When v ision was removed as movement began, children in the control spent more tim e decelerating and reached peak aperture earlier.. Children in the DCD grou p did not do that, although, like the control group, they did increase grip aperture in the dark. When depth cues were reduced and only the target or only the target and hand were visible, children in the control group used t arget information to maintain the same grip aperture in all conditions, but DCD children behaved as if the target was not visible. Throughout the stud ies, the control group of 9- to 10-year-olds did not produce adult-like ada ptations to reduced vision, suggesting that they had not yet attained adult -like integration of sensory input. Compared with control children, childre n with DCD did not exhibit increased dependence on vision but showed less r ecognition of accuracy demands, less adaptation to the removal of vision, a nd less use of minimal visual information when it was available.