Visually guided hand movements in children with minor neurological dysfunction: response time and movement...

Many children with signs of minor neurological dysfunction (MND) are unable to adapt precisely their movements to external goals, in particular when they are under time pressure. Pilot studies in our laboratories suggested that response times in various sorts of tapping tasks were longer in such children than in controls with an optimal neurological status. In the present study an experimental tapping task, presented in 'self-paced mode', is applied to explore further the relationships between response time and spatio-temporal organization of movements in children with MND as compared to optimal controls. Differences were found with respect to inter-response intervals as well as to the organization of the movements; children with MND have longer overall response times than controls, more movement elements per tap and shorter first movement elements. Further, the moment of maximal acceleration comes later in the children with MND than in the controls. Such differences in response time and movement organization may be due to information processing limitations and increased attentional demands for the execution of movements in MND children.