Visuomotor tracking related to attention-deficit hyperactivity disorder (ADHD).

Deficient visuomotor tracking in children with attention-deficit hyperactivity disorder (ADHD) has been described, but the specific influence of attention on this deficit has not yet been elucidated. The present study compares visuomotor tracking under different conditions of attentional loading in children with ADHD with that of age-matched controls. A computerized visuomotor attentional tracking test that incorporated several levels of distraction was administered to 13 typical children. The same test, as well as a standard Matching Familiar Figures Test and the Proteus Maze test, was administered to 32 children with ADHD and 21 control children. Significant differences between children with ADHD and controls in visuomotor attentional tracking indices that relate to pacing and the accuracy of the tracking movements were observed under all levels of distraction. In parallel, a significant performance decrement was observed in all subjects once distraction was introduced. Discriminant analysis, based on the visuomotor attentional tracking test findings, resulted in correct classification of 92.3% of the typical children and 46% of the children with ADHD. Significant correlations between Matching Familiar Figures Test latency, as well as errors and visuomotor attentional tracking indices, were noted among children with ADHD when the visuomotor attentional tracking did not involve distraction. Under distraction, these correlations extended to the control group as well. In conclusion, visuomotor tracking appears to reflect the availability of attentional resources in general and is significantly affected by the presence of ADHD in particular. These results have potential implications related to the evaluation of children with ADHD on and off drugs.