Visual-motor tracking by hyperkinetic children.

Two studies of a visual-motor tracking task purported to be an effective discriminator of subtypes of minimal brain dysfunction are presented. Performances of 16 psychiatric inpatients were compared with those of 14 hyperactive males and of 15 normal controls. A second study evaluated effects of practice and drug sensitivity on tracking. The task discriminated patients from normals but did not discriminate the groups of patients from each other. Interactions of practice, age, and diagnosis were found. Some degree of sensitivity of the task to stimulant medication was also obtained. Visual-motor tracking is a useful measure of stimulant drug action but does not measure a defect specific to hyperkinetic patients.