Sustained attention and pervasive hyperactivity.

A sustained attention deficit is defined as a significant decrement in task performance with task duration (time-on-task). Time-on-task effects are reported using a self-paced paper and pencil cancellation test (PPCT) in normals and in subgroups of pervasively hyperactive children. The hyperactive subgroups were pervasively hyperactive both at home and at school. They differed in degree of pervasiveness in three laboratory conditions. Task inefficiency was most pronounced in the most pervasively hyperactive group. There was no evidence in favour of a sustained attention deficit in hyperactivity: no differences were found in decline in task efficiency between the controls and the subgroups of hyperactive children.