A developmental study of vigilance in learning-disabled and nondisabled children.

To test the proposition that learning-disabled children manifest a sustained attentional deficit, the Continuous Performance Test was administered to learning-disabled and nondisabled children at three age levels. Children were tested on three task lengths (5, 10, and 15 minutes) and two modalities (auditory and visual) in which dependent measures were correct detections and false responses, d' and B values. As expected, learning-disabled children male fewer correct detections and more false responses and were less sensitive (d') to critical stimuli than were nondisabled children at all ages. There was also evidence to indicate that learning-disabled children apply different response criteria across age when compared to nondisabled children. B values varied significantly across age, group, modality, and time on task; d' remained relatively unchanged across time periods. The popular notion that learning-disabled and younger subjects start a vigilance task with the same capacity as nondisabled older children but show a decline in attention as time on task increases was not supported.