Focused attention in pervasively hyperactive children

This experiment was designed to investigate the hypothesized distractibility of hyperactive children in a focused attention task. Distractibility was defined in terms of Shiffrin and Schneider's model of focused attention as the ability to ignore irrelevant in favor of relevant information. Failure to inhibit processing of irrelevant information indicates a focused attention deficit. Task efficiency in all children decreased when irrelevant information was presented. The mean reaction time, within-subject variance of reaction time, and error percentage all increased compared with a nondistraction condition. Thus, the demands of focused attention, as formulated in the model, were measured optimally. Since hyperactives and controls did not differ significantly with respect to task efficiency in the distraction condition, a focused attention deficit in hyperactives was not demonstrated. The hyperactives did nevertheless make more errors and their responding was more variable than the controls. However, the difference in error percentages between hyperactives and controls was associated with the difference in IQ. It is speculated that the variable responding in hyperactives is caused by a less optimal state of performance unrelated to distractibility.The authors wish to thank L. Leertouwer for making the drawings. This research was supported by grants from the Netherlands Foundation for the Advancement of Pure Research (ZWO) and the Professor Duijker Fund.