Auditory event-related potentials in attention and reading disabled boys.

Event-related potentials (ERPs) were recorded from 4 groups of children: (1) reading disabled, (2) attentional deficit disorder with hyperactivity, (3) attentional deficit disorder without hyperactivity, and (4) normal controls. Subjects were instructed to press a button to a low probability tone (target, P = 0.168) and to ignore all other events which included a high probability tone (non-target, P = 0.664) and an unexpected novel sound (P = 0.168). The amplitude of several late ERP components and the latency of the P3b component were examined. As in a previously reported visual study with the same sample of children, the overall amplitude of the P3b component was significantly smaller in all the clinical groups than in controls. Two other late components (slow wave and Pc) were also smaller in the clinical groups than in controls. P3 latency did not, however, differentiate the groups.