The study examined the electrophysiologic organization of cognitive function in 12 normally achieving righthanded boys and 12 reading disabled third and sixth grade boys. Ss were administered reading comprehension and spelling recognition subtests from the Peabody Individual Achievement Test. Electroencephalography (EEG) scores were recorded for each task. Data suggested the existence of a developmental component in slow wave activity of the EEG as the Ss performed cognitive tasks. Further, differences existed between normal and LD Ss which may be attributed to a developmental component in the EEG. (CL)