Forty-two volunteer subjects, mostly young adults, participated in developing a methodology for studying cognitive processes and cerebral lateral functions in relation to individual cognitive styles and age. Four test batteries were developed and refined in this study: the adult cognitive, the adult electroencephalogram (EEG), the children's cognitive, and the children's EEG. Subjects were given group cognitive tests four weeks prior to EEG testing and individual cognitive tests at the time of EEG testing. A resting EEG was obtained for ten minutes before the laterality cognitive testing. Start and stop times for each cognitive task and for the rest period were logged, and activation of right and left brain hemispheres was plotted. Input data were filtered with bandpass filters in order to evaluate relative EEG activation as indicated by the power and bandwidth of an activated hemisphere. For most subjects, there was no consistent use of one or another hemisphere for any task; in fact, there were occasional shifts of activation from one hemisphere to the other. A uniquely different subject was a 13-year-old girl who had outgrown a mild dyslexia; the usual oscillation of dominance activity during task performance was lacking, and there was a failure to shift hemisphere-dominance in relation to task. Several of the tests are appended. (Author/MV)