ABSTRACTThe use of the Drohocki integrator to quantitate the area under the curve of the electroencephalogram (EEG) has provided useful information in earlier studies. However, difficulties arise in comparing data obtained with different types of EEG machines and integrators because of differences in the frequency spectra to which the machines respond. The slope of the regression line of SD on mean integrated area was studied to provide a measure of group variability which would not be unduly sensitive to these differences in equipment. It was found that the slope decreased from group to group in going from normalSs to catatonic schizophrenics, with alcoholics and undifferentiated schizophrenics in intermediate positions in that order. It was suggested that the clockwise rotation of the regression line provides a convenient measure of the level of cerebral activation.