Abstract: A method and apparatus for analyzing an electro-encephalogram (EEG) are described. EEGs from the left and right sides of the head are analyzed substantially simultaneously by detecting bursts of activity having amplitudes which exceed a threshold voltage. Each burst of activity is determined to have ended, i.e. the amplitude is below the threshold voltage, when it is followed by a quiescent interval having a duration of, for example, at least six seconds. The total time of all quiescent intervals occurring within a time period, e.g. ten minutes, is then calculated and displayed. The apparatus includes a digital computer for effecting statistical analysis of total times for many consecutive time periods. The computer may also be used in generating total times. A graphical output representing total times may be generated allowing rapid access of patient progress.