Using the method of sequential analysis, clinical EEGs are transformed into a temporal sequence of individual events with specification of amplitude, wave or segment interval, channel of origin and paroxysmal character in relation to background activity. These data can be viewed immediately in graphic form and stored for subsequent display or numerical analysis. The speed, format, and high information content of this method of data reduction allow real time topographic display of individual background and paroxysmal events - computed EEG topography (CET). Alpha asymmetry, slow activity, paroxysmal events and bilateral spike-wave activity are vividly represented and distinguished. There appears to be a close correlation between the usual method of EEG interpretation and the independent interpretation of a very compact quasi-anatomic CET with respect to nature and localization of normal and abnormal EEG activity. Initial observations suggest particular value of the CET in defining the extent of functional disturbance related to an anatomical lesion and in communicating this information to the electroencephalographer and to the clinician.