Individual-typologic features of EEG structure

EEG monopolarly recorded in points F3, F4, O1, O2 of 20 healthy subjects in six states (quiet wakefulness with open or closed eyes, spontaneous button pressings in arbitrary moments of time, listening to clicks, reaction to clicks by pressing the button at random or at equal intervals between stimuli), were processed by means of the computer program transforming the raw EEG tracings to a sequence of stationary segments. The accumulated segments were divided into classes of "similar" ones by a two-stage procedure of cluster analysis. In each lead six types of segments were identified forming populations of structural units of an individual human EEG. Four types were recorded all over the brain: their spectra were of a great resemblance in different brain areas. The EEG of each individual was characterized by a certain combination of segment types which practically did not change by their quality in different states of the subject.