A device for evaluation of the dominant component of the EEG activity.

A setup composed of a bioanalyser and additional electronic circuits is described allowing to measure the instantaneous frequency and amplitude of the dominant component of EEG activity. Besides recording the above values on paper by means of the EEG apparatus, functions of probability density of both the amplitude and the frequency of EEG activity are estimated on-line during preadjusted time intervals, and displayed on the screen of the bioanalyser. The mutual relationship between instantaneous EEG amplitude and frequency can be expressed in two-dimensional histograms displayed on a memory scope. The system described is suitable for laboratories having no possibility to use general purpose computer on-line.