Application of the Beating Method to Define the Electroencephalogram α−Rhythm Frequency Content

Among plenty of the brain oscillation electrical patterns, the spindle oscillations in the alpharhythm band has main functional significance, in particular in emotional, memory, motivation and attention processes. At the same time, signal processing techniques well developed in radio engineering are not used in electroencephalogram (EEG) processing. For the first time the beating method was applied to electroencephalograms. It is shown that the beating method allows the determination of α−rhythm frequencies, which are not always resoluted using Furrier transform. EEG is non-stationary process that’s why instantaneous frequency is a very important characteristics of EEG. The calculation of instantaneous frequency values was carried out based on the Hilbert transform and intersection detector method. A comparative analysis of electroencephalograms frequency content obtained by Furrier transform, Hilbert transform and Zero-level intersection detector method was carried out.