[Basic steps of EEG topogram analysis development by the Livanov's school]

The basic steps of development of the topogram analysis technique are outlined with its prerequisites. A topogram is defined as a set of momentary EEG values simultaneously recorded from the whole scalp surface with multiple electrodes. Experimental evidence points to existence of two main types of the spatiotemporal organization of the cortical potentials varying in time in the whole range of the EEG frequencies. Animal and human experimental data are described which reveal either dominance of one of these types or their complex interaction.