Localization of encephalogram spectral features in psychic disorders

Changes in spectral and spatial features of encephalograms are considered, which are observed in various mental disorders. A systematic bibliographic review is presented, including papers on the estimation of pathology spectrum and its position in brain. First of all, the spontaneous activity of the brain in various states is considered, differing in spatial localization and in coherence between brain areas. Articles presented in review show, that the rhythmic activity of the brain in mental disorders differs from normal in several frequency bands. The method is proposed for precise quantitative analysis of this activity based on the encephalography data. Spatial position of the sources of pathological activity is a key issue of brain studies and it is solved by various localization methods. Results of the localization are presented at the anatomical scheme of the brain or at the subject’s magnetic resonance image and as a result, hypotheses of neurophysiological mechanism of pathology under study are proposed. The comparative analysis of encephalography spectra, registered in various channels, distributed over the scalp, can be considered as the simplest of pathology localization methods. Such localization is qualitative and makes it possible to make very rough conclusions. The method, proposed in this paper, is based on Fourier transform of multichannel encephalography data and on the localization of spectral components. Such approach permits to study in detail some or other frequency features of the brain pathological activity and to reveal their connections with the brain anatomy.