1. Institute of Cell Biophysics, Russian Academy of Sciences
Type: Experimental/clinical study
Year: 2004 vol: 50 application: 1
Abstract: Computerized system for precise stimulation and analysis of electroencephalographic (EEG) reactions to simultaneously presented two frequencies of sine-wave light (one constant, 13 Hz, and another varying from 1 to 6 Hz and vice versa) was used to study the mechanisms of human brain reactivity to complex rhythmical stimulation. The frequencies were presented by three different ways: as a sum, as a product of multiplication (amplitude modulation of constant frequency by the varying frequency) or by separate presentation to different eyes. Comparisons of Fast Fourier Transform (FFT)-based dynamic spectral compositions for presented stimuli and for each channel EEG reactions were used in the study. Under all three experimental conditions the dynamics of EEG spectra has demonstrated the same general pattern of resonance activation which is similar to the one observed for the presented signals in the case of their amplitude modulation. Significant positive shifts in the functional state of subjects were observed as a result of stimulation. Obtained results show the leading role of the processes of amplitude modulation in the interaction of integrative, adaptive and trace mechanisms of the brain functioning during human perception of complex rhythmical stimuli.
Reference: Fedotchev A.I., Bondar A.T., Larionova A.V., Pivovarova O.V., Computer technologies in the research of brain activity mechanisms: how does human nervous system react to polyfrequency stimulation?, Biomeditsinskaya khimiya, 2004, vol:
50(application 1), 188-194.