Parametric mechanism of excitation of the electroencephalographic rhythms by modulated microwave radiation.

PURPOSE The aim of this study was to evaluate the mechanism of parametric excitation of the electroencephalographic (EEG) rhythms by modulated microwave radiation. MATERIALS AND METHODS The model of parametric excitation based on polarization of water molecules was proposed and experimental results compared to the model. The experiments were carried out on 28 human volunteers. The 450 MHz microwave radiation modulated at 7, 14, 21, 40 and 70 Hz frequencies was applied at the field power density 0.16 mW/cm(2). The resting EEG was recorded in 8 channels and EEG power at selected frequencies was analyzed. A relative change in the EEG power during 10 cycles with and without radiation was used as a quantitative measure. RESULTS Microwave radiation caused an increase in the average EEG power in all selected EEG frequency bands. Increase in the EEG power was statistically significant only at the EEG frequency f(0) to modulation frequency F ratios f(0) /F = 0.25, 0.5 and 0.75. CONCLUSIONS Results of the experimental study are in accordance with the proposed model of parametric excitation of the brain neural oscillations and demonstrate that modulated microwave radiation causes excitation of the brain EEG rhythms at the frequencies predicted by the non-linear model.