RESONANCE EEG RESPONSES TO RHYTHMICAL PHO TOSTIMULATION AND FUNCTIONAL-STATE CHANGES

Changes in EEG fine structure in the occipital areas, heart rate, and breath pattern were recorded in 10 male volunteers under photic stimul ation with slowly varying frequency in the range of lower or higher EE G alpha-subbands. Self-ratings (on the scale SAN - self-assesment of s tate of health, activity, and mood) of the functional state, general a ctivity, and mood were obtained before and after stimulation. EEG effe cts of such photostimulation were represented by the resonance EEG res ponses of discrete spectral EEG components, frequencies of which perio dically coincided with varying rate of flashes. Resonance alpha-enhanc ement levels depended on the initial individual EEG alpha-voltage and stimulation frequency. Average changes in objective and subjective par ameters did not differ between the conditions of lower and higher freq uencies of stimulation but were significantly different and of opposit e signs when the subjects gave higher and lower self-ratings of positi ve stimulation effect regardless of the stimulation frequency.