Electrical activity of the cortex and reaction times to auditory signals and light stimuli

We investigated the electrical activity of the occipital, sensorimotor, and frontal zones in the right and left hemispheres of the cerebral cortex and times for bimanual motor response in healthy adult experimental subjects between the ages of 15 and 25 receiving photostimulation by means of pulse trains with frequencies increasing from 15 to 25 Hz and pulse trains with frequencies decreasing from 15 to 5 Hz. We observed nonspecific physiological reactions in the organism regardless of the type of photostimulation presented and also observed specific reactions dictated by the parameters of the light stimulus acting upon the brain. It was demonstrated that the action of the light was most effective when the frequency of the stimuli was gradually increased. The expressiveness of the alpha-band of oscillations in the electrical brain activity increased in this case, and the asymmetry of the bimanual motor responses changed significantly. A definite connection was noted between the physiological reactions of the experimental subjects and their subjective states.