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In 43 female Wistar rats, a loud sound did not alter the asymmetry in behavioral tests even if is was loud enough to induce seizure. Under apomorphine test, the sound tended to decelerate the rotation, the asymmetry being preserved both in sound-activated and in sound-resistant subgroups. A shortening of the rotation onset latency occurred in sound-activated subgroup which may be associated with an increased permeability of the hemato-encephalic barrier following the sound-induced seizure.

The EEG of occipital areas was recorded in adult healthy male subjects on presentation of haphazardly alternating intermittent light stimuli with frequencies varying from 15 to 5 Hz and from 15 to 25 Hz every 5 sec. Two groups were distinguished in respect to a greater or lesser domineering of the main frequency band of the range. Dynamic spectral analysis revealed obvious shifts of the EEG spectral composition in respect to the background under the effect of the stimulation, an enhancement of different bands of the range in light flickering, and the suppression of the EEG trace responses to the time in the EEG range coinciding in frequency with the frequency range of the photostimulation. The above changes were mainly characteristic of the 2nd group of subjects and mostly of the left hemisphere of the brain.

Grown-up subjects revealed both unspecific and specific bimanual motor responses to photostimulation with growing and declining frequency. The former mode of stimulation proved more effective. A relation was found between the physiological responses of subjects and their subjective condition.