Conditioned reflex changes in the human electroretinogram

Summary The conditioned reflex changes were formed in the human electroretinogram. The ERG was registered with the aid of an active electrode soldered into the contact lens. The EEG of both occipital regions was registered simultaneously. Light (which gave about 600 lux illumination on the pupil) served as an unconditioned stimulus. Sound served as conditioned stimulus (60 decibel over the threshold of hearing, 250 cycles per sec) which had no effect by itself on the ERG. Numerous combinations of this sound with the light stimulus brought about the development of conditioned reflex changes in the ERG. This was manifested by the fact that in response to the mild light stimulation, preceded by sound, the amplitude of the electroretinographic wave b became higher than in response to the weak stimulation by light alone. In both cases the light which was employed as a stimulus gave an illumination on the pupil equal to about 80 lux and the wave b the amplitude of which was much lower than in light stimulus with 600 lux. The conditioned reflex changes were simultaneously observed in the EEG.Presented by Active Member of the AMN SSSR V. V. Parin