ABSTRACT

Cortical potentials (VECP) evoked by visual grating stimulation were recorded. The dependence of VECP amplitude and phase on spatial frequency, quality of the retinal image, and grating preadaptation was investigated. A linear dependence of phase on the logarithm of spatial frequency was found. Significant effects of optical blur on amplitude, but not on phase, occurred above 5 cycles per degree. Grating preadaptation of the eye caused a loss of amplitude and induced phase-shifts. These effects showed interocular transfer, as occurs in psychophysical studies. More specifically, a decrease in latency was observed when the ipsilateral eye was preadapted, whereas an increased in latency was observed when the contralateral eye was preadapted. No subjective counterpart of such effect is known.