MECHANISM OF TEMPORAL FUSION EFFECT OF PHOTIC STIMULATION ON ELECTRICAL ACTIVITY OF VISUAL STRUCTURES

Abstract

The driving effect of intermittent photic stimulation on the electrical activity of the optic nerve, lateral geniculate body, tectum mesencephalon, optic radiations and cortex has been explored in monkey (Macaca mulatta). At an intensity of 10 fc, the optic nerve and lateral geniculate body could be driven at a maximum rate of 62 c.p.s., and 59 c.p.s., respectively, a rate that is well above the maximal critical fusion frequency for man and probably for monkey. The cortex of the striate area could be driven at a maximum rate of 34 c.p.s. While a driving effect could be obtained from the tectum mesencephali and from the optic radiations, it was not sufficiently stable to permit a detn. of maximum rate. The possibility is considered that findings indicate a fusion mechanism in the cortex, which limits the temporal resolving power of the primate visual system.