Abstract
The curve showing the time course of electrical excitability of the eye determined after exposure to colored light and then to white light is mater-ially different from the curve for white light alone, but closely similar to that for the complementary colored light alone. This phenomenon is termed “retinal induction”.
1. In the present experiment it is shown that direct currents of suitable form and time constant may be used as a substitute for inducing colored light in the experiments of retinal induction.
2. Condenser discharges; exponentially increasing currents and re-ctangular pulses of various time constants and durations are used, and it is found that the inducing effect is maximal when they are of threshold strength, irrespective of the wave form and time constant.
3. Condenser discharges of small time constants show an inducing effect equivalent to that of lights of longer wave-lengths, while exponentially increasing currents of large time constants behave like blue light in retinal induction.
4. When light complementary to the inducing light is interposed between this and the subsequent white light, no retinal induction can be found, and this phenomenon is termed “neutralization of retinal induction.” It is shown that electric stimuli of suitable wave form and time constant can neutralize the retinal induction caused by colored light.
I am greatly indebted to Prof. K. Motokawa for his kind guidance and helpful criticism.
