Abstract
By the method ofelectrostimulation, the relation between the magnitude of cone-processes and the duration of the light stimulus was investigated at the human fovea.
1. The magnitudes of cone processes increased almost proportional to the logarithm of the duration of light till a certain critical duration was attained beyond which the response remained constant. The critical duration was designated “aturation time”.
2. The saturation time was 200 msec, remaining unaltered, no mat-ter what the wave lengths and intensities of the spectral lights used might be.
3. The saturation time for white light was always 500 msec. regard-less of its intensity.
4. The difference in saturation time between spectral and white lights was interpreted in terms of interaction among the receptor systems involved.
The writer is greatly indebted to Prof. K. Motokawa, under whose guid-ance this investigation was performed, for his generous advice and valuable suggestions throughout the course of the experiment and the preparation of the manuscript.
