PERIPHERAL CRITICAL FLICKER FREQUENCY

Measurements of critical flicker frequency (CFF) were taken in steps of 5° along the horizontal meridian in the nasal visual field under systematic variation of luminance, area and temporal modulation (ripple ratio) of the test stimulus: for photopic luminances CFF increases from the fovea to the periphery for about 5-15 c/sec. passes several maxima and minima and falls off again at greater values of eccentricity (individually different at 30-60°). showing that parts of the retinal periphery clearly surpass the fovea in the capability of processing temporal information. It is shown that the Ferry-Porter and Granit-Harper laws are only valid in the fovea and at several points in the periphery up to about 30° of eccentricity: for greater values of eccentricity deviations occur from a strongly logarithmic relationship. The non-monotonic course of peripheral CFF is compared to Payne's measurements of reaction times to peripherally presented stimuli (Vision Res. Vol. 6, p. 729) revealing a similar behaviour. © 1979.