Critical flicker-fusion frequency as an indicator of human receptive field-like properties.

A psychophysical function, believed to reflect receptive field-like properties, is described. It is based on the determination of the critical flicker fusion frequency (CFF) of a tiny test target, centered on a round background of fixed luminance, the size of which is varied as the test parameter. Under optimal conditions, the maximal obtained frequency difference is 10 Hz. This function is compared with the so-called sustained-like function, with which it has some common aspects. Additionally, a portion of the flicker-based function apparently derives from a non-sustained-like source.