I discuss evidence for spatial frequency channels in the human visual system.
Spatial frequency channels consist of neurones hypothesised to be sensitive to particular spatial frequencies that together make up a visual stimulus.
Spatial frequency is a measure of the number of pairs of light and dark bars (cycles) in the stimulus that fall within one degree of visual angle (c/deg) of the eye.
Blakemore and Campbell (1969) measured the minimum contrast at which sine wave gratings were visible. Then participants viewed a high contrast sine wave grating for a minute. The minimum contrast at which the original grating could be discriminated was increased in the spatial frequency of the high contrast grating previously viewed. It was hypothesised that this was due to neurones selectively sensitive to a particular spatial frequency [spatial frequency channels]. This explanation was ...
Spatial frequency channels are discussed.