Mach bands are phase dependent

The prevailing explanation of Mach bands, the paradoxical bands of light and dark seen where luminance gradients meet plateaux, is that they are due to lateral inhibition in the visual system1–4. This explanation equates Mach bands with distortions in a processed luminance distribution due to selective attenuation of low frequency components. But square waveforms exhibit no Mach bands2,5,6, although they should also be distorted after processing. Measurements of the contrast required to see Mach bands in trapezoidal waveforms and manipulations of their spectra lead us to conclude that phase relationships between Fourier components are important to the structure we perceive. A model based on the odd and even symmetry of visual receptive fields explains our results.

[1]  D. Hubel,et al.  Receptive fields, binocular interaction and functional architecture in the cat's visual cortex , 1962, The Journal of physiology.

[2]  G. Békésy.  Mach- and hering-type lateral inhibition in vision , 1968 .

[3]  D. Tolhurst.  On the possible existence of edge detector neurones in the human visual system , 1972 .

[4]  M. Sanders.  Handbook of Sensory Physiology , 1975 .

[5]  L. Maffei,et al.  Spatial frequency rows in the striate visual cortex , 1977, Vision Research.

[6]  G. Sandini,et al.  Responses of visual cortical cells to periodic and non‐periodic stimuli. , 1979, The Journal of physiology.

[7]  D Marr,et al.  Theory of edge detection , 1979, Proceedings of the Royal Society of London. Series B. Biological Sciences.

[8]  D. Pollen,et al.  Phase relationships between adjacent simple cells in the visual cortex. , 1981, Science.

[9]  J. Ross,et al.  High frequency limitations on mach bands , 1981, Vision Research.

[10]  D. Pollen,et al.  Spatial computation performed by simple and complex cells in the visual cortex of the cat , 1982, Vision Research.

[11]  D. G. Albrecht,et al.  Spatial frequency selectivity of cells in macaque visual cortex , 1982, Vision Research.

[12]  D. Field,et al.  Phase reversal discrimination , 1984, Vision Research.

[13]  F. Ratliff.  Why mach bands are not seen at the edges of a step , 1984, Vision Research.

[14]  R. Watt,et al.  Spatial filters and the localization of luminance changes in human vision , 1984, Vision Research.

[15]  Ingo Rentschler,et al.  Loss of spatial phase relationships in extrafoveal vision , 1985, Nature.