Frontiers in Human Neuroscience (May 2017)

The Constancy of Colored After-Images

  • Semir Zeki,
  • Samuel Cheadle,
  • Joshua Pepper,
  • Dimitris Mylonas

DOI
https://doi.org/10.3389/fnhum.2017.00229
Journal volume & issue
Vol. 11

Abstract

Read online

We undertook psychophysical experiments to determine whether the color of the after-image produced by viewing a colored patch which is part of a complex multi-colored scene depends on the wavelength-energy composition of the light reflected from that patch. Our results show that it does not. The after-image, just like the color itself, depends on the ratio of light of different wavebands reflected from it and its surrounds. Hence, traditional accounts of after-images as being the result of retinal adaptation or the perceptual result of physiological opponency, are inadequate. We propose instead that the color of after-images is generated after colors themselves are generated in the visual brain.

Keywords