July 2019
Volume 19, Issue 8
Open Access
OSA Fall Vision Meeting Abstract  |   July 2019
“The Snake” equally modulates both brown and brightness
Author Affiliations
  • Steven Buck
    Psychology, University of Washington
Journal of Vision July 2019, Vol.19, 35. doi:https://doi.org/10.1167/19.8.35
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Steven Buck; “The Snake” equally modulates both brown and brightness. Journal of Vision 2019;19(8):35. doi: https://doi.org/10.1167/19.8.35.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Adelson’s Snake background is famous for producing dramatic brightness-induction effects. To explore the relation of brown induction to brightness induction, we measured both brown boundaries (the luminance at which brown completely replaces yellow) and brightness matches on Snake and Anti-Snake backgrounds. Effects of the backgrounds were quantified by the ratio of luminances (modulation) of brightness matches or brown boundaries on the two bands of each background.

The results show that brightness matches and brown boundaries were equally modulated by the simultaneous luminance contrasts present in the Anti-Snake and shared by the Snake. In addition, both brightness matches and brown boundaries were further modulated in equal measure by the constellation of stimulus features unique to the Snake, over and above the effects of simultaneous contrast. The perceptual processes by which the Snake produces its modulations have long been debated but the present results show that they influence both brightness and brown inductions equally.

It remains a mystery why brown progressively replaces yellow as stimuli darken but the present results are consistent with the hypothesis that the degree of brownness is directly determined by stimulus brightness.


This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.