August 2012
Volume 12, Issue 9
Vision Sciences Society Annual Meeting Abstract  |   August 2012
Two routes to suppression of signals in color vision
Author Affiliations
  • Kathy T. Mullen
    McGill Vision Research, Dept of Ophthalmology, McGill University
  • Mina Gheiratmand
    McGill Vision Research, Dept of Ophthalmology, McGill University
  • José M. Medina
    McGill Vision Research, Dept of Ophthalmology, McGill University
  • Yeon Jin Kim
    McGill Vision Research, Dept of Ophthalmology, McGill University
Journal of Vision August 2012, Vol.12, 107. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Kathy T. Mullen, Mina Gheiratmand, José M. Medina, Yeon Jin Kim; Two routes to suppression of signals in color vision. Journal of Vision 2012;12(9):107.

      Download citation file:

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

  • Supplements

There are at least two routes to psychophysical cross-orientation suppression prior to binocular summation of the signal in achromatic vision: (1) a monoptic, non-adaptable sub-cortical pathway and (2) a dichoptic, adaptable interocular pathway (Baker et al., Neuroscience, 146, 2007). Here we test psychophysically whether cross orientation masking (XOM) in color vision (Medina & Mullen, JOV 9(3), 2009) has gain-control pathways that are separable from achromatic responses or whether chromatic and achromatic responses interact. Methods: Detection threshold vs contrast (TvC) masking functions were measured for red-green isoluminant, horizontal Gabor targets overlaid with achromatic vertical Gabor masks. We tested for XOM under a range of spatiotemporal conditions (0.375, 0.75 & 1.5 cpd; 2 & 8 Hz), and with the chromatic test and achromatic mask presented under monoptic, dichoptic, and binocular viewing conditions. Results: We find that: (1) there is little or no cross orientation masking of color by achromatic contrast under monoptic or binocular conditions at any of the spatio-temporal frequencies tested, although some facilitation may occur; (2) there is significant dichoptic XOM, when mask and test are present to different eyes, which increases with mask contrast; (3) the dichoptic XOM is greater at low temporal frequencies (2 Hz) than high (8Hz). Conclusion: The significant inter-ocular cross orientation suppression of color by luminance contrast indicates that gain control pools at this level are unselective for chromaticity. Our results support a two-stage contrast normalization model with both a monocular and a dichoptic stage prior to binocular summation: the within eye, monocular stage of suppression is selective for color contrast whereas the inter-ocular second stage, revealed under dichoptic conditions, has color-achromatic interactions. This differential effect provides evidence for at least two distinct sites for suppressive gain control in color vision.

Meeting abstract presented at VSS 2012


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.