Binocular contrast-gain control for natural scenes: Image structure and phase alignment

Vision Res. 2018 May;146-147:18-31. doi: 10.1016/j.visres.2018.02.012. Epub 2018 Apr 30.

Abstract

In the context of natural scenes, we applied the pattern-masking paradigm to investigate how image structure and phase alignment affect contrast-gain control in binocular vision. We measured the discrimination thresholds of bandpass-filtered natural-scene images (targets) under various types of pedestals. Our first experiment had four pedestal types: bandpass-filtered pedestals, unfiltered pedestals, notch-filtered pedestals (which enabled removal of the spatial frequency), and misaligned pedestals (which involved rotation of unfiltered pedestals). Our second experiment featured six types of pedestals: bandpass-filtered, unfiltered, and notch-filtered pedestals, and the corresponding phase-scrambled pedestals. The thresholds were compared for monocular, binocular, and dichoptic viewing configurations. The bandpass-filtered pedestal and unfiltered pedestals showed classic dipper shapes; the dipper shapes of the notch-filtered, misaligned, and phase-scrambled pedestals were weak. We adopted a two-stage binocular contrast-gain control model to describe our results. We deduced that the phase-alignment information influenced the contrast-gain control mechanism before the binocular summation stage and that the phase-alignment information and structural misalignment information caused relatively strong divisive inhibition in the monocular and interocular suppression stages. When the pedestals were phase-scrambled, the elimination of the interocular suppression processing was the most convincing explanation of the results. Thus, our results indicated that both phase-alignment information and similar image structures cause strong interocular suppression.

Keywords: Binocular contrast-gain control; Dichoptic; Natural image; Phase-scrambled.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Contrast Sensitivity / physiology*
  • Humans
  • Perceptual Masking / physiology
  • Photic Stimulation
  • Sensory Thresholds
  • Vision, Binocular / physiology*
  • Visual Perception / physiology*