Detection of vertical interocular phase disparities using luster as cue

Area of Science:

• Visual Perception
• Binocular Vision
• Computational Neuroscience

Background:

• Interocular contrast disparities produce binocular luster, aiding detection.
• Spatial phase disparities in Gabor patches also elicit binocular luster.

Purpose of the Study:

• To determine if local contrast disparities accompanying phase disparities cause luster.
• To compare the detection of interocular spatial phase and contrast disparities.

Main Methods:

• Detection thresholds for interocular phase and contrast disparities in Gabor patches were measured.
• Stimuli varied in spatial frequency and Gabor envelope standard deviation (number of cycles).

Main Results:

• Detection patterns for phase and contrast disparities were similar when bandwidth was constant and spatial frequency varied.
• Phase disparity thresholds showed a U-shaped function with increasing Gabor standard deviation.
• Contrast disparity thresholds remained relatively constant after an initial decrease with increasing Gabor standard deviation.

Conclusions:

• Binocular sensory fusion, strengthening with more modulation cycles, likely explains the U-shaped function for phase disparities.
• Binocular sensory fusion selectively reduces phase disparities but not contrast disparities, elevating phase disparity detection thresholds.