Surface edges mitigate the disparity gradient constraint on binocular fusion and visual direction

Area of Science:

• Vision science
• Perceptual psychology
• Computational neuroscience

Background:

• Binocular vision combines two eye views for single object perception.
• Steep disparity gradients between isolated dots typically cause diplopia (double vision).

Purpose of the Study:

• To investigate if binocular fusion is possible with steep disparity gradients when they occur between surfaces.
• To determine the role of surface texture in overcoming disparity gradient constraints on fusion.

Main Methods:

• Presented target squares with steep disparity gradients alone or within foreground/background surfaces.
• Analyzed the effect of added surfaces and support texture on fusion and visual direction.

Main Results:

• Fusion was restored despite steep disparity gradients when targets were incorporated into surfaces.
• Support texture mitigated the disparity gradient constraint, enabling single vision.
• Visual direction indicated fusion, not suppression, when surfaces provided support.

Conclusions:

• Surface texture and support effectively overcome the disparity gradient constraint on binocular fusion.
• A close relationship exists between the disparity gradient constraint and the mitigating effect of support texture.
• These findings have implications for understanding depth perception and visual processing in complex scenes.