The Riemannian Geometry Theory of Visually-Guided Movement Accounts for Afterimage Illusions and Size Constancy

Area of Science:

• Visual perception
• Computational neuroscience
• Geometric vision

Background:

• Previous work suggested vergence affects perceived size.
• Size constancy is a fundamental aspect of visual perception.
• Afterimage experiments provide insights into visual processing.

Purpose of the Study:

• To explain why vergence does not affect perceived size using a Riemannian framework.
• To account for size-change illusions related to afterimages and body movement.
• To propose a Riemannian visual-somatosensory-hippocampal association memory network.

Main Methods:

• Developing a Riemannian formulation of visual space.
• Utilizing a novel association memory network incorporating a Riemannian metric.
• Analyzing afterimage experiments, including the Taylor illusion.
• Connecting visual perception with somatosensory information and proprioception.

Main Results:

• The Riemannian formulation accurately explains why vergence does not influence perceived size.
• The proposed network emulates the warping of 3D visual space by the eye.
• The network predicts changes in retinal image size based on object distance.
• The model successfully accounts for size-change illusions occurring with moving afterimages.

Conclusions:

• The Riemannian metric is crucial for accurately emulating visual space distortions.
• The association memory network provides a mechanism for size constancy.
• Discrepancies between anticipated and actual retinal image sizes explain size-change illusions.