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Geometric

Ponzo Perspective Illusion

Linear Perspective Size Distortion • Two identical horizontal lines appear radically different lengths due to converging tracks.

Parameter Controls

Adjust procedural mathematical parameters in real-time to alter or break the illusion.

Perspective Track Angle (°) 35
Bar Vertical Separation 70
Horizontal Bar Length (px) 100
Target Bar Color #f59e0b

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🧠 Scientific Explanation & Psychophysics

Underlying Mechanism: Size Constancy Scaling & Depth Cue Integration

Visual cortical neurons scale perceived size according to distance cues (size constancy). Because the upper bar lies deeper within converging perspective lines, the visual system infers that it is farther away. Since both bars produce equal-sized retinal images, the brain concludes the top bar must be physically larger.

Why This Works in the Brain

The visual cortex processes incoming sensory information using specialized receptive fields and cortical feature detectors. Illusions occur when mathematical geometries produce conflicting spatial signals, exposing how the brain constructs subjective perception from objective electromagnetic light waves.

💬 Community Notes & Observations

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