Adelson's Checker Shadow
Luminance & Color Constancy Illusion • Two squares of identical physical RGB shade look completely different.
Parameter Controls
Adjust procedural mathematical parameters in real-time to alter or break the illusion.
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🧠 Scientific Explanation & Psychophysics
The visual system does not function as a photometer. It actively discounts estimated light sources and soft shadows to extract true surface reflectance. Because Square B is perceived as lying within a cylinder's shadow, the brain boosts its perceived brightness value.
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.