Optical illusions involving luminance and lines result from distributed mental processing, beginning with the cells which first catch sight.
The 2 dots above are a classic visual illusion. Although the dots are identical, their luminance appears divergent, with the left dot lighter than the one on the right.
Above is a 2nd example of simultaneous brightness contrast. The 2 stacked cuboids appear somewhat similar, but they have distinct effects on identical dots on their faces. The right dot on the upper cuboid looks brighter, while the left dot appears brighter on the lower cuboid.
The question is how these visual deceptions occur – a question which has vexed psychologists for over a century. The effect of falsely conveying brightness has been known for much longer. Chinese painters had mastered the technique of having a face seem brighter despite lower luminance over 8 centuries ago.
Such is the instance in the cuboids shown. The dot on the face that seems in shadow appears darker than an identical dot on a face receiving more light.
“This is the opposite of what happens in standard simultaneous contrast displays, in which a dot on a dark background appears brighter than a dot on a light background,” observed psychologist Pawan Sinha. “This result runs counter to the idea that high-level analysis of lighting conditions contributes to brightness estimation.”
In a recent study, researchers determined that luminance evaluation occurs before imagery is mentally merged from its binocular source (the eyes). This indicates that brightness is decided by cells in the retina. These early luminance determinations guide mental contrast construction of the entire snapshot take by the eyes, thereby creating optical illusions.
Comparative line length determinations are also made in cells, before the organismal mind perceives imagery. The Ponzo and Müller-Lyer illusions were found to originate with eye interpretations.
“Perhaps this is an innate dispensation,” Sinha suggested. “This is something that the visual system comes prepared to do, right from birth.”
Children with preventable blindness were tested shortly after operations which restored their sight. “If brightness estimation is truly an innate mechanism, then right after sight is initiated in children who were congenitally blind, they should fall prey to the simultaneous contrast illusion,” Singh surmised. This hypothesis turned out to be correct.
Every organic entity – whether protein, cell, organ, or entire organism – is responsive to its environment because it has a mind of its own. Physicality is itself a collage mirage of the minds that an organism has. As optical illusions illustrate, these minds collaborate to present a seamless, elaborate ruse.
Innate mental processing is only possible because mentation patterns are heritable – a facility inexplicable from a material foundation. The encoding which provides precocious knowledge cannot be explained by molecular combinations – only by coherent energy configurations.
Pawan Sinha et al, “Mechanisms underlying simultaneous brightness contrast: Early and innate,” Vision Research 173: 41-49 (August 2020).
“Study sheds light on a classic visual illusion,” Medical Xpress (17 June 2020).
Ishi Nobu, “Optical illusions,” in The Echoes of the Mind, BookBaby (2019).