An optical illusion tricks the brain into seeing a bright white glow, but it could be due to an evolutionary impulse, researchers say.
Fuzzy vision shows how your eyes can lie.
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Akiyoshi Kitaoka’s Asahi Illusion tricks your eye into thinking that the center of the image is more luminescent than the periphery Credit: Akiyoshi Kitaoka
The image shows what Akiyoshi Kitaoka called the “Asahi” glow illusion.
The image shows petals with yellow to black transitions surrounding a white center.
But the central part seems to look brighter than the white background, even though it is the same tone throughout the image.
There is a scientific explanation for the illusion.
According to the journal Frontiers in Human Neuroscience, the reason for the eye trick is that central light patterns of different colors (for example, green, magenta, and also white) suggest light propagation.
And the reason they trick the eyes could be that our brains have evolved to avoid sudden bright light.
The researchers found that the Asahi illusion caused people’s pupils to constrict, similar to when the eye looks up into sunlight.
The researchers write: “Preliminary restriction to illusory light could serve an important role in promoting behavior to avoid being ‘blinded’ by (real) physical light.”
Illumination illusions like Asahi bear a geometric resemblance to the gradients formed by the glare of bright sunlight when partially blocked by plant leaves or cloud formations.
The pupils will unconsciously adapt to the light in their environment.
They will widen when it is dark to take in more light and narrow when it is bright to protect the eye from overexposure.
“There is no reason per se that the student must change in this situation, because nothing changes in the world,” said Bruno Laeng, professor of psychology at the University of Oslo and author of the study, in a statement to the New York Times.
“But something clearly changed in the mind,” he said.
The researchers hypothesize that the illusion works because the gradient in the central hole makes it appear as if the viewer is entering a glowing hole, causing the participant’s pupils to constrict.
The study taps into a fundamental problem facing all animals, including humans, according to Dale Purves, Ph.D., a neurobiologist and professor emeritus who studies visual perception at Duke University.
Purves told the Times that while a camera can directly measure the amount of light it captures, “we don’t have that physical apparatus, we don’t have a measure of the world.”
dr. Laeng said in the same article that when the eye is faced with a scene, your brain “analyzes what it sees and builds a possible scenario and adapts to it.”
This is because a stimulus, such as light, takes time to reach the sensory organs that need to send it to the brain, which in turn needs to process it, make sense of it, and do something with that information.
And by the time our brain catches up with the present, time has already moved on and the world has changed.
To avoid this, the brain may be constantly trying to predict the future a bit in order to predict the present, in a survival instinct.
Categories: Optical Illusion
Source: HIS Education