A weird new optical illusion deceives the vast majority of individuals into believing that a dark “black hole” region in the middle of a motionless image is rapidly expanding as if the observer is moving toward it. Researchers now believe that the visual deceives the brain into believing that the spectator is entering a darker location, such as a cave or tunnel.

On a white background packed with smaller black ellipses, there is a massive black ellipse surrounded by a dark halo. When a person looks at the image for a few seconds, the dark elliptical section appears to extend outward, which is why the design is known as the “expanding hole.”

According to a new study, 86 percent of the 50 individuals who gazed at the optical illusion saw the increasing blackness. The illusion, according to the researchers, is based on the brain’s processing of changing light levels.

In a statement, principal researcher Bruno Laeng, a psychologist at the University of Oslo in Norway, said, “The expanding hole is a highly dynamic illusion.” “As if the observer were heading forward into a hole or tunnel” Laeng noted, the illusion tricks the mind into experiencing a shift in brightness that isn’t really there.

According to the researchers, the illusion hijacks a natural brain reflex that detects when light is about to change. The black patch in the image’s center resembles the entrance to a cave or tunnel, while the surrounding pattern provides the sensation that the observer is heading toward it. When the brain detects a probable change in light intensity, such as entering a cave, the pupils constrict or dilate in order to prepare you for the impending disruption.

The illusion is so effective at fooling the brain that it leads people’s pupils to expand as if they were moving into a darker environment. They tracked the eye movements of their participants using special cameras, and they discovered that their patients’ pupils were enlarging in sync with the illusion’s black region expanding in their minds. Researchers found that those who saw a larger “black hole” had more dilatation than those who perceived a smaller “black hole.”

“The illusion of the expanding hole prompts a corresponding dilation of the pupil, as it would happen if darkness really increased,” Laeng explained. This demonstrates that even if the light is fictitious, “the pupil reacts to how we perceive light.”

The researchers also showed the people different versions of the illusions where the ellipses were a different color. The enlarging effect of the illusion was diminished as a result, and the observer’s pupil dilations were less evident. The viewers’ pupils constricted rather than expanded when the colors were inverted (white ellipses on a black backdrop) as if they were heading toward a bright light.

The researchers are baffled as to why some people who gaze at the widening hole fail to notice the black zone moving. To address this riddle, the team plans to test the illusion on other animals to see if they can learn more about how those visual systems differ from those in humans.

The new research was published in the journal Frontiers in Human Neuroscience on May 30.

Image Credit: Study Authors

You were reading: This Weird Illusion Will Make You See An Expanding Black Hole