Widening the aperture: Optical illusion can widen pupils – Wikipedia

Don’t worry, the black hole visible here is not getting bigger. The drag you feel when you see the black dot is just an optical illusion. An optical illusion was created by a research team and analyzed in the context of a study. The researchers published their findings in the journal Frontiers in human neuroscience chest.

For the study, the team led by psychologist Bruno Ling from the University of Oslo used different versions of widening holeThe dilated aperture was shown to 50 women and men with normal vision. The images were shown not only with a black hole and a white background, but also with white or colored dots in the middle. The backgrounds also varied, they wore colors like blue, purple or green.

As people looked at the images, the researchers analyzed eye movements and pupil size changes using an infrared eye tracker. After viewing, participants rated how strong the illusion of the growing spot seemed to them personally. 86 percent of participants noticed this effect when the central hole was black. 80 percent were able to identify it through the colored holes. Participants noticed the greatest expansion of the black dot when the background was colored purple, the study researchers wrote.

Like driving in a ditch or tunnel

When the participants looked specifically at black holes, their pupils dilated. Conversely, when the participants saw the images with colored spots, their pupils narrowed. The special adaptation of the pupils is a reaction to different lighting situations. When it gets dark, the pupils dilate to let more light into the eye. In cases of bright light, the pupils become smaller so as not to let in too much light.

The results of the study also showed that pupil enlargement and subjective perception of illusion intensity are related. The more participants perceived the optical illusion, the larger their pupil size. This connection cannot be established for colored holes. These findings confirm a study by Laeng from 2012. There, participants were shown an “Asahi illusion,” which aims to simulate a situation in which sunlight is partially obscured by obstacles such as trees or clouds. At that time, it was recognized that the pupils of the test subjects get smaller when looking at them.

The “Asahi illusion” makes the pupils shrink because one feels blind.

(Photo: Akiyoshi Kitaoka)

Effect widening hole It is an example of how one’s perception can be deceived. “The progression of the central black hole’s circular shadow gives a distinct impression of optical flow, such as driving through a hole or tunnel,” explains Bruno Ling in a statement from the magazine. The brain thus prepares the eye for a new light setting that does not actually occur. “By this deception, we show that the pupil responds to how we perceive light – even if that light is imaginary – and not to the amount of light energy actually entering the eye,” Lange says.

The eyes and brain work together to perceive the world around us. The eye perceives something and the brain tries to interpret what it perceives. To do this, the brain uses past and already known events to deal with the new situation. When the brain misinterprets the visual stimulus it is getting from the eye, an optical illusion occurs.

who – which widening hole It doesn’t have to be expansion Because there is also the possibility of no optical illusion when seeing the pattern. If that happens, you’re in a fairly small community as an observer: 14 percent of the study participants couldn’t see this effect in the black point painting, and 20 percent were in the color versions.

Researchers have not yet been able to explain exactly why this is. Perhaps, they wrote, these observers might see the patterns not as holes but as “expanding dots of ink.” That is, they will see the image in 2D instead of in 3D.

Leave a Comment