Home Science Optical illusion mystery

Optical illusion mystery

Author

Date

Category

1 in 7 don’t see this black hole ‘moving,’ and scientists don’t know why

Notice anything strange about this image? When most people look at the “expanding hole” optical illusion, they see the black hole at the center growing. This new illusion is incredibly adept at deceiving most brains and fooling the reflexes of our eyes, according to new research from Norway.

“The ‘expanding hole’ is a highly dynamic illusion: The circular smear or shadow gradient of the central black hole evokes a marked impression of optic flow, as if the observer were heading forward into a hole or tunnel,” says the first study author Dr. Bruno Laeng, a professor at the Department of Psychology of the University of Oslo.

Nearly 9 in 10 experience a pupil reflex

Many may disregard optical illusions as nothing more than child’s play, but researchers explain they hold legitimate scientific psycho-sociological merit. Scientists study optical illusions to better understand the complex visual systems at play as the eye and brain both make sense of and anticipate the visual world.

This latest report documents the astounding deceptive abilities of the expanding hole illusion. The image actually tricks the human mind so well that it triggers a dilation reflex in the pupils for 86 percent of the people who see it! This reflex allows in more light, just like what would happen if someone moved into a dark area.

“Here we show based on the new ‘expanding hole’ illusion that that the pupil reacts to how we perceive light – even if this ‘light’ is imaginary like in the illusion – and not just to the amount of light energy that actually enters the eye. The illusion of the expanding hole prompts a corresponding dilation of the pupil, as it would happen if darkness really increased,” Prof. Laeng explains.

Study authors explored a large variety of other possible hole or surrounding dot colors besides black: blue, cyan, green, magenta, red, yellow, and white. The team displayed numerous variations of the expanding hole illusion on a screen for 50 people with normal vision (both male and female). Each participant was asked to rate subjectively how strongly they perceived the illusion.

Meanwhile, as each person looked at the images, researchers were measuring their eye movements and pupils’ unconscious constrictions and dilations. To serve as controls, participants were also shown “scrambled” versions of the illusion (equal luminance and colors, but no colors).

Why don’t some people see the illusion?

The optical illusion was most effective with a black hole. Even so, 14 percent of participants still didn’t perceive any illusory expansion when the hole was black. In comparison, 20 percent didn’t see anything if the hole was in color.

Among those who do see the illusion, the subjective strength of the effect varies. For some it is quite noticeable, while others see a more subdued expansion.

The research team also notes black holes specifically promoted strong reflex dilations in pupils, while colored holes actually had the opposite effect: participants’ pupils constricted. The stronger a person rated their perception of the illusion, the more their pupil diameter changed. Importantly, however, this only held true regarding black holes.

As far as why some people still don’t see the illusion, researchers can’t say for now.

“Our results show that pupils’ dilation or contraction reflex is not a closed-loop mechanism, like a photocell opening a door, impervious to any other information than the actual amount of light stimulating the photoreceptor. Rather, the eye adjusts to perceived and even imagined light, not simply to physical energy. Future studies could reveal other types of physiological or bodily changes that can ‘throw light’ onto how illusions work,” Prof. Laeng concludes.

6 COMMENTS

  1. Hubby can’t see the blob growing… But he has macular degeneration (has had it for 4 years and requires monthly eyeball injections)

    He informs me that 1 in 7 of us will get macular degeneration as we head into the twilight zone.

    4

    0

      • The injections sound ghastly.

        I really didn’t know how he was going to cope the first time he had it…..as he had managed to forgo his TB jab at high school and had only ever had one Tetanus jab after cutting himself on some rusty iron, and had refused to go to the Dentist for 40+ years, and makes a bloody grand performance every time a vax needle is shown on TV.

        However, it was me that nearly vomited…and now I don’t accompany him to any of the appointments.

        He goes ballistic when he thinks the appointments will be delayed (thanks Jacinda), but to-date they haven’t been..

        It appears that there aren’t many(?any) nerves in our eyeballs…and Hubby says you feel pressure on the eyeball, but not pain…. The eye feels a bit gritty for a day or so.

        5

        0

Recent posts

Tell Your Stupid Greenie Mates

Plant-based meats are less nutritious than the real thing, study reveals Plant-based meats don’t pack the same protein punch, making them less nutritious than the...

Lefties In USA At It Again.

Biden Announces a New Plandemic Right before the Midterm Elections The Democrats aren’t even bothering to hide it anymore. They need lockdowns and mail-in ballots...

Recent comments

Simpleton1 on Have Your Say
Curious on Have Your Say
Simpleton1 on Have Your Say
nasska on Have Your Say
waikatogirl on Have Your Say
waikatogirl on Have Your Say
Beorn on Have Your Say
Simpleton1 on Have Your Say

The way we all feel about this useless government

Hamilton
overcast clouds
10.3 ° C
11.7 °
7.9 °
98 %
0.5kmh
98 %
Sat
10 °
Sun
14 °
Mon
14 °
Tue
13 °
Wed
13 °
NZD - New Zealand Dollar
USD
1.5692
EUR
1.6538
AUD
1.1090
CAD
1.2274
GBP
1.9434
JPY
0.0117
CNY
0.2338
INR
0.0201