This optical illusion plays tricks on your brain
Check out these mysterious optical illusions that affect our visual perception.
- Troxler's effect or "fading" causes images to disappear from your field of vision.
- Scientists don't have a full understanding yet of how this works.
- The effect is linked to the way neurons are adapted by the visual system.
Why do we some times see things that aren't there? Delighted by stories of vengeful ghosts and spirits, we largely assume there's a world outside of our regular field of vision. Whether it's inhabited is certainly debatable but the curious psychological condition called Troxler's Fading or Troxler's Effect may explain one optical illusion.
This effect is named after a Swiss physician and philosopher Ignaz Paul Vital Troxler (1780-1866), who discovered it in 1804. It is essentially a trick of perception that describes what happens if you fix your gaze upon a single point in the visual field. It doesn't even have to be for a long time – 10 seconds would do. That can make images and colors disappear from your peripheral vision.
THE LILAC CHASER
Look at the black cross at the center of the image and the spots in this "lilac chaser" illusion will fade away in a few seconds. A grey background and the cross will remain unless you are among those who will also see a moving blue-green spot. You might even notie a bunch of green spots when you move your eyes away after a while.
HOW DOES IT WORK?
Research indicates the effect is related to how neurons important for perceiving stimuli are adapted by the visual system. Unchanging stimuli will eventually disappear from our awareness while our mind will fill the areas where they used to be with the background information (or color). A "sensory fading" or "filling-in" is linked to saccades – involuntary eye movements that happen even when the gaze appears settled. If we fixate on a point, an unmoving image or scene would fade from view in a few seconds thanks to the "local neural adaptation of the rods, cones and ganglion cells in the retina," explains the Illusions Index.
The effect is made stronger if the stimulus image is low contrast or blurred.
While studies showed the effect doesn't only occur in the eyes but partially in the brain, there's not yet a definitive explanation for everything involved in this unusual visual phenomenon.
Another example image of the Troxler effect. Look at the center of the image for about 10 seconds.
And another fun example:
Step inside the unlikely friendship of a former ACLU president and an ultra-conservative Supreme Court Justice.
- Former president of the ACLU Nadine Strossen and Supreme Court Justice Antonin Scalia were unlikely friends. They debated each other at events all over the world, and because of that developed a deep and rewarding friendship – despite their immense differences.
- Scalia, a famous conservative, was invited to circles that were not his "home territory", such as the ACLU, to debate his views. Here, Strossen expresses her gratitude and respect for his commitment to the exchange of ideas.
- "It's really sad that people seem to think that if you disagree with somebody on some issues you can't be mutually respectful, you can't enjoy each other's company, you can't learn from each other and grow in yourself," says Strossen.
- The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Scientists make an important discovery for the future of computing.
- Researchers find a new state of matter called "topological superconductivity".
- The state can lead to important advancements in quantum computing.
- Utilizing special particles that emerge during this state can lead to error-free data storage and blazing calculation speed.
Erik Verlinde has been compared to Einstein for completely rethinking the nature of gravity.
- The Dutch physicist Erik Verlinde's hypothesis describes gravity as an "emergent" force not fundamental.
- The scientist thinks his ideas describe the universe better than existing models, without resorting to "dark matter".
- While some question his previous papers, Verlinde is reworking his ideas as a full-fledged theory.
As tempting as it may be to run away from emotionally-difficult situations, it's important we confront them head-on.
- Impossible-sounding things are possible in hospitals — however, there are times when we hit dead ends. In these moments, it's important to not run away, but to confront what's happening head-on.
- For a lot of us, one of the ways to give meaning to terrible moments is to see what you can learn from them.
- Sometimes certain information can "flood" us in ways that aren't helpful, and it's important to figure out what types of data you are able to take in — process — at certain times.