Hering Illusion

Hering Illusion

In this geometrical-optical illusion, discovered by the German physiologist Ewald Hering in 1861, two straight and parallel lines look as if they bow outwards. Hering ascribed the effect to our brains overestimating the angle made at the points of intersection between the radiating lines and the red ones. But why do we miscalculate?

Researcher Mark Changizi of Rensselaer Polytechnic Institute in New York believes it has to do with the human tendency to visually predict the near future. Because there's a lag between the time that light hits the retina and the time when the brain perceives that light, Changizi thinks the human visual system has evolved to compensate for the neural delay by generating images of what will occur one-tenth of a second into the future. He explained the Hering illusion in a 2008 article:

"Evolution has seen to it that geometric drawings like this elicit in us premonitions of the near future. The converging lines toward a vanishing point (the spokes) are cues that trick our brains into thinking we are moving forward as we would in the real world, where the door frame (a pair of vertical lines) seems to bow out as we move through it and we try to perceive what that world will look like in the next instant."

Black Dot Illusion

How many black dots are in the image? How many black dots can you see?

Mind Trick?

Have you ever wondered if your mind is normal? Well, do this little mind exercise and find out ---- Free will or synaptic wiring? You be the judge.

Check out the following exercise, guaranteed to raise an eyebrow. There's no trick or surprise. Just follow these instructions, and answer the questions one at a time and as quickly as you can. Again, as quickly as you can but don't advance until you've done each of them...really.

Now, scroll down (but not too fast, you might miss something)...

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Now repeat saying the number 6 to yourself as fast as you can for 15 seconds. Then scroll down.

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> QUICK! THINK OF A VEGETABLE! Then arrow down.
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> You're thinking of a carrot, right?
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If not, you're among the 2% of the population whose minds are different enough to think something else. 98% of people will answer with carrot when given this exercise.

Optical Illusion

Optical illusions prove human senses are fallible, that what you see does not always correspond to reality. People tend to think of optical illusions as tricks in books, but they actually effect nearly every part of modern life as the eye's capacity to be manipulated is what makes all print and visual media possible. Learning some facts about optical illusions is to learn essen
tial information for understanding the information age.

History

In the ancient world, people didn't know if optical illusions were the "fault" of the eyes or the mind. The first recorded theorizers on optical illusions were the Greek thinkers Epicharmus and Protagorus in 450 BCE. Epicharmus implicated the body whereas Protagorus implicated the mind. One hundred years later, Aristotle came up with a view balancing these extremes. In the twentieth century, artists began experimenting with illusions, in a movement known as optical art or "op art." By challenging the viewer to make sense of all sides of the illusion, op art made its audience participants in the artwork.

How Optical Illusions Work

Optical illusions occur when what the eyes see conflicts with what the brain expects. For example, if a series of concentric unconnected curved lines appears like a spiral, it is because the brain is so accustomed to perceiving such figures as spirals that it takes work to realize the drawing is, in fact, not a continuous spiral. Similarly, the "infinite staircase" illusion is possible, in part, because the brain is so used to the length of a drawing representing three-dimensional height.

Dithering

Nearly all forms of media are optical illusions. Print in books and newspapers is not made up of solid letters, but are in fact dots of black, red, yellow and blue ink placed so closely together the mind perceives them as solid. Television screens work in a similar way -- images on screen are not always the colors they appear to be but are in fact tiny dots of red, blue and green light projected so closely together that they are perceived as all different colors. This illusion of making a full-color image from only primary colors is called dithering.

Movies and Colorblindness

Movies are possible because of principle called "persistence of vision," the principle that images remain on the eye for 1/17 of a second, meaning images flashed faster than that (most movies are shot at 24 frames per second) cannot be perceived as separate images, creating the illusion of moving images. Common colorblindness tests are types of optical illusions. Everyone sees the same image, but a normal sighted person perceives the pattern of dots in a circle as one number, and colorblind people will perceive different numbers depending on their type of colorblindness.

The Hidden Tiger Illusion Answer

The hidden tiger can be found in the tiger's stripes.  Read his stripes - they spell - 
"THE HIDDEN TIGER".

 Check here for more Optical Illusions.

The Hidden Tiger Illusion

For today I prepared an interesting spot the object painting, created by American wildlife artist Rusty Rust, that shows a huge Bengal Tiger standing in a bamboo forest. If you are asking yourself why Rusty named this picture “The Hidden Tiger“, your assignment is to figure out why! When you find it – comment, just don’t reveal the secret, so other users can have fun spotting it to.

Check here for the Hidden Tiger Illusion Solution.

The Illusion of Free Choice

Left or Right, Both lead to Slaughter House.

Lilac Chaser Illusion

The lilac chaser is a visual illusion, also known as the Pac-Man illusion. It consists of 12 lilac (or pink, rose or magenta), blurred discs arranged in a circle (like the numbers on a clock), around a small black, central cross on a grey background. One of the discs disappears briefly (for about 0.1 seconds), then the next (about 0.125 seconds later), and the next, and so on, in a clockwise direction. When one stares at the cross for about 20 seconds or so, one sees three different things:

1. A gap running around the circle of lilac discs;
2. A green disc running around the circle of lilac discs in place of the gap;
3. The green disc running around on the grey background, with the lilac discs having disappeared in sequence.

The chaser effect results from the beta movement illusion, combined with an afterimage effect in which an opposite, complementary, colour—green—appears when each lilac spot disappears (if the discs were blue, one would see yellow), and Troxler's fading of the lilac discs.

Explanation 

The lilac chaser illusion combines three simple, well-known effects:

1. When a visual event occurs briefly at one place in the visual field, and then a similar event occurs at an adjacent place in the same visual field, we perceive movement from the first place to the second. This is called apparent movement or beta movement, because no actual movement has occurred. Beta movement is the basis of moving neon signs, film, and video. We see movement because such displays stimulate receptors (called Reichardt detectors) in our brains that encode movement. The visual events in the lilac chaser initially are the disappearances of the lilac discs. The visual events then become the appearances of green afterimages.
2. When a lilac stimulus that is presented to a particular region of the visual field for a long time (say 10 seconds or so) disappears, a green afterimage will appear. The afterimage lasts only a short time, and in this case is effaced by the reappearance of the lilac stimulus. The afterimage is a simple consequence of adaptation of the rods and cones of the retina. Colour and brightness are encoded by the ratios of activities in three types of cones (and also the rods under mesopic conditions). The cones stimulated by lilac get "tired". When the stimulus disappears, the tiredness of some of the cones means that the ratios evoked by the grey background are the same as if a green stimulus had been presented to these cones when they are fresh. Adaptation of rods and cones begins immediately when they are stimulated, so afterimages also start to grow. We normally do not notice them because we move our eyes about three times a second, so the image of a stimulus constantly falls on new, fresh, unadapted rods and cones. In the lilac chaser, we keep our eyes still, so the afterimages grow and are revealed when the stimulus disappears.
3. When a blurry stimulus is presented to a region of the visual field away from where we are fixating, and we keep our eyes still, that stimulus will disappear even though it is still physically presented. This is called Troxler's fading. It occurs because although our eyes move a little when we are fixating a point, away from that point (in peripheral vision) the movements are not large enough to shift the lilac discs to new neurons of the visual system. Their afterimages essentially cancel the original images, so that all one sees of the lilac discs is grey, except for the gap where the green afterimage appears.

These effects combine to yield the remarkable sight of a green spot running around in a circle on a grey background when only stationary, flashing lilac spots have been presented. Occasionally it seems as though the green afterimage has eaten up the lilac discs, this resembles Pac-Man accounting for the illusion's alternative name.

Gradient Optical Illusion

Simultaneous Contrast Illusion. The background is a color gradient and progresses from dark grey to light grey. The horizontal bar appears to progress from light grey to dark grey, but is in fact just one color.

Forked

I bet you will view the picture twice

Did you notice the gal is sitting and the boy is hugging her neck.
Look again - it is actually the other way around. Which side of your brain is being used. You will enjoy this if you're using the right side of your brain.

Elevator Illusion

Go ahead. It's safe, you can trust me.

Elevator floor illusion painted to look like the floor is missing and just a bottomless pit.

Flamingo, Second Glance Illusion

Gesine Marwedel is a brilliant body painting artist based in Germany who creates both beautiful and terrifying pieces of art right on the models who serve as her living canvases.

Marwedel is a master of painting on and with the human form – she can either emphasize it to work with her painting, or eliminate it to let her painting shine through. In both cases, she creates beautiful art that melds together with the people it’s painted on.

These aren’t just pretty pictures – Marwedel also believes in the therapeutic qualities of art. She has even published a book exploring how body painting can be used as therapy.

Put Your Nose on the Black Dot...

Put your nose on the black dot and watch the girl pass through the circle.

It's a magical illusion.

Endless Hallway Illusion

So close and yet so far away.

White Picket Fence

Oops -- I broke physics

How Many Do You See?

Illusion of the Week

Notice the grid of black, white and two shades of blue. Would you believe that all the blue is precisely the same shade of blue, instead of there being some light blue bars and some dark blue bars? There are endless variations of this color contrast illusion, which is sometimes called the Munker-White Illusion and sometimes the Bezold Effect. When the shades involved are black, white and grey the same illusion is called White's Illusion.

All of the small bars within each pattern are actually the same color (i.e., all of the blue segments are the same color blue, all of the red segments are the same color red, and all of the small grey bars are the same color grey). The lightness differences you are experiencing are massive illusions. A theory of what's underlying the lightness illusions in this figure is described in a paper to appear in as special issue of Perception on "Contextual effects on color appearance."

Easy as 1, 2, 3

1. Focus on Black dot in the center.

2. Give a like if the blue rectangle disappeared.

3. Share if you enjoyed it :)

Optical Illusion

The carpeting design inside Paris Fnac at La Defense and by the way the floor is pure FLAT.