The optical illusions have become very popular recently and they have been posted virally on many sites. These images can trick the mind and makes us wonder about the outcoming result.
There has been one image that puzzled so many people as only 1% could detect the animal image on this picture.
The McCollough Effect – ME
This phenomenon is a trick on the mind that after staring at colored alternating lines for several minutes you will start to see a pinkish tinge or other colors when looking at black-and-white lines. By tilting the head at 90 degrees, you may succeed in improving or lowering the effect, and after that reverse it by rotating the induction images. The longer you stare at the original induction images, the longer the effect will be.
It is a kind of an afterimage and according to researchers it is a result of the continued activation of the visual system. The strong colors of the image create an impression on the visual system by tricking it into believing that it is still looking at the colors when it is actually not. As a result of that one believes that what he sees are black and white stripes, tinged with red and green. This effect is compared to the one of bright flash of the camera that stays in the vision for a longer period of time. This effect can be present for more than three months if the person looks at the colorful gratings persistently.
This phenomenon was named by the US psychologist Celeste McCollough Howard, who discovered the “contingent aftereffect” which is an illusion that lingers in your brain for a longer period of time.
There have been many studies on this issue in the past like the one in 1975 when two researchers tested five groups of 16 people. All groups were given the same image but one of them still experienced its effect after five days in the same degree, and after three months still had it.
You can do it by yourself with the images below, and see how it will affect your vision. Have in mind that it will not cause any harm to your vision.
Several researchers have offered different scientific explanation believing that the cause of these effects is related to the neurons in the visual cortex. On the other hand, others believe that the brain tries to color-correct the world and in that way gets a little bit stumbled. The third group of researchers thinks that this phenomenon is in a way a withdrawal symptom, in this case, an absence of color.
In 1995, researchers have come to the conclusion that this effect was happening within the visual cortex, or somewhere between the eye and the brain. They deducted this after a performed experiment on patient who has suffered significant brain damage. He was shown red-and-green gratings, and after that he was shown black-and-white grating, but the effect still remained from the previous grating.
Julien Ciroux complies with these latest findings and states that the processing mechanisms involved in the ME are located in the primary visual cortex. The two induction images can stimulate the ME if you change them meanwhile looking at their centers for a few minutes. After a certain period of time, once you look at this particular image, you can see it in red or green parts and even pinkish.
According to a 1969 study various stripes in red and green color produce the after-effects and that if the induction image is in different color like green, the person afterwards sees red colors on vertical grates and green colors on horizontal grates. When the green was changed with red induction image, the colors reversed. It has been discovered that this effect is produced only be red and green colors.
In terms of grating, scientists think that it is related to the neurons in the visual cortex that respond more strongly to their preferred orientation and spatial frequency. They have determined the JPEG image format is based on chequered patterns, which are in fact two gratings overlaid on each other.
Nonetheless, experts recommend caution when checking your vision for the ME. Namely, if you don’t see the effect after a few minutes of looking back and forth, think twice before going for the longer option.