Talk about trippy.
New research has analyzed human reactions to several optical illusions in which a black mass appears to expand before someone’s very eyes, the New York Times reported.
These kinds of static images offer insight into how the human brain perceives the visual world, according to a recent study published in Frontiers in Human Neuroscience.
Psychologists showed a photo of the black blot centered over a black and white, ovally checkered background to 50 men and women with normal vision. It was found that the stronger a participant’s reaction to the elusive photo, the more their pupils would dilate, according to the findings.
“There is no reason per se that the pupil should change in this situation, because nothing is changing in the world,” Bruno Laeng, Ph.D., study author and psychology professor at the University of Oslo, told the paper. “But something clearly has changed inside the mind.”
He describes human sight as “an eye with a brain attached,” adding that one’s brain “is analyzing what it’s seeing and building up, constructing a possible scenario and adapting to it.”
Fellow study authors say this illusion is so captivating because it gives viewers the feeling of stumbling into a dark tunnel or hole. When other variations in colors were also tested, a black hole over a magenta fill was found to get the strongest reaction.
It was also found that some, an estimated 14%, did not see the center color take over the whole image. Laeng pontificates that this has to do with past experiences or that they perceive the image in only two dimensions.