Laeng / Nabil / Kitaka
New research indicates that optical illusions do not occur only in the brain and its effect can also influence the automatic responses of our body, such as dilation of pupils.
A new one published in Frontiers in Human Neuroscience revealed that a simple optical illusion can deceive not only the mind, but also one of the body’s most automatic answers: a dilation and reflective contraction of the pupils. The phenomenon, however, does not affect everyone equally, leaving scientists with new questions about how perception shapes physiology.
Researchers at the University of Oslo investigated the so -called illusion of “expanding hole“An image that presents a cluster of black points on a white background with a black circle in the center. When people stare at the“ hole ”, many realize it as if was expanding outas if they were being pulled into a tunnel. The illusion is so convincing that it causes the pupils of many observers to dilate, as if they are entering a darker space.
Interestingly, according to the, when the central orifice was presented in color instead of black, the opposite occurred: the participants’ pupils contracted, imitating the reaction to a brighter light.
“The ‘expanding hole’ is a highly dynamic illusion”Explained Dr. Bruno Laeng, lead author of the study and professor of psychology at the University of Oslo.” Evokes a strong impression of optical flow, as if the observer was moving into a hole or tunnel. “
To test the effect, the team presented the illusion to 50 volunteers with normal vision. Participants were requested to evaluate the intensity of your perception while investigators recorded their eye movements and pupillary responses. Approximately 80% of individuals reported having seen the expansion effect, while about 14% did not notice any movement. When the hole was colored, 20% of participants were not sure if they had seen the effect, the.
The results showed a direct correlation: The stronger an individual evaluated the illusion, the more his pupils responded. Those who could not see the expansion did not have any changes in the size of the pupil.
The results point out that pupillary reflexes are not simply mechanical reactions to the physical levels of light, but they can also be driven by subjective perception. “Our results show that the dilation or contraction of the pupils is not a closed circuit mechanism, such as a photoelectric cell that responds only to light,” said Laeng. “The eye adjusts to the perceived and even imagined light, not just to physical energy.”
