Scientists from the Massachusetts Institute of technology in the United States explained the nature of classical optical illusions based on the perception of the background. The results of the study are published in the journal Vision Research.
The authors of the study found that simultaneous light contrast is based on an assessment of brightness that occurs before visual information reaches the visual cortex of the brain.
The researchers studied documentation describing observations of blind Indian children who had their vision restored by surgery. It turned out that patients perceived the simultaneous light contrast almost immediately after they saw the light. This example shows that the basis for this effect is a relatively simple neural system that can function without pre-tuning.
Another series of experiments was designed to localize the processes of brightness estimation. It is based on the fact that when receiving a combined image from two eyes, the brain almost completely loses information about which eye received specific data. However, using specially designed paintings of parallelepipeds with gradient gray faces, the researchers found that it is not necessary to wait for information from the two eyes to be combined to estimate brightness. According to the hypothesis put forward by the authors, the assessment process takes place in the retina of the eye.
According to scientists, the study provides an opportunity to understand how the brain analyzes information received through optical channels. They note that the results of the survey answer the question of what mechanism underlies the fundamental process of brightness estimation.