Experts from the United States set out to find out whether a person is capable of seeing his own hands in the complete dark and wearing a light-tight bandage over his eyes, without using his physical vision and relying only on the unconscious brain activity.
Scientists tried to find out how often and under what conditions people can see a faint silhouette of their own hands, even when there is a complete darkness and the eyesight is not used at all.
As reported Eurekalert, the experiment involved 129 people. Each of them was required to wear two different types of bandages. The first type blocked the light completely, and the second one – almost completely, which was required to study the perception of moving objects in low light conditions.
Then each participant was asked to hold his own hand in front of his eyes and describe the feeling. As it turned out, some of the subjects saw the vague silhouette of their hands, despite the fact that the bandages on their eyes completely blocked their vision.
These results could be attributed to errors in the experiment, but, according to the scientists, this assumption is not able to explain why the participants who received the bandages that let a little light in saw their hands more often than those who got the completely opaque ones.
After going through the various options and repeating the experiment several times with different groups of subjects, the researchers came to the conclusion that the probability to “see” in the dark was associated with the expectations of the participants.
The researchers also put some of the participants of the experiment in a completely dark room and there the experiment was repeated with the use of special infrared system that monitored the eye movements of the subjects. These observations showed that if the participants had a foreign object before their eyes, such as someone else’s hand or a cardboard silhouette of a hand, they did not see anything at all, and their eyes do not move after the object.
Moreover, the subjects who were told that they were in a poorly illuminated room could see their hands more often than those who were aware that the room had no light at all.
For the purity of the experiment, the scientists invited a person whose different sensations are mixed with each other, so-called synesthete. Lindsay Bronnenkant, assistant working in the laboratory of the University of Rochester, accepted this role.
The phenomenon of synesthesia
Each letter and number for Bronnenkant has its special color. During the experiment, she described not just a fuzzy shadow, but a complete silhouette in a weak light.
Other synesthetes who took part in the experiment spoke about similar feelings. They managed to see the movements of their hands in the dark more clearly, claiming to have distinguished all the fingers, not just vague outlines of hands.
Besides, observing the eye movement of synesthetes showed differences from the eye response of the average people: their eyes followed the hand in the dark as smoothly as if it was visible to them.
According to the researchers, the phenomenon of “false vision” showed in the experiment can help better understand how the human brain perceives the world through the mental and physical sensations and organizes the information from different senses.