Seeing in the dark is a super power that many may wish to have. As it turns out, new research suggests that at least half of human beings can actually see their body movements, for example their hand gestures, in the dark.
"Seeing in total darkness? According to the current understanding of natural vision, that just doesn't happen," said Duje Tadin, a Vanderbilt University news release reported. "But this research shows that our own movements transmit sensory signals that also can create real visual perceptions in the brain, even in the complete absence of optical input."
The researchers conducted two experiments and for both of them, participants were shown two blindfolds. They were told that one of the blindfolds "may allow a small amount of light to pass through." In reality, both blindfolds blocked all light.
Some participants believed they were not going to see anything through the blindfold, while another group told they may be able to detect movement. Then research participants were asked to wave a hand over their eyes at a slow, comfortable pace while wearing one of the two blindfolds. Researchers then asked them whether they saw anything, and if they did, what they saw.
The new scientific discovery offers insight into how our brains process information and see the outside world.
"Any time you willfully execute a movement-such as waving your hand in front of your face-your brain generates command signals sent to the muscles causing them to produce the movement. Having issued those motor orders, the brain also expects them to be carried out, and that expectation is signaled to other parts of the brain as a heads-up that something is about to happen," Randolph Blake, Centennial Professor of Psychology at Vanderbilt University and co-author of the study, said.
"We surmise that those heads-up signals find their way into the visual pathways, thus producing an illusory impression of what would ordinarily be seen-a kind of self-fulfilling prophecy," he added.
