A few years ago, cognitive scientist Duje Tadin and his colleague Randolph Blake decided to test blindfolds for an experiment they were cooking up.
They wanted an industrial-strength blindfold to make sure volunteers for their work wouldn’t be able to see a thing. “We basically got the best blindfold you can get.” Tadin tells Shots. “It’s made of black plastic, and it should block all light.”
Tadin and Blake pulled one on just to be sure and waved their hands in front of their eyes. They didn’t expect to be able to see, yet both of them felt as if they could make out the shadowy outlines of their arms moving.
Being scientists, they wondered what was behind the spooky phenomenon. “We knew there wasn’t any visual input there,” Tadin says. They figured their minds were instinctively filling in images where there weren’t any.
After conducting several experiments involving computerized eye trackers, they proved themselves right. Between 50 and 75 percent of the participants in their studies showed an eerie ability to “see” their own bodies moving in total darkness. The research, put together by scientists at the University of Rochester and Vanderbilt University, is published in the journal Psychological Science.
How were they so sure? “The only way you can produce smooth eye movements is if you’re following a target,” Tadin tells Shots. When our eyes aren’t tracking something very specific, they tend to jerk around randomly. “If you just try to make your eyes move smoothly, you can’t do it.” The researchers used this knowledge to test whether people could really distinguish their hand movements in the dark.
Text and Image via Neuromorphogenesis