Many people swear by the so-called spelunker’s illusion, in which they think they can see their own hands moving even in the total absence of light. You don’t have to see it to believe it: in a recent article in Psychological Science, cognitive scientists based at Vanderbilt University and the University of Rochester have demonstrated that this spooky illusion is real, and some individuals are more prone to these visions than others.

Read More: Synesthesia Helps Explain Mysterious Spelunker’s Illusion – Scientific American.