This experiment induces the sensation of a phantom presence in the room. The participant blindfolded is asked to use a stylus to prod an empty space in front of them. Using a tactile feedback system and a robot arm, the participant feels as if they are prodding themselves in the back. As the experiment progresses the system adds a delay to this prodding. At this stage, the participants become freaked out believing that someone else if prodding them... https://youtu.be/GnusbO8QjbE Link to the paper... Neurological and Robot-Controlled Induction of an Apparition https://www.cell.com/current-biology/abstract/S0960-9822(14)01212-3