We used a modified version of the experimental setup described in Ehrsson (2007), which is illustrated in Fig. 1 (left
panel; see Supplementary material for full description of the experimental procedures). The participants sat on a chair,
wearing a set of HMDs, in which they saw a real-time video feed from a pair of cameras located 2 m behind them. The left
eye displayed the video image from the left camera, and the right eye displayed the video image from the right camera. Thus,
the participants observed their own back with stereoscopic vision from the perspective of a person sitting 2 m behind them.
The experimenter was located just behind the participant’s right shoulder, and for 1 min simultaneously touched the
participant’s chest, which was out of view, and the space below the cameras (i.e., the chest of the ‘illusory body’) with
two small plastic rods. The touching of the participant’s real chest and the ‘illusory chest’ was either synchronous, a condition
that induces the out-of-body illusion, or asynchronous, a mode of stimulation which significantly reduces the illusion
and allows for the comparison of otherwise equivalent conditions.