Fig 1. Experimental setup.

Four vibro-tactile stimulators were attached to the palm and back of each hand (marked with white circles). The hands were either held in the same orientation with both palms facing downwards (A) or in different orientations with one hand flipped upside-down (B). In each trial, a target stimulus was randomly presented at one of the four locations. Simultaneously, a distractor stimulus was presented randomly at one of the two stimulator locations on the other hand. Target and distractor stimuli differed with respect to their vibration pattern. Participants were asked to localize the target stimulus as quickly and accurately as possible. For statistical analysis and figures, stimulus pairs presented to the same anatomical locations were defined as congruent, as illustrated by dashed (target) and dashed-dotted (distractor) circles, which both point to the back of the hand here. Note that with differently oriented hands (B) anatomically congruent locations are incongruent in external space and vice versa.