Localizing 3D motion through fingertips : following in the footsteps of elephants

Different senses are thought to serve different specific tasks. For instance, through hearing we localize sounds made by objects in 3D space (i.e. in the extrapersonal space), while touch allows us to localize objects in contact with our body (i.e. in the peripersonal space). This study employs a novel in-house touch-motion algorithm (TMA) to emulate sound source locations as vibrations on fingertips. We use it to evaluate individuals' capability to understand spatial extrapersonal 3D-information through touch. Three experiments demonstrate rapid learning and high accuracy localization in novel tasks, as well as audio-tactile integration within naturalistic environments. Subjective responses imply extrapersonal spatial experiences, through visualization and beyond-reach perception of tactile "moving" sources. We discuss our findings with respect to developing novel sensory capabilities in an adult brain and computation-based brain organization. We also propose further research directions and future applications of our technology.