Vibration of the Feet Soles Inducing a Walk Sensation Expands Peripersonal Space

Abstract

The representation of the peripersonal space is remapped by body action such as integrating tactile stimuli from the body's surface with multisensory stimuli presented within a limited distance from the body. Previous study showed that boundaries of the peipersonal space extend while walking with listening to a looming sound, but it is unclear whether the boundaries change when a sensation of walking is induced with no physical body motion. Here, we examine the change using a technique to induce a sensation of pseudo-walking by presenting vibrotactile stimuli of recorded footsteps sound at the feet soles. Experiments were performed to compare the reaction times to detect a vibrotactile stimulus on the chest with listening to a looming sound toward the body, taken as a proxy of the peripersonal space boundary. Experimental evaluations showed that the peripersonal space seems to expand when a sensation of pseudo-walking was clearly induced.