A continuous vibration-based virtual tactile motion across fingertips

Abstract

AbstractMotion is one of the fundamental qualities not only of vision, but also of touch. Manipulation and exploration of objects involves different forms of movement between the skin and objects. A different form of tactile motion from remote sources is through substrate vibrations, and is present in arthropods such as insects and spiders, enabling them to localise approaching preys and predators. Here, we quantify the extent to humans perceive tactile motion based on vibrations sensed by fingertips. We employed a novel stimulation paradigm in which a pair of vibrations (100 Hz) with sinusoidal envelopes (0.5 cycle/s) and various phase differences between the two vibrations were delivered to two fingertips. The phase difference between the vibrations generated perception of a virtual motion across the fingertips. The findings suggest that human tactile system possesses the sensory channel for detection of motion through substrate vibrations, which is fundamentally different from tactile motion mechanisms during active surface exploration. We propose two potential neural computations underlying processing this form of motion; one based on phase difference or time delay detection, and the second based on temporal order and interval duration processing.