Tactile Rivalry Demonstrated with an Ambiguous Apparent-Motion Quartet

Abstract

When observers view ambiguous visual stimuli, their perception will often alternate between the possible interpretations, a phenomenon termed perceptual rivalry [1]. To induce perceptual rivalry in the tactile domain, we developed a new tactile illusion, based on the visual apparent-motion quartet [2]. Pairs of 200 ms vibrotactile stimuli were applied to the finger pad at intervals separated by 300 ms. The location of each successive stimulus pair alternated between the opposing diagonal corners of the ∼1 cm2 stimulation array. This stimulation sequence led all participants to report switches between the perception of motion traveling either up and down or left and right across their fingert..