Toward Augmented Reality of Textures: Vibrotactile High-Frequency Stimuli Mask Texture Perception to Be Rougher or Smoother?

Augmented reality technology realizes variable sensory feedback while maintaining a high perceptual quality by superposing real and virtual stimuli. In this research, we experimentally verified whether the masking effects of high-frequency vibrotactile stimulation on fingers is applicable to augmented reality of the tactile texture of materials. A vibrotactile stimulator was worn on a finger (ring-vibrating condition) or mounted on materials (material-vibrating condition). We investigated the effect of vibratory stimuli on perception of sand-paper roughness under these two conditions. Under both conditions, participants' performances to discriminate the roughness diminished because of the masking effects of the high-frequency vibratory stimuli (experiment 1). Subsequently, we specified how the masking effects influenced the perceived roughness using Scheffe's paired comparison. For the ring-vibrating condition, as accelerations of the vibrotactile stimuli increased, all participants reported a decrease in the perceived roughness of the sand-paper. For the material-vibrating condition, the roughness percepts increased or decreased depending on the individual (experiment 2). Although both implementation methods affect roughness perception, the ring-vibrating condition is recommended for augmented reality of tactile textures because it can steadily control the decrease in perceived roughness of touched materials.