The perception of ecological textures by touch: does the perceptual space change under bimodal visual and haptic exploration?

In 2 experiments, we investigated the dimensionality of 20 ecological surface textures explored haptically (Exp. 1) and by vision and touch (Exp.2). The goal was to find out how haptic texture perception is integrated with visual information and whether the dimensionality of the perceptual space changes with multimodal perception. In each experiment, human participants performed a spatial arrangement task, a free classification task, and a hedonic rating task. The results suggested that two dimensions interpreted as roughness/smoothness and slippery/adherent explain most of the data not only in touch but also in bimodal surface texture exploration.