Differences in pleasant texture stimuli between fingertips and the palm

Because of the differences in the mechanical and anatomical properties of body parts, including the density of mechanical receptors, humans’ perception of pleasantness varies depending on which body part is affected. We tested this hypothesis on fingertips and palm centers using 18 types of 3D-printed dots scales. The participants pressed their finger or palm to these dots scales with no sliding motions, and reported the degree of pleasantness. For the fingertip, finer surfaces felt more comfortable than rougher ones; this finding agrees with the results of earlier studies. However, for the palm, pleasantness reached its peak when a moderately rough scale was touched. These findings will help design comfortable surfaces for different body parts.