Haptic Perception of Whole and Partial Extents of Small Objects

Abstract

Success at using hand-held objects in the absence of vision implies that the haptic perceptual system is capable of registering information that specifies certain properties of the objects, such as object length or orientation. Research has indicated that people are capable of non-visually perceiving a multitude of object properties. Moreover, research has revealed that those haptic perceptions seem to be constrained by an object's distribution of mass (i.e., inertial properties). However, the majority of this research has been done with large hand-held objects. We sought to test if this relation holds with very small objects. We concluded that participants were able to perceive the whole lengths of the small rods and that whole and partial length are perceptually independent. The results lend support to the hypothesis that this form of touch perception (at the small scale) is anchored in the haptic system's sensitivity to the object's resistance to being rotated (i.e., inertia). Human Factors applications of this line of research are discussed.