Human haptic perception in virtual environments: An investigation of the interrelationship between physical stiffness and perceived roughness.

Research in the area of haptics and how we perceive the sensations that come from haptic interaction started almost a century ago, yet there is little fundamental knowledge as to how and whether a change in the physical values of one characteristic can alter the perception of another. The increasing availability of haptic interaction through the development of force-feedback devices opens new possibilities in interaction, allowing for accurate real time change of physical attributes on virtual objects in order to test the haptic perception changes to the human user. An experiment was carried out to ascertain whether a change in the stiffness value would have a noticeable effect on the perceived roughness of a virtual object. Participants were presented with a textured surface and were asked to estimate how rough it felt compared to a standard. What the participants did not know was that the simulated texture on both surfaces remained constant and the only physical attribute changing in every trial was the comparison object’s surface stiffness. The results showed that there is a strong relationship between physical stiffness and perceived roughness that can be accurately described by a power function, and the roughness magnitude estimations of roughness showed an increase with increasing stiffness values. The conclusion is that there are relationships between these parameters, where changes in the physical stiffness of a virtual object can change how rough it is perceived to be in a very clear and predictable way. Extending this study can lead to an investigation on how other physical attributes affects one or more perceived haptic dimensions and subsequently insights can be used for constructing something like a haptic pallet for a haptic display designer, where altering one physical attribute can in turn change a whole array of perceived haptic dimensions in a clear and predictable way.