Components of haptic information: skin rivals kinaesthesis

Four components of the haptic system were investigated, in isolation and in various combinations, during passive-guided exploration of raised-line drawings. The components were kinaesthesis, cutaneous input from the presence of a raised line, shear forces from relative movement between the skin and a textured surface, and attenuated distortions at the fingertip resulting from relative movement between the fingertip and a surface. Although the presence of kinaesthetic information was found to be positively correlated with performance in a task of identifying raised-line letters, conditions involving touch alone yielded performance equivalent to that when kinaesthesis was involved. Together, these results suggest that tactile information could be as effective as kinaesthetic information. The results are discussed in terms of applications to the design of human-machine interfaces.