Janet M. Weisenberger
Speech and Hear. Sci., Ohio State Univ., Columbus, OH 43210
Christopher J. Hasser
Human Systems Ctr., Air Force Materiel Command, Wright-Patterson AFB, OH 45433
Craig [Percept. Psychophys. 30, 151--166 (1981)] found that tactile perception of complex vibratory patterns presented to the fingertip was better for ``static'' patterns that did not move across the display than for ``scan'' patterns that moved horizontally across the display. It is possible that Craig's finding resulted from the fact that observers did not have active control of the movement of the scan patterns. In the present work, tactile patterns were presented to the fingertip under three modes: a static mode in which stimuli did not move; a passive scan mode in which stimuli moved horizontally across the display under a stationary fingertip; and a haptic scan mode in which observers moved the fingertip and the display across a virtual surface containing the stimulus. Results with a set of simple patterns showed no differences across modes, with all modes yielding performance greater than 90% correct. To eliminate the possibility of ceiling effects, a second experiment was conducted with a more complex stimulus set. Preliminary results showed lower levels of performance for all presentation modes, with the haptic scan mode showing the best performance. Results are discussed in terms of development of tactile displays for sensory communication and telerobotics applications.