Choice of Stimulator Frequency for Tactile Arrays

An experiment is described that tested subjects´ ability to recognize letters presented tactually by an array of airjets in a manner simulating a moving belt. Recognition accuracy was measured as a function of reading rate and stimulator frequency. For constant stimulus pulsewidth, performance increased significantly as stimulator-repetition rate was increased from 20 to 160 pps. A second experiment is discussed that is designed to measure the spatial resolution of two hypothetical neural systems, which are the basis for tactile sensations. The data presented indicate that sensitivity to differences in amplitudes of two stimulators is comparable for spacings of 6-10mm on the fingertip. At spacings of 2 mm there is a significant difference between the two systems with the superior resolution obtained at the high frequencies.