Information transfer via tangential haptic stimulation

Few studies have explored haptic sensing on a finger pad as a means of transferring complex directional information. Stimuli presentation using Braille or tactile vibrators use binary ("on/off") signals which require large areas to adequately represent data. Our research seems to support that tangential motion on a finger pad is a promising means of transmitting tactile information more compactly at equal or better rates than current methods. The index fingertips of 62 subjects were stimulated using random pattern of tangential motion in eight directions over two distances. Basic subject physiology data (age, gender, and phalange dimensions length and width) was recorded, as were ambient conditions (temperature and relative humidity) to examine their effect on perception as well. An ANOVA found distance statistically significant as well as direction for 0.5 mm displacements, but not at 1.5 mm. A General Linear Model found age, phalange length, temperature, and humidity also significantly affected tangential motion perception, as did several interactions of these covariates with gender and phalange width. These results suggest tangential motion could transmit certain type of haptic information effectively but its effectiveness varies by several conditions.