Multidimensional tactile displays: identification of vibratory intensity, frequency, and contactor area

Experiments were conducted to determine the ability of subjects to identify vibrotactile stimuli presented to the distal pad of the middle finger. The stimulus sets varied along one or more of the following dimensions: intensity of vibration, frequency of vibration, and contactor area. Identification performance was measured by information transfer. One-dimensional stimulus sets produced values in the range 1-2 bits and, for most subjects, three-dimensional sets produced values in the range 4-5 bits. Of the three dimensions considered, performance on the intensity variable was most affected, and performance on contactor area least affected, by simultaneous variations in the other dimensions.