Individual Differences in Skin Vibration Characteristics and Vibrotactile Sensitivity at Fingertip

There are individual differences in human tactile sensation, but it is not clear what causes these differences. One possible cause is the varying mechanical properties of the skin. To unravel this, we focused on the skin-propagated vibration characteristics and vibrotactile sensitivity. First, we measured the skin-propagated vibration of the fingertip for 28 participants and then conducted a cluster analysis to determine how the transfer function of the skin vibration differs among participants, estimating mechanical parameters based on the mechanical model. The results indicated that the transfer functions could be grouped according to the magnitude of the high-frequency gain. Subsequently, the detection thresholds for the 200 and 450 Hz vibrotactile stimulation were measured. The correlation analysis between the gain and the detection threshold showed a statistically significant correlation at 450 Hz. The results suggest that individual differences in human perception are influenced by the mechanical differences in the skin as well as the cognitive processing.