Figure 3.

Fingertip tactile sensation scores without and with white-noise vibration at different noise intensities and locations are shown (A). Fingertip tactile sensation scores are fingertip tactile sensory thresholds expressed as the minimum voltage needed to drive the vibrator whose vibration could be detected by the subject’s fingertip pad (minimum perceptible vibration intensity). Fingertip tactile sensation scores changed significantly with intensity of remote white-noise vibration applied to the back of the hand, palm, or wrist (*P < 0.0005) (A). Specifically, the mean fingertip tactile sensation score decreased (improved) with imperceptible remote white-noise vibration at 60% of sensory threshold, compared with no remote vibration (*P = 0.0001). The fingertip tactile sensation score increased (worsened) with perceptible remote white-noise vibration at 120% of sensory threshold, compared with no remote vibration (*P = 0.0072). The 80% white-noise vibration intensity at one of the four remote vibration locations did not significantly change the fingertip tactile sensation (P = 0.7667). Averaged data across the fingers and subjects are shown with the stars indicating significant differences from post hoc results (A). This effect of white-noise vibration intensity was observed for all four remote vibration locations (A) for both fingertips’ sensation scores (B). All error bars indicate confidence intervals. In addition to the group data (A), individual subjects’ data are shown for each remote white-noise vibration location, with fingertip tactile sensation scores normalized to each individual’s baseline score (with zero vibration), and the two fingers averaged (C).