Stochastic resonance occurring in tactile sensation of human finger

Abstract

In this paper, we review the influence of external noise on human tactile sensation as outlined in prior and current studies. In the last few decades, researchers have found that, although noise is always considered detrimental, it provides the benefit of stochastic resonance (SR) phenomena. Based on previous studies, we investigate the effect of the SR phenomenon on human tactile sensation. In this context, we developed a system consisting of an experimental apparatus and a computer program, and performed a series of psychophysical experiments using different types of stimulus with normal vibration. The experimental results show that tactile sensation precision can be enhanced by an appropriate level of external noise. Furthermore, we introduce a neural network model composed of nonlinear neurons with a bi-stable equilibrium condition to clarify the result. Finally, we perform a sequence of psychophysical experiments with tangential vibration to clarify which conditions of vibration direction and stimulus size cause the strongest SR. The results show that the normal difference limen (DL) is significantly affected by stimulus point size. On the other hand, neither normal nor tangential DL is significantly affected by stimulus point size. Moreover, the characteristics of SR with normal vibration are quite different from those with tangential vibration.

The Promise of Stochastic Resonance in Falls Prevention

“…Similar effects were reported by Sawada et al (2015). Furthermore, Beceren et al (2013) demonstrated that adjusted subthreshold vibratory noise to the fingertips reduces the sensitivity threshold. Interestingly, normal vibration of the fingertip differed from the tangential vibration in their study.…”

“…Interestingly, normal vibration of the fingertip differed from the tangential vibration in their study. While normal vibration seemed to stimulate mainly fast-adapting Type I fibers, the tangential vibration also resulted in triggering slow-adapting Type II receptors (Beceren et al, 2013).…”