Enhancing the Human Tactile Sensitivity through an Individually Optimized Imperceptible Vibration Stimulation

Stochastic Resonance (SR) is known as a method to increase tactile sensitivity by applying weak vibrations. We investigated how the tactile sensitivity can be enhanced using sinusoidal vibrations with a specific frequency instead of conventionally applied white noise. The results demonstrated that sensory sensitivity with sinusoidal vibrations between 200 and 400 Hz increased much more than that obtained with white noise vibrations. To confirm the enhanced sensitivity effects, we propose a test based on cloth discrimination. Accordingly, it was found that the average correct rate increased using vibrations generated with optimal frequency compared to white noise vibrations. Notably, some participants stated a significant increase in tactile sensitivity when using the optimal vibration for SR. As a result, we showed that by using the optimal sinusoidal wave noise for each participant, it is possible to improve the tactile sensitivity far beyond that achieved with conventional SR using white noise.