Can Stochastic Resonance Improve Sensorimotor Performance in Hand Motor Control?

Recent researches have demonstrated that noise, whether mechanical or electrical, can enhance somatosensation and optimize balance control in humans. However, the influence of stochastic resonance (SR) on the human motor system, particularly regarding hand motor control, remains largely unexplored. This study examines the impact of stochastic resonance on enhancing sensorimotor performance in the human motor system, specifically in the context of hand motor control when tools are held. While many of the previous studies have focused on SR in free-hand motions, few studies have examined the effects when tools are adopted. Our experimental campaign involved forty participants who were asked to track a given trajectory displayed in mixed reality while holding various tools. The experiment considered four subthreshold levels of vibratory mechanical noise, three hand stimulation sites with three different haptic interfaces, and three distinct 3D trajectories. Results indicate that wearing a device typically degrades performance in trajectory tracking. However, when SR is applied, the precision of hand motor control is restored to levels comparable to those observed without any devices. These findings suggest that SR can mitigate the negative impact of holding tools on sensorimotor precision.