Effects of Dual-Frequency Environment Exploration on Stiffness Discrimination Thresholds

Previously, excitation frequency has been found to alter perceptual discrimination thresholds of stiffness, mass, and damping. Here, we explore how the blending of two frequencies could affect the just noticeable difference for stiffness. In a perceptual experiment based on the method of adjustments, we tested participants’ ability to match a reference stiffness moving at combinations of two frequencies to explore the effects on stiffness discrimination. As more of the lower frequency was added, participants’ ability to accurately match the reference was hampered. Results suggest that as two frequencies are excited, the resulting perceptual thresholds are blended between the levels for the individual frequencies.