Texture-Elicited Vibrations Stretch Or Contract Systematically Depending On Scanning Speed

To sense the texture of a surface, we run our fingers across it, which leads to the elicitation of skin vibrations that depend both on the surface microgeometry and on exploratory parameters, particularly scanning speed. In the present study, we seek to characterize the effect of changes in scanning speed on texture-elicited vibrations to better understand how speed shapes the neuronal representation of texture. To this end, we scanned a variety of textures across the fingertip of human participants at a variety of speeds (10 to 160 mm/s) while measuring the resulting vibrations using a laser Doppler vibrometer. We found that increases in speed led to systematic increases in vibratory power and to a systematic upward shift in the frequency composition of the vibrations Furthermore, we show that the increase in power is caused by the upward shift in frequency composition. The enhancement of higher frequency components accounts for the observed increase in the firing rates of nerve fibers, particularly Pacinian corpuscle-associated fibers, which are most sensitive at the high frequencies.