Abstract
Using vibrotactile stimuli, equal-sensation contours and a threshold curve were determined on the glabrous skin of the human hand. Equal-sensation contours were measured between 1Hz and 16Hz. When plotted on log-log coordinates, they monotonically decreased as a function of frequency and were downward by concaved. The threshold curve was measured between 1Hz and 50Hz. Its values decreased linearly from 1Hz to 16Hz, became constant at 16-35Hz, and decreased again at 35-50Hz. Therefore, at the stimulus range of 1-16Hz, equal-sensation contours were downward concave and the threshold curve was more or less linear. This discrepancy seems to be caused by the differences in mechanoreceptor types which take part in subjective responses: suprathreshold sensation depends on several types of mechanoreceptors, whereas vibrotactile thresholds depend mainly on RA receptors (Meissner corpuscles).
