A four-channel analysis of the tactile sensitivity of the fingertip: frequency selectivity, spatial summation, and temporal summation

Abstract

Thresholds were measured for the detection of vibratory stimuli of variable frequency and duration applied to the index fingertip and thenar eminence through contactors of different sizes. The effects of stimulus frequency could be accounted for by the frequency characteristics of the Pacinian (P), non-Pacinian (NP) I, and NP III channels previously determined for the thenar eminence (Bolanowski et al., J Acoust Soc Am 84: 1680-1694, 1988; Gescheider et al., Somatosens Mot Res 18: 191-201, 2001). The effect of changing stimulus duration was also essentially identical for both sites, demonstrating the same amount of temporal summation in the P channel. Although the effect of changing stimulus frequency and changing stimulus duration did not differ for the two sites, the effect of varying the size of the stimulus was significantly greater for the thenar eminence than for the fingertip. The attenuated amount of spatial summation on the fingertip was interpreted as an indication that the mechanism of spatial summation consists of the operations of both neural integration and probability summation.

Vibrissal sensitivity in a harbor seal (Phoca vitulina)

“…The performance of the four human subjects in the present study agreed with the available data for the human hand, with best sensitivity of 250 Hz. The notch at 20 Hz in the human sensitivity curves is consistent with the data from previous studies and is representative of a shift in the receptors that mediate the sensation of vibration (Johansson et al, 1982;Gescheider et al, 2002;Morioka and Griffin, 2005). The similarities in the performance of the human subjects in the present study to prior measures of tactile sensitivity for humans confirms the accuracy of the experimental methods used and provides further confidence in the measured thresholds for the seal.…”

Effect of individual finger skin temperature on vibrotactile perception threshold

“…It would be interesting to find what the limit value of the difference in finger skin temperature at 63 Hz that would induce a significant effect on VPT should be. As revealed by the studies conducted by Bolanowski et al [23] and Gescheider et al [24] there is no evident boundary between vibration perception by the Meissner corpuscles or the Pacinian corpuscles. Accordingly, it is only at the frequency of 125 Hz that induces the highest perception sensitivity of …”

Magnitude-dependence of equivalent comfort contours for fore-and-aft, lateral and vertical hand-transmitted vibration

“…Studies of vibrotactile perception by Bolanowski, Gescheider, Verrillo and co-workers [13,14,15] led to an understanding of the properties of the four information-processing channels in the glabrous skin by applying a small vibrating probe (varying from 0.1 to 2.9 cm 2 ) with a surround (usually 1 mm gap between the probe and the surround) to the fingertip or the thenar eminence to elicit, or isolate, responses from a particular tactile channel. Morioka and Griffin [4] extended this to the palmar area of the hand by examining the effect of contact area and contact location on thresholds of perception of vibration applied to the fingertip and the hand and concluded that thresholds for the perception of vibration applied to the whole area of the hand seemed to be mediated by the Pacinian, NP I and NP II channels with some influence of biodynamic responses.…”