The frequency selectivity of information-processing channels in the tactile sensory system

Abstract

The frequency selectivity of the P, NP I, and NP II channels of the four-channel model of mechanoreception for glabrous skin was measured psychophysically by an adaptation tuning curve procedure. The results substantially extend the frequency range over which the frequency selectivity of these channels is known and further confirm the hypothesis that the input stage of each of these channels consists of specific sensory nerve fibers and associated receptors. Specifically, the frequency characteristics of Pacinian nerve fibers, rapidly adapting (RA) nerve fibers, and slowly adapting Type II (SA II) nerve fibers were found to be the peripheral neurophysiological correlates of the P, NP I, and NP II channels, respectively. The finding that the tuning characteristic for a test stimulus of 250 Hz delivered through a small (0.008 cm2) contactor depended dramatically on the duration of the test stimulus whereas the detection threshold did not, provides new evidence in support of the hypothesis that separate NP II and P channels exist.

Noninformative Vision Causes Adaptive Changes in Tactile Sensitivity

“…The adapting vibration elevated detection thresholds by ϳ50% (t (8) ϭ 4.23; p Ͻ 0.001, comparing thresholds in the no-view condition against baseline thresholds measured without an adapting vibration), consistent with previous reports (Gescheider et al, 2001). The adapting vibration also lowered discrimination thresholds by ϳ25% (t (8) ϭ 2.47; p ϭ 0.039), an effect that has been reported for discrimination of vibration frequency (Tommerdahl et al, 2005) but not, to our knowledge, for amplitude.…”

Equivalent comfort contours for vertical vibration of steering wheels: Effect of vibration magnitude, grip force, and hand position

“…40, 5, p. 817-825. Another approach to identifying tactile channels responsible for perception thresholds is to determine a slope that represents the frequency-dependence of the perception threshold expressed in terms of the vibration displacement. The slope of the displacement threshold of the Pacinian receptors between 15 and 200 Hz has been suggested to be approximately -12 dB per octave (e.g., Verrillo, 1963;Gescheider, 1976;Verrillo and Gescheider, 1977;Bolanowski et al, 1988;Gescheider et al, 2001). When the present thresholds are expressed in terms of displacement (see and 35 Hz (Bolanowski et al 1988;Gescheider et al, 2001;, while the Ruffini endings (NP II) respond with a slope of -5.0 to -6.0 dB per octave between about 15 and 250 Hz (Capraro et al, 1979;Gescheider et al, 1985;Bolanowski et al, 1988).…”

“…The slope of the displacement threshold of the Pacinian receptors between 15 and 200 Hz has been suggested to be approximately -12 dB per octave (e.g., Verrillo, 1963;Gescheider, 1976;Verrillo and Gescheider, 1977;Bolanowski et al, 1988;Gescheider et al, 2001). When the present thresholds are expressed in terms of displacement (see and 35 Hz (Bolanowski et al 1988;Gescheider et al, 2001;, while the Ruffini endings (NP II) respond with a slope of -5.0 to -6.0 dB per octave between about 15 and 250 Hz (Capraro et al, 1979;Gescheider et al, 1985;Bolanowski et al, 1988). For both the UPPER and the LOWER hand positions in the current study, the slope of the thresholds at frequencies less than 16 Hz were about half the slope expected for the Pacinian channel but typical of the slope of the NP I and NP II channels.…”

“…NP I, NP II and NP III channels, respectively), some of which seem incapable of temporal or spatial summation and whose responses depend on stimulus gradients (Gescheider, 1976;Verrillo, 1985). Studies have demonstrated 'tuning curves' for thresholds of vibrotactile perception for each of the four tactile channels in the glabrous skin of the hand (Bolanowski et al, 1988;Gescheider et al, 2001). It is reasonable to assume that the absolute threshold for the perception of steering wheel vibration is determined by the tactile channel that has the greatest sensitivity (i.e.…”

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

“…FA I, SAI and SA II fibres, respectively), some of which seem incapable of temporal or spatial summation and whose responses depend on stimulus gradients (Gescheider [7]; Verrillo [8]). Later studies by Bolanowski et al [13] and Gescheider et al [14] demonstrated a fourchannel model of vibrotactile perception by determining threshold responses of three tactile channels within the non-Pacinian system (NP I, NP II, and NP III channels corresponding to FA I, SA II and SA I fibres, respectively) in the glabrous skin of the hand.…”