Vebrotactile adaptation of a RA system: A psychophysical analysis

Hollins, Mark; Delemos, K. A.; Goble, Alan K.

doi:10.1007/978-3-0348-9016-8_9

Cited by 10 publications

(4 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Plot of d's from the low-frequency condition of experiment 3, standardized within participant, as a function of the difference in ratios, also standardized within participant, for each waveform pair. The model parameters used were: P r ϭϪ70, ϭ600, thresholdϭϪ50Ϯ2 ͓standard deviation ͑s.d.͔͒, maximal ␣ ranged from 1.0 to 1.35 across participants to reflect differences in threshold, and Ј ranged from 43.5 to 69.5 ms. lus energy over time and behaves as a critical band filter in touch ͑Verrillo and Gescheider, 1975;Marks, 1979;Makous et al, 1995͒. The results obtained using low-frequency test stimuli suggested that the RA system supports discrimination of complex waveforms as suggested by Hollins et al ͑1996͒. A model of low-frequency complex waveform discrimination was proposed according to which the waveforms were discriminated on the basis of uniformity or nonuniformity of the sequences of perceived peaks within stimulus cycles.…”

Section: Resultsmentioning

confidence: 94%

Complex tactile waveform discrimination

Bensmaı̈a

Hollins²

2000

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

Complex vibrotactile waveforms consisting of two superimposed sinusoids at varying phases were presented to the fingertip, and observers made "same-different" judgments. It was found that the low-frequency (10Hz+30Hz) waveforms were discriminable from one another while discrimination of the high-frequency (100Hz+300Hz) vibrations was poor. High-frequency adaptation did not impair discrimination of the low-frequency waveforms, suggesting that the RA channel mediated discrimination. Low-frequency adaptation impaired discrimination of the high-frequency stimuli, suggesting that the RA channel likewise mediated the modest level of performance observed in the absence of an adapting stimulus. The results indicate that this channel encodes complex waveforms temporally. A simple model for low-frequency waveform discrimination is proposed. The results obtained with the high-frequency complex waveforms are compatible with the hypothesis that the PC channel integrates stimulus energy over time.

show abstract

Section: Resultsmentioning

confidence: 94%

Complex tactile waveform discrimination

Bensmaı̈a

Hollins²

2000

The Journal of the Acoustical Society of America

View full text Add to dashboard Cite

show abstract

“…Unfortunately we were unable to test this possibility in the present study, because low ( 5100 Hz) frequencies did not combine with our textured surfaces to yield a stable percept. Other properties of the RA channel, however, including its acute sensitivity to the waveform of complex vibrations (Bensma|« a and Hollins 2000), appear to make it well suited for such a role (Hollins et al 1996). It may, in fact, be this sensitivity which precluded stable percepts when low frequencies of vibration were used in our pilot work, because the phase relationship between imposed and normally generated vibrations no doubt shifted erratically as the fingertip moved across the grating.…”

Section: Discussionmentioning

confidence: 97%

Imposed Vibration Influences Perceived Tactile Smoothness

2000

View full text Add to dashboard Cite

According to the duplex theory of tactile texture perception, detection of cutaneous vibrations produced when the exploring finger moves across a surface contributes importantly to the perception of fine textures. If this is true, a vibrating surface should feel different from a stationary one. To test this prediction, experiments were conducted in which subjects examined two identical surfaces, one of which was surreptitiously made to vibrate, and judged which of the two was smoother. In experiment 1, the vibrating surface was less and less often judged smoother as the amplitude of (150 Hz) vibration increased. The effect was comparable in subjects who realized the surface was vibrating and those who did not. Experiment 2 showed that different frequencies (150-400 Hz) were equally effective in eliciting the effect when equated in sensation level (dB SL). The results suggest that vibrotaction contributes to texture perception, and that, at least within the Pacinian channel, it does so by means of an intensity code.

show abstract

“…But precise judgments of frictional resistance often depend on detection of slip (Johansson & Westling, 1987), which, for a finely textured surface, can include explicit vibratory sensations (Srinivasan et aI., 1990). Moreover, vibrations resulting from movement of textured surfaces across the skin have been recorded (Hollins, Delemos & Goble, 1996) and found to vary with the character of the surface. There is thus reasonably convincing circumstantial evidence that vibration does make a major contribution to the perception of fine textures.…”

Section: Discussionmentioning

confidence: 99%

Evidence for the duplex theory of tactile texture perception

Hollins

Risner

2000

Perception & Psychophysics

376

269

View full text Add to dashboard Cite

Three experiments are reported bearing on Katz's hypothesis that tactile texture perception is mediated by vibrational cues in the case of fine textures and by spatial cues in the case of coarse textures. Psychophysical responses when abrasive surfaces moved across the skin were compared with those obtained during static touch, which does not provide vibrational cues. Experiment 1 used two-interval forced-choice procedures to measure discrimination of surfaces. Fine surfaces that were readily discriminated when moved across the skin became indistinguishable in the absence of movement; coarse surfaces, however, were equally discriminable in movingand stationary conditions. This was shown not to result from any inherently greater difficulty of fine-texture discrimination. Experiments 2 and 3 used free magnitude estimation to obtain a more comprehensive picture of the effect of movement on texture (roughness) perception. Without movement, perception was seriously degraded (the psychophysical magnitude function was flattened) for textures with element sizes below 100 llm; above this point, however, the elimination of movement produced an overall decrease in roughness, but not in the slope of the magnitude function. Thus, two components of stimulation (presumably vibrational and spatial) contribute to texture perception, as Katz maintained; mechanisms for responding to the latter appear to be engaged at texture element sizes down to 100llm, a surprisingly small value.In his classic treatise The World of Touch, David Katz (1925 advanced the view that the tactile perception of the texture of surfaces is a complex process, depending on a "spatial sense" for discernment of coarse textures and a "vibration sense" for an appreciation offiner textures. Katz offered a number of ingenious observations to support his theory: For example, he demonstrated that papers can be discriminated by an observer drawing a wooden rod across them but that wrapping the rod in cloth greatly impairs performance (p. 115). These results suggest the use of vibrational cues. Katz's view, referred to here as the duplex theory oftactile texture perception, is succinctly captured in his statement that surfaces touched very lightly could not be clearly perceived, because "the spatial sense ofthe skin could no longer discern the coarse texture of the materials, and the vibrations necessary for the recognition of fine texture were lost as a result of the minimal friction" (p. 138).

show abstract

Vebrotactile adaptation of a RA system: A psychophysical analysis

Cited by 10 publications

References 35 publications

Complex tactile waveform discrimination

Complex tactile waveform discrimination

Imposed Vibration Influences Perceived Tactile Smoothness

Evidence for the duplex theory of tactile texture perception

Contact Info

Product

Resources

About