Effects of receptor density on the tactile perception of roughness: implications for neural mechanisms of texture perception.

The purpose of this study was to investigate the effects of receptor density in the glabrous skin of the hand on the perception of the roughness of a textured surface. This was done by having observers make magnitude estimates of the perceived roughness of raised-dot surfaces at the fingertip, with its high receptor density, and the thenar eminence, with its much lower receptor density. Judgments of perceived roughness averaged over the inter-dot spacings (0.

Perception of the tactile texture of raised-dot patterns: further evidence of an opponent process in the sense of touch.

Observers judged the tactile dissimilarities of raised-dot surfaces presented in pairs. The role of the SA I channel in determining these tactile dissimilarities was investigated by examining the dissimilarity judgments when this channel was adapted and when it was not. In an earlier study, the role of the PC channel in determining tactile dissimilarity was examined using the same stimulus materials when the PC channel was adapted and when it was not.

Roughness perception in tactile channels: evidence for an opponent process in the sense of touch.

Magnitude estimates of the tactile roughness of raised-dot surfaces revealed that perceived overall roughness, defined as the combination of the perceived roughness of the dot pattern and the perceived roughness of the individual dots in the pattern, is an inverted U-shaped function of dot spacing, reaching a maximum at approximately 3.0 mm of dot separation. The hypothesis that Pacinian corpuscles are involved in roughness perception has been supported by the finding that selective adaptation of the Pacinian corpuscle (PC) channel with a 250-Hz stimulus at 20-dB SL results in a decrease in the perceived overall roughness of the raised-dot surface at the fingertip.

Learning in tactile channels.

Vibrotactile intensity-discrimination thresholds for sinusoidal stimuli applied to the thenar eminence of the hand declined as a function of practice. However, improvement was confined to the tactile information-processing channel in which learning had occurred. Specifically, improvements in performance with training within the Pacinian-corpuscle (PC) channel with a 250-Hz stimulus failed to transfer to performance within the rapidly adapting (RA) nerve fiber channel and the slowly adapting Type I (SA I) nerve fiber channel with a 20-Hz stimulus; similarly, improvements in performance with training within the RA/SA I channels failed to transfer to the PC channel.

The development and validation of sensory and emotional scales of touch perception.

No comprehensive language exists that describes the experience of touch. Three experiments were conducted to take steps toward establishing a touch lexicon. In Experiment I, 49 participants rated how well 262 adjectives described sensory, emotional and evaluative aspects of touch.