Behavioural brain research
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Comparative Study
Evidence that tactile stimulation inhibits nociceptive sensations produced by innocuous contact cooling.
It was recently shown that stinging, pricking or burning is reliably perceived by some individuals when the skin is cooled to temperatures as mild as 25-30 degrees C. These seemingly paradoxical sensations, which have been termed innocuous-cold nociception (ICN), were significant only when cooling was produced by a thermode resting statically on the skin (static contact); touching an already cooled thermode to the skin (dynamic contact) produced reports of only coolness and cold. The present study investigated the hypothesis that ICN is inhibited by tactile stimulation produced when a thermode contacts the skin. ⋯ Experiment 2 confirmed the latter result and showed that suppression was greatest at 28 degrees C, less at 24 degrees C, and not significant at 18 degrees C. We conclude that dynamic tactile stimulation produced by contact with a surface inhibits the nociceptive component of innocuous but not noxious cooling. The implications of this conclusion for the role of cold perception in behavioral thermoregulation versus haptic perception, and for theories of cold perception in general, are discussed.