Effect of skin surface temperature on localization error and two-point threshold.

The average localization error and two-point threshold were determined from 9 subjects at 5 skin temperatures on the volar forearm. The temperatures were physiological zero (31 degrees--32 degrees C), 19 degrees C, 25 degrees C, 38 degrees C, and 44 degrees C. Localization error was not significantly affected by skin surface temperature. This was verified on palm and forehead locations. The two-point threshold was increased by skin surface temperatures above physiological zero and decreased by skin surface temperatures below physiological zero. These results are consistent with a previous report of similar changes in punctate pressure sensitivity with varied skin surface temperatures. Such cross-model effects are considered in terms of cutaneous sensory mechanisms combining broad receptor specificity and subsequent coding of information by patterns of neural impulses.