Physiological Variations of Warm and Cool Sense with Shift of Environmental

Abstract

In order to obtain control data on the temperature sense (warm and cool threshold values) of fingertips, the relationships between room temperature and either skin temperature, warm threshold or cool threshold of the middle fingertips were investigated in healthy subjects (6 males), using our thermo-esthesiometer. The skin temperature changes in a sigmoidal response with the variation of room temperature. A point of inflection for this response was observed at the room temperature of 15 degrees C, at which the greatest standard deviation of skin temperature occurred. The warm and cool thresholds, on the other hand, were also affected by variations of room temperature. Warm threshold and skin temperature or cool threshold and skin temperature bore a linear relation to each other, and the correlation coefficient was 0.854 in the former, and 0.925 in the latter, respectively. The disorder of temperature sensitivity (warm and cool thresholds) must always be considered together with the room temperature or skin temperature. On the other hand, the width of the neutral zone between warm and cool thresholds was affected by neither the changes of room temperature nor the changes of skin temperature. Hence, the width of the neutral zone was approximately constant, especially, at the room temperatures in the vicinity of 15 degrees C to 25 degrees C.

Regional distribution of thermal sensitivity to cold at rest and during mild exercise in males

“…Indeed, a decrease in T sk in exercise would result in thermoreceptors being stimulated with a smaller ∆ T sk , which would decrease the impulse frequency and in turn reduce the intensity of a thermal sensation. This was confirmed in several studies looking at the effects of skin temperature on warm and cool thresholds (Hirosawa et al, 1984;Lele, 1954). This could only affect the transient cold sensation results in the present study.…”

Thermal perception thresholds recorded using method of limits change over brief time intervals

“…Hirosawa et al (1984), using increments of 5 C change, found that thermal perception threshold values were only affected if environmental temperature deviated by 10 C or greater from a baseline of 20 C. The very small magnitude of change in the present study (0.18 C) is therefore unlikely to have been of consequence.…”

Thermal Feedback Identification in a Mobile Environment

“…Cold perception is generally faster [11,20] and more precise [10] than warmth perception. Cold or warm environments have the effect of cooling or warming the skin, respectively [6,15] and we become more sensitive to changes that move further away from neutrality towards the pain thresholds [13]. The thermal sense is not a good "thermometer": it is not good at identifying specific temperatures, as it is based on changes in the overall magnitude of sensation, which translates into a subjective appraisal of the intensity.…”

“…No significant correlation was found between trial number and Accuracy, however, so it seems that extra time was taken to maintain Accuracy. Environmental temperature influences skin temperature, which, in turn, influences thermal perception [6,13,15]. Warmer environments (and walking) may have elevated the temperature of skin surrounding the Peltiers, potentially leading to domination or referral [3] of warmth and erroneous interpretation of greater warmth at the stimulation site.…”

“…Previously [19], we developed two-dimensional structured 'thermal icons', which could be identified with 83% accuracy, however, the participants in this study were sat indoors. Both walking [20] and environmental temperatures [6,15] significantly influence thermal perception, so it was necessary to test identification of thermal icons when the user is sitting and walking outdoors, to judge the feasibility of thermal feedback for more realistic mobile interaction. As such, this paper reports an experiment that tested identification of twoparameter thermal icons presented to the palm of the hand from a mobile device when the user was both sitting and walking in an open-air, outdoor environment.…”