Asymmetrically-applied hot and cold stimuli gives perception of constant heat

This study investigated how the perception of skin temperature is affected by asymmetrically changing hot and cold stimuli applied to nearby sections of the skin. In the first part of the study, different rates and starting temperatures were applied to evaluate the time at which the temperature change was first noticed. In the second part, a method of asymmetrically-applied hot and cold stimuli was tested on the participants to generate a constant heating sensation without changing the average temperature of the skin. This method applies a combination of fast heating and slow cooling rates using multiple thermal actuators. The slow cooling rate is under the perceptual threshold level, hence it is not perceived. The fast heating rate, however, is perceived, which creates the feeling that the temperature is warmer than it actually is. The results showed that participants were able to perceive a constant heating effect at normal skin temperature as hypothesized. This effect was most effective at normal skin temperatures and became less effective at higher baseline temperatures.