THE EFFECTS OF TEMPERATURE AND CONCENTRATION ON THE PERCEIVED INTENSITY AND QUALITY OF CARBONATION

Perceptual interactions between CO2 and temperature were investigated over a range of concentrations of aqueous solutions. It was found in experiment 1 that cooling carbonated solutions significantly increased ratings of oral irritation, and at the two lowest temperatures raising the CO2 concentration also tended to increase ratings of perceived cold. Experiment 2 showed that the sensation of carbonation sometimes grew painful when exposure was allowed to continue for several seconds, and the frequency with which pain was encountered varied directly with concentration and inversely with temperature. The final experiment demonstrated that the sensation of carbonation is more nociceptive (pungent) than tactile in quality and that the clearly nociceptive sensations are strongly enhanced by cooling. In addition. tingling, which defies easy physiological classification, was also found to be an important aspect of the sensation of carbonation, and both tingling and numbness were noticeable attributes of the carbonation aftersensation. The results of all three experiments are discussed in terms of possible underlying physiological mechanisms.