Investigating taste sensitivity, chemesthetic sensation and their relationship with emotion perception in Chinese young and older adults

Food is essential in our daily life and it is important to learn about changes in taste sensitivity and chemesthetic sensation of food with increasing age. The present study aimed to 1) assess young and older adults' taste sensitivity (sweetness, saltiness) and chemesthetic sensation (induced by capsaicin and Sichuan peppercorn), and 2) explore the relationship between taste sensitivity and chemesthetic sensation with emotion perception. Thirty young and twenty-four older healthy Chinese adults took part in this study, in which their taste sensitivity and chemesthetic sensation were measured and recorded. We observed a significant decrease in taste sensitivity (sweetness) but not chemesthetic sensation (capsaicin and Sichuan peppercorn) with ageing, showing that ageing affects taste sensitivity and chemesthetic sensations in different ways. Furthermore, our results have revealed significant correlations between taste sensitivity (sweetness) and chemesthetic sensation (capsaicin) with facial emotion perceptual performance, while no significant correlation was found between any taste sensitivity/chemesthetic sensation with facial identity perceptual performance. Based on the current literature, we assume that the observed associations between taste sensitivity and chemesthetic sensation with emotion perception might be due to their shared neural processing regions or their interconnection with interoception. The findings of the present study not only revealed the age-related changes in taste sensitivity and chemesthetic sensation, but also provided the first behavioural evidence showing the cross-domain associations between emotion perception with taste sensitivity/chemesthetic sensation.