[Studies on the taste perceptive threshold for 4 basic taste qualities at various sites of lingual surface]

Using filter-paper-disk method for 20 approximately 23 year-old 60 healthy females, taste perceptive thresholds for 4 basic taste qualities (sweetness, saltiness, sourness and bitterness) were measured detailedly at various sites of the lingual surface (lingual apex, lingual center, lingual margin, lingual radix). Sucrose, sodium chloride, sodium tartarate and quinine hydrochloride as taste-producing substances were used for the sweetness, saltiness, sourness and bitterness, respectively. The results revealed the apical site to be most sensitive to all of the sweetness, saltiness and sourness (and especially to the saltiness) and to be followed by marginal and radical sites in sensitiveness. The radical site was revealed to be most sensitive only to the bitterness, and the central site was remarkably hyposensitive to all of these taste qualities. These experimental results differ, in many respects, from those results of study which have been published by Kiesow in 1894 and are already established today (lingual sensitivity to taste qualities is found separately by site: sweetness, sourness and bitterness and highly perceptible at apical, marginal and radical sites, respectively, and saltiness is not very differently perceptible by site), indicating that further detailed reexamination will be needed to know how taste perceptive thresholds for 4 basic taste qualities are distributed in the lingual surface.