TASTE PERFORMANCE ON THE ANTERIOR HUMAN TONGUE VARIES WITH FUNGIFORM TASTE BUD DENSITY

This study demonstrated that individual diversities of taste sensitivi ty on the anterior tongue are due, in part, to variations in fungiform taste bud density. Citric acid solutions were delivered to a closed, spatially-matched (each test site was 43 mm2) flow chamber attached to the surface of die anterior tongue in 84 subjects. A two-alternative forced choice, modified staircase procedure was used to derive a detec tion threshold value for citric acid. The same session also included a visual analog rating procedure to scale the taste intensity judgement of five concentrations of citric acid. The taste buds within die cham ber were distinguished by methylene blue stain and recorded by videomi croscopy. The sip-and-spit method was used to contrast the spatially-m atched condition with whole mouth stimulation. We found that detection threshold values were inversely related to the number of fungiform ta ste buds, independent of gender or age. Whole-mouth threshold values d etermined for each subject were always well below the spatially-matche d threshold values. In addition, the data demonstrated that subjects w ere able to scale the dynamic range of citric acid solutions. However, gamma-intercept approached zero intensity as the number of fungiform papillae decreased. The observed differences in citric acid sensitivit y and fungiform taste bud density indicated that taste performance on the anterior tongue in humans varies, in part, with the number of tast e buds.