Objective evaluation method of taste stimulation with pupil response

Abstract

We attempted to obtain an index for evaluating oral senses by quantitatively analyzing pupil responses on taste stimulation. The subjects were 11 adults. For stimulation, the concentration of bitter-taste solution was adjusted, and the whole mouth stimulation method was employed. Pupil responses were serially measured and recorded before and after bitter-taste stimulation using an infrared electron pupillometer. The pupil response rate was employed as an analytical parameter. We examined the relationship between this parameter and the concentration. Variance analysis showed that the pupil response rate depended on the subject and concentration. Results of a multiple comparison test showed that concentrations without significant differences in the pupil response rate could be divided into 6 groups. A significant regression line was obtained on regression analysis. We concluded that the sense of taste could be quantitatively evaluated based on pupil responses. This suggests that measurement of pupil responses facilitates the assessment of oral senses.