Pupillary responses to gustatory stimulation-Methodological evaluation

Abstract

We attempted to determine the optimal combination of stimulation and measurement method for the objective assessment of the sense of taste using pupillary responses. We examined the pupillary responses using an infrared electronic pupillometer when 7 adult subjects were exposed to the gustatory stimulation of bitterness. Comparisons were made between the measurement of pupillary light reflex and continuous measurement, between the filter paper disc method and whole mouth stimulation method, and between high-concentration stimulation and low-concentration stimulation. Differences in the amount of pupillary response were analyzed for each situation. We found that dispersion in the amount of pupillary response was less with whole mouth stimulation than with filter paper disc stimulation, and that it was significantly less with continuous measurement than with measurement by the pupillary light reflex. We consider a combination of continuous measurement and whole mouth stimulation optimal to assess the sense of taste using the pupillary response.