[Gustatory input affects breathing pattern: a method for objectifying of gustatory perception]

There is currently no commercial tool available to examine gustatory perception objectively. We investigated whether early changes of breathing patterns can be evoked by gustatory stimulation, and whether there are differences between sweet, sour, salty and bitter stimulation.

Using a randomised design, 34 young adult subjects (15 male, 19 female; average age: 24.6 years, median: 23, minimum: 22, maximum: 33) with normal sense of taste were stimulated by supra-threshold taste solutions for approximately 6 s. A pressure sensor recorded nasal respiratory changes using LabView software. The interstimulus-interval was longer than 1 min depending on regular status of unstimulated breath. Durations of inspiration (DIN) and expiration (DEX) were analysed. Values outside the 95%-confidence intervals were defined as gustatory evoked changes.

The rates of alteration differed significantly in the first, second and third post stimulatory breath. The rates were regarding to DIN between 25.87% and 36.49%, and regarding to DEX between 35.31% und 43.13%. Blank stimuli showed a rate between 5.97% and 8.96% in DIN and in DEX between 10.66% and 11.48%. There were no differences in reaction frequency between the four taste solutions. Every subject reacted to gustatory stimulation more frequently than to blanks.

Like other sensory modalities, gustatory input is able to evoke early respiratory orienting responses. The reaction rate is not dependent on the hedonic component of the gustatory input, as has already been shown for respiration-olfactometry.