Taste often takes time to develop and varies over mouthfuls, but we rarely perceive this. In other modalities, perceptual constancy acts to smooth over such variation and we test for effects on taste here. Taste-constancy may be driven by the assumption that food items are homogeneous in taste throughout. We developed a paradigm to prompt this assumption for drink-stimuli. In Experiments 1 and 2, participants sipped 2 drinks and indicated whether the two drinks tasted the same (using a sureness-scale). In some trials, the drinks appeared to be poured from the same jug, prompting the homogeneous-taste assumption. Taste constancy should reduce perceived differences in taste here and this was observed: same-jug drink-pairs were reported more similar than different-jug drink-pairs, in which the drinks were seen to be poured from different jugs. However, when we assessed whether a sweeter first drink had a greater impact on the perceived sweetness of the second drink in same-jug pairs, no evidence for taste-constancy was found for either the sweetness measure (Experiments 3 and 4) or the similarity rating (Experiment 4) suggesting that an analytical cognitive strategy acted to inhibit constancy here (Le Berre et al, 2008; Prescott et al, 2004). Summarising, our findings provide first support for taste constancy.

Le Berre, E., Thomas-Danguin, T., Beno, N., Coureaud, G., Etievant, P., & Prescott, J. (2008). Perceptual processing strategy and exposure influence the perception of odor mixtures. Chemical Senses, 33, 193-199.

Prescott, J., Johnstone, V., & Francis, J. (2004). Odor-taste
interactions: Effects of attentional strategies during exposure. Chemical Senses, 29, 331-340.