Wundt's schema of sensory affect in the light of research on gustatory preferences

Summary

According to Wundt's schema of sensory affect, increases of stimulus intensity above threshold are felt as increasingly pleasant up to a peak value beyond which pleasantness falls off through indifference to increasing unpleasantness. In psychophysical studies salty and sour taste solutions follow such a biphasic curve. Bitterness is mostly increasingly unpleasant, sweetness is mostly increasingly pleasant to a maximum with little fall off with stimulus intensity. Individual differences among adult subjects reveal some — e.g., sugar dislikers — bitter likers who depart from, or attenuate, these general trends. Studies of one- to three-day-old human neonates show rejection and negative affect for sour and bitter, but only acceptance and pleasant affect for sugar.

Taste preferences of animals, albeit with expections in some species, show mostly increasing aversion for acid and quinine, biphasic preference curves for salt and sugar. When post-ingestive effects are eliminated, animals show only increasing preference for sugar as concentration increases again, a departure from the Wundtian schema. Stimulus intensity, however, is only one factor influencing hedonic value which may be drastically changed by satiety, physiological need, and learning.