Taste

Abstract

Mammalian taste systems are complex. Taste buds, the taste receptor organs, are composed of many gustatory receptor cells that are themselves transient structures, and contain a wide variety of transduction mechanisms. Some details of these transduction mechanisms are now known, and candidate receptor molecules for initial interactions with tastants have been identified. Often, the degree to which these observations can be generalized to humans is unresolved. For humans, tasting requires the presence of taste buds. Initial processing of taste responses may occur in taste buds before any neural output to the central nervous system (CNS). The CNS gustatory anatomy of humans and other higher primates is fundamentally different from that of most mammals, further limiting facile generalizations. Imaging techniques such as fMRI and PET, as well as recording approaches such as MEG, are revealing the complex CNS functional anatomy and processing of the human taste system. A fundamental theoretical issue, the organizational and informational characteristics of the human taste systems, remains debatable, with both the Basic Tastes model and the Pattern model receiving empirical support. Although some differences between these models may be only semantic or illusory, other differences generate opposite testable predictions and lead to divergent research programs.

Basic Taste: A Perceptual Concept

“…There is one psychophysical procedure that is often alluded to as a powerful test of the four basic taste point of view: metameric matching. ,,, According to this idea, if the perceptual taste world is made up of four basic (and here the term primary might better be used; see below) tastes, it should be possible to create mixtures of exemplars of these four that cannot be discriminated from any other single taste compound. Although metameric matching of sweet sugars (sucrose, glucose, and fructose) has been accomplished, similar studies with more complex stimuli are technically difficult or perhaps even impossible given temporal and anatomical variations in the perceptual characteristics of even single compounds.…”

“…In the following, I have made no attempt to be comprehensive in discussing the concept of basic tastes. Significant historical background can be found in commentaries by Bartoshuk, Halpern, and Erickson . The analysis of McBurney and Gent of the nature of taste qualities remains among the best overviews of the psychological and physiological issues underlying the concept of basic tastes.…”