Palatability shift of a salt-associated incentive during sodium depletion.

Previous studies of natural palatability-sensitive reactions, elicited from rats by tastes, have indicated that the taste of concentrated NaCl becomes more palatable during states of body sodium depletion. A training procedure based upon "sensory preconditioning" or "irrelevant incentive" designs was used here to establish gustatory conditioned labels (quinine or citric acid) for either NaCl or fructose while rats were in a normal physiological state. Experiment 1 replicated demonstrations by others that gustatory conditioned labels for salt can attract and act as independent incentives during the salt appetite induced by sodium depletion. Experiment 2 used the taste reactivity measure to show that the enhanced palatability of the taste of NaCl transfers to produce enhanced palatability of the taste of the isolated conditioned label for salt in a state-dependent fashion. These results offer further support for the proposition that conditioned incentives not only predict hedonic events to follow, but themselves become attributed with the hedonic properties of their reinforcers.