Sucrose-based flavor preferences in rats: Factors affecting detection of extinction

Abstract

Rats that have consumed a novel target flavor added to a sucrose solution will develop a preference for that flavor. Such preferences appear to persist over the course of many presentations of the flavor alone when animals are not food-deprived. However, previous research indicates that an extinction effect (a reduction in preference) can be obtained when training or testing is carried out in animals that are hungry. In a series of experiments that produced flavor preferences in hungry rats by adding the flavor to a sucrose solution, three (Experiments 1, 2A, 2B) established that the concentration of sucrose and the nature of the flavor influenced the results but failed to detect extinction. Two-bottle choice tests showed some loss of preference but this occurred both in subjects given the extinction treatment (flavor-only presentations) and in control subjects given just water. A loss of preference in rats given an extinction treatment as opposed to controls given only water was, however, found in Experiments 3 and 4. These experiments differed from Experiments 1 and 2 in that the extinction stage involved the presentation of two bottles containing the flavor, thus matching the two-bottle procedure used in the test phase. These results confirm that experiencing a flavor alone can result in extinction of a conditioned flavor preference in hungry rats but indicate that the effect is highly context-specific, requiring the conditions of the test to match those of the extinction procedure. (PsycInfo Database Record (c) 2021 APA, all rights reserved).