Conditioned flavor preferences based on hunger level during original flavor exposure

Abstract

In five experiments, rats' preference for a flavor was greater if the flavor had previously been consumed under low rather than high deprivation. This preference was conditioned in as few as three flavor-deprivation pairings (Experiment 1), and persisted through 28 test days, half under each deprivation level (Experiment 2). Rats never preferred the flavor associated with high deprivation even when calories were increased by giving 40 ml of 8% sucrose or when caloric density was increased to the equivalent of 20% sucrose. The preference for the lowdeprivation flavor was greater when saccharin solutions were used rather than sucrose solutions, but the preference did emerge when sucrose solutions were used as testing proceeded and when a lower concentration of sucrose was used. We suggest that these preferences may be a result of flavor-taste associations rather than associations between flavors and postingestive consequences, and that the taste of the solutions under low deprivation is preferred to the taste under high deprivation.We recently found that rats' preference for a flavor was greater if they had previously consumed it under low rather than high hunger when flavors were given separately from the daily feeding (Capaldi & Myers, 1982). Given the widespread assumption that the incentive value of food increases with increased hunger (e.g., Kurtz & Jarka, Revusky, 1967), this finding is surprising. Our aim in the first two of the present experiments was to establish the reliability of this effect and the range of conditions under which it occurs. Experiment 1 looked for the effect with minimal training, and Experiment 2 measured the persistence of the effect. EXPERIMENT 1Experiment 1 used 6 training days. In all our previous experiments, we have used 20 training days. However, taste aversions based on illness can be conditioned rapidly (Logue, 1979), so it was of interest to determine if taste preferences! based on hunger level were also learned rapidly. MetbodSubjects. The subjects were 24 male albino rats, 174 days old at the beginning of the experiment. They were 78 days old on arrival from the Holtzman Co., Madison, Wisconsin, and had been employed in a straight alley instrumental learning experiment in which they had received 14 g of food per day for 69 days. New groups were formed by evenly redistributing the rats from the old groups.Reprints can be obtained from Elizabeth D. Capaldi, Department of Psychological Sciences, Purdue University, West Lafayette, Indiana 47907. 107Materials. Flavored solutions were presented in 50-ml Nalgene centrifuge tubes with rubber stoppers and metal spouts. Flavor cues consisted of 111fo cinnamon (211fo imitation cinnamon flavoring mixed with 100llfo ethanol) or 111fo wintergreen (211fo imitation wintergreen flavoring mixed with IOOllfo ethanol) dissolved in a saccharin solution with water (.15I1fo saccharin) or a sucrosewater solution (811fo sucrose).Procedure. All training and testing occurred in the rats' home cages. Ad-lib water was available throughout the experime...

A learned flavor preference persists despite the extinction of conditioned hedonic reactions to the cue flavors

“…This preference was apparent in both two-and one-bottle tests and did not reduce, despite repeated testing in extinction. This result replicates those in previous reports that flavor preferences are resistant to behavioral extinction (see, e.g., Capaldi et al, 1983;Drucker et al, 1994;Harris et al, 2004). The novel finding from the present study is that although preference .001, respectively].…”

“…Methods for conditioning flavor preferences include flavor-nutrient learning, in which the conditioned stimulus (CS) flavor is p paired with nutrients, such as starch (see, e.g., Sclafani & N Nissenbaum, 1988), as well as flavor-flavor learning, in which the CS is paired with the oral consumption of a particularly palatable taste, such as saccharin (e.g., Holman, 1975). These conditioned preferences can be remarkably p persistent even when the positive consequences on which the preference was originally based are no longer present (e.g., Capaldi, Myers, Campbell, & Sheffer, 1983;Drucker, Ackroff, & Sclafani, 1994;Harris, Shand, Carroll, & Westbrook, 2004).…”

Food deprivation and conditioned flavor preferences based on sweetened and unsweetened foods

“…These results are consistent with theories of motivation that assume increasing deprivation enhances the reinforcing value offood (e.g., Bolles, 1972;Kurtz & Jarka, 1968). Capaldi and Myers (1982) and Capaldi et al, (1983) showed that when flavors were given in saccharin and sucrose solutions under the same conditions as in Experiment 1, rats preferred a flavor received under low deprivation to a flavor received under high deprivation. A comparison of these results with those of Experiment 1 suggested that the reinforcing value of sweetness may be reduced by higher deprivation.…”

“…There were many differences in procedure between that experiment and the present Experiment 1 that could be responsible for the difference in results. However, results of Experiment 1 also contrast with those obtained by Capaldi and Myers (1982) and Capaldi et al (1983). In those studies using saccharin or sucrose solutions and procedures comparable to those of Experiment I, rats preferred the flavor received under lower deprivation to that received under higher deprivation.…”

“…The flavor given before feeding can be associated with the subsequent large feeding; the flavor given after feeding can be associated with effects of having just completed a meal. In a series of experiments, Capaldi and Myers (1982) and Capaldi, Myers, Campbell, and Sheffer (1983) gave flavors either separately from feeding or before and after feeding. In these studies, This research was supported in pan by Grant MH 39453 to the first author from the National Institute of Mental Health.…”