Control of fluid palatability by exteroceptive Pavlovian signals.

Abstract

Tastes elicit a set of palatability-dependent orofacial and somatic responses in rats. We investigated whether discrete auditory conditioned stimuli that signal the availability or onset of unconditioned taste stimuli (sucrose, quinine) can control orofacial responses in the absence of those unconditioned stimuli. In Experiment 1, one auditory stimulus (CS+) was paired with the delivery of a sucrose solution to the magazine floor, and another auditory stimulus (CS-) was never followed by sucrose. Following conditioning, oral infusions of water that were preceded by the CS+ were found to elicit more ingestive (sucrose-typical) orofacial responses than did water alone or water preceded by the CS-. In Experiment 2, the conditioned ingestive reactions to a signal for sucrose observed in Experiment 1 again occurred, and conditioned aversive (quinine-typical) orofacial responses occurred in response to water infusions preceded by a former signal for quinine. These data suggest that perceived palatability may be influenced by Pavlovian associations involving exteroceptive conditioned stimuli. Further, they illustrate the importance of supporting stimuli in modulating the effects of Pavlovian associations upon behavior.

Amount of training and cue-evoked taste-reactivity responding in reinforcer devaluation.

“…Delamater et al (1986) observed positive TR responses to water in the presence of CSs that had been paired with sucrose either 20 (Exp. 2) or 84 (Exp.…”

“…Thus, their assessment of TR responses might have been more sensitive than ours. Third, as Berridge and Schulkin (1989) noted, in the absence of devaluation or other such procedures, an S-R basis for the TR responses Delamater et al (1986) observed with more extended training can not be ruled out.…”

“…For example, Delamater, Berridge, and LoLordo (1986) found that auditory cues paired with sucrose or quinine later could provoke positive or negative TR responses, respectively, when those CSs were presented while unflavored water was infused into the rats' oral cavities. Delamater et al (1986) interpreted these data as indicating that the tones had acquired the capacity to alter Berridge and Schulkin (1989) noted, these data might instead reflect simple S-R learning, by which the behavior patterns initially controlled by the USs were transferred to the control of the CSs.Berridge and Schulkin (1989) used a reinforcer revaluation procedure to demonstrate the acquisition of control of TR responses by CSs under circumstances that made an S-R account unlikely. Rats received pairings (in simultaneous compounds) of one neutral CS flavor (weak acetic acid or quinine HCl) with a strong (0.39M) NaCl flavor, which elicited negative TRs, and the other neutral CS with a sucrose solution.…”

“…For example, Delamater, Berridge, and LoLordo (1986) found that auditory cues paired with sucrose or quinine later could provoke positive or negative TR responses, respectively, when those CSs were presented while unflavored water was infused into the rats' oral cavities. Delamater et al (1986) interpreted these data as indicating that the tones had acquired the capacity to alter the palatability of water by evoking detailed representations of the sensory and motivational properties of sucrose and quinine. However, as Berridge and Schulkin (1989) noted, these data might instead reflect simple S-R learning, by which the behavior patterns initially controlled by the USs were transferred to the control of the CSs.…”

Modulation of taste affect by hunger, caloric satiety, and sensory-specific satiety in the rat

“…Oral infusions of water occurred for most rats in a context where infusions of sucrose or sucrose/quinine already had been experienced (since the order of taste presentation was random). The palatability of water can be influenced by associative experience with exteroceptive cues that have been paired with sweet or bitter tastes (Delamater, et al, 1986).…”