| dc.description | Animals acquire preferences for foods associated with nutrients or sweet tastes. The present set of ten experiments sought to determine first, whether rats would acquire conditioned preferences for tastes that are normally avoided (a bitter and a sour aqueous solution) and second, whether palatability shifts occur to these tastes and to other stimuli containing taste and odour components (i.e., flavours; grape and cherry Kool Aid) as a function of preference conditioning. In the first set of experiments, water and food restricted rats were conditioned with a differential reverse-order procedure. When rats were food and water restricted during conditioning and test, significant preferences were conditioned only when saccharin was added to each of the taste cues, thereby making them more acceptable. However, when rats were conditioned and tested while water but not food restricted, stronger preferences were expressed if rats received the taste cues without saccharin in test. In the second set of experiments, taste reactivity responses, which are considered to be a reliable measure of palatability, were also assessed to determine whether preference conditioning produces shifts in palatability. When rats were conditioned with the reverse-order procedure, preferences and palatability shifts were observed when the taste solutions were voluntarily consumed, but not when they were involuntarily consumed. When rats were conditioned with flavours, however, preferences and palatability shifts occurred when rats received involuntary oral infusions of the CS flavours, indicating that flavour preferences are more readily conditioned than taste preferences. Finally, in the last experiment rats were conditioned with a long-exposure simultaneous conditioning procedure in which they received differential taste or caloric reinforcement. This experiment indicated that although rats acquired conditioned flavour preferences regardless of the reinforcer used in training, only those that received differential calorific reinforcement demonstrated palatability shifts in test. | en_US |
