Rapid acquisition of conditioned flavor preferences in rats.
Rats learn to prefer flavors paired with the post-oral effects of glucose. The present study examined how rapidly they acquire this preference. In Experiment 1, food-restricted rats were given repeated three-session training/testing cycles: one 30-min session with a CS+ flavor paired with intragastric (IG) infusion of 16% glucose, another session with a CS- flavor paired with IG water, and a third session with a choice between the flavors with their infusates. The rats preferred the CS+ (69%) in the first choice session, and preference increased across the six cycles to 86%. These data demonstrate that the post-oral reinforcing action of glucose is potent enough to support one-trial learning. In Experiment 2, two groups of rats were trained in the same way, with the CS+ flavor paired with IG infusion of 16% glucose or 7.1% corn oil emulsion, but tests were conducted under extinction conditions, with both CS+ and CS- flavors paired with IG water. Significant preference for the CS+ was acquired more rapidly with glucose (71% CS+ in test 1) than with oil (69% CS+ in test 4). Consistent with previous work, the post-oral stimulation by glucose was more potent than that of isocaloric oil emulsion in conditioning preferences. The last experiment examined the acquisition rate for a flavor-taste conditioned preference. Rats were trained with a CS+ flavor mixed into an 8% fructose + 0.2% saccharin solution and a CS- flavor in 0.2% saccharin. The same three-session training/testing cycles were used, and in the tests the flavors were presented in saccharin. A significant 74% preference for the CS+ flavor was apparent by the second test. Together these studies show that the acquisition of flavor preferences, whether based on flavor-taste or flavor-nutrient associations, can be quite rapid.
Ackroff
Karen
K
Department of Psychology, Brooklyn College-CUNY, Brooklyn, NY 11210, USA. KAckroff@gc.cuny.edu
Dym
Cheryl
C
Yiin
Yeh-Min
YM
Sclafani
Anthony
A
D000818:Animals; D001522:Behavior, Animal; D002755:Choice Behavior / Q000502:physiology; D003214:Conditioning, Classical / Q000502:physiology; D003216:Conditioning, Operant / Q000502:physiology*; D005108:Extinction, Psychological / Q000502:physiology; D005260:Female; D005518:Food Preferences / Q000502:physiology*; D005947:Glucose / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D012439:Saccharin / Q000008:administration & dosage; D013549:Sweetening Agents / Q000008:administration & dosage; D013649:Taste / Q000502:physiology*; D013997:Time Factors
D013549:Sweetening Agents; D012439:Saccharin; D005947:Glucose