Learned preferences for real-fed and sham-fed polycose in rats: interaction of taste, postingestive reinforcement, and satiety.
Nutrient-conditioned flavor preferences have been obtained with a variety of procedures, but one study indicates that rats do not readily learn to prefer the flavor of real-fed food to the flavor of sham-fed food. This issue was reexamined in food-deprived rats trained to real feed (gastric fistula closed) and sham feed (gastric fistula open) different flavored Polycose solutions (cherry or grape). Sham-feeding intakes in the one-bottle training sessions (30 min) were limited to the amount consumed in real-feeding sessions; intakes were not limited during two-bottle preference tests (10 min). In Experiment 1, when tested with 32% Polycose solutions, the animals tended to prefer the sham-fed Polycose to the real-fed Polycose. When subsequently trained and tested with 8% Polycose solutions, the same animals displayed a strong preference (approximately 90%) for the real-fed Polycose. These findings were confirmed in Experiment 2 using separate groups. Rats trained with 8% Polycose readily learned to prefer the real-fed solution, and rats trained with 32% Polycose initially preferred the sham-fed Polycose solution. With additional training the 32% Polycose group developed a preference for the real-fed solution. In experiment 3, rats trained to real feed flavored 8% and 32% Polycose solutions developed strong preferences for the 32% solution. This finding suggests that the tendency to prefer sham-fed to real-fed 32% Polycose is not due to aversive postingestive effects of the real-fed solution. Taken together, the results indicate that Polycose has a postingestive positive reinforcing effect that can be revealed using the sham-feeding preparation.(ABSTRACT TRUNCATED AT 250 WORDS)
Sclafani
A
A
Department of Psychology, Brooklyn College, City University of New York 11210.
Nissenbaum
J W
JW
Ackroff
K
K
D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology; D005260:Female; D005518:Food Preferences / Q000502:physiology*; D005746:Gastric Emptying / Q000502:physiology*; D005936:Glucans; D009042:Motivation; D051381:Rats; D012528:Satiety Response / Q000502:physiology*; D013270:Stomach / Q000294:innervation*; D013395:Sucrose; D013649:Taste / Q000502:physiology*
D005936:Glucans; D013395:Sucrose