Polydipsia induced in the rat by a second-order schedule.
Drinking was studied in rats pressing a bar on a second-order schedule in which every third completion of a 1-min fixed interval was followed by food presentation. A brief flash of light signaled the completion of each fixed-interval component. The rats drank not only after the food presentations but also after presentations of the light flash alone. A high rate of steady drinking followed intervals terminated by a food presentation. Drinking that followed intervals terminated by a light flash alone was of comparable rate, but characteristically interrupted by bar pressing. When 250-mg food pellets were used instead of 45-mg pellets, both drinking and bar-pressing rates increased substantially.
D000818:Animals; D003214:Conditioning, Classical; D003213:Conditioning, Psychological; D004327:Drinking Behavior; D005247:Feeding Behavior; D005502:Food; D008029:Lighting; D008297:Male; D051381:Rats; D012055:Reinforcement Schedule