Schedule-Induced Licking and Polydipsia

Abstract

Detailed observations were made of the eating and drinking behavior of a pair of hooded rats under a VI 1 min schedule of food reinforcement after one of them (executive) had been trained alone to bar-press. Reinforcements could be consumed by either rat. The executive nearly always drank after eating, the other (control) never did. Eventually the control acquired the bar-press response. When it was then run alone it too came to drink after eating. It is argued that as drinking after eating is a result of reinforcement scheduling it is improper to ascribe schedule-induced polydipsia to a tendency of rats to drink after eating. Instead it is suggested that a wet mouth becomes a discriminative or otherwise favorable stimulus for bar-pressing with food reinforcement.