The Reinforcing value of water in a Schedule-Induced Drinking situation

Abstract

In a Schedule-Induced Drinking procedure (SID) water reinforces the water-producing response. Water acquires its reinforcing value as a conseguence of food-deprivation. Several studies have shown that fooddeprivation reduces home-cage water intake but during the SID session when food is delivered again food and water intake are re-established. Three rats served as subjects. The water-reinforcing value in a SID condition was compared with the water-reinforcing value under differente degrees of explicit waterdeprivation and under two control conditions. In one condition food was delivered during the session but the rats were not food deprived. In the other control condition rats were food deprived but food was not delivered during the session. Lever pressing was reinforced with water on a Progressive Ratio 5 Schedule and the maximum ratios completed were taken as a measure of the water-reinforcing value. Concurrently food was delivered on a Random Time 64 s schedule. It was found that the maximum ratios completed decreased as direct water deprivation diminished. In the SID condition the maximum ratio completed was similar to that obtained under 5:45 hours of direct water-deprivation. In the control conditions the waterreinforcing value was five times smaller compared to the SID condition. The interaction between direct food-deprivation, indirect water-deprivation and the delivery of food during the session on the wáter reinforcing value on a SID procedura are discussed.