Behavioral history effects on the maintenance of schedule-induced drinking in rats

Variables affecting scheduled-induced drinking (SID) have been widely studied. Previous experience with other food schedules can slow or prevent acquisition of SID, and its rate can decrease once it has developed if the conditions of the experimental sessions change. These findings conform to the idea that the distribution of behaviors during interreinforcement intervals depends on the occurrence of other behaviors. The goal here was to investigate the effect of interrupting access to water on the subsequent maintenance of SID when access to water was restored. First, in Phase A, rats developed SID under three different fixed-interval (FI) schedules. Then, in Phase B, access to water was removed in the conditioning chambers while food continued to be delivered under the same schedules. Last, when access to water was restored, rats that continued under the food-reinforcement schedule showed lower levels of SID than subjects that remained in their home cages throughout Phase B. Competition between licking and lever pressing was observed, particularly during short FI schedules. These data expand previous findings on behavioral history effects on SID and suggest that SID is part of behavioral patterns developed during interreinforcement intervals in which distribution of behaviors depends on occurrence of all other behaviors.