EFFECTS OF FREE-FOOD AND CONTINUOUS REINFORCEMENT SCHEDULE PRESENTATION ON LEVER PRESSING FOR FOOD BY RATS

Six food-deprived rats were each exposed to a procedure in which lever pressing produced food in the presence and absence of free food. Although the highest frequency of lever pressing was observed when each lever press was reinforced with food in the absence of any supplementary free food, all six rats continued to press the lever when free food was available. The rats consumed approximately the same amount of food when free food was available, whether or not lever pressing was also reinforced. When each lever press was reinforced in the presence of free food, approaches to the free-food cup (and free-food consumption) decreased from the beginning to the end of the session, whereas lever pressing increased gradually across the session. These intra-session changes in behavior were interpreted in terms of the satiation of consummatory behavior.