Discrimination of Contingencies under Conditions of Contrafreeloading

Abstract

common to use an only one operandum during the training as well as in the test sessions. To corroborate the appearance of CFL in presence of two levers, and with it to demonstrate that more than an anomalous phenomenon is a particular case that responds to a cost-benefit relationship among the available different sources, six rats had the opportunity to respond to two levers, of which only one of them provided the reinforcer. Three rats worked in a fixed ratio one (FR1) while the other ones three made it in a FR3. In each session it was selected in a random way a lever to produce the reinforcer, while the other one remained inactive. During the base line, the reinforcers could only be obtained when animal responding to the operative lever, while in the test phases besides the above-mentioned it was added a drinking trough with 80 ml of the same reinforcer (milk). The results during the test sessions showed a considerable number of responses to the two levers, with most of them directed to the operative lever. This number of responses diminished throughout the test phases, slowly for the group of RF1 and abruptly for the group RF3. The discussion is made in terms of patterns of exploration-exploitation of resources and of the relationship cost-benefit in each source.