Rats’ Choice in a Coordination Task

We designed a free-operant choice procedure that represents a technical improvement to assess the control of mutual reinforcement contingencies over the choice of coordinated behavior. We demonstrate the advantages of the new procedure with eight rats that were trained to continuously move a steel ball from end to end of a gutter. Subjects were assigned to pairs and had to choose between two response options: one in which reinforcement was contingent upon an individual response, and another in which reinforcement depended on the coordination of intra-pair behavior. We evaluated (a) the effect of reinforcement magnitude over the distribution of responses, and (b) the role of behavioral cues on the rats’ coordinated actions via dividing the experimental chamber in two compartments with a clear/opaque partition. The coordinated actions were more likely when the larger reinforcer was initially associated with the mutual reinforcement option. The visual interaction between subjects did not impact their coordinated actions. The possibility to control organisms’ preference for social or nonsocial alternatives opens potential lines of research. For instance, identifying how the coordination of activities combines with the future value of outcomes to produce stable cooperative equilibria.