Model of Response-Reinforcer Contingency

Response-reinforcer contingency is the degree of association or correlation between reinforcer delivery and criterion responses and may be indexed by the correlation statistic known as the phi coefficient. Experimental manipulation of this contingency metric requires control of the probability of a criterion response. If the response property used to partition responses into criterion and noncriterion subsets permits the construction of an ordinal scale, then a percentile schedule can be used to control the probability of a criterion response. A model for guiding research is offered. The model identifies three experimentally manipulable parameters that jointly determine phi and clarifies the nature of their interactions. Four experiments using rats in a spatial differentiation paradigm were conducted to test predictions derived from the model. In these experiments, reinforcer delivery was contingent on the location of a joystick displacement response, and a criterion response was one with a location close to a target value relative to the distribution of locations generated by recent responses. Higher degrees of location differentiation were produced by higher degrees of location-reinforcer contingency as indexed by phi, and the results of all four experiments were parsimoniously accounted for by the model of contingency presented here.