Response-reinforcement relationships in chronic pain syndrome: applicability of Herrnstein's law

The quantitative relationship between chronic pain behavior and reinforcement has been generally found to be positive. Herrnstein's statement of the law of effect adds a qualification: it predicts that response rate varies hyperbolically with contingent reinforcement, and that response rate is also negatively related to extraneous reinforcement. The present study is an original investigation of the first of these assertions with regard to the naturally occurring behaviors in chronic pain syndrome. It was found that the stereotypic pain behaviors of 12 chronic pain patients were hyperbolically rather than proportionally related to contingent reinforcement from their significant others. Likewise, healthy behaviors in the same group were a hyperbolic function of contingent reinforcement. Estimates of extraneous reinforcement were also obtained for each category of behaviors. As a group, the subjects showed an inverse relationship between pain behaviors and healthy behaviors, consistent with previous research in the pain area. The present findings add generality to Herrnstein's matching law which serves as a descriptive model of target behaviors in chronic pain patients. The findings also have prescriptive implications for the modification of behavior among chronic pain sufferers.