CAM - AN ANIMAL LEARNING-MODEL OF EXCESSIVE AND COMPULSIVE IMPLEMENT-ASSISTED DRUG-TAKING IN HUMANS

Animal learning studies reveal that locating the reward cue (discrimin ative stimulus positively correlated with the presentation of positive reinforcement) at the site of the response manipulandum (object conta cted in performing the instrumental response), an arrangement referred to as CAM (cue and manipulandum), induces excessive instrumental resp onding. CAM induces excessive responding even when responding is negat ively related to reinforcement and serves only to delay or cancel rein forcement, revealing that excessive responding induced by CAM is unres trainable and compulsive. In addition, the response form induced by CA M resembles patterns of consummatory behaviors. Thus, animal learning studies reveal that CAM induces excessive and compulsive appetitive-co nsummatory responding that is triggered by objects predictive of rewar ding substances. The CAM model defines conditions under which the drug -taking implement (the response manipulandum at which instrumental dru g-taking behavior is directed) will contribute to the development of e xcessive and compulsive drug-taking in humans. Implement-assisted drug -taking procedures in humans provide for CAM whenever the drug-taking implement is positively correlated with the drug's reinforcing effects . This correlation is highest when the drug-taking implement is employ ed only to consume the drug and the drug is consumed in no other fashi on. Evidence relating drug-taking implements to drug abuse is reviewed and implications for prevention and therapy are considered.