Varying response effort in the treatment of pica maintained by automatic reinforcement.

Pica is a life-threatening behavior displayed by many individuals with developmental disabilities. In the current study, automatic reinforcement maintained the pica of 3 participants. Following functional analyses of pica, response-effort manipulations were conducted in which the effort to obtain pica or alternative items was varied systematically. Several general relations emerged as a result of the study. First, levels of pica were reduced relative to baseline when alternative items were available independent of the effort required to obtain alternative items or pica. Second, increasing the effort for alternative items resulted in increases in pica relative to when effort for alternative items was low. Third, increasing response effort for pica produced reductions in pica relative to baseline when alternative items were unavailable. Fourth, the highest levels of pica occurred when the effort to engage in pica was low or medium and no alternative items were available. These findings are discussed in terms of the relative effects of quality of reinforcement and response effort on behavior.