Rate-decreasing effects of the atypical neuroleptic risperidone attenuated by conditions of reinforcement in a woman with mental retardation.

Effects of two doses of risperidone on the performance of a matching task under tangible reinforcement and nonreinforcement conditions were measured in a woman with mental retardation. In both conditions, time to complete the task increased and response rates decreased under two doses of risperidone. Accuracy was generally unchanged.