Establishing preference for unreliable reinforcement in adults with dual diagnoses.

We evaluated the choice responding of three adults dually diagnosed with developmental and psychiatric disabilities using concurrent schedules of reinforcement. Specifically, participants were given a choice between a response option resulting in reliable reinforcement and a response option resulting in unreliable reinforcement. Our primary purpose was to shift preference from reliable to unreliable reinforcement via the systematic presentation of stimuli during delay intervals. A second purpose was to evaluate the effectiveness of intervening stimuli in shifting preference at differing delay-to-reinforcement intervals. Preference for unreliable reinforcement was first examined in the absence of stimulus presentations during delays, at three different delay values. Next, we aimed to establish preference for unreliable reinforcement by presenting pictures of reinforcers during delays preceding unreliable reinforcement. Preference was again examined at three different delay values. In the absence of stimulus presentations during delays, participants were shown to prefer reliable reinforcement, particularly at the longer delay value. When stimuli were presented during the delays, two of the three participants preferred unreliable reinforcement, particularly the longer the delay value. These results suggest that the presentation of intervening stimuli during delays may help facilitate tolerance for unreliable reinforcement.