Token reinforcement and resistance to change

Interventions based on a token economy effectively reduce problematic behavior. Yet, treatment gains deteriorate once an intervention is discontinued. It is important to better understand the persistence of behavior maintained by token reinforcement in simple experimental procedures. A Pavlovian association with primary reinforcement is said to endow neutral stimuli (e.g., coins, poker chips, lights, signs, stickers, etc.) with their own function to strengthen behavior as conditioned reinforcers. Behavioral momentum theory suggests that resistance to change under conditions of disruption is the appropriate measure of response strength. However, some animal studies have suggested that conditioned reinforcement may not affect resistance to change of a response. Here, a novel token reinforcement procedure was developed to investigate the resistance to change of responding maintained by token reinforcement. Pigeons responded on a key to produce tokens displayed on a touchscreen monitor in two signaled token-production components. Tokens accumulated over the two production components prior to a common exchange component where pecks to the tokens on the touchscreen produced food reinforcement. Resistance to change of responding maintained by different rates of token reinforcement was assessed by disrupting baseline token-production responding with presession feeding. Token reinforcement rates had inconsistent effects on baseline token-production response rates. However, small effects of token reinforcement rate on resistance to change were found. Results provide weak support for a response-strengthening account of conditioned reinforcement and insightful directions for future studies of token reinforcement in related procedures

Examining the Effects of Reinforcement Context on Relapse of Observing

Attentional biases occur with various psychological disorders, including drugaddiction and anxiety. Conditioned reinforcement likely plays a role in maintainingattentional biases to stimuli associated with reinforcement for unwanted behavior. Theobserving-response procedure is considered a model of attending as reflected byresponding maintained by conditioned reinforcement. Effects of primary reinforcement on the persistence of observing have been studied in the framework of behavioral momentum theory. Studies have shown observing-responses to be more resistant tochange in contexts arranging relatively higher rates of primary reinforcement. Recently, behavioral momentum theory has been extended to describe the effects of primary reinforcement context in relapse phenomena. The present thesis aimed to extend research on the resistance to change of observing to animal models of relapse. Pigeons responded on a two-component multiple schedule of observing-response procedures. In a rich component, observing responses produced stimuli correlated with a high rate of variableinterval (VI) food reinforcement (Rich S+). In a lean component, observing responses produced stimuli correlated with a low rate of VI food reinforcement (Lean S+). Following stable performance, responding was extinguished by removing food and S+ presentations. After extinction, relapse was assessed by reinstatement tests consisting of response-independent presentations of food or S+. Replicating earlier results, observingand food-key responding was more resistant to extinction in the Rich component. Food reinstatement had no systematic effect on extinguished food- and observing-key responding. However, S+ reinstatement resulted in relapse of extinguished observingand food-key responding. Relapse during S+ reinstatement was greater in the Rich component than the Lean component. Reinstatement of responding by S+ presentations resulted in a greater overall increase in responding on the food-key relative to the observing-key. This result suggests that an important functional relationship between the presence of S+ stimuli and increased rates of primary reinforcement for food key responding remained intact during extinction. The results show that observing is susceptible to relapse, and the magnitude of relapse depends on baseline primary reinforcement rate in a context