Date of Award:


Document Type:


Degree Name:

Master of Arts (MA)




Timothy A. Shahan


The fundamental unit of behavior, defined by the discriminated operant, can be reduced to the three-term contingency, which includes an antecedent stimulus, a response, and a reinforcing consequence. Behavioral momentum theory suggests that resistance to disruption (i.e., resistance to change) of operant behavior is governed by the relation between the antecedent stimulus context and the rate of reinforcement within that context (i.e., Pavlovian stimulus-reinforcer relation). Further, behavior momentum theory suggests that resistance to change is independent of the contingency between the response and the reinforcer (i.e., operant response-reinforcer relation). Thus, although additional response-independent food decreases response rates by greatly degrading the response-reinforcer relation, resistance to change is increased because the stimulus-reinforcer relation is enhanced. Inconsistent with behavioral momentum theory, unsignaled delays decrease response rates and resistance to change by slightly degrading the response-reinforcer relation while maintaining equal stimulus-reinforcer relations. Therefore, it is unclear exactly how degrading response-reinforcer relations with response-independent food and delayed reinforcers affects resistance to change because the stimulus-reinforcer relations have generally differed across components and studies. Thus, the present experiment examined whether differentially degrading response-reinforcer relations affects resistance to change while maintaining equal stimulus-reinforcer relations. In the present experiment, a three-component multiple schedule with equal rates of immediate response-dependent reinforcement (15 per hr) was used with pigeons keypecking for food. Equal rates of response-independent food (60 per hr) and 3-s unsignaled delayed reinforcers (60 per hr) were added to two different components in baseline. Thus, the stimulus-reinforcer relations were equal in the two components with added reinforcers and were greater than in the component without added reinforcers . Any differences in resistance to change across the components with added reinforcers should reflect only differences in the response-reinforcer relations because the stimulus-reinforcer relations were equal. Consistent with behavioral-momentum theory, however, resistance to presession feeding, response-independent food presented during intercomponent intervals , and extinction was greater in the components with added reinforcers. There were no differences in resistance to change between the two components with added reinforcers. These results replicate the finding that adding response-independent food increases resistance to change and extends this finding to the effects of added delayed reinforcement.



Included in

Psychology Commons