Hayes, Brownstein, Devany, Kohlenberg, & Shelby, 1987

Six subjects formed two three-member equivalence classes following conditional discrimination training in a matching-to-sample procedure using nonsense syllables as stimulii. For three subjects, a stimulus from each equivalence class was then given a distinct discriminative function. For the remaining three subjects, a stimulus from each equivalence class was given a conditioned reinforcing function. Six additional subjects served as controls. Three received the discriminative control training and three the conditioned reinforcement training, but non received the conditional discrimination training required to form the equivalence class. Following training, testing was done using an element of the equivalence classes related symmetrically and transitively to the element used in the discriminative or reinforcement training. For the equivalence subject, but not the control subjects, discriminative control and conditioned reinforcement effects transferred to other members of the equivalence classes. This transfer of discriminative and reinforcing functions across members of equivalence classes may provide a more complete account of some types of generalization and maintenance. In addition, stimulus equivalence and related phenomena may help explain the control exerted by symbolic stimuli such as in rule-governed behavior.