Effects of Immediate Tests on the Long-Term Maintenance of Stimulus Equivalence Classes

Abstract

It has been suggested that stimulus equivalence is a central component of language and symbolic behavior. When teaching symbolic behavior, the goal is often to achieve a more or less permanent alteration of an individual’s behavioral repertoire. As such, it seems important to assess not only variables affecting the establishment of stimulus equivalence but also variables affecting continued stimulus control exerted by stimulus equivalence class members over time. The current study investigated the role of the test for stimulus equivalence on the long-term maintenance of stimulus equivalence classes. Using one-to-many conditional discrimination training, 24 adult participants were taught to respond in line with three five-member stimulus classes. One group of 12 participants immediately completed a test for stimulus equivalence, and 12 other participants did not receive such a test. All 24 participants were subsequently tested for trained and derived relations under extinction conditions 2 and 4 weeks later without any further exposure to the contingencies of the conditional discrimination training. Results showed no differences between the two groups, with four participants in each group responding in accordance with both trained conditional discriminations and stimulus equivalence in the 4-week test. Six additional participants did, however, display systematic conditional performance during retention tests only partly consistent with the experimenter-defined classes.