Erratum to: The Effect of Conditional Discrimination Reversals with SMTS and DMTS on Reorganization of Equivalence Classes

Abstract

Delayed matching-to-sample (DMTS) training is generally found more effective than simultaneous matching-to-sample (SMTS) training in yielding equivalence class formation. In this study, we examined whether the same differential effects might result from use of these procedures to train reversals of conditional discriminations already providing the bases of equivalence classes. Specifically, we asked whether DMTS rather than SMTS training would more readily produce the reorganization of existing equivalence classes. Sixteen participants were first exposed to an SMTS procedure that established two 4-member equivalence classes, A1B1C1D1 and A2B2C2D2, consisting of arbitrary forms. Next, the contingencies that established the AD matching relations, A1D1 and A2D2, were reversed so that participants were trained to perform the new relations A1D2 and A2D1. Half of these participants continued in SMTS conditions and the other half were exposed to DMTS training. The results showed that the large majority of participants in both groups not only acquired the reversed conditional discriminations but also demonstrated on class reorganization tests that the class membership of the D1 and D2 stimuli shifted in the predicted directions. Both the DMTS and SMTS reversal training thus effectively reorganized the equivalence classes A1B1C1D1 and A2B2C2D2, producing instead the classes A1B1C1D2 and A2B2C2D1. A consistent, between-groups difference in the accuracy of responding on class reorganization tests was observed. Individuals in the SMTS group were the more accurate, many demonstrating class reorganization fully and immediately. The implications of these results are discussed in light of behavioral processes active during conditional discrimination training, including development of precurrent behavior.