Effects of Training Structure and the Passage of Time on Trained and Derived Performance

Abstract

Conditional discriminations established using a linear series training structure were shown in a previous study to be intact when unreinforced trials assessing such performance were presented interspersed among stimulus equivalence test trials. Experimenter-defined correct performance on these trials was seen both for participants responding in accordance with stimulus equivalence and for some participants who did not. The goal of the current study was to investigate the status of previously trained relations at the time of stimulus equivalence tests in further contexts. Experiment 1 investigated this following many-to-one conditional discrimination training with 20 adult participants. Experimenter-defined correct performance on probes for trained relations was observed for 16 out of 17 of participants who formed stimulus equivalence classes, as well as for all participants not responding in accordance with stimulus equivalence. In Experiment 2, 18 adult participants received linear series, many-to-one, or one-to-many conditional discrimination training and tests for stimulus equivalence with interspersed training trials. Subsequently, participants experienced three additional tests for derived and trained performance within a month of the original training. Continued testing and the passage of time had little effect on the stability of both learned and derived performance for participants initially responding in accordance with stimulus equivalence. Participants who failed to form stimulus equivalence classes in the initial test, but responded in line with the trained relations, displayed more varied performance over time. Results from both experiments indicate that the lack of stimulus equivalence performance is not commonly caused by a breakdown of trained relations at the time of the stimulus equivalence test.