Effects of Unreinforced Conditional Selection Training, Multiple Negative Comparison Training, and Feedback on Equivalence Class Formation

Abstract

Eighty-eight college students learned a series of unlinked conditional discriminations designed to induce a repertoire of unreinforced conditional selection of comparison stimuli. The 80 subjects who completed this pretraining then learned the new conditional relations AB, BC, and CD in each of two stimulus sets. The A, B, and C stimuli were novel nonsense syllables. The D stimulus was a “short” line in one class and a “long” line in the other class. Half the subjects received response contingent feedback during baseline training trials; within this group, subjects were exposed to either 1, 2, 4, or 8 negative comparisons while the baseline relations were being presented. The other half did not receive response contingent feedback; within this group subjects were exposed to either 1, 2, 4, or 8 negative comparisons during the training of the baseline relations. On any given training trial, however, only two comparisons were presented. For subjects who received feedback during training, an increase in the number of negative comparisons used in training led to an increase in the number of subjects who formed classes. When feedback was used during training, the percentage of subjects who formed classes increased from 80 to 100% as the number of negative comparisons increased from 1 to 8. When feedback was not used during training, the percentage of subjects who formed classes decreased from 60 to 40% as the number of negative comparisons increased from 1 to 8. Thus, feedback influenced the likelihood of class formation and interacted with the number of negative comparisons used in training.