FUNCTIONAL AND EQUIVALENCE CLASSES DERIVED FROM A BASELINE OF SIMPLE AND CONDITIONAL DISCRIMINATIONS IN CHILDREN

Abstract

Functional classes can be established thorough simple discrimination and repeated reversals training. However, successive reversals necessarily involve experience with the occurrence of errors, which may interfere with class formation. The purpose of this study was to investigate the effects of a teaching procedure with no reversals on the acquisition of simple and conditional discriminations, on the transfer of stimulus functions, and on the formation of functional and equivalence classes, in preschool children. The children learned three simple discriminations and the S+ and S– of one of the discriminations were presented as samples in a matching-to-sample task with a novel pair of comparison stimuli. Six participants learned the simple and conditional discriminations with a few errors. Probe trials were inserted among trials of a baseline of simple and conditional discriminations. In probes of simple discrimination with the stimuli that served as comparisons in the conditional discrimination, all children selected the novel stimulus correlated with the sample that had a previous S+ function in a simple discrimination. In conditional discriminations probes, participants showed emergence of new relations (immediate or delayed), what can be interpreted as the formation of functional classes. Then, two participants learned new conditional discriminations and responded in simple and conditional discrimination probes according to the stimulus functions established in training (formation of functional and equivalence classes). The variability in individual performances was similar to that observed under reversal procedures, which generated more errors than the present study, thus suggesting that errors are not the critical variable responsible for the variability. Keywords: simple discrimination, conditional discrimination, functional classes, equivalence classes, preschool children.