Emergent Relations of Equivalence Generated by Outcome-Specific Consequences in Conditional Discrimination

Abstract

This study examined the effects of outcome-specific consequences on the formation of stimulus equivalence classes. Five-year-old children learned conditional discriminations with four sets of visual stimuli (Sets A-D) using matching to sample. In Experiment 1, eight children received AA, BB, CC, and DD identity-matching and AB and BC arbitrary-matching training. Throughout the training, correct selections of A1, B1, C1, and D1, for example, produced a red bead (R1), and correct selections of A2, B2, C2, and D2 produced a blue bead (R2). Results on class-formation probes demonstrated the formation of two ABC stimulus equivalence classes for seven subjects. Subsequent test probes involving D stimuli demonstrated that for six subjects the ABC stimulus classes were expanded with D1 and D2 based on relations with R1 and R2, respectively. In Experiment 2, eight other subjects received the same identity-matching training as in Experiment 1 but were refrained from arbitrary-matching training. Test probes documented the formation of two ABCD stimulus classes for six subjects. Subsequent tests involving visual representations of R1 and R2 demonstrated that these six subjects related R1 and R2 to the corresponding A, B, C, and D stimuli. It was concluded that stimulus equivalence classes may be not only expanded but also established via outcome-specific consequences and that R1 and R2 stimuli may acquire the same status as their respective class members.