Effects of Procedural Variations in the Training of Negative Relations for the Emergence of Equivalence Relations

Abstract

This study aimed to determine whether the exclusive positive conditional relations established by the matching-to-sample (MTS) procedure are sufficient for equivalence class formation, or whether the negative conditional relations established with stimuli of alternative classes are necessary for it. In Experiment 1, two 3-choice MTS procedures were compared regarding equivalence class formation. The standard MTS procedure, where negative relations among stimuli of alternative classes are trained, was compared to an altered MTS procedure, where negative relations with stimuli that were not positive to any sample were trained. In Experiment 2, the positive and negative control patterns established by the standard and altered MTS procedures were assessed. Experiment 3 compared 2 further variations: (a) training only 1 negative relation with stimuli of alternative classes in each training trial type (semi-standard MTS procedure) or (b) varying the negative stimuli that did not belong to any class (varied-altered MTS procedure). The overall results indicate that for participants demonstrating high positive conditional baseline relations and high negative relations to stimuli from alternative classes, the probability of equivalence class formation was high, but when participants showed only high positive conditional baseline relations, the probability of equivalence class formation was very low. All main theories of equivalence class formation have difficulty accounting for these results, and an account based on a learning history of classifying behavior is offered.

Transfer of baseline reject control to transitivity trials and its effect on equivalence class formation

“…However, responses to the D1 stimulus appears to indicate reject control between the B1 sample stimulus and the C2 and C3 comparison stimuli. The results of these experiments appear to provide further support for previous evidence highlighting the role of reject control on the emergence of stimulus equivalence classes, and particularly in the emergence of transitivity relations (Carr et al, ; Harrison & Green, ; Plazas & Peña, ; Plazas & Villamil, , b).…”

“…Taking into consideration that symmetry responses might emerge under the exclusive control of select baseline relations (Plazas & Villamil, ) and that the probability of the emergence of transitivity is reduced when reject between‐classes relations are not trained (Harrison & Green, ; Plazas & Peña, ; Plazas & Villamil, ; b), as well as the results of the current study, a “route” for the emergence of transitivity can be suggested. According to this, reject between‐classes baseline relations are transferred by way of select within‐class baseline relations, so that this reject control determines at least partially correct and consistent responding on transitivity test trials.…”

“…Other studies employing the altered MTS procedure (Plazas & Peña, ; Plazas & Villamil, , b) have shown that participants who develop select sample S+ control, but not between‐class reject control, frequently show the emergence of symmetry, but not transitivity; hence, these participants do not show evidence of the formation of equivalence. In contrast, those participants trained with the standard MTS procedure showed establishment of select sample S+ and reject sample S‐ control, and emergence of symmetry and transitivity relations (Plazas & Peña, ; Plazas & Villamil, , b). This suggests that while within‐class select control might be sufficient for the emergence of symmetry, the emergence of transitivity appears to require both within‐class select and between‐class reject control among baseline stimuli.…”

“…The particular contribution of baseline select and reject relations in the emergence of equivalence classes are among such conditions. Most theories about how equivalence class relations emerge, such as the respondent account (Clayton & Hayes, ; Tonneau, ); the naming account (Horne & Lowe, , ); and relational frame theory (Hayes, Barnes‐Holmes, & Roche, ; Barnes‐Holmes et al, ), have emphasized the select, within‐class relations involved during baseline training (Plazas & Peña, ). Moreover, some authors have proposed that emergence of equivalence relations might occur as a result of the learning of exclusive select or reject control (Carrigan & Sidman, ).…”

“…Although participants showed acquisition of select relations, most did not display emergence of transitivity. Plazas and Peña () employed an altered MTS procedure (an “unbalanced procedure” cf. Sidman, ) in which select within‐class relations were trained but reject between‐classes relations were not: Baseline trials were composed of S‐ comparisons that were not used as S+ stimuli on any other trial.…”