Effects of a Meaningful, a Discriminative, and a Meaningless Stimulus on Equivalence Class Formation

Abstract

Thirty college students attempted to form three 3-node 5-member equivalence classes under the simultaneous protocol. After concurrent training of AB, BC, CD, and DE relations, all probes used to assess the emergence of symmetrical, transitive, and equivalence relations were presented for two test blocks. When the A-E stimuli were all abstract shapes, none of 10 participants formed classes. When the A, B, D, and E stimuli were abstract shapes and the C stimuli were meaningful pictures, 8 of 10 participants formed classes. This high yield may reflect the expansion of existing classes that consist of the associates of the meaningful stimuli, rather than the formation of the ABCDE classes, per se. When the A-E stimuli were abstract shapes and the C stimuli became S(D)s prior to class formation, 5 out of 10 participants formed classes. Thus, the discriminative functions served by the meaningful stimuli can account for some of the enhancement of class formation produced by the inclusion of a meaningful stimulus as a class member. A sorting task, which provided a secondary measure of class formation, indicated the formation of all three classes when the emergent relations probes indicated the same outcome. In contrast, the sorting test indicated "partial" class formation when the emergent relations test indicated no class formation. Finally, the effects of nodal distance on the relatedness of stimuli in the equivalence classes were not influenced by the functions served by the C stimuli in the equivalence classes.

Training order and structural location of meaningful stimuli: Effects on equivalence class formation

“…The simultaneous protocol was used for training and testing (Buffington, Fields, & Adams, 1997;Fields et al, 1997;Imam, 2006). Because this protocol typically produces relatively poor yields, it is a preparation that is sensitive to variables that influence the likelihood of equivalence class formation (Arntzen, 2012;Fields et al, 2012;Fields, Hobbie-Reeve, Adams, & Reeve, 1999). Baseline relations were established in a serial order as AB, BC, CD, and DE, respectively.…”

“…Lower and equal yields were produced when the meaningful stimulus was used as the B or the D member in the class, and a very low percentage of participants formed classes when the meaningful stimulus was the E member of the class. Previously, separate articles have reported the enhancement effects produced by some of these conditions: meaningful stimuli as C stimuli Fields et al, 2012;Nartey et al, 2015;Travis et al, 2014) and meaningful stimuli as A and E stimuli . In the present study, we explored the effects of all of the conditions in a single experiment and replicated the findings obtained in the prior experiments.…”

“…The sensory modality of the stimuli used as class members-for instance, visual (e.g., Fields, Arntzen, Nartey, & Eilifsen, 2012), tactile (e.g., Belanich & Fields, 1999), and gustatory (e.g., Hayes, Tilley, & Hayes, 1988)-has also been shown to influence the formation of equivalence classes. When visual stimuli were used as the class members, they consisted of abstract shapes (e.g., Sidman & Tailby, 1982) or meaningful pictures (e.g., Arntzen, 2004;Fields et al, 2012). In addition, the inclusion of a meaningful stimulus at different temporal points in training influenced the likelihood of equivalence class formation (Arntzen, 2004;Fields et al, 2012;.…”

“…When visual stimuli were used as the class members, they consisted of abstract shapes (e.g., Sidman & Tailby, 1982) or meaningful pictures (e.g., Arntzen, 2004;Fields et al, 2012). In addition, the inclusion of a meaningful stimulus at different temporal points in training influenced the likelihood of equivalence class formation (Arntzen, 2004;Fields et al, 2012;. In Nartey et al (2014), participants attempted to form three 3-node, 5-member equivalence classes that consisted of four abstract stimuli and one meaningful stimulus.…”

“…Thus, that study did not fully disclose how the class-enhancing effects of a meaningful stimulus is modulated by its order of introduction during training and/or by its structural location in a potential equivalence class. Fields et al (2012) explored the use of the meaningful stimulus as the C member of the class. None of the participants formed classes when all of the stimuli were abstract.…”