EFFECTS OF VERBAL-LABELED RESPONSES ON STIMULUS CLASS FORMATION IN A COMPOUND STIMULUS PROCEDURE

Abstract

Evidence suggests that humans form stimulus classes when they learn the baseline relations in a compound stimulus format with two response options. When two 3-member stimulus classes are trained with these procedures, the training contingencies establish the possibility of evoking any of the response options for the within-class transitive compound stimuli; this is described as an ambiguous set of training trajectories. We argue that verbal labels on the response options help human participants surpass the ambiguous training. Here, six adults were assigned to one experimental condition with verbal labels on the response options, other six participants served the second experimental condition with color patches on the response options. Five out of six participants responding with verbal labels responded correctly to symmetry and transitivity tests. Only one participant responding with colors responded correctly to those tests. We discuss a possible role of verbal mediation during equivalence class formation in these procedures.