Complex stimulus control in humans: Merging functional and equivalence classes

Abstract

This dissertation investigated the merging of functional and equivalence classes produced by training responding to either simple or conditional discriminations. Experiment 1 targeted the acquisition of three three-member equivalence classes featuring class-specific reinforcers and three three-member functional classes each controlling the occurrence of a nonsense vocal response. Four female college students completed testing for the targeted stimulus classes. Two subjects demonstrated classconsistent emergent responding, but only one of them maintained class-consistent responding across repeated testing. This student withdrew from the experiment before class merging was arranged. Experiment 2 simplified and expedited the procedures for producing independent emergent classes. Four female college students demonstrated class-consistent responding for three three-member equivalence classes and three two-member functional classes. Classes merged successfully after subjects completed training relating each equivalence class to a functional class via one simple or conditional discrimination. Subsequently, each merged class was expanded by training one additional simple or conditional discrimination.