An Experimental Analysis of Higher-Order Stimulus Control in Humans

This dissertation explored sane effects of context on the development of stimulus classes and the transfer of stimulus functions to novel stimuli. The research was also intended to demonstrate the utility of current behavioral theories for prediction and control of contextual effects on class formation. In Experiment lA, contextual control of stimulus classes was established successfully in all six college-student subjects. Matching-to-sample training successfully transferred the function of the contextual stimuli to four novel stimuli, whim resulted in the formation of two three-member classes of contextual stimuli. The first portion of Experiment 1B replicated Experiment 1A with three additional subjects. In the second portion, matching-to-sample training resulted in the establishment of two six-member contextual classes. In Experiment 2, three of four subjects learned a matching-to-sample task in whim the role of the contextual stimuli was controlled by a pair of \u27\u27higher-order\u27\u27 contextual stimuli. \u27Iwo of the subjects received matching-to-sample training in whim the function of the higher-order contextual stimuli was transferred to four novel stimuli, which resulted in the development of two three-member, higher-order contextual classes. Experiments 3A, 3B, and 3C demonstrated that sane groupings of stimuli are more difficult to learn than other groupings. The experiments found that overlapping roles of stimuli tended to confuse subjects and that subjects, when confused, would respond based on familiarity to stimuli rather than on the conditional relations. Experiments 4A and 4B demonstrated that types of matching performance (identity, oddity, and arbitrary) can be controlled by the presence of contextual stimuli. The experiments also provided evidence supporting the idea that generalized identity (reflexivity) and generalized oddity performances are closely related to, if not prerequisites for, successful arbitrary matching and the development of stimulus classes