Association for Behavior Analysis International

Errorless transfer of stimulus control in the absence of reinforcement (i. e., stimulus fading) was studied with eight pigeons. First, participants learning to respond left to red and right to green by use of differential reinforcement. In contrast, white horizontal and white vertical lines do not control these responses. Then, low salience lines were superimposed on the colors with horizontal on red and vertical on green. After gradually increasing the salience of the lines, color salience was gradually attenuated in the absence of reinforcement. Eventually, the line stimuli in the absence of the colors- occasioned the responding trained to the colors: left to horizontal and right to vertical. This occurred for six of the eight pigeons in less than 30 minutes. Thus, errorless transfer of stimulus control occurred without the reinforcement. Errorless transfer then was produced by stimulus-stimulus pairings. Since fading entailed many fading levels, the procedure was a form of multiple exemplar training. Thus, fading may have involved the induction of resemblance based classes, which influenced errorless learning.

A relatively well-accepted hypothesis about equivalence class formation suggests that emergence of programmed equivalence relations depends on the nature of controlling relations learned during training. We investigated the establishment of Sample/S- controlling relations in a modified three-choice MTS procedure. Black squares covered stimuli during experiment. Participants could briefly observe one stimulus at a time contingent to observing responses (OR) to a button below each square. OR were not mandatory. A software presented S+ as the last stimulus displayed to participants in 80% of trials to promote Sample/S- relations (choosing the square after observing both S-; i. e. without observing S+). Five children and three adults were participants. All adults and four children met learning criterion and presented equivalence class formation. Two adults and four children presented responding under Sample/S- controlling relations at the end of training phase. Children and adults showed similar patterns of controlling relations acquisition, which is, starting to respond under control of Sample/S- relations after occurrences of correct choices that included S+ observation. Responding controlled by Sample/S- relations became preponderant at the end of training. Results suggests that sample/S- relations acquisition not necessarily disrupts equivalence class. Additionally, allowed to provide a description of sample/S- relations acquisition process.

Sidmans (2000) theory of stimulus equivalence suggests that equivalence relations arise out of the contingencies that also develop analytic units. As such, the theory predicts an interaction between the development of analytic units and the development of equivalence relations. Vaidya & Brackney (2014) documented one such type of interaction for groups of stimuli, simple discriminative functions were acquired more rapidly when the groups were drawn from within the an equivalence class than when the groups were drawn from different equivalence classes. Thus, equivalence relations facilitated the development of analytic units. The current set of studies further explore these interactions. Can equivalence relations also retard the development of analytic units? Can existing analytic units (such as simple discriminations) influence the development of equivalence relations? This address will present data addressing each of these questions. The implications of these analyses for developing stimulus control in applied settings will be discussed.