Association for Behavior Analysis International

When a class of equivalent stimuli is demonstrated, functions attributed to one class member may transfer to the other members, an effect usually named transfer of functions. The present symposium comprises basic and translational papers related to equivalence class formation and transfer of functions. The first study presents data on eye movements when a class of equivalent stimuli is being expanded. Data show alterations in, particularly, fixation times and fixation rates. The second study investigated equivalence classes that contained "aesthetic" stimuli, images of Degas' statues of ballerinas, showing transfer of judgments about movement to abstract equivalent stimuli. On the same vein, classes investigated in the third study included stimuli related to pain: pictures of needle injections on a human hand. Results show that pain judgments transferred to abstract equivalent stimuli. The final paper reports a translational study that explored the use of transfer of functions to reduce racial bias. Results showed that using a respondent-type procedure to establish equivalence classes is less effective than the standard matching to sample procedure in the reduction of racial bias. These results show the potential of the equivalence paradigm for investigations and interventions on relevant and diverse aspects of human behavior.

In matching-to-sample research, fixation measures as time, rate, number, and sequence have substantial implications because they reveal important information about eye-movement behavior during the response delay. Previous explorations on ocular observing response topography, during establishment of conditional discriminations and test of five potential 3-member stimulus equivalence classes, with the MTO, OTM, and LS training structures, respectively, suggest that fixation times and fixation number follow a certain pattern, that is, in general, 1) longer fixation times to sample stimuli during training and 2) longer fixation times and fixation rates to correct comparison stimuli, regardless of demonstrating equivalence class formation. In our ongoing investigation, we seek to answer a question raised in a previous study: In the LS-structure, how will an increase in class-size, from three to four members, affect eye-movement measures during testing, especially concerning test-trials that pertain no common class-member? Initial results suggest that equivalence relations are more affected than transitivity relations are (see Figures 1 thru 4).

This experiment verified whether abstract stimuli assume aesthetic significance based on equivalence classes. Sixteen participants learned MTS relations involving imagens of ballerinas (A1, A2 and A3), and abstract forms (B1, B2, B3, C1, C2, C3, D1, D2, D3, E1, E2 e E3). To eight participants (Group Class), the MTS procedures established three ABCD classes. To the remaining participants (Group No Class), training precluded the class memberships of A with D. Upon completion of MTS all participants rated the D stimuli with four likert scales to evaluate their perception of motion. A Control Group evaluated the A and D stimuli. Results showed that the evaluations of D by participants that formed the ABCD classes (Group Class) were similar to the evaluations of A and differed from the evaluations of D by the Control Group. The evaluations of D by the Group No Class differed from the evaluations of A by the Control Group. We observed that stimuli D assumed the functions of A when they shared common class membership. These data are consistent with the notion that aesthetic experiences may involve derived relations and untrained acquisition of behavioral functions.

Stimuli in equivalence classes can acquire functions that are added to the other members of the class. Furthermore, if stimuli with a pre-experimental meaning are added to already established equivalence classes, the remaining members might acquire the functions of the added member. Five participants were trained six conditional discriminations (AB/BC) and tested for formation of three 3-member classes before training D stimuli to the A stimuli (D-A). The participants rated six pictures of needle injections towards different places on a human hand. The pictures are rated on a 5-point Likert scale. The picture rated as most painful is used as stimulus D1 and the picture rated as least painful is used as stimulus D2. A picture where the needle is replaced with a Q-tips is used as D3. The final test for emergent relations included a test for formation of three 4-member classes. Then, the participants are asked to rate the B-stimuli on a similar 5-point Likert scale. The main findings show a correspondence in pain-ratings towards the injection images (D-stimuli) and the B-stimuli.

A recent study showed that it is possible to reverse pre-experimental relations between Black faces and a negative attribute using Matching-To-Sample (MTS). However, this has not yet been done with Respondent-type Training (ReT) and was, thus, the purpose of this study. Fourteen children, aged between 9 and 10, who showed, in a screening pretest, negative racial bias towards faces of Black people were exposed to pairings of a positive symbol and an abstract one, and of the abstract symbol with faces of Black people. The same procedure was used to relate a negative symbol with two abstract ones. Finally, participants were tested for the formation of equivalence relations, using MTS, and then, with a modified MTS test which included a White face as a third comparison-stimulus. No programmed consequences were delivered throughout the study. Six children formed the equivalence classes, but selected the White face given the positive symbol in the modified MTS test. The absence of positive consequences, the nature of the stimuli used (socially loaded stimuli) and the number of pairings could account for the results and should be addressed in future research.