João Henrique de Almeida

Changing the Meaningfulness of Abstract Stimuli by the Reorganization of Equivalence Classes: Effects of Delayed Matching

Previous research has shown that arbitrary stimuli acquire the valence of facial expressions that convey different emotions when both become members of the same equivalence class. The present study investigated whether stimuli that shifted class membership and became equivalent to another facial expression would change in valence accordingly. Fifty-four college students formed equivalence classes A1B1C1D1, A2B2C2D2, and A3B3C3D3, where A1, A2, and A3 were facial expressions of happiness, neutrality, and anger, respectively. Semantic differential ratings showed that D1, D2, and D3 acquired the valences of the equivalent facial expressions. Training for class reorganization was then conducted, altering the CD relation, so that D2, D3, and D1 would become equivalent to expressions of happiness, neutrality, and anger, respectively. This training was conducted in a delayed matching-to-sample format for one group of participants and in a simultaneous matching-to-sample format for another group. When asked to rate the D stimuli again, participants who showed class reorganization showed valence changes according to the facial expression to which these stimuli became equivalent after training of the altered CD relation. Valence changed more for participants trained for class reorganization with delayed matching. Participants who did not pass the test for class reorganization did not show changes in the valence of the D stimuli. These results indicate that training parameters affect the extent to which stimuli change in meaning when they shift membership in equivalence classes.

Análise da Validade e Precisão de Instrumento de Diferencial Semântico

This study assessed evidence of validity and precision of a semantic differential test that has been used to measure the transfer of meaning among equivalent stimuli. Participants were 196 college students who evaluated pictures of faces expressing emotions and also abstract pictures using an instrument comprised by 13 bipolar scales anchored by opposite adjectives. The factor analysis of the data evidenced the validity of the instrument. Values of alpha coefficients indicated that the factors extracted by this analysis have acceptable levels of precision, although one of the factors might be revised. It is discussed that the stimulus equivalence paradigm, an experimental model for symbolic relations, can benefit from instruments that provide valid measures of meaning transfer.

The transfer of Crel contextual control (same, opposite, less than, more than) through equivalence relations

According to Relational Frame Theory (RFT) Crel denotes a contextual stimulus that controls a particular type of relational response (sameness, opposition, comparative, temporal, hierarchical etc.) in a given situation. Previous studies suggest that contextual functions may be indirectly acquired via transfer of function. The present study investigated the transfer of Crel contextual control through equivalence relations. Experiment 1 evaluated the transfer of Crel contextual functions for relational responses based on sameness and opposition. Experiment 2 extended these findings by evaluating transfer of function using comparative Crel stimuli. Both experiments followed a similar sequence of phases. First, abstract forms were established as Crel stimuli via multiple exemplar training (Phase 1). The contextual cues were then applied to establish arbitrary relations among nonsense words and to test derived relations (Phase 2). After that, equivalence relations involving the original Crel stimuli and other abstract forms were trained and tested (Phase 3). Transfer of function was evaluated by replacing the directly established Crel stimuli with their equivalent stimuli in the former experimental tasks (Phases 1 and 2). Results from both experiments suggest that Crel contextual control may be extended via equivalence relations, allowing other arbitrarily related stimuli to indirectly acquire Crel functions and regulate behavior by evoking appropriate relational responses in the presence of both previously known and novel stimuli.