Renato Bortoloti

Equivalent Stimuli Are More Strongly Related after Training with Delayed Matching than after Simultaneous Matching: A Study Using the Implicit Relational Assessment Procedure (IRAP).

Bortoloti and de Rose (2009) found evidence that the level of functional transfer is higher in equivalence classes generated by delayed matching to sample (DMTS) than in classes generated by simultaneous matching (SMTS). We attempted to replicate these findings with the Implicit Relational Assessment Procedure (IRAP). Two experimental groups established two equivalence classes, each comprised of faces expressing either anger or happiness and nonsense words. The classes were established with SMTS for one group and with DMTS for the other. Then, nonsense words and the faces were respectively presented as “attribute” and target stimuli in IRAP tasks. The DMTS group yielded the expected IRAP effect; the SMTS group yielded an IRAP effect only when the target was a happy face. It is discussed that DMTS can enhance transfer of “semantic” functions between equivalent stimuli, supporting the idea that the relatedness of stimuli can vary as a function of experimental parameters.

An “Orwellian” Account of Stimulus Equivalence. Are Some Stimuli “More Equivalent” Than Others?

Stimulus equivalence is widely accepted as a model of semantic relations. However, few studies have used methods other than matching-to-sample to assess whether equivalent stimuli are semantically related. This article describes that formed equivalence classes with arbitrary stimuli and faces expressing emotions. A semantic differential showed that the arbitrary stimuli were then evaluated similarly to the faces, indicating that they had acquired similar meanings. The semantic differential permitted a quantitative assessment of the degree of relatedness between equivalent stimuli, and showed that relatedness varied as a function of nodal distance and simultaneous or delayed matching in training. Another study confirmed the semanticity of relations between faces expressing emotions and their equivalent stimuli through the IRAP. This study also confirmed that stimuli in classes formed with delayed matching-to-sample are more strongly related than those in classes formed with simultaneous matching.

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.