Merging meaningful classes and abstract equivalence classes by exclusion

The current experiment assessed whether relating abstract stimuli with familiar pictures by exclusion would produce the formation of a meaningful equivalence class. Ten participants learned conditional discrimination relations with abstract stimuli and established equivalence classes (ABC classes). They then learned DA (D1A1, D2A2, and D3A3) conditional discriminations with written words as D stimuli; two words (D1 and D2) were meaningful stimuli in the participants verbal community ("Dentist" and "Baker"), whereas the third (D3) was a pseudoword ("Tabilu"). In testing trials, participants evidenced derived relations between pictures related preexperimentally to D1 and D2 with the experimental equivalence classes related to D1 and D2. For some participants, the decontextualized stimuli were a set of boat pictures (Condition 1), whereas for others they were a set of miscellaneous pictures (Condition 2). Participants in both conditions successfully matched decontextualized pictures (unrelated to dentist and baker contexts) to all abstract stimuli in the class related to D3 (exclusion responding). In Condition 1 the meaning reported to the word Tabilu was similar across participants, but in Condition 2 participants showed more variations to answer to the meaning of Tabilu. These results suggest that exclusion learning can occur under different stimulus control topographies.