Merger and expansion of equivalence classes via meaningful stimuli
Real words automatically pull matching pictures into equivalence classes—fake words do not.
01Research in Context
What this study did
Marin and team worked with 24 college students.
They taught the students to match nonsense shapes to real words like "dog" or fake words like "blor".
Later they showed pictures that fit the real words, like a dog photo.
The question: would the pictures join the equivalence class only when the word had real meaning?
What they found
When the word had meaning, the dog picture slipped right into the class.
Students matched it correctly without extra training.
Fake words never pulled their pictures in.
Real meaning acted like glue for new relations.
How this fits with other research
Brayner de Freitas Gueiros et al. (2020) saw the same glue effect in preschoolers.
Their kids linked printed words to pictures after Go/No-Go training.
Together the studies show the effect holds from age 4 to adult.
Yuan et al. (2022) looked like a contradiction at first.
They found adults with autism kept emotional pictures and words separate.
But the key difference is population: neurotypical adults integrate, while adults with autism may need extra help.
The findings do not clash—they map boundary conditions.
Why it matters
Check the meaning of your stimuli before you test emergent relations.
If you use real words, expect pictures to join the class for free.
If you use nonsense words, plan extra teaching steps.
This saves time and prevents false negatives in your assessments.
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02At a glance
03Original abstract
The present experiments evaluated the effect of meaningful stimuli on the inclusion of a set of extra-experimental meaningful pictures into equivalence classes using within- and between-subjects designs. There were 35 adult participants in total (NEXP1 = 22; NEXP2 = 13). In both experiments, participants were first trained on six baseline relations with abstract stimuli (A, B, and C) and assessed on the emergence of three 3-member equivalence classes. Next, they were trained on DA relations and assessed on the inclusion of the D stimuli and a set of meaningful pictures in the equivalence classes. In Experiment 1, D1 and D2 were meaningful written words and D3 was a written pseudoword. In Experiment 2, for 2 groups, D1, D2, and D3 were meaningful words; for another group, D1, D2, and D3 were pseudowords. In both experiments, participants formed the ABC classes and included the D stimuli in the classes. When D was a meaningful word, participants also included a set of pictures potentially related to the word in the ABC class established experimentally. The results have implications for the definition of meaningfulness and contribute to discussions on the impact of test arrangements on emergent responding.
Journal of the Experimental Analysis of Behavior, 2022 · doi:10.1002/jeab.726