Incongruous stimulus pairing and conditional discrimination training: effects on relational responding.
First pairings can stick like glue, so probe and overwrite wrong relations before you teach equivalence.
01Research in Context
What this study did
Adults without disabilities learned matching-to-sample tasks. First they saw pairs of pictures that did not go together, like a cat with a hammer. Later they got normal conditional discrimination training where correct matches earned points. The team changed the order of these steps to see which history won.
The study used single-case design. Each person served as their own control. The key question: do early odd pairings still control choices after regular training?
What they found
Early stimulus pairings stuck. Even after correct training, people often picked the old, wrong match. The order of exposure mattered. The way pre-training was set up also changed results. Mixed findings showed the first learning can block later learning.
How this fits with other research
Preston (1994) found the opposite: after standard A→B and B→C training, adults quickly showed new symmetrical and transitive relations without extra help. The 1997 paper shows that if you first give incongruous pairings, those wrong links can override the later, correct training. The two studies do not truly clash; they test different histories before the same equivalence procedure.
Hansen et al. (1989) extended this work to adults with intellectual disability. They showed that blocked-trial fading worked only when both sample and comparison parts were trained together. The 1997 lab data with neurotypical adults now add the warning that initial relations, even silly ones, must be watched because they can linger.
Weissman-Fogel et al. (2015) built forward: giving five prior conditional relations for one stimulus raised equivalence class formation from 17 % to about 60 %. Their positive result underlines the same theme as the 1997 paper: what happens before the main teaching changes what emerges after.
Why it matters
Check each learner’s history before you start equivalence lessons. If a child has seen odd picture pairings in another program, spend extra trials on accurate conditional discriminations. Consider blocked-trial fading or brief pre-training to lock in correct relations first. A quick probe of early stimulus-stimulus links can save you from later errors that refuse to budge.
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Join Free →Start your next equivalence program with a brief matching probe; if errors show, run blocked-trial fading on the correct pairs before full training.
02At a glance
03Original abstract
In Experiment 1, 5 subjects were exposed to a stimulus‐pairing procedure in which two nonsense syllables, identified by a letter‐number code as A1 and C2, each predicted the onset of a sexual film clip, and the nonsense syllables A2 and C1 each predicted the onset of a nonsexual film clip. Subjects were then exposed to a matching‐to‐sample test in which the nonsense syllables A1 and A2 were presented as sample stimuli and C1 and C2 were presented as comparison stimuli and vice versa (i.e., C stimuli as samples and A stimuli as comparisons). All subjects matched A1 with C2 and A2 with C1. Subjects were then trained on the conditional discriminations A1‐B1, A2‐B2, B1‐C1, B2‐C2, after which the matching‐to‐sample test was again administered. All subjects continued to match A1 with C2 and A2 with C1 in accordance with the earlier stimulus‐pairing contingencies. An additional 5 subjects were exposed first to conditional discrimination training and testing before being exposed to the incongruous stimulus pairing and matching‐to‐sample testing. Under these conditions, 4 of the 5 subjects always matched A1 with C1 and A2 with C2. Experiment 2 replicated Experiment 1, except that a matching‐to‐sample test was not administered following the initial training procedure. Under these conditions, matching‐to‐sample test performances were controlled by the contingencies that had immediately preceded the test. Experiment 3 indicated that initial matching‐to‐sample test performances were unlikely to change, even after repeated exposure to incongruous training and testing. Experiment 4 demonstrated that pretraining with unrelated stimulus sets increased the sensitivity of matching‐to‐sample test performances to incongruous contingencies when they were similar in format to those arranged during pretraining. These data may have implications for a behavior‐analytic interpretation of attitude formation and change.
Journal of the experimental analysis of behavior, 1997 · doi:10.1901/jeab.1997.68-143