Equivalence relations, contextual control, and naming

Abstract

This paper reports two experiments that investigated the role of verbal behavior in the emergence and generalization of contextually controlled equivalence classes. During both experiments, participants were trained with two different combinations of the same easily nameable, yet formally unrelated, pictorial stimuli. Match-to-sample baselines for eight four-member classes were established under the contextual control of two colors. In the presence of one color, conditional relations were established between stimuli whose normative names rhymed. In the presence of the other color, conditional relations were established between stimuli whose normative names did not rhyme. Although, during Experiment 1, all participants demonstrated equivalence classes involving rhyming stimuli, none demonstrated the formation of nonrhyme equivalence classes. To investigate this finding, Experiment 2 evaluated whether participants would demonstrate both rhyme and nonrhyme equivalence classes given more extensive exposure to the experimental contingencies. All participants demonstrated contextually controlled rhyme and nonrhyme equivalence classes, although rhyme classes were demonstrated with greater facility than nonrhyme classes. Results indicate that visual stimuli are named, that verbal bases for stimulus classification can affect the emergence of contextually controlled equivalence classes, and that untrained contextually controlled conditional discriminations involving novel stimuli can emerge on the basis of participants' verbal behavior.

Fig 1. Class configurations, stimuli, and normative names of stimuli presented to all participants during baseline training and review, and emergent testing in Experiments 1 and 2.

Lettered columns denote stimuli, numbered rows denote classes.

Fig 2. Stimuli, stimulus compounds, and normative names of stimuli presented to all participants during stage 1 and 2 generalization testing in Experiments 1 and 2.

Numbered rows denote rhyme classes or compounds; lettered columns denote stimuli.

Fig 3. Mean number of trials and errors (+SE) during rhyme and nonrhyme baseline training (Phases 1 and 3, top graph) and baseline review (Phases 2 and 4, bottom graph).

Accuracy criteria were 12 consecutive correct trials for each baseline training block and 12/12 trials correct for each baseline review block.

Fig 4. Number of errors on rhyme (open bars) and nonrhyme (filled bars) trials for each participant during emergent testing (Phase 6) Block 1 (top graph) and Block 2 (bottom graph).

Minimum accuracy criterion for each block was 68/72 trials correct.

Fig 5. Number of trials required by each participant to meet criteria for reinforcement (bottom graph) and extinction (top graph) during full baseline review (Phase 5) prior to each block of emergent testing.

Minimum accuracy criterion for each block was 22/24 trials correct.

Fig 6. Number of errors for each participant on rhyme (top graph) and nonrhyme (bottom graph) trials during emergent testing (Phase 6).

Minimum accuracy criterion for each block was of 68/72 trials correct.