The role of irrelevant, class-consistent, and class-inconsistent intraverbal training on the establishment of equivalence classes

The current study evaluated whether participants' performance on visual-visual matching-to-sample (MTS) tasks were differentially affected by learning how to verbally relate the names of visual stimuli. In Experiment 1, we trained eight participants to tact arbitrary pictures, followed by intraverbal training that either related the names of these pictures (e.g., A1B1C1; class-consistent), or included irrelevant names. Next, we exposed participants to baseline MTS training, and tested for emergent visual-visual conditional relations. During Experiment 2, intraverbal training included either class-consistent (CC), or class inconsistent intraverbal (CI) training (e.g., A1B2C3). For both experiments, CC training yielded fewer trials to criterion, and fewer errors during baseline MTS training. Most (94%) participants passed transitivity and symmetry tests following class-consistent training, while 88% passed these tests following irrelevant intraverbal training. However, only 38% passed both following class-inconsistent intraverbal training. These results suggest that verbal behavior may play an important a role in MTS performance.