Sources of Stimulus Control in Tests for Emergent Stimulus Relations.

The purpose of this study was to examine the effects of interfering with verbal and visual mediation in groups that received different training sequences in the intraverbal naming task. Experiment 1 examined the effects of disrupting verbal mediation during the image-matching test. Participants were assigned to one of four groups. Two groups received tact instruction prior to intraverbal instruction (TI groups) and the other two received the opposite training sequence (IT groups). One TI and one IT group were instructed to engage in a task intended to disrupt verbal mediation during test. The disruption task did not differentially affect the groups based on instruction sequence. Experiment 2 examined the effects of disrupting visual imagery during intraverbal training. Participants were assigned to one of four groups, two TI and two IT. One TI and one IT group were instructed to engage in a task intended to disrupt visualization during intraverbal training. This disruption task differentially affected response speed during test for the IT group. Results indicate that verbal behavior at test may contribute to correct responding yet also point to the availability of an additional source of stimulus control when names are acquired prior to intraverbal training.