Inhibition and facilitation by B over C after A+, AB–, and ABC+ training with multimodality stimulus combinations.

Previous research with keylight conditioned stimuli has revealed that pigeons failed to show inhibition by Stimulus B over Stimulus C in BC versus C testing after A+, AB–, ABC+ training where Stimulus A and Stimulus Compound ABC had signaled food, and Stimulus Compound AB had signaled no food. Indeed, B slightly facilitated responding to C on the BC trials. The present research addressed the same issue with multimodality stimulus arrangements in autoshaping with pigeons, conditioned suppression with rats, and instrumental discrimination learning with rats. Stimulus B facilitated responding to C if A and B were of the same modality and C was of a different modality. However, B inhibited responding to C if A and C were of the same modality and B was of a different modality, or if B and C were of the same modality and A was of a different modality. These results are correctly predictable by Pearce's configural model with a minor modification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)