TRANSFER AND COUNTERCONDITIONING OF CONDITIONAL CONTROL IN THE RABBITNICTITATING-MEMBRANE RESPONSE

Two experiments using the rabbit nictitating membrane response investi gated whether training in one conditional discrimination (A-->X+, B--> X-), enabled the feature cues (A and B) to modulate responding to anot her CS (Y) trained as a target stimulus in a second conditional discri mination (C-->Y+, D-->Y-). There was near-complete transfer of the fea ture cue's conditional control, indicating that the feature cue's abil ity to modulate responding is not based on an association specific to the training target. Experiment 2 also revealed that the role of a sti mulus to act as a conditional cue is affected by its ability to act as a simple conditioned exciter or inhibitor. Following initial acquisit ion of two conditional discriminations, two feature cues were reinforc ed in a pattern consistent with the initial conditional discrimination (A-->+, B-->-), whereas the other two feature cues were reinforced in the reverse pattern to that of the original conditional discriminatio n (C-->-, D-->+). Subsequent tests revealed that the reversed training of the feature cues interfered with the original conditional discrimi nations. The results are consistent with theories that the feature cue gains an association with a representation of the emotional attribute s of the US, which acts to modulate responding to the target stimulus through a diffuse change in motivational level. However, hierarchical theories of conditional discriminations that assume a lack of CS-speci ficity may also be able to explain the findings.