Loss of Latent Inhibition of Contextual Conditioning following Non-Reinforced Context Exposure in Rats

Three experiments with rats demonstrated that preexposure to an experimental environment retarded the level of conditioned freezing observed on a test in that environment after it had been paired with mild footshock. Furthermore, Experiment 1 demonstrated that this latent inhibition effect could be abolished if preexposed rats were exposed to a second experimental environment following conditioning to the preexposed environment. Experiments 2 and 3 demonstrated that this second environment had to be similar, but not identical, to the preexposed environment, and that the influence of exposure to the second environment on latent inhibition could be abolished by exposure to that environment prior to footshock conditioning. These results are considered in terms of the Dickinson-Burke (1996) theory of retrospective revaluation, and their implications for experiments demonstrating a loss of latent inhibition across a delay are considered.