Distractor effects on latent inhibition are a consequence of generalization decrement

In two experiments rats were exposed to a novel vinegar solution and subsequently given a single conditioning trial on which consumption of vinegar was followed by an injection of lithium chloride. In conformity to other results on distractor effects, the latent inhibition produced by this treatment could be disrupted if the rats drank a second novel solution (sucrose) immediately after their initial exposure to vinegar. But latent inhibition was equally disrupted if rats were initially exposed to vinegar alone and subsequently drank vinegar immediately followed by sucrose on the conditioning trial. Thus latent inhibition was disrupted whenever there was a change between the solutions presented on initial exposure and conditioning trials. Generalization decrement seems the most parsimonious explanation of this pattern of results.