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Rats were trained to lick and were tested for lick suppression to a tone in one apparatus/context. They were conditioned (tone-shock) in a different apparatus/context. Prior to conditioning, they received unreinforced preexposure to the tone (PCE) in the lick test box (Group A), in the conditioning box (Group X), or in a box different from both the test and conditioning boxes (Group B), or they received no PCE (Group N). In both Experiments 1 and 2, Group A was the only group to show latent inhibition (i.e., to show less conditioned lick suppression than did Group N). Context-dependent retrieval of “this CS signals nothing” information acquired during PCE reduces lick suppression when PCE and test contexts match, but not when PCE and conditioning contexts match.

Recently, Wright, Skala, and Peuser (1986) reported a failure to find latent inhibition in rats given unreinforced preconditioning exposure to a tone (PCE) when PCE and conditioning (tone-shock) occurred in the same apparatus/context and testing for lick suppression occurred in a different context. The no-PCE control group used for comparison had not been exposed to the tone or the conditioning context prior to conditioning. In the present experiment, the no-PCE control/comparison group received preexposure to the conditioning context, but not to the tone. Although the three groups given 12, 28, or 60 PCEs in the conditioning context did not differ from each other, they all showed less lick suppression in the test context than the no-PCE control group.