Latent inhibition and contextual associations.

Attenuated responding to a conditioned stimulus (CS) after preexposure to that CS (latent inhibition) has traditionally been attributed to reductions in CS associability. Alternatively, CS-context associations formed during CS preexposure later interfere with the acquisition or expression of CS-outcome associations. Three lick suppression experiments with rats contrasted these accounts. Presumably, exposure to the context attenuates the CS-context association without altering CS associability. With a fixed amount of CS preexposure, latent inhibition decreased with increasing context exposure during or after (but not before) CS preexposure. When the ratio of context preexposure duration to CS preexposure was fixed, latent inhibition increased with CS preexposure. These results suggest that latent inhibition is a direct function of the strength of CS-context associations formed during preexposure.