Postconditioning recovery from the latent inhibition effect in conditioned taste aversion.

Two experiments were conducted examining the effects of flavor (CS) preexposure on the retention of conditioned taste aversion. In Experiment 1, rats received preexposure to sucrose solution followed by a sucrose-illness pairing. The expected "latent inhibition" effect was obtained when testing occurred after a two-day but not an eleven-day training-to-test interval. Experiment 2 extended these results by employing five- and twenty-one-day training-to-test interval parameters and provided evidence that the stronger taste aversion displayed by preexposed subjects following long retention intervals is not attributable to differences in training consumption of sucrose solution. This posttraining increase in conditioned taste aversion (CTA) suggests that preexposure blocks expression of memory.