Increasing trial number produces augmentation, not blocking, in flavor-aversion conditioning

Abstract

Typically, A+→AX+ conditioning yields significantly weaker responding to CS X, a phenomenon known as blocking. Yet, in flavor-aversion conditioning, A+→AX+ conditioning yields a significantly stronger response to X, termed augmentation. Two flavor-aversion experiments with rat subjects and rotationally induced illness were conducted to determine if trial number was a factor that affected the expression of augmentation. An increase in the number of A+ preconditioning trials resulted in a stronger augmented aversion (Experiment 1). Similarly, an increase in the number of AX+ compound conditioning trials also produced a significantly stronger augmentation effect (Experiment 2). Therefore, these data show that variations in trial number are not the determining factor in the expression of augmentation or blocking, and they confirm that the strength of augmented aversions are directly related to the strength of the aversion of the preconditioned cue. Finally, these results are the first to show odor-aversion conditioning and augmented taste aversions produced via rotational stimulation.