CS-US interval determines the transition from overshadowing to potentiation with flavor compounds.

The present series of five flavor aversion experiments with rat subjects examined compound conditioning at varying CS-US intervals. Using a taste-taste design, Experiments 1A and 1B demonstrated overshadowing at a 0-min CS-US interval and potentiation at a 120-min CS-US interval, and these effects occurred with both tastes of the compound. Experiment 2 showed that the aversion to a single element is reduced when the CS-US interval is increased to 120 min, but the aversion for a compound taste is not.