Flavor preexposure and "learned safety."

Conducted 3 experiments with a total of 131 male Wistar rats. Results indicate that (a) a single preexposure to a distinctive flavor resulted in both a retardation of aversion learning (if the flavor was later paired with toxicosis) and a preference for this flavor (if the flavor was not paired with toxicosis); (b) preexposure-induced preferences were retained over a 24-day period and were not attributable to thirst reduction consequent upon …