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 ingestion; and (c) Ss evidenced a preference for a preexposed solution by subsequently ingesting relatively great amounts of this solution when it was the only fluid available (as well as by choosing it over an alternative, simultaneously available solution). Results are discussed in terms of a "learned safety" interpretation of the deleterious effects of flavor preexposure on flavor-aversion learning. (27 ref)