Even though many investigators have observed increased intakes of edibles as a function of prior exposure, little systematic research has been done on the effect. The present study was designed to investigate the phenomenon in domesticated rats with a concentrated solution of sodium saccharin used as the ingested substance. (Author)

A general hypothesis of associative learning should be based on the broadest possible foundation of empirical evidence, including confirmation in both aversive and appetitive situations. For this reason the present experiment was designed to test the surprise hypothesis using a procedure in which the unconditioned stimulus was the presentation of…