抄録
The hypothesis that the inaccessible reward has the secondary reinforcement value for hungry rats was tested experimentally. In Exp. I, where 26 albino rats were run in the straight runway without reward, the hypothesis was not confirmed, whereas the alternative hypothesis that the inhibitory effect is produced by the cognition learning of the inaccessibility of food was found to fit. In Exp. II with 20 rats, the insertion of acquisition session prior to extinction was found to make the original hypothesis tenable, though the inhibitory effect as was found in Exp. I was still detectable. However, the analysis of the randomness in response measures of individual rats did not detect a specific tendency as revealed by group averages.