Within-subjects partial-reinforcement effects in acquisition and in later discrimination learning.

Abstract

Fifty male albino rats, in 5 groups, were run 4 trials a day, 2 in a black runway and 2 in a white runway. Ss were continuously rewarded on 48 trials in 1 runway (S1[image]) and rewarded on a percentage of the 48 trials in the other (S2[plus or minus]) at 100, 50, 25, 12.5, or 0%. In a 2nd phase, conditions were changed so that none of the trials to S1 were rewarded while all S2 trials were. In Phase 1, speeds to S2 [plus or minus] increased as a negatively accelerated function of percentage of reward. Speads to S1[image] increased slightly as well. In Phase 2, resistance to extinction to S1- was related to prior percentage of reward to S2[image] but speeds to S2+ were not. The findings were interpreted within the framework of Amsel''s theory of frustrative nonreward.