Influence of a small number of partial reinforcement training trials on resistance to extinction.

Abstract

Two experiments were performed in which rats were trained to traverse a straight alley under either continuous, irregular, or single alternation of reward. In the initial experiment, which employed 27 training trials, the continuous group was found least resistant to extinction. The single alternation group was found to be more resistant than the irregular one. Previous experiments have shown that after a moderate number of training trials, alternation and irregular groups are about equally resistant to extinction, but after considerable training the alternation group is less resistant than the irregular one. In the second experiment, extinction training was given after just 18 training trials. Whereas the irregular and continuous groups did not differ in extinction, the single alternation group showed the typical partial reinforcement effect. The findings were discussed in connection with the Hull-Sheffield aftereffects hypothesis.