Stimulus aftereffects and the partial-reinforcement extinction effect.

Abstract

The effectiveness of stimulus aftereffects and other factors in the production of the partial-reinforcement extinction effect was compared. Rats received training in two distinctively different straight alleys, Situations I and n, with a trial in II given 20 sec. after a trial in I. A 15-min. intertrial interval separated pairs of trials. Group P-C followed a partial-reinforcement training schedule in Situation I and a continuous-reinforcement training schedule in Situation II; Group C-P the reverse of Group P-C; Group C-C continuous reinforcement in both situations. All groups received 30 massed extinction trials in Situation H. The results indicate that Group C-P demonstrated greatest resistance to extinction, with Group P-C next, and Group C-C least. All differences were significant. The presence of some form of transfer from Situation I to Situation II was suggested by the training data, and confounds the interpretation of the superiority of Group P-C over Group C-C. The superiority of Group C-P over Group P-C indicates, however, that stimulus aftereffects are of less importance than other factors.