The partial reinforcement extinction effect: Learning about trial sequences or time to reinforcement

The partial reinforcement extinction effect (PREE) occurs when conditioned responses that were acquired with partial (inconsistent) reinforcement (PRf) extinguish more slowly than responses acquired with continuous (consistent) reinforcement. Sequential theory (Capaldi, 1966, 1994) offers the most popular account of the PREE-that, under PRf, subjects learn that they are reinforced after experiencing sequences of nonreinforcement, and this promotes continued responding during extinction. Recently, Jiao and Harris (2024) showed that rats could learn to anticipate reinforcement after a sequence of nonreinforced trials, but for these rats, being able to predict reinforcement reduced the PREE. However, it is possible that those rats learned to anticipate reinforcement based on time intervals rather than trial sequences. This issue was addressed in the present study. Four groups of rats were trained with both a continuous (consistent) reinforcement and PRf stimulus, and the timing and sequences of reinforcement were systematically manipulated between groups. The results showed that rats used temporal intervals, and not sequences, to predict reinforcement of the PRf stimulus, which calls into question previous findings for sequence learning and directly challenges the main premise of sequential theory. Moreover, during subsequent extinction, a PREE was only observed in groups that had not been able to predict reinforcement. The findings suggest that the PREE depends on uncertainty about reinforcement, and thus increased certainty about reinforcement makes the absence of reinforcement more informative, which promotes faster extinction learning. (PsycInfo Database Record (c) 2026 APA, all rights reserved).