Contrasting predictions of extended comparator hypothesis and acquisition-focused models of learning concerning retrospective revaluation

Abstract

Three conditioned suppression experiments with rats investigated contrasting predictions made by the extended comparator hypothesis and acquisition-focused models of learning, specifically, modified SOP and the revised Rescorla-Wagner model, concerning retrospective revaluation. Two target cues (X and Y) were partially reinforced using a stimulus relative validity design (i.e., AX-Outcome; BX-No outcome; CY-Outcome; DY-No outcome), and subsequently one of the companion cues for each target was extinguished in compound (BC-No outcome). In Experiment 1, which used spaced trials for relative validity training, greater suppression was observed to target cue Y for which the excitatory companion cue had been extinguished in relation to target cue X for which the nonexcitatory companion cue had been extinguished. Experiment 2 replicated these results in a sensory preconditioning preparation. Experiment 3 massed the trials during relative validity training, and the opposite pattern of data was observed. The results are consistent with the predictions of the extended comparator hypothesis. Furthermore, this set of experiments is unique in being able to differentiate between these models without invoking higher-order comparator processes.

Figure 1

Experiment 1: Mean suppression ratio of lever pressing in the presence of the target cues. Brackets indicate standard error of means. See Table 1 for the experimental design.

Figure 2

Experiment 2: Mean suppression ratio of lever pressing in the presence of the target cues. Brackets indicate standard error of means. See Table 2 for the experimental design.

Figure 3

Experiment 3: Mean suppression ratio of lever pressing in the presence of the target cues. Brackets indicate standard error of means. See Table 3 for the experimental design.