Behavioral History and Pigeons' "Guiding Cues" Performance

Abstract

Response-sequence learning is often studied by manipulating consequences for sequence completion. Results of research evaluating how changes in discriminative stimuli disrupt the accuracy of response sequences suggest that transitions to reversed but highly predictive discriminative stimuli are more disruptive than the removal of discriminative stimuli. Two experiments assessed effects of changing discriminative stimuli on response-sequence accuracy while reinforcement remained contingent on a left-peck, right-peck response sequence. Initially, pigeons were trained on the response sequence in which the S+ key was illuminated red and the S- key was illuminated white. For all conditions of both experiments, the "accurate" response sequence that led to food was the same, but the way the accurate sequence was signaled sometimes differed. In Experiment 1, after training, discriminative stimuli were either removed (by lighting both keys white) or reversed. Accuracy was lower when discriminative stimuli were reversed than when they were removed. Experiment 2 showed that after training with discriminative stimuli, a history of reinforcement without discriminative stimuli was sufficient for the response sequence to emerge at high levels of accuracy when the discriminative stimuli were reversed. Results suggest a parsimonious explanation for why highly predictive discriminative stimuli sometimes fail to control behavior based on behavioral history.