Simultaneous and successive contrast with delay of reward

Abstract

In Experiment I, rats showed no evidence of a successive negative contrast effect (NCE) when shifted from immediate reward to a 15-sec delay of reward. Experiment II provided a direct comparison of NCE in both successive and simultaneous paradigms. As in Experiment I, there was no evidence of a successive NCE, but a reliable simultaneous NCE was observed. These results add support for the view that simultaneous and successive NCEs are not due to a single, common process. © 1973 Psychonomic Society, Inc.