Contrast effects and delay of reward in the double alleyway

Four groups of albino rats received a factorial arrangement of contrasting rewards in G1 (2 or 8 pellets) and G2 (2 or 8 pellets) of a double alleyway. After 63 trials, each group was divided into two equal groups and shifted to either a 15-sec or 0-sec delay of G1 reward. During preshift trials, a “depression” effect occurred in A1. During postshift trials, delay of G1 reward inhibited A1 speeds but had no effect on A2 speeds. The results were interpreted as supporting the notion that the double alleyway may be considered as a differential conditioning situation. The postshift A2 speed data were interpreted within the framework of frustration theory.