Figure 2.

Instrumental choice test performance in experiment 1. A shows responses to the omission-cue-producing and no-consequence chains in group O-SC, and B shows responses to the control-cue and no-consequence chains in group OC-S. C shows cue preference ratios (cue-producing responses/total responses), normalized by training performance (test preference ratio/preference ratio in the final 2 training sessions). *p = 0.010, significantly lower preference ratio in group O-S than in group OC-S. The group designations indicate the nature of training received. Group O-S received training with both a food-omission cue and a shock-paired cue, and group OC-S received training with a shock-paired cue and a control cue unpaired with food or food omission. There were 12 rats in each behavioral training condition.