Figure 1.

Experimental design. (A) Trial sequence for the fear acquisition phase. CS+ were followed by the shock UCS in 60% of trials. (B) Trial sequence for the counterconditioning phase. Half of the CS+ and CS− stimuli from the acquisition phase were coupled with monetary reward with 60% contingency, and the other half were never followed by reward. (C) Trial sequence for the reinstatement phase. To test for fear recovery, four UCS were unexpectedly given at the beginning of this phase. None of the CSs were followed by shock or reward.