Figure 1.

Spontaneous recovery test, Experiment 1 (three-trial blocks). (A) Immediate condition (extinction 10 min after acquisition); (B) delayed condition (extinction 24 h after acquisition). Extinction subjects received X presentations during the extinction phase, whereas Control subjects received equivalent A presentations; “Immediate” refers to extinction 10 min after acquisition, whereas “Delayed” refers to extinction 24 h after acquisition. Trial blocks 1 and 2 present the data collected during the first test, which occurred 72 h after extinction; trial blocks 3 and 4 present the data collected during the re-test, which occurred 48 h later. Brackets represent SEMs.