Reinstatement of acquisition performance by the presentation of the outcome after extinction in causality judgments.

Two experiments were conducted with the aim of exploring reinstatement after extinction using a causality judgment task in human beings. In Experiment 1, participants learned first that a fictitious medicine produced a side-effect. The medicine was then presented in extinction. Re-exposure to the side-effect by itself before the test reinstated acquisition performance. Reinstatement was greater when exposure took place in the test context than when it took place in a different context. Experiment 2 replicated reinstatement in a situation that ensured equivalent extinction for the different groups before the test.