Amnesia: Tests of the effect of delayed footshock-electroconvulsive shock pairings

In several recent studies in which temporal relations of a footshock or a conditioned stimulus and electroconvulsive shock were varied, results have been obtained which support either a proactive or a reactivation explanation of the results of memory consolidation experiments. In one of these experiments, delayed footshock-electroconvulsive shock pairings produced amnesia at a time after learning when the memory trace is usually not susceptible to disruption. In the studies reported here, Experiment 1 repeated the essential features of an experiment providing evidence for such delayed amnesia; Experiment 2, involving some modifications of the previous study, was also designed to study such effects. No delayed amnesia was found in these experiments and this argues against either the proactive or reactivation hypotheses.