Following suggested posthypnotic amnesia highly hypnotizable subjects differ from those less hypnotizable not only regarding the small number of items recalled after hypnosis is terminated but also in the high proportion of forgotten items subsequently remembered at an appropriate signal.
The joint effect of these processes is the absence of differences in total recall once amnesia is removed. Recovery of amnesic items after amnesia is lifted may serve as a criterion to distinguish ordinary forgetting from hypnotic amnesia and the ability to recover this transiently forgotten material may be used to predict future hypnotic performance. Reversibility is as effective a predictor as amnesia itself.
Results suggest that hypnotic amnesia can best be understood as an active process involving a reversible disturbance of memory retrieval.
Edgar P. Nace, Martin T. Orne, A. Gordon Hammer. Posthypnotic Amnesia as an Active Psychic ProcessThe Reversibility of Amnesia. Arch Gen Psychiatry. 1974;31(2):257–260. doi:10.1001/archpsyc.1974.01760140099018