Episodic and semantic memory in posthypnotic amnesia: A reevaluation.

Recently, Kihlstrom found that a suggestion for posthypnotic amnesia produced impairments on episodic but not semantic memory tasks. During amnesia testing, highly and very highly susceptible subjects showed reduced recall for a previously learned word list but no deficits on a word association task designed to elicit the forgotten words as associates. He hypnotized that posthypnotic amnesia involved a dissociation between episodic and semantic components of memory. We tested the alternative hypothesis that Kihlstrom's findings resulted from experimental demands conveyed by the wording of the amnesia suggestion he employed. We found that subjects could be induced to show only episodic impairments (thereby replicating Kihlstrom) or both episodic and semantic impairments (contrary to Kihlstrom) by subtly varying the wording of amnesia suggestions. These findings are inconsistent with a dissociation hypothesis. Instead, they support the notion that hypnotic amnesia is a strategic enactment strongly influenced by expectations generated in the amnesia testing situation.