HYPNOTIC HYPERMNESIA - THE EMPTY SET OF HYPERMNESIA

Although a long tradition exists suggesting that hypnosis can enhance memory (hypnotic hypermnesia), the experimental literature is quite mi xed. When, however, laboratory studies are classified according to the type of stimulus and memory tests employed, a remarkable orderliness of outcomes emerges: Recall tests for high-sense stimuli (e.g., poetry , meaningful pictures) almost always produce hypermnesia, but not reco gnition tests for low-sense stimuli (e.g., nonsense syllables, word li sts). An important methodological issue is whether the recall incremen ts for high-sense stimuli constitute enhanced memory or enhanced repor ting (laxer response criteria). Recent laboratory literatures show tha t, beyond response criterion effects, true memory enhancement (hypermn esia) exists. Experiments conducted over the past decade, however, dem onstrate that it is repeated retrieval effort and not hypnosis that is responsible for hypermnesia: Repeated testing without hypnosis yields as much hypermnesia as with hypnosis.