Selective information processing in hypnotic identity delusion: the impact of time of encoding and retrieval

This experiment indexed the impact of hypnotic identity delusion on information processing. During hypnosis, high and low hypnotizable participants received a suggestion to become a same-sex friend (with opposite personality characteristics) and listened to a structured story about two characters with opposite personality characteristics. Importantly, half the participants encoded the story before the delusion suggestion and retrieved it after the suggestion, and half encoded the story after the delusion suggestion and retrieved it after cancellation. The majority of highs, but few lows, passed the suggestion and reported a compelling delusion experience. Of particular interest is that whereas lows' processing of the story was not influenced by the delusion suggestion or the time of encoding and retrieval (they recalled more than highs overall, identified with the story character consistent with their actual identity, and showed no selectivity in recall), highs' processing was influenced both by their delusional experience and the time of encoding and retrieval. Highs who encoded the story after the delusion suggestion identified with the character consistent with their suggested identity and retrieved more information about this character. In discussing these findings we consider the role of encoding vs. retrieval processes, the impact of current conceptions of self on information processing, and the relevance of this work to memory and clinical delusions. Copyright © 2008 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.