The Effect of Prior Knowledge of Hypnotic Items on Hypnotic Performance and Depth

Abstract

First we exposed experimental subjects to either the hypnotic items they were about to experience or to those items embedded in a longer list of hypnotic items. We then asked them to give item-difficulty ratings prior to administration of a standard group susceptibility scale. Controls received no prior exposure to any hypnotic items. We obtained four dependent measures: hypnotic susceptibility score, an in-hypnosis depth report, Field (1965) Depth Inventory score, and retrospective depth reports. The three groups did not differ significantly on any of the dependent measures. Although this result differs from that of Shor, Pistole, Easton, and Kihlstrom (1984), who found that prior knowledge of items depressed susceptibility scores, this may be due to procedural differences between the two studies. Subjects' self-predictions of item difficulty were poor to modest, and accuracy of predictions was not related to any of the four dependent measures.