Recent trends in experimental hypnosis

Research on hypnosis has been influenced by recent methodological contributions. Objective, standardized susceptibility scales have provided adequate measurement, leading to the differentiation of hypnotic from waking behavior, and recognition that hypnotic phenomena are multifactorial. Social-psychological factors (demand characteristics) influence experimental results and special control procedures have been developed to evaluate the essentially subjective nature of hypnosis. Experimental evidence relating to the so-called motivational theory of hypnosis does not provide support for this approach. Several studies are reviewed covering posthypnotic suggestion and amnesia, and counter-expectational effects of hypnosis which cannot be attributed to the demand characteristics of the experimental context (trance logic, source amnesia, posthypnotic behavior occurring outside the experimental context, and the nontennination of hypnosis following the “disappearance” of the hypnotist). These studies support a “state-oriented” theory of hypnosis.