Abstract

The status of hypnosis as an altered state of consciousness has long been controversial. The classic phenomena of hypnosis, such as sensory anaesthesias, analgesia, amnesia, and posthypnotic suggestion, provide prima facie evidence of altered consciousness, but some theorists contend that these are the products of normal mental processes, such as suggestion and expectation. In this article, hypnosis is viewed against a general framework for describing ASCs in terms of four converging operations: induction procedure, subjective experience, behavioural correlates, and physiological correlates. Although 'neutral' hypnosis, in the absence of specific suggestions, has few distinctive characteristics, many of the classic phenomena of hypnosis involve dissociations between explicit and implicit memory, or perception, such that percepts, memories, and thoughts influence ongoing experience, thought, and action outside conscious awareness and control.