Definitions

The kinds of definitions that are offered for hypnosis tend to depend heavily on the author's theoretical perspective. Within the field there has been a robust debate about whether hypnosis constitutes an 'altered state of consciousness', that is, whether an individual's consciousness is altered by becoming hypnotised. This debate is currently unresovled and is considered in another section. Regardless of whether hypnosis is an altered state of consciousness, many of the interesting effects associated with hypnosis are actually brought about by suggestion - a hypnotised person is typically given suggestions to experience changes in sensation or perception.

So we can usefully split hypnosis and hypnotic procedures into two basic elements - Trance and Suggestion (see also Heap, 1996).

Trance

A central issue in the history of hypnosis has been whether we need to hypothesise a special state of mind, or even a special altered state of brain functioning, in order to explain the phenomena we observe in hypnosis; the so-called 'state' vs. 'non-state' debate. Without taking sides in this theoretical debate, the term 'trance' can still be helpful when thinking about hypnosis if we use it in its weaker version. That is, if we use the term in the way we might in everyday language to denote a state of mind, such as being happy or sad, interested or bored, attentive or disinterested. We define trance as:

i) Focused attention
ii) Disattention to extraneous stimuli
iii) Absorption in some activity, image, thought or feeling

Put this way, the 'state' in everyday terms is one of being 'entranced' and people can, and do, enter this 'entranced' state spontaneously. Common examples of 'everday hypnosis' are:
• being 'lost in thought' or day dreaming
• absorption in sport, reading, listening to music etc
• driving for long distances and not recalling the route taken
• being absorbed in meditation / relaxation procedures.

Hypnotic procedures formalise this process of 'entrancement' and intensify it. Potential hypnosis subjects are given a series of instructions which, if they follow them, are intended to assist them in achieving a trance state. Hypnotic procedures are intended to encourage focussed attention, disattention to surroundings, and absorption in innter mental world. (Note that this list does not include relaxation - this is a suggested effect - see below).

Some people are able to enter the desired state quickly, either spontaneously or through a hypnotic procedure. Hypnotic procedures are generally facilitated by:
i) encouraging the subject to be non-analytical in their thinking
ii) increasing the subjects motivation and willingness to actively involve themselves with the procedures
iii) raising subjects expectancies of a positive outcome

Suggestion

The verbal communications that the hypnotist uses to produce responses are termed "suggestions". Suggestion differ from everyday kinds of instructions in that a "successful" response is experienced by the subject as having a quality of involuntariness or effortlessness One widely held belief is that being in a 'hypnotic state' facilitates responsiveness to suggestion. Though that while this might be the case people can also respond to suggestions of the sort given in hypnosis without being taken through a hypnotic procedure first.

Suggestions are often accompanied by appropriate imagery but the following effects can be produced by direct suggestion without imagery:
• Relaxation
• Arm levitation
• Analgesia
• Amnesia
• Post hypnotic suggestion

Classic suggestion effect

The key characteristic of hypnotic responding is what is called the "classic suggestion effect" (Weitzenhoffer, 1980). As a hypnotic suggestion is carried out by a subject, the subjective experience is that the behavior is happening all by itself, involuntarily. For example, if the suggestion is that the subject's arm is rigid like a bar of iron, the classic hypnotic experience is that one's arm has really become rigid, on its own. It is not that one is deliberately holding one's arm stiffly. This phenomenon is also referred to as "hypnotic involuntariness", that is, the lack of an experience of one's own will in producing the behavior.