Abordando las raíces

Woody & Bowers (1994) contrast their dissociated control model of hypno-sis with the neo-dissociation model of Ernest Hilgard (1986). Hilgard adopted a broader definition of dissociation than Janet (see Ch. 1), one that underlies a whole range of everyday phenomena. Unlike the theory of dis-sociated control, Hilgard's model assumes that the actions of the hypno-tised subject are controlled in the normal way; it is the subject's awareness of this that is dissociated.

Let us first give further consideration to the regulation of behaviour.

Imagine that you are driving to a meeting at which you will be expected to give a presentation. Unfortunately you have not yet prepared what you are going to say and you are spending much of the time rehearsing this in your mind. At the same time, you are having to execute a perceptual-motor skill of the highest order, namely drive your car. Somehow you manage to focus on the cognitive rehearsal of your talk sufficiently, even though you also success-fully operate the car and negotiate the traffic. Indeed, you are doing this so well that you cannot even recall certain parts of your journey. Suppose, more-over, you are giving a lift to a colleague who insists on telling you about his holiday. Somehow you are managing to process the information he is giving you sufficiently to be able to make the right sorts of comments, such as 'How nice!' when he tells you how friendly the people were and, 'Oh dear!' when he tells you that his wife fell over and hurt her knee. While all this is going on, from time to time you notice you have a headache, while, at other times, although the headache does not exactly disappear, you somehow 'forget it'.

We can imagine that all this is possible because there is a part of your mind that controls what requires your attention at any particular time and yet this does not mean that all the other activities that you engage in have to stop. Like Hilgard, we can call this part of your mind the 'executive ego' and all the other units of activity 'cognitive control structures'.

Now, the executive ego is limited in the priority it is able to assign to any particular activity. In the example of your driving to the meeting, there may be parts of your journey that are unfamiliar to you, or the driving condi-tions become very difficult, and it is impossible for you not to give your attentional priority to your driving and ignore the other activities men-tioned. Thus, Hilgard talks about 'constraints on ego autonomy'.

To simplify his theory, hypnosis and hypnotic suggestions are ways in which the hypnotist can influence the subject's executive ego in the assign-ment of attentional priority to various activities and experiences. Thus, through hypnosis, experiences and activities that would normally be repre-sented in consciousness may become dissociated from awareness. Hilgard uses the concept of 'amnesic barrier' to describe the mechanism whereby this is achieved. Amnesic barriers have the quality of permeability so that some processes, experiences or activities may be considered to be highly autonomous, separated from the rest of the system by an impermeable amnesic barrier. Others are considerably less so.

This account of dissociated cognitive control structures that are separated by amnesic barriers of varying permeability forms the basis of a psycho-dynamic model of personality structure that has been very influential in the field of hypnosis. The idea of 'parts' of a personality or 'ego states', will be discussed in Chapter 16.

The hidden observer

The most famous laboratory demonstrations of Hilgard's neo-dissociation theory involved the elicitation of profound analgesia in highly susceptible subjects (Hilgard et al 1975). Subjects are required to keep their hand in a bucket of ice-cold water and rate the degree of pain experienced on a scale from, say, 0 to 10. Without suggestions of analgesia, the ratings, given orally, are towards the upper end of the scale. In response to suggestions of analgesia, these ratings may come down to the lower end of the scale. In accordance with the neo-dissociation model, the experimenter then sug-gests that there is a hidden, 'unhypnotised' part of the person that is still experiencing the pain in the usual manner. This 'hidden observer' is asked to rate the pain experienced on the 0-10 scale in writing, using the free hand. Typically, these ratings correspond to the pain ratings given without suggestions of analgesia but still during hypnosis. These experiments have been repeated using suggested deafness (Crawford et al 1979).

Some writers, for reasons that we will see later, consider that the hidden observer effect is an artefact created by the experimenter, with the subject duly complying. Other people have taken it more seriously. For example, Watkins & Watkins (1990) consider that when hypnosis is used for pain relief, and indeed when patients undergo any analgesic procedure, there is a hidden part that is feeling the pain that would normally be present at a

conscious level. Watkins & Watkins (1990) consider that this is not without adverse consequences for the patient. In the present authors' opinion, how-ever, this is an example of an idea taken beyond its useful sphere of appli-cation. Indeed, it is not clear where the hidden observer effect fits in the alleviation of clinical pain through hypnosis (see Ch. 26).

It is worth mentioning here the work of the late Professor Martin Orne at Harvard University. Like Hilgard, Orne has been one of the commanding figures in the field of modern hypnosis. Although it seems that he tended to adopt a state orientation, he nevertheless conducted some influential research on the role of contextual demands and social pressures in hypnotic phenomena. Orne (1959, 1962) considered that there were observable dif-ferences between the behaviour of susceptible subjects during hypnosis and those instructed to simulate hypnosis. The differences hinge on a con-cept that he termed 'trance logic'. For example, he demonstrated that genu-ine hypnotic subjects, when asked to hallucinate a person sitting in a chair in front of them, would also describe objects that would ordinarily be obscured by the person's body. This is of course illogical. Simulators tended to deny being able to see the objects because the hallucinated person was in the way. Orne also reported that true hypnotic subjects, as they traversed the room, avoided colliding with a chair for which they had been given a negative hallucination suggestion. Simulators tended to b u m p into the chair, as one would logically expect. In another demonstration of trance logic, Orne (1972) regressed a student to a time when he was unable to speak English. Orne conversed with him in his native tongue (German) and then suddenly asked him 'Do you speak English?' Variations of this ques-tion were given and each time the student replied 'Nein'. Again this is illogical. (This effect can also be demonstrated by regressing subjects to their early years and asking them questions in a vocabulary that they would not at that time understand; they still tend to respond to the questions.)

Trance logic' is the ability to hold two contradictory beliefs or pieces of information in mind without experiencing the usual sense of conflict, and this may be understood in dissociative terms. Needless to say this concept has its detractors. For example, in the positive hallucination test, it may simply be that hypnotic subjects create a transparent image of the person.

Although it may be debated whether the neo-dissociation theory is actu-ally positing a 'special state', Hilgard is clear that some important change is happening when a person is subjected to a traditional hypnotic induction.

He says:

Looked at in other ways, we find that hypnotic procedures are designed to produce a readiness for dissociative experiences by disrupting the ordinary continuities of memories and by distorting or concealing reality orientation through the power that words exert by direct suggestion, through selective attention or inattention and through stimulating the imagination appropriately.

(Hilgard 1986, p 226)