Enhancing Hypnotizability: Differential Effects of Flotation REST and ...

12 Enhancing Hypnotizability: Differential Effects of Flotation REST and Progressive Muscle Relaxation Glenn M. Kaplan and Arreed F. Barabasz

ABSTRACT The purpose of th is study was to determi ne the effect i veness of flotation Restricted Environmental Stimulation Technique (REST) for enhancing hypnotizability. Thirty subjects randomly assigned to a) flotation REST (N=10), b)Progressive Muscle Relaxation (PMR) (N=10), or c) no treatment Control (N=10), were pretested with the Stanford Hypnotic Susceptibility Scale, form C (SHSS:C), and re-administered the SHSS:C after treatment and at follow-up. PMR enhanced hypnotizabil ity more than no treatment Control. Contrary to previous studies using chamber method REST, flotation REST did not enhance hypnotizability more than PMR as predicted. Both REST and PMR subjects significantly increased hypnotizability over time while Control subjects did not. The role of relaxation in hypnosis was discussed. I NTRODUCTI ON Hypnotizability has been defined as the ability to become hypnotized and is thus conceptual ized by some researchers as a stable trait of an individual (As, Hilgard, &Weitzenhoffer, 1963). An operational definition of hypnotic susceptibility which permits behavioral measurement is given as "the number of times the subject acts like a hypnotized person when hypnosis is induced by a standard procedure" (Weitzenhoffer &Hilgard, 1959, p. 5). In contrast to viewing hypnosis as a stable trait, evidence has accumulated supporting the notion that hypnotizability can be learned and is therefore modifiable. In an early study, Pascal and Salzberg (1959), found significant increases in hypnotic susceptibility as a function of a systematic training procedure. Since this 1959 study, research has been 143

P. Suedfeld et al. (eds.), Restricted Environmental Stimulation © Springer-Verlag New York Inc. 1990

directed toward the modification of hypnotic susceptibility with a range of techniques, including chamber restricted environmental stimulation technique (REST) (Barabasz, 1982; 1984; Leva, 1974; Sanders & Reyher, 1969; Zubek, 1969), perceptual isolation (Pena, 1963), behavioral modeling cues (Cooper et al., 1967, observational learning (DeVoge & Sachs, 1973), written instructions (Diamond et al, 1975), successive approximation and verbal reinforcement (Sachs &Anderson, 1967), dream deepening suggestions (Wiseman & Reyher,

1962), rel axation training

(Edmonston,

1977), rel axing music

(Talone, Steadman & Diamond, 1973), EMG feedback training (Wickramasekera, 1971) and encounter group experiences (Shapiro & Diamond, 1972). The discrepancy in explaining hypnotizability either as a stable trait or a learned skill may be due to methodological inconsistencies in earlier studies that did not have subjects brought up to their 'plateau' level of hypnotizability prior to their being pretested.

The concept of plateau

hypnotizability or plateau susceptibility (Shor, Orne & O'Connell, 1966) has led investigators to report that most subjects will reach a plateau of hypnotic performance once a number of hypnotic sessions have occurred. The usual research practice of modifying hypnotizability has been to obtain a basel ine score on an accepted measuring instrument such as the Stanford Hypnotic Susceptibility Scale:

Forms A (SHSS:A),

B (SHSS:B)

(Weitzenhoffer & Hilgard, 1959), or C (SHSS:C) (Weitzenhoffer & Hilgard, 1962), the Harvard Group Scale of Hypnotic Susceptibility:

Form A (HGSHS:A)

(Shor & E. Orne, 1962), or the Stanford Hypnotic Clinical Scale (SHCS) (Morgan

& Hilgard, 1975).

Following this measure, some training procedure

is utilized to increase hypnotizability after which the subject is reevaluated either using the initial

measuring instrument or a different

hypnotic scale in order to establish generalization of the effect.

Control

subjects are usually evaluated on the pretest and post test measures but are not subjected to the training procedures. Barabasz

(1982)

has

shown

that

one

way

to

effectively

enhance

hypnotizability is to have subjects participate in restricted environmental stimulation technique (REST).

The chamber REST procedure involves exposure

to a reduced stimulation environment input,

reduction

stimulation.

of

tactile

involving attenuation of auditory

stimulation

and

elimination

of

visual

According to Suedfeld (1980) the subject is asked to reduce

motor activity to the minimum required to maintain comfort, communicating only with the therapist or experimenter. who controls the situation to some 144

extent; that is, she/he indicates when the subject is to perform certain tasks and when the session is over. The achievement of a state of relaxation is usually the major goal of REST in formal cl inical practice. This is different from studies which emp 1oyed 'sensory reduct ion' or 'sensory depri vat ion' whi ch was used to increase the susceptibility of the subject to persuasion and major personality change (Suedfeld, 1980). The current use of the REST procedure involves stimulation from the environment that is in some way restricted and kept to a minimum. In comparison to other training procedures, namely, progressive muscle relaxation, REST does not require continued practice and it can be used for individuals who might otherwise stop practicing. What it does require is some special facility, for example, a chamber environment or flotation tank. The isolation environment minimizes interactions with external reality and provides an opportunity to fully explore one's inner domain. It has been postulated that while in the tank one is allowed to separate the mind and body and to become aware of "hundreds if not thousands of other states of being in which one's consciousness is unimpaired and apparently disconnected from the brain and the body" (Lilly, 1977, p. 104). Modern investigators and practitioners rely, almost exclusively, on induct i on procedures i nvo 1vi ng the concept of re 1axat ion. As. noted by Edmonston (1972, p. 227-228), "It has been evident for two centuries that relaxation is an inseparable part of what is traditionally known as hypnotic procedures". However, as presented in a study by Banyai and Hilgard (1976), a relaxed state is not necessary for hypnosis, which may be induced via an act i ve- alert induct ion. In a recent study, Mi tche 11 and Lundy (1986) examined induction procedures in which relaxation and imagery were isolated in terms of their relative effect on hypnotic responsivity. Regardless of hypnotizability levels, a combined induction (relaxation plus imagery) led to a greater subjective report of hypnotic response than did either the relaxation or the imagery inductions. It may follow that the subjective experience of hypnosis is facilitated by inductions which include relaxation. While findings from previous studies support the efficacy of chamber REST in enhancing hypnotizability, published studies using flotation REST for this purpose are non-existent. In addition, it is important to examine the potent i a1 effect of muscl e relaxation on the enhancement of 145

hypnotizability. Since the Stanford scales utilize an hypnotic induction involving relaxation prior to hypnosis, it is important to examine whether it is muscl e re 1axat i on brought about vi a the fl otat i on REST tank or PMR that accounts for the potential enhancement of hypnotizability. Thus, the purpose of this study was to compare the differential effects of flotation REST and Progressive Muscle Relaxation (PMR) for increasing hypnotizability. It was predicted that, (1) subjects exposed to flotation REST will significantly increase their hypnotizabil ity more than subjects in the control group, (2) subjects trained in Progressive Muscle Relaxation (PMR) will significantly increase their hypnotizability more than subjects in the control group, (3) subjects exposed to flotation REST will significantly increase their hypnotizability more than subjects trained in PMR, and (4) subjects in both the flotation REST and PMR groups will show significant increases in hypnotizability test scores from pretest to post test, while control subjects will not. METHOD Subjects Subjects consisted of Washington State University graduate and undergraduate students who volunteered for a study on hypnos is. Th i rty subjects were randomly assigned to the two treatment groups and the control group. Ages ranged from 17 to 44 years with a mean age of 23.1 years. The flotation REST tank group had 7 females and 3 males with a mean age of 23.6 years, the PMR group had 5 females and 5 males wi th a mean age of 24.1 years, and the Control group had 5 females and 5 males with a mean age of 21.7 years. Apparatus The 'Floatarium' REST tank is essentially an enclosed fiberglass tub that contains a dense solution of water and epsom salts. The density of the solution is so great that the subject floats effortlessly on top of the water. The experience is usually described as 'weightlessness'. The solution, 13"-15" (33 cm - 38 cm) deep is maintained at average skin temperature of 93.5 degrees Fahrenheit (34'C) so the subject does not feel the water. The tank is sound attenuated and once the door is closed, is 1ight free. The floatarium is ventilated by a positive pressure system. Underwater transducers allow transmission of messages to the subject. The subject may also talk with the experimenter at any time via the built in 146

communications system. The large overhead door has spring-assisted hinges to allow easy entrance and exit at any time by the subject. The system includes a complete water filtration and purification system. The maximum dimensions of the tank are: L-I0l" (2.56 m), W-60" (1.5 m), H-54" (1.37 mI. A shower facility installed in the lab was used by subjects before and after each session in the tank. Instrument The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) of Weitzenhoffer and Hilgard (1962), consists of an hypnotic induction, followed by 12 items on the SHSS:C utilized in determining hypnotizability levels of the subjects. The hypnotic induction employed in this study was taken from the Stanford Hypnotic Clinical Scale (SHCS) of Morgan and Hilgard (1975). This induction utilizes relaxation techniques. Procedure The purpose of this study (i.e., "to test for any changes in hypnotizabil ity") was explained to all subjects during the initial group meeting. Subjects were then randomly assigned to their specific groups and instructed to move to different rooms where they were ori ented to thei r part i cul ar treatment. Each subject was then instructed to fi 11 out a personal questionnaire with demographic information and to sign a consent form containing a description of their specific treatment. Confidentiality was assured, both verbally and in writing on the consent form. The following procedure was then used to help maximize each subject's plateau level of hypnotizability. After the brief meeting with the three individual groups, all subjects re-united in a large classroom. At this time they were admi ni stered the Harvard Group Scale of Hypnotic Suscept i bil ity [HGSHS] (Shor & Orne, 1962), to famil i ari ze subjects with the procedures and experiences of an hypnotic induction and hypnosis test items. The HGSHS was not scored. This procedure lasted approximately 60 minutes. Subjects in the two treatment groups and the control group met one week later for their second session. The procedures in this session were again used to help maximize each subject's plateau level of hypnotizability. During this second session, subjects spent approximately 60 minutes undergoing hypnosis experiences similar to the HGSHS procedure. This session, conducted by a psychologist experienced in clinical and experimental hypnosis, involved question and answer time, demonstrations, and brief hypnotic inductions. Subjects in each group were then scheduled 147

on an individual basis for their pretest, subsequent treatments, and post test. Procedures for the individual groups were as follows: Subjects in the REST group were administered the pretest of the SHSS:C on an individual basis, and were then scheduled for flotation REST tank sessions. Subjects were assured of the safety of floating and told that while they were permitted to leave the tank at any time, they were encouraged to remain for the full session. Once in the tank, subjects were read the following message (based on instructions from Barabasz, 1982, and Sanders & Reyher, 1969): Listen carefully to what I say ... Please tell me whatever you can about your reactions to this session. Your experiences will be helpful in understanding the results of the study. Whatever you choose to talk about will of course be kept confidential. Also, try not to sleep during the session, but if you should doze off, don't feel guilty about it. At no time will I respond to what you say or answer any questions you may ask, or communicate with you in any way until the experiment is over. However, I shalla 1ways be in the adjacent room listening to what you say. Do you have any questions? Very good. Have a nice float and I'll let you know when your time is up. Subjects were mon i tored throughout the sess i on by the Experi menter using the intercommunications system. Subjects floated for two 90 minute sessions scheduled one week apart (total time = 180 minutes). Upon completion of the second float they were again administered the SHSS:C. Each subject was asked to return in three weeks for a follow-up test of the SHSS:C. Progressive Muscle Relaxation (PMR): Subjects in the PMR group were administered the pretest of the SHSS:C on an individual basis and then met as a group for three 60 minute sessions of Progressive Muscle Relaxation (PMR) within a one-week period (total time + 180 minutes). While PMR is usually performed in a dimly lit room with little extraneous sound and with subjects' eyes closed, this procedure may function as a form of sensory restriction (Pena, 1963; Wickramasekera, 1970). To reduce the possibility of such sensory restriction, PMR sessions were conducted in a normally lighted room and subjects were instructed to perform the steps of PMR with 148

their eyes open. Rel axation training, based on the model presented by Bernstein and Borkovec (1973), was introduced to the group during the first session. In each session the PMR techniques were demonstrated by the experimenter. Paul and Trimble (1970), and Beiman, Graham and Ciminero (1978), have found live training to be superior to audiotaped versions of the standard relaxation procedure. Upon completion of the third PMR session subjects were re-administered the SHSS:C on an individual basis. Each subject was instructed to return in three weeks for a follow up test of the SHSS:C. Control: Subjects in the control group were pretested on an individual basis with the SHSS:C. Subjects then returned to spend three hours together as a group in a large classroom one evening (total time=180 minutes). Subjects were instructed to study or read material of their own choosing, but were not allowed to talk or interact with the others. They were permitted to use the restroom or to get a drink of water at any time. The purpose of the control group was to allow subjects to think they were being administered a treatment, thereby maintaining subject interest in the study. Upon completion of this session subjects returned after a 24 hour period and were re-administered the SHSS:C on an individual basis. Each subject was instructed to return in three weeks for a follow-up test of the SHSS:C. RESULTS A one-way Analysis of Variance (ANOVA) indicated the three groups did not differ in pretest SHSS:C scores, F(2,27) = 1.38, R = ns, thus suggesting successful randomization. Pretest means and Standard Deviations (SO) for the flotation REST, PMR and Control groups were: 5.50 (3.06), 4.00 (2.98), and 6.50 (4.00), respectively. In order to determi ne overall changes in SHSS: C scores, AN OVA was performed on the difference scores resulting when pretest scores were subtracted from post test scores. Results indicated a trend, F(2,27 = 2.72, R