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 <.08, in the predicted direction for treatment subjects to increase in
hypnotizability compared to control subjects. Means and Standard Deviations
(SO) for the REST, PMR, and Control groups were: 1.10 (1.52), 1.70 (1.77),
and .20 (.92), respectively. Post hoc analyses were subsequently conducted
to test the a priori predictions in Hypotheses 1 through 4.
Dunnet IS (1955) mult i p1e compari son procedure for compari ng several
treatments with a control group resulted in no significant difference
149
between subjects in the flotation REST tank group and the Control group.
The results of this test did not support Hypothesis 1. Pretest Means and
Standard Deviations (SO) for the REST and Control groups were: 5.50 (3.06),
and 6.50 (4.00), respectively. Means and Standard Deviations (SO) for the
REST and Control group on Post test scores were: 6.60 (3.13), and 6.70
(3.77), respectively.
Ounnet's (1955) multiple comparison procedure resulted in statistical
s i gnifi cance between the PMR group and the Control group, 11<.05, thus,
results of thi s test supported Hypothesi s 2. Pretest Means and Standard
Deviations (SO) for the PMR and Control groups were: 4.00 (2.98), and 6.50
(4.00), respectively. Means and Standard Deviations (SO) for the PMR and
Control groups on Post test scores were: 5.50 (3.20), and 6.70 (3.77)
respectively.
In order to determine changes in SHSS:C scores, a one-way Analysis of
Variance was performed on the difference scores resulting when pretest scores
were subtracted from post test scores.
The results of this test,
F(1,18)=.66, 11=ns, did not support Hypothesis 3. The Difference score Means
and Standard Deviations (SO) for the REST and PMR groups were: 1.10 (1.52),
and 1.70 (1.77), respectively. To determine support for Hypothesis 4, ttests for correlated samples using pretest and post test scores for each
group were performed. The REST group, t=2. 28, 11<.05, and the PMR group,
t=3.04, 11<.02, showed a significant difference between pretest and post test
scores, while no significant difference was found between pretest and post
test scores for the Control group (t=.68,11=ns).
To test for follow-up changes in hypnotizability, a Repeated Measures
ANOVA for three groups (flotation REST tank, PMR, Control) across three time
periods (pretest, post test, follow-up) was performed. The Repeated Measures
AN OVA indicated a significant Group X Time interaction, F(4,36)=3.19, 11<.05.
Follow-Up Means and Standard Deviations (SO) for the REST, PMR, and Control
groups were: 6.40 (2.84), 5.60 (3.27), and 6.40 (4.03), respectively.
Results of this test indicated significant increases in means from pretest
to post test and from pretest to follow-up within each of the two treatment
groups (REST and PMR), but no significant increases from pretest to post
test, or pretest to follow-up for the Control group. An examination of mean
scores for each test period (pretest, post test, and follow-up) between each
group (REST, PMR, and Control) indicated no significant differences.
Within Group Changes
150
A Repeated Measures ANOVA for the flotation REST Tank and PMR groups
indicated significant differences over the three time periods (pretest, post
test, follow-up).
Results of this measure for the REST group were:
F(2,lS)=4.47, Q<.05, and for the PMR group were F(2,lS)=7.0S, Q <.01.
A Repeated Measures ANOVA for the Control group indicated no
significant difference over the three time periods (pretest, post test,
follow-up), F(2,lS)=.67,Q=ns.
ANOVA was performed on the difference scores that resulted when pretest
scores were subtracted from follow-up scores for the three groups. Results
of this test indicate a significant increase across time (pretest to followup) F(2,27)=3.7S, Q<.05. Means and Standard Deviations (SO) for the REST,
PMR, and Control groups were: .90 (1.37),1.60 (1.S4), and -.10 (.74),
respectively.
To test the differences between groups, a Student Newman-Keuls test was
performed to determine which of the three group means differed significantly
from each other. Results of this test indicated that the PMR group differed
significantly from the Control group (Q <.05). The REST and Control group
means did not differ significantly from each other. In addition, the REST
and the PMR group means did not differ significantly from each other.
DISCUSSION
In contrast to the view that hypnotizability is a stable and enduring
feature of an individual, evidence has accumulated supporting the notion
that hypnotizability can be modified. Results of this investigation provide
further support for the notion that hypnotic susceptibility can be increased
as a function of appropriate training techniques. Present results support
Hilgard's (1965) conclusion that,
"without special intrusion, hypnotic susceptibility
is reasonably stable; with intrusions of various
kinds, with repeated inductions running upward of a
dozen or so, some dramatic changes may occur,
including loss of susceptibility as well as increase"
(p.ll).
Hypothesis 1 may not have been supported due to a ceiling effect
occurring in the Control group, as four subjects in this group scored over
10 on the pretest SHSS:C compared to only one subject in the flotation REST
group. While pretest SHSS:C scores among the three groups did not differ
151
significantly, the Control group mean was the highest of the three.
Repeated test i ng i nd i cated that Control subjects' scores did not change
across the three measurement periods, while scores for the REST group showed
a significant increase. However, even though there was a significant change
in the flotation REST tank group mean from pretest to follow-up, it was not
a substant i a1 improvement over the Control group's mean to support th is
hypothesis. That Hypothesis 1 was not supported may suggest the 1imited
effect i veness of fl otat i on REST compared to chamber REST for enhanc i ng
hypnotizability. Further research is needed before such a conclusion can be
made.
The results were in support of Hypothesis 2. This hypothesis stated
that subjects exposed to Progressive Muscle relaxation (PMR) would
significantly increase their hypnotizabil ity more than subjects in the
Control group on pretest to post test measures. This hypothesis was based
on previous studies which found that relaxation training would improve
hypnotizability (Edmonston, 1977; Ham & Edmonston, 1971; Springer, Sachs, &
Morrow, 1977; Talone, Diamond, &Steadman, 1975; Wickramasekera, 1973, 1983;
see this volume).
Results did not support Hypothesis 3, as PMR and flotation REST
subjects had comparable increases in thei r hypnot i zabi 1i ty scores. One
major difference in comparing the two experimental treatment groups is that
PMR involves an active role on the part of the subject while flotation REST
emphasizes a passive role. It is possible that the state of relaxation
brought about by the active role of subjects in PMR may have accounted for
s i gnifi cant increases over the Control group (Hypothes is 2) whil e the
pass i ve role of subjects in the fl otat i on tank did not account for any
significant difference over Controls (Hypothesis 1). One implication for
future study may be to compare active versus passive roles of subjects
within the flotation REST tank.
Results were in support of Hypothesis 4. This hypothesis stated that
subjects in both the flotation REST tank group and the PMR group would show
significant increases in hypnotizability test scores from pretest to post
test, while subjects in the Control group would not. This hypothesis was
based on previous studies which found that hypnotic susceptibility can be
enhanced through REST (Barabasz, 1980, 1982, 1983; A. Barabasz et al., 1984;
Diamond, 1974; Gill & Brenman, 1961; Leva, 1974; Pena, 1963; Sanders &
Reyher, 1969; Shor & Cobb, 1968; Wickramasekera, 1970; Zubek, 1969, 1973),
152
and relaxation training (Edmonston, 1977; Ham & Edmonston, 1971; Springer,
Sachs &Morrow, 1977; Talone, et al., 1975; Wickramasekera, 1973, 1983; see
this volume).
Subjects in all three groups were involved in procedures used to help
maximize their plateau level of hypnotizability. In addition to subjects
being plateaued, the hypnotic inductions and administration of the SHSS:C
were performed by the same person. Other researchers have noted that
hypnotizability may result if the subjects' fears abate through some
tra in i ng techn i que or through increased mot i vat i on and rapport wi th the
hypnotist (Blatt, Goodman & Wallington, 1969; Kramer, 1969). Therefore,
since only the experimental treatment groups showed significant increases
across post test and follow-up, it may be concluded that these increases in
hypnotizability may be a result of the specific treatment.
Conclusions and Implications
While previous studies have found chamber REST to effectively enhance
hypnotizability, present findings do not support the efficacy of flotation
REST for such purposes. One reason for the ineffectiveness of flotation
REST may be the short fl otat ion sess i on used in the study.
Previ ous
research using chamber REST has employed longer treatment durations. For
example, Barabasz (1982) used 6 hours of chamber REST and found significant
increases in hypnotizabil ity (all REST subjects more than doubled their
hypnosis scores). To explore the variable of session length, future studies
may have subjects, (a) spend a longer amount of time in the flotation tank,
(b) spread the time out over a number of sessions, or (c) increase the
length of time subjects would spend floating in the tank in any given
sess i on. Present results suggest that the re 1at i ve 1y short sess ions of
flotation REST may not significantly enhance hypnotizability.
Another reason flotation REST may not have effectively enhanced
hypnot i zabi 1i ty scores is that subjects may not have experi enced sensory
restriction phenomena. In previous successful chamber studies (Barabasz,
1982; Barabasz et al., 1984) subjects reached a point where sensory
restri ct ion signs were evi dent, us i ng the criteri a of Sanders and Reyher
(1969). Thus, future studies using the flotation REST tank might have
subjects float until these sensory restriction signs become evident. For
example, the subject could communicate this experience to the experimenter
via the build-in communications system.
Previous studies employing chamber REST (Suedfeld et al., 1982;
153
Kristeller et al., 1982) and flotation REST (Jacobs et al., 1984) have had
subjects actively practice relaxation techniques while in the REST
environment.
Such a procedure serves to enhance the subject's active
involvement, which appears to make the subject more sensitive to internal
stimuli. In the present study, subjects were instructed to simply relax
while in the tank. To enhance this internal focus, future studies may
instruct subjects to practice such relaxation techniques while floating.
REFERENCES
As, A., Hilgard, LR. & Weitzenhoffer, A.M. An attempt at experimental
modification of hypnotizability through repeated individualized
hypnotic experience. Scandinavian Journal of Psychology, 1963, 1, 3139.
Banyai, E.I. &Hilgard, E.R. A comparison of active-alert hypnotic induction
with traditional relaxation induction. Journal of Abnormal Psychology,
1976, 85, 218-224.
Barabasz, A.F. Effects of hypnosis and perceptual deprivation on vigilance
in simulated radar target detection task. Perceptual and Motor Skills,
1980, 50, 19-24.
Barabasz, A.F. Restricted environmental stimulation and the enhancement of
hypnotizabil ity; pain, EEG alpha, skin conductance and temperature
responses.
International Journal of Clinical and Experimental
Hypnosis, 1982, ~, 147-166.
Barabasz, A.F.
EEG alpha-hypnotizability correlations are not simple
covariates of subject self-selection. Biological Psychology, 1983, 1I,
169-172.
Barabasz, A.F. Antarctic isolation and imaginative involvement - Preliminary
findings. International Journal of Clinical Hypnosis, 1984, d, 296300.
Barabasz, A.F., Baer, L., Sheehan, D. &Barabasz, M. Effects of Hvonosis and
Restricted Environmental Stimulation Therapy (REST) on Chronic Smoking.
Proceedings of the 23d International Congress of Psychology, Sept.
1984, Acapulco, Mexico.
Beiman, I., Graham, L.E. & Ciminero, A.R.
Self-control progressive
relaxation as an alternate non-pharmacological treatment for essential
hypertension:
Therapeutic effects in the natural environment.
Behaviour Research and Therapy, 1978, lQ, 371-375.
154
Bernstein, D.A. & Borkovec, T.D. Progressive Relaxation Training: A Manual
for the Helping Professions. Champaign, Illinois: Research Press, 1973.
Blatt, S.J., Goodman, J.T. & Wallington, S.A. Is the hypnotist also being
hypnotized?
International Journal of Clinical and Experimental
Hypnosis, 1969, 1I, 160-166.
Cooper, L.M., Banford, S.A., Schubot, E. &Tart, C.T. A further attempt to
modify hypnotic susceptibility through repeated individual experience.
International Journal of Clinical and Experimental Hypnosis, 1967, ~,
11B-124.
DeVoge, J.T. & Sachs, L.B. The modification of hypnotic susceptibility
through imitative behavior. International Journal of Cl inical and
Experimental Hypnosis, 1973, £1, 70-77.
Diamond, M.J. Modification of hypnotizabil ity: A review. Psychological
Bulletin, 1974, B1, 180-198.
Diamond, M.J., Steadman, C., Harada, D. & Rosenthal, J. The use of direct
instructions to modify hypnotic performance: The effects of programmed
learning procedures. Journal of Abnormal Psychology, 1975, 84, 109113.
Dunnet, C.W.
A multiple comparison procedure for comparing several
treatments with a control.
Journal of the American Statistical
Association, 1955, 50, 1096-1121.
Edmonston, W.E., Jr. Relaxation as an appropriate experimental control in
hypnosis studies. American Journal of Cl inical Hypnosis, 1972, l!,
218-229.
Edmonston, W.E., Jr. Neutral hypnosis as relaxation. The American Journal
of Clinical Hypnosis, 1977, 20, 69-75.
Gill, M.M. & Brenman, M. Hypnosis and Related States. New York, NY:
International Universities Press, 1961.
Ham, M.W. & Edmonston, W.E., Jr.
Hypnosis, relaxation, and motor
retardation. Journal of Abnormal Psychology, 1971, 77, 329-331.
Hilgard, E.R. Hypnotic Susceptibil ity. New York, NY: Harcourt, Brace &
World, 1965.
Jacobs, G.D., Heilbronner, R.L. & Stanley, J.M. The effects of short term
flotation REST on relaxation: A controlled study. Health Psychology,
1984, J, 99-112.
Kramer, E.
Hypnotic susceptibil ity and previous relationship with the
hypnotist. American Journal of Clinical Hypnosis, 1969, 11, 175-177.
155
Kri ste 11 er, J. , Schwartz, G. L
Bl ack, H.
The use of Restri cted
Environmental Stimulation Therapy (REST) in the treatment of essential
hypertension: Two case studies. Behavior Research and Therapy, 1982,
20, 561-566.
Leva, R.A. Performance of low susceptibility subjects on Stanford Profile
Scales after sensory deprivation. Psychological Reports, 1974, 34,
835-838.
Lilly, J.C. The Deep Self. New York, NY: Simon and Schuster, 1977.
Mitchell, G.P., Jr. & Lundy, R.M. The effects of relaxation and imagery
induct ions on responses to suggest ions.
Internat i ona 1 Journal of
Clinical and Experimental Hypnosis, 1986, 34, 98-108.
Morgan, A.H. & Hilgard, J.R. Stanford Hypnotic Clinical Scale (SHCS). In:
E.R. Hilgard and J.R. Hilgard. Hypnosis in the Rel ief of Pain. Los
Altos, CA: Kaufman, 1975.
Pascal, G.R. & Salzberg, M.C. A systematic approach to inducing hypnotic
behavior. International Journal of Clinical and Experimental Hypnosis,
1959, I, 161-167.
Paul, G.L., Trimble, R.W. Recorded vs. live relaxation training and hypnotic
suggestion:
Comparative effectiveness for reducing physiological
arousal and inhibiting stress response. Behavior Therapy, 1970, l.
285-302.
Pena, F. Perceptual Iso 1at i on and Hypnot i c Suscept i bi 1ity. Unpubl i shed
doctoral dissertation, Washington State University, 1963.
Sachs, L. B. & Anderson, W. L.
Mod i fi cat i on of hypnot i c suscept i bil i ty.
International Journal of Clinical and Experimental Hypnosis, 1967, ~,
172-180.
Sanders, R.S. & Reyher, J. Sensory deprivation and the enhancement of
hypnotic susceptibility. Journal of Abnormal Psychology, 1969, 74, 375-381.
Shapiro, J.L. &Diamond, M.J. Increases in hypnotizability as a function of
encounter group training:
some confirming evidence.
Journal of
Abnormal Psychology, 1972, 79, 112-115.
Shor, R.E. &Cobb, J.C. An exploratory study of hypnotic training using the
concept of plateau responsiveness as a ferrent. American Journal of
Clinical Hypnosis, 1968, lQ, 178-193.
Shor, R.L & Orne, LC. Harvard Group Scale of Hypnotic Susceptibility.
Palo Alto, CA: Consulting Psychologists Press, 1962.
156
Palo Alto, CA: Consulting Psychologists Press, 1962.
Shor, R.E., Orne, M.T. &O'Connell, D.N. Psychological correlates of plateau
susceptibility in a special volunteer sample. Journal of Personality
and Social Psychology, 1966, l, 80-95.
Springer, C.J., Sachs, L.B. & Morrow, J.E. Group methods of increasing
hypnotic susceptibility.
International Journal of Clinical and
Experimental Hypnosis, 1977, 25, 184-191.
Suedfeld, P. Restricted Environmental Stimulation: Research and Clinical
Applications. New York, NY: Wiley, 1980.
Suedfeld, P., Roy, C. & Landon, B.P. Restricted environmental stimulation
therapy in the treatment of essential hypertension. Behavior Research
and Therapy, 1982, 20, 553-559.
Talone, J.M., Diamond, M.J. & Steadman, C. Modifying hypnotic performance
by means of brief sensory experiences.
International Journal of
Clinical and Experimental Hypnosis, 1975, 23, 190-199.
Talone, J.M., Steadman, C. &Diamond, M.J. The use of music and silence to
increase hypnotizability. Paper presented at the Annual Meeting of the
Hawaii Psychological Association, Honolulu, Hawaii, 1973.
Weitzenhoffer, A.M. &Hilgard, E.R. Stanford Hypnotic Susceptibility Scale,
Forms A and B. Palo Alto, CA: Consulting Psychologists' Press, 1959.
Weitzenhoffer, A.M. & Hilgard, E.R. The Stanford Hypnotic Susceptibil ity
Scale, Form C. Palo Alto, CA: Consulting Psychologists' Press, 1962.
Wi ckramasekera, I.
Effects of sensory restri ct i on on suscept i bil ity to
hypnosis: A hypothesis and more preliminary data. Journal of Abnormal
Psychology, 1970, 76, 69-75.
Wickramasekera, I.
Effects of electromyographic feedback on hypnotic
susceptibility.
More preliminary data.
Journal of Abnormal
Psychology, 1973, 82, 74-77.
Wickramasekera, I. The common therapeutic elements and procedural components
in self-hypnosis and other stress reduction techniques. In: Fine,
T.H. &Turner, J.W., Jr. (Eds.) Proceedings of the First International
Conference on REST and Self-Regulation. Toledo, OH: Iris Publ., 1983.
Wi seman, R. J. & Reyher, J. A procedure ut il i zing dreams for deepeni ng
hypnotic trance. American Journal of Clinical Hypnosis, 1962, ~, 105110.
Zubek, J.P. Sensory Deprivation: Fifteen Years of Research.
Appleton-Century Crofts, 1969.
157
New York, NY:
Zubek, J.P. Behavioral and physiological effects of prolonged sensory and
perceptual deprivation: A review. In: Rasmussen, J. (Ed.) Man in
Isolation and Confinement. Chicago, IL: Aldine-Atherton, 1973.
158