Peripheral skin temperature and vasomotor responses during hypnotic induction

The present study is a further investigation of the hypothesis proposed by Reid and Curtsinger (1968) that hypnosis involves changes in peripheral vasomotor responses and skin temperature. 20 male Ss, screened for hypnotic susceptibility, participated in 2 experimental sessions. Each S was hypnotized in 1 session and simply given instructions to relax in the other session. Peripheral skin temperature and pulse volume were continuously monitored through-out each session. The resulting data were analyzed to determine the effects of hypnosis on these physiological measures. Under both conditions, a tendency for increased skin temperature and increased vasodilation was found. It was concluded that neutral hypnosis does not involve changes in these measures which are appreciably different from the changes associated with relaxation.     

Hypnotic Susceptibility,Hypnosis, and EMG Biofeedback in the Reduction of Frontalis Muscle Tension

In the course of validating with 100 Ss the concept of a “classical suggestion-effect,” i.e., the existence of a class of non-voluntary behaviors elicited by communications intended to serve as traditional “suggestions,” evidence has been incidentally obtained which clearly shows that many so-called “instructions” given to presumably hypnotized Ss also function like “suggestions.” The data show that in these circumstances it is not possible to state a priori that a verbal communication will function as an “instruction” in contrast to being a “suggestion.” Such a statement can be made with certainty only a posteriori, on the basis of the nature of the resulting behavior. This finding has implications both for research and for the clinical uses of hypno-suggestive phenomena.     

The disappearing hypnotist: The use of simulating subjects to evaluate how subjects perceive experimental procedures

This study examines the effects of a temporary power failure while S was hypnotized during a tape-recorded session. It was necessary that the power failure be perceived by S as an accident and not as an experimental deception. In a previous study (Orne & Evans, 1966), Ss simulating hypnosis with a “blind” E continued faking throughout the “power failure,” apparently suspecting they were being observed. Therefore, no conclusions could be drawn about the behavior of the hypnotized Ss. After the procedure was modified, simulating Ss ceased faking as soon as the hypnotist left the room, thereby demonstrating that they believed that a power failure had actually occurred and that they were not being watched. Hypnotized Ss spontaneously, although slowly and with subjective difficulty, terminated hypnosis by themselves. The spontaneous behavior of the hypnotized Ss in the absence of a hypnotist seems inconsistent with predictions based on motivational or role-taking theories of hypnosis.     

Eye-roll and hypnotic susceptibility

Stager and Lundy (1985) found hypnotic hypermnesia without increased memory errors. The present study, an attempted partial replication of Stager and Lundy (1985), presented Ss with free recall and multiple choice questions about a short movie they had seen a week earlier. The experimental Ss, who were hypnotized, given hypermnesia suggestions, and retested, did not generally increase their accurate memory scores on posttest; the Stager and Lundy (1985) findings were thus not confirmed. An increase in memory scores did occur, however, but only with high hypnotizable Ss, whether they were hypnotized or not, and only with multiple choice questions. The high hypnotizable Ss had the greatest increase in inaccurate memory scores on the free recall questions.     

Self-exploration in the hypnotic state

Forty-five volunteer Ss were hypnotized in small groups of 4, 5, or 6 and were subsequently hypnotized in individual sessions. In both sessions observer- and self-scores were recorded for all suggestions of the Harvard Group Scale adaptation of the Stanford Hypnotic Susceptibility Scale. The correlation between observer- and self-scores was .83 for the group session and .89 for the individual session. Hypnotic susceptibility in the group session was very similar to susceptibility in the individual session; mean observer-scores were 6.80 and 6.67 on a 12 point scale. Group self-scores were found to predict quite accurately objective hypnotist scores of the subsequent individual session, 93 per cent of the cases being within 3 points of each other. The correlation was .74.

A second sample of 34 non-volunteer male Ss were hypnotized individually following Form A of the Stanford scale. Observer- and self-scores correlated .81. Thus self-scoring was found to be remarkably successful, and the results of group administration very comparable to those of individual administration of hypnotic susceptibility tests.     

The shared neurosis: Hypnotist and subject

12 Ss-6 highly hypnotizable, and 6 unhypnotizable but with instructions to simulate hypnosis-were given hypnotic instructions by means of a tape-recordmg. All Ss had participated in at least 2 previous tape-recorded sessions which took place in the same room, equipped with a one-way screen. The E did not know which Ss were hypnotizable and which had instructions to simulate hypnosis. Continuous measures of subjective hypnotic depth and GSP were recorded to allow E to take the role of technician. After Ss had been hypnotized by the tape-recorder, a light went out, the tape-recorder stopped, and E rushed from the room-apparently in search of a fuse box. The Ss were observed for 30 minutes through the one-way screen after which the current was turned on, and 2% minutes later E returned. During this time the hypnotic suggestions appeared to lose their effectiveness, and the hypnotized Ss gradually awoke. However, 5 of 6 simulating Ss behaved as though they were in hypnosis throughout. On inquiry, it was determined that 5 of 6 deeply hypnotized Ss assumed that the fuse really had blown, whereas 5 of 6 simulating Ss perceived the “accident” t o be part of the experiment. Because of the behavior of simulating Ss, the theoretical implications of the study are limited. It was concluded that it is necessary to construct a situation in which not only deeply hypnotized Ss, but also simulating Ss, perceive the power failure to be genuine.     

The possibility of creativity in the active stage of hypnosis

Creative capacity was studied by means of suggestions given to Ss under the condition of active hypnosis. In deep hypnosis it was suggested to S that he was a famous person with a specific talent. In a series of experiments Ss performed under active hypnosis such tasks as drawing, playing musical instruments, and playing chess. The results illustrated that creative processes can be facilitated in Ss capable of deep hypnosis and there is a carry-over of the creative achievements from hypnosis to the waking state. Low hypnotic Ss and control groups did not show improvements in the tasks. A particularly significant increase in creativity was observed when Ss capable of deep hypnosis performed several successive creative tasks while hypnotized. The theoretical and experimental definitions of several new approaches to active hypnosis are also discussed.     

Analysis of the heterogeneity of “faking” and “simulating” performance in the hypnotic setting

A balanced design was adopted where an attempt was made to replicate Overley and Levitt's (1968) finding of “faking heterogeneity” by applying their essential procedures, while also attempting to show that under demonstrably different conditions heterogeneity no longer exists. Results for 4 independent sets of 10 “faking” Ss given Overley and Levitt's set of role-playing instructions were compared with data from real and “simulating” Ss tested in application of Orne's (1959) real-simulating model of hypnosis. Heterogeneity of role-playing performance in the hypnotic test-setting was replicated for “faking” but not for “simulating” Ss, and both delay-in-instruction and the susceptibility level of the faking S were related to the effect. Evidence indicated that the earlier finding of heterogeneity of faking performance was a real one, but that Overley and Levitt's faking procedures were not proper to the task of simulation that they were questioning.     

Salient findings: Summaries of key findings in the research literature

An experiment was performed to investigate the relationship of hypnosis and posthypnotic amnesia to retroactive inhibition. 4 groups of 10 Ss each learned lists of adjectives in a retroactive inhibition paradigm. 2 of the groups learned the intervening list while they were hypnotized. Ss of one of these were given instructions for posthypnotic amnesia, while Ss of the other were told to recall what they had learned under hypnosis. The savings and recall scores of both these groups for items of the original list were not different from a third group that learned all 3 lists in the waking state. All 3 groups showed substantial retroactive inhibition when compared to a control group that learned no intervening list.     

Toward a theory of “hypnotic” behavior: Replication and extension of experiments by barber and co-workers (1962–65) and Hilgard and Tart (1966)

Responses to test suggestions (e.g., hallucination and amnesia) were assessed under the following treatments: motivational instructions alone; hypnotic procedure with motivational instructions; and imagination-control. Comparisons were made across independent groups, each tested under one treatment, and also within the same Ss tested twice under various combinations of the treatments. Although Ss were suggestible under the imagination-control treatment, both the motivational instructions alone and the hypnotic procedure given together with the motivational instructions raised suggestibility above the control level. The hypnotic-motivational treatment tended to produce an increment in suggestibility which went slightly beyond that attributable to the motivational instructions. The latter increment is interpreted as due to the slightly greater effectiveness of the hypnotic procedure in defining the situation as one in which unusual manifestations, such as hallucination and amnesia, are within Ss' capabilities and definitely expected by E.     

Reactivation of memory by hypnosis and suggestion

The effects of hypnotic susceptibility (high vs. low), hypnotic condition (hypnotized vs. waking), and the order of testing (hypnosis first vs. waking first) on S's ability to recall meaningful material (specific facts about a rare chemical) 2 weeks after it was originally learned were studied using a 3-way, repeated-measures, factorial design. 52 college students (both male and female) acted as Ss for the study. No significant main effects were found, and the only significant interaction effect indicated that the memory was enhanced when tested the second time, regardless of whether it was in the waking or the hypnotized condition. The results were compared with the findings of other studies in this area using a less complex design.     

The effect of “alert” hypnosis and hypnotic responsiveness onreading comprehension

3 antecedent conditions were compared for their ability to increase reading comprehension. The conditions were: (a) “alert” hypnosis followed by posthypnotic suggestion of enhanced recall, (b) task motivation instructions to Ss to imagine and concentrate as much as possible, and (c) no special instructions (control). No differences in reading comprehension were found among the conditions. Also, high and low susceptible Ss performed essentially the same. The findings indicate further study and possibly long-term hypnotic training to clarify the usefulness of hypnosis for enhancing meaningful learning.     

Brightness contrast by hypnotic hallucination

A study was performed to test the veridicality of a hypnotic hallucination elicited by a buzzer through a conditioning procedure. The stimulus to be hallucinated consisted of 2 gray circles, 3′′ in diameter, mounted on a white card. 11 highly susceptible Ss were able to produce this hallucination upon hearing the buzzer during a series of test trials following the training. Following a second training series, a black and white background was provided for the hallucination and S tended to report the hallucinated circles as a brightness contrast. A second group of highly susceptible Ss was not hypnotized, but was asked to respond as if hypnotized. These Ss tended not to report the contrast.     

An experimental study of the nature of hypnotic deafness: Effects of delayed speech feed-back

The purpose of this investigation was to assess the ability of hypnotic Ss to voluntarily resist a neutral suggestion when a monetary reward is offered for resistance. 19 of 40 Ss (47.5%) successfully resisted after money was offered by the “resistance instructor.” The correlation between resistance/compliance and hypnotizability was – .44 (high hypnotizables were more likely to comply). Ss' impressions of the hypnotist tended to be positive; impressions of the resistance instructor tended to be neutral. There was a tendency for nonresistors to have a more positive view of the hypnotist but it is not as marked as was found in an earlier study (Levitt &; Baker, 1983).     

The effects of suggestions of altertness in hypnosis on pupillary response: Report on a single subject

The pupil size of a single S was recorded under 2 types of hypnotic suggestion: alertness instructions and traditional relaxation instructions. It was found that the size of the pupil increased significantly under alertness instructions. This result was taken as further corroboration of the hypothesis that changes in various parameters of arousal apparently associated with hypnosis may be attributed to specifiable characteristics of the instructions used rather than to stable characteristics of the “state” of hypnosis.     

A note on shock tolerances of real and simulating hypnotic subjects

Prior to the induction of hypnosis, Ss who later in an experiment were actually to be hypnotized selected lower criterion electric shock levels than did Ss who later were only to simulate hypnosis. This is the first quantified objective difference found to date between the behavior of Reals and Simulators.     

Amnesia and Hypnosis

The present study explored the relative effects of 2 factors (3 levels of measured hypnotic susceptibility and 3 kinds of motivation procedures) on short-term memory for a paired associate learning task. 36 Ss were stratified, according to their HGSHS:A scores (Shor & E. Ome, 1962), into 3 groups (low, medium, and high susceptibility) of 12 Ss each. The Ss within each of the 3 groups were then evenly but randomly assigned to 3 treatment conditions, which differed in terms of the kind of motivational procedure (hypnotic, waking, or waking non motivational) in which suggestions of amnesia for a recently learned paired associate task were given. Generally, results did not directly support or were sometimes contrary to predictions derived from popular hypnosis theories, which assert that posthypnotic amnesia is a reliable behavioral criterion for the “hypnotic state”.     

Analysis of the cue characteristics of task motivational instructions

This study investigated the assumption of Barber's model of hypnosis that its set of task motivational instructions is thoroughly “nonhypnotic” in character. If this assumption is correct, then the cues associated naturally with task motivational instructions should be more compatible with a suggestibility test situation explicitly defined as nonhypnotic than with one defined as hypnotic, and this affinity should be reflected in both Ss' objective and subjective suggestibility test scores. Barber's (1965) Suggestibility Scale data collected from 90 Ss did not confirm the main prediction under test, but results failed to provide unequivocal support for the model; subjective evidence, in particular, supported least well the assumptions of the paradigm.     

A normative study of suggestibility in a mental patient population

The postural sway technique was used to make suggestibility measurements on a total of 490 Ss of which 279 were hospitalized psychiatric patients. The remaining Ss were “normal” college students. The “normal” Ss were significantly more suggestible than the psychiatric group. Within the psychiatric group, the psychotics, nonpsychotics, and organics differed significantly, with the nonpsychotics being least suggestible, the psychotics most suggestible, and the organics intermediate. The hospital group was further reduced into diagnostic subcategories and postural sway parameters were shown. The sample distributions were essentially normal although the sample drawn from a psychiatric population showed positive skewness.