Hypnotic susceptibility as related to gestalt closure tasks.

Studied the relationship of gestalt closure tasks to hypnotizability (Harvard Group Scale of Hypnotic Susceptibility and Stanford Hypnotic Susceptibility Scale) as a test of the hypothesis that the more highly hypnotizable do better on a task of holistic visuospatial functioning than those less responsive to hypnosis. Several other cognitive tasks were included. Four studies were conducted with 125 male and 106 female high school and college students. In Study I, high hypnotizables scored significantly higher than low hypnotizables on the gestalt closure tasks, but there were no significant correlations between hypnotizability and the other cognitive tasks. In Studies II and III, females showed significant correlations between hypnotic susceptibility and gestalt closure scores. In Study IV, a significant correlation between hypnotic susceptibility and gestalt closure was found for males. Results are consistent with studies of different types of cognitive functioning (hemispheric preference, creativity, attentional distribution, imaginative involvement, and absorption), all indicating differences in cognitive abilities associated with high hypnotizability. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the degree of stability of measured hypnotizability over a 25-year period.

Conducted a longitudinal study of hypnotizability, as measured by the Stanford Hypnotic Susceptibility Scale, Form A, that yielded a relatively high degree of stability in hypnotic responsiveness over repeated testings spanning a 25-year period. The 50 Ss were retested in 1985, after tests when they were students, between 1958–1962 and again in 1970. The statistically significant stability coefficients were .64 (10-year retest), .82 (15-year retest), and .71 (25-year retest). The means did not change significantly, and the median change in the scores of individuals was only 1 point on the 12-item scale. A set of score measures and their intercorrelations are insufficient to resolve the issue of why stability occurs. The stability of hypnotizability over time compares favorably with that of other measures of individual differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increases in hypnotizability as a function of encounter group training: Some confirming evidence.

Investigated the effects of encounter group experience on hypnotizability. 34 graduate students were assigned to 3 experimental encounter groups and 1 no-treatment control group. The encounter groups varied in the amount of interpersonal contact between Ss. Equivalent forms of the Stanford Hypnotic Susceptibility Scale were administered before and after the groups. Significant increases in hypnotizability occurred as a result of encounter group experience. Results are interpreted with regard to the interpersonal nature of group participation and with reference to previous findings. The value of hypnotic susceptibility as a measure of interpersonal behavioral change is considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive skill-training enhancement of hypnotizability: Generalization effects and trance logic responding.

Compared low-hypnotizable Ss who simulated hypnosis, underwent cognitive skill training, or served as no-treatment controls to Ss who scored as high hypnotizables without training (natural highs) on response to analgesia, age-regression, visual hallucination, selective amnesia, and posthypnotic suggestions. Ss who attained high hypnotizability following skill training (created highs) did not differ from natural highs on any response index. Natural and created highs scored lower than simulators but higher than controls on the behavioral and subjective aspects of test suggestions. Simulators, however, were significantly less likely than natural highs or skill-trained Ss to exhibit duality responding or incongruous writing during age regression or transparent hallucinating. Results suggest that the hypnotic responses of natural and created highs are mediated by the same cognitive variables and that enhancements in hypnotizability produced by skill training cannot be adequately explained in terms of compliance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotizability and the deployment of waking attention.

Although most theoretical accounts of hypnosis stress the contribution of attentional processes, such processes have not been considered extensively in past efforts to identify correlates of hypnotizability. A recently developed measure of waking attention deployment—the random-number generation task (RNG)—is described, and the relation between RNG scores and hypnotizability is presented. In 5 heterogeneous subgroups, 68 college-age Ss performed a 2-min RNG task and were administered the Harvard Group Scale of Hypnotic Susceptibility, Form A. 41 of these Ss later received the individually administered Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C). Highly susceptible Ss (score of 8+ on each scale) demonstrated significantly better RNG performance than less susceptible Ss. This finding was replicated when using the SHSS:C as the measure of hypnotizability. Good randomizers scored an average of 2–3 points higher on both hypnotizability scales than poor randomizers. It is suggested that the process of deautomatization may be the common attentional mechanism that underlies hypnotizability and that is reflected in differential RNG performance. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Memory liabilities associated with hypnosis: does low hypnotizability confer immunity?

Retrospective analyses of data from the authors' program of research on hypnosis and memory are presented, with special emphasis on effects observed among low hypnotizable individuals. In Experiment 1, participants completed seven forced-recall trials in an attempt to remember a series of pictures that had been shown 1 week earlier. For half the participants, the middle five trials were carried out using hypnotic procedures; the remaining participants performed all recall attempts in a motivated waking condition. Hypnosis failed to enhance correct recall for either high or low hypnotizable participants beyond the hypermnesia and reminiscence effects associated with repeated retrieval attempts over time. However, whereas high hypnotizable participants produced substantial numbers of confident recall errors (i.e., intrusions) independent of the use of hypnosis, low hypnotizable participants exposed to hypnotic procedures reported significantly more intrusions than their counterparts in the waking condition. In Experiment 2, participants were asked to identify whether specific recollections, reported during two forced-interrogatory recall tests conducted 1 week earlier, had originated in the first or second of those tests. A general bias to misattribute previously reported recollections to the first of two recall occasions was observed; however, the effect was greatest among low hypnotizables who had undergone the second recall attempt in hypnosis. The findings imply that highly hypnotizable individuals are not unique in their vulnerability to distortions of memory induced by hypnotic techniques. Individuals of lesser hypnotic capacity also manifest memory alterations when exposed to such procedures.     

The predictive utility of hypnotizability: The change in suggestibility produced by hypnosis.

Objective: The predictive utility of hypnotizability, conceptualized as the change in suggestibility produced by a hypnotic induction, was investigated in the suggested reduction of experimental pain. Method: One hundred and seventy-three participants were assessed for nonhypnotic imaginative suggestibility. Thereafter, participants experienced hypnotic and nonhypnotic imaginative analgesia suggestions, counterbalanced for order. Hypnotic suggestibility was then assessed. Results: Hypnotizability, operationalized as hypnotic suggestibility with imaginative suggestibility statistically controlled (Braffman & Kirsch, 1999), predicted intraindividual differences in responding to the hypnotic and imaginative analgesia suggestions. Higher hypnotizability was associated with relatively greater response to the hypnotic analgesia suggestion than to the imaginative analgesia suggestion. Conclusions: Operationalized in this way, hypnotizability may be a useful predictor of the effect of adding a hypnotic induction to a specific imaginative suggestion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The heritability of hypnotic susceptibility in twins.

Tested 140 pairs of twins (mean age = 9 yrs) and their families on the Stanford Hypnotic Susceptibility Scale, Form A. A significant heritability index for the scores of the twin pairs and a significant correlation between the midparent score (i.e., the average of the mother's and father's score) and the mean child score were obtained, supporting a genetic component in hypnotizability. However, a statistically significant interaction between parent hypnotizability and the child's hypnotizability, conditional upon the resemblance of the child to the like-sexed parent in personality, was interpreted as a consequence of environmental influence, either through social learning or identification. (25 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of verbal and experiential expectancy manipulations on hypnotic susceptibility.

The hypothesis that an expectancy manipulation based on direct experience would have a greater effect on hypnotic behavior than one based on verbal persuasion was tested. Consistent with this hypothesis, the experiential expectancy manipulation was more effective than the verbal manipulation in enhancing hypnotizability. A combination of the 2 expectancy manipulations resulted in a sample in which 73% of the Ss scored as highly hypnotizable, 27% as moderately hypnotizable, and none as low hypnotizable on Form C of the Stanford Hypnotic Susceptibility Scale. These data support I. Kirsch's (see record 1986-13702-001) response expectancy hypothesis. They also suggest that R. H. Fazio and M. P. Zanna's (1981) contention that attitudes formed via direct experience are more consistent with behavior may hold for expectancy–behavior consistency as well. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Posthypnotic amnesia for material learned before hypnosis

The impact of a suggestion for posthypnotic amnesia on material learned either before or during hypnosis was investigated across 2 experiments. In Experiment 1, very high, high, and low hypnotizable participants learned a word list either before or immediately after a hypnotic induction. During hypnosis, participants were given a suggestion for posthypnotic amnesia for the word list. After hypnosis, they were tested on recall, word-fragment, and word-recognition tasks. Experiment 2 replicated and extended Experiment 1 through application of the real-simulating paradigm. Across the 2 experiments, there was no difference in the performance of participants who learned the word list either before or during hypnosis. Although amnesia on direct memory measures was associated with high hypnotizability (Experiment 1), an explanation based on demand characteristics could not be excluded (Experiment 2). The implications of these findings for the use of post-hypnotic amnesia as a laboratory analog of disorders of autobiographical memory are discussed.     

Fate of an uncompleted posthypnotic suggestion.

Used 50 male undergraduates to test the possibility that Ss who resist completing a posthypnotic suggestion may, at a later time, in a situation which is not seen as related to the hypnotic session, carry out the earlier suggested behavior. Such Ss were found to fall within the medium range of hypnotizability as evaluated over 3 sessions by the Stanford Scales of Hypnotizability. Ss with low hypnotizability failed to complete the posthypnotic suggestion and did not demonstrate a subsequent tendency toward the earlier suggested behavior. Ss with high hypnotizability tended to complete the posthypnotic suggestion and, in about 1/2 of the cases, demonstrated a subsequent tendency toward the earlier suggested behavior. Within the medium range of hypnotizability were found those Ss who did not complete the posthypnotic suggestion, but subsequently, in the extrahypnotic setting, behaved in accordance with the earlier suggestion. Hypnotizability as an overall characteristic was clearly related to the demonstration of this action tendency. (19 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotizability and phobic behavior: Further supporting data.

20 21–59 yr old women who were phobic to snakes, spiders, or rats were individually evaluated for hypnotic susceptibility, using the standard audiotaped version of the Harvard Group Scale of Hypnotic Susceptibility, Form A. Consistent with the findings of earlier studies using similar methods for measuring hypnotizability but not with a recent study using the Hypnotic Induction Profile (HIP), 55% of the present sample was found to be highly responsive to hypnosis. An item analysis comparing item pass percentages for the phobic Ss with item difficulties obtained from a normative sample of 357 female college students indicated that the 2 samples were significantly correlated. The discrepancy between the findings using standard measures of hypnotizability and studies using HIP is discussed. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EEG activity and heart rate during recall of emotional events in hypnosis: relationships with hypnotizability and suggestibility

The purpose of the present research was to find physiological and cognitive correlates of hypnosis, imaginative suggestibility and emotional experiences. After the administration of a standard hypnotic induction, the EEG and heart rate (HR) were recorded during self-generated happy and sad emotions using a relaxation condition as a control. Physiological recordings were also obtained during three eyes-open and eyes-closed baseline periods: (1) waking rest; (2) early-rest in hypnosis (just after the hypnotic induction); (3) late-rest hypnosis (at the end of hypnotic condition). EEG was recorded at frontal (F3, F4), central (C3, C4), and posterior sites (middle of O1-P3-T5 and O2-P4-T6 triangles). Using log transform of mean spectral amplitude, eight EEG frequency bands (4-44 Hz) were evaluated. High hypnotizable subjects, as compared to the lows, produced a higher theta1 amplitude (4-6 Hz) across both left- and right-frontal and right-posterior areas. These subjects also produced smaller alpha1 amplitude (8.25-10 Hz) over both left and right frontal recording sites. High suggestible subjects, during resting conditions, disclosed higher theta2 (6.25-8 Hz) and alpha1 amplitudes in eyes-closed as compared to an eyes-open condition than did low suggestible subjects. High suggestible subjects also showed, in hypnosis-rest condition, higher 40-Hz amplitudes (36-44 Hz) and HR activity than did low suggestible subjects. Hypnotizability and not suggestibility was found to moderate emotional processing: high hypnotizable individuals self-reported greater levels of emotional experiences than did low hypnotizables especially in terms of negative emotion. High hypnotizables, during processing of emotional material, also disclosed opposite 40-Hz hemispheric asymmetries over anterior and posterior regions of the scalp. These subjects during happiness showed an increased production of 40-Hz activity in the left frontal and central regions of the scalp, while during sadness they showed an increased activity in the right central and posterior regions. The hemispheric asymmetries for relaxation condition were similar, but less marked, to those obtained for happiness. No significant interactions involving both hypnotizability and imaginative suggestibility were found for physiological variables considered in this study. This demonstrates that hypnotizability and suggestibility reflect different underlying psychophysiological activities.     

Hypnotizability as a function of repression, adaptive regression, and mood.

40 male undergraduates individually participated in a personality assessment session and hypnotic susceptibility session (using the Stanford Hypnotic Susceptibility Scale). Scales derived from the Rorschach test were used to measure the personality traits of repressive style and adaptive regression. The transitory variable, mood just prior to hypnosis, was assessed by a mood index derived from the Nowlis Mood Adjective Check List (MACL). Results show that hypnotizability was a significant interactive function of repressive style and mood (Ss high in repressive style and in bright moods tended to be hypnotizable) but not of adaptive regression and mood. Mood as a main variable was significantly related to hypnotizability. The MACL Surgency scale (which contains the adjectives carefree, playful, and witty) was the best single predictor of hypnotizability, accounting for 25% of the variance. Neither personality trait as a main variable was related to hypnotizability. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced hypnotizability by cerebrally applied magnetic fields depends upon the order of hemispheric presentation: an anistropic effect

A significant alteration in the hypnotizability of normal subjects after brief (15 min) exposures to weak (1 microT) pulsed magnetic fields over the temporal lobes was determined by the serial order of hemispheric stimulation. Only subjects who received the right hemispheric stimulation first displayed significantly elevated hypnosis induction profile scores (effect size equivalent to a correlation of 0.41). Implications for a technology that can: a) modify hypnotizability, b) encourage the consolidation of quasiexperiences that are reconstructed as autobiographical memory, and c) change the sense of self, are discussed.     

Enhancing visual memory: Trying hypnosis, trying imagination, and trying again.

Tested visual recall memory of high (n?=?24) and low (n?=?24) hypnotizable undergraduates (screened under the Harvard Group Scale of Hypnotic Sensibility and the Stanford Hypnotic Sensibility Scale) for black and white line drawings of common objects in either hypnosis, imagination, or control conditions. Memory performance in terms of both correct and incorrect items increased appreciably across the recall tests. Neither hypnosis nor imagination enhanced recall beyond that of normal repeated testing. Hypnotizability was not related to the amount of correct material recalled but was related to the amount of incorrect material reported. High hypnotizable Ss in the hypnosis condition were more likely than other Ss to confidently rate the incorrect material as correct. Findings are discussed in terms of the impact of hypnosis on and the relevance of hypnotizability to enhancing visual memory. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intentional and spontaneous imagery in hypnosis: the phenomenology of hypnotic responding

Students were given 1 of 2 versions of the Carleton University Responsiveness to Suggestion Scale (CURSS): (a) the original version, which contains instructions to intentionally imagine goal-directed fantasies, and (b) a modified version, in which instructions for suggestion-related imagery were deleted. Participants were asked to report their goal-directed fantasies and to indicate whether these occurred spontaneously or were generated intentionally. They were also asked whether they had tried intentionally to generate the suggested experience and to indicate whether they had believed that the suggested states of affairs were real (e.g., whether they thought a hallucinated cat really existed). The deletion of instructions for goal-related imagery significantly increased responsiveness to CURSS suggestions. Spontaneous goal-directed imagery was significantly correlated with behavioral response, but intentional imagery was not. Most successful responders tried to generate suggested experiences intentionally, indicated that they could have resisted challenge suggestions if they really wanted to, and reported believing in the reality of suggested ideomotor and challenge experiences but not of cognitive suggestions. Voluntary attempts to generate suggested experiences were correlated with subjective responding.     

Surreptitiously observed hypnotic responding in simulators and in skill-trained and untrained high hypnotizables.

Low-hypnotizable Ss (LHs) administered cognitive skill training exhibited substantially higher posttest hypnotizability than LHs administered no treatment. Next, the Ss in these 2 conditions as well as Ss who attained high hypnotizability without training and LHs instructed to fake hypnosis (i.e., simulators) were individually tested for hypnotizability twice while their responses were recorded by a hidden camera. In the individual session, Ss were first tested for hypnotizability while alone and then tested again in the presence of an experimenter. The skill-trained Ss and high-hypnotizable controls attained equivalent (high) hypnotizability scores with the experimenter both absent and present. However, when the experimenter was absent, the simulators exhibited lowered hypnotizability and apparently failed to adopt the hypnotic role. These findings contradict the hypothesis that high hypnotizability in skill-trained Ss reflects compliant responding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotizability as a function of nonhypnotic experiences.

The relationship between various subjective experiences and susceptibility to hypnosis was studied in 2 samples of female college students, totalling 102. The subjective experiences were registered by the Experience Inventory, a questionnaire developed earlier for this purpose. Hypnotizability was determined by administering objective hypnotic scales individually. Correlations between hypnotizability and the total Experience Inventory score as 'well as a composite score of selected items were significant in both samples, but the latter failed in predicting hypnotizability better than the total score. Items of subjective experiences significantly related to hypnotizability in the total sample were analyzed in terms of the personality dimensions implied. alyzed (17 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hypnotizability and automaticity: Toward a parallel distributed processing model of hypnotic responding.

Tested a hypothesis from parallel distributed processing theory that highly hypnotizable Ss have greater connection strengths along verbal pathways and would show greater Stroop effects than low hypnotizable Ss. Using the paradigm from J. Cheesman and P. M. Merikle (see record 1989-03722-001) which varied cue visibility and probability, automatic and strategic effects on Stroop performance were assessed. Compared with 9 low and 9 moderately hypnotizable Ss, 9 highly hypnotizable ones showed significantly greater Stroop effects for both visible- and degraded-word trials. No strategic differences emerged for the 3 hypnotizability groups. These findings support the contention that highly hypnotizable persons have stronger verbal connection strengths than their moderately and low susceptible counterparts, and they may account for highly hypnotizable persons' propensity to disregard personal attributions and label their responses in hypnosis as being involuntary. (PsycINFO Database Record (c) 2010 APA, all rights reserved)