Italian norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

A General Factor of Hypnotizability Revealed by Confirmatory Factor Analysis

The objective of this study was to determine the model fit of a standardized hypnotizability measure in a targeted clinical sample. The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) was administered to 168 post-menopausal women aged 39 to 75 years. Confirmatory factor analysis was conducted, and comparative fit index (CFI) and root mean square error of approximation (RMSEA) were used to determine goodness of fit. Results indicated that the single-factor structure modeled with twelve indicators based on the individual items on the SHSS:C provided the best description of fit. Results of the present study demonstrate that the SHSS:C has a single-factor structure. These findings suggest that new scales of hypnotizability can be optimized by focusing on the use of items that correlate highly with the overall score representing the unidimensional construct of hypnotizability. The findings should be interpreted with caution due to the small sample size, and further research is needed with other populations to clarify generalizability.

How hypnotic suggestions work - A systematic review of prominent theories of hypnosis

In recent decades, hypnosis has increasingly moved into the mainstream of scientific inquiry. Hypnotic suggestions are frequently implemented in behavioral, neurocognitive, and clinical investigations and interventions. Despite abundant reports about the effectiveness of suggestions in altering behavior, perception, cognition, and agency, no consensus exists regarding the mechanisms driving these changes. This article reviews competing theoretical accounts that address the genesis of subjective, behavioral, and neurophysiological responses to hypnotic suggestions. We systematically analyze the broad landscape of hypnosis theories that best represent our estimation of the current status and future avenues of scientific thinking. We start with procedural descriptions of hypnosis, suggestions, and hypnotizability, followed by a comparative analysis of systematically selected theories. Considering that prominent theoretical perspectives emphasize different aspects of hypnosis, our review reveals that each perspective possesses salient strengths, limitations, and heuristic values. We highlight the necessity of revisiting extant theories and formulating novel evidence-based accounts of hypnosis.

French Norms for a Shortened Online Adaptation of the Harvard Group Scale of Hypnotic Susceptibility, Form A

This study presents the norms and psychometric properties for a shortened online adaptation of a French version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A). Assessment of involuntariness and subjective intensity was added to the traditional scoring. A total of 373 individuals completed an online hypnotizability screening test on their own computer. Participants received the HGSHS:A script through an audio recording lasting about 30 minutes. The results showed that the item difficulty and reliability of the short online HGSHS:A were consistent with the offline version of the scale and with the reference samples. Involuntariness and subjective intensity corrections improved significantly the accuracy in the measurement of the scale and helped to dissociate between different phenomenologies in hypnotic responding. These findings indicate that the short online HGSHS:A is a reliable tool for measuring hypnotizability. Moreover, we suggest that using complementary measures of involuntariness and subjective intensity helps to shed more light on hypnotizability as part of a multi-componential approach to hypnotic response.

Italian adaptation of the Multidimensional Iowa Suggestibility Scale (MISS)

Background

Suggestibility is a personality trait that reflects a general tendency to accept messages. The Multidimensional Iowa Suggestibility Scale (MISS) is a self-report scale developed to measure the degree of individuals' perceptions of their suggestibility. This study aimed to adapt the MISS in an Italian sample.

Methods

We conducted two studies. In the first study, 345 subjects (270 females (78%), mean age = 36.21 years ± 14.06 SD) completed the translated Italian version of the MISS, composed of five subscales (consumer suggestibility; persuadability; sensation contagion; physiological reactivity; peer conformity). We investigated the structural validity of the scale through confirmatory factor analysis (CFA) testing four measurement models (unidimensional, four-factor, hierarchical four factors, and bifactor) and explored reliability in terms of internal consistency through the McDonald's omega. In the second study, we cross-validated the MISS on a new independent sample. We enrolled 277 participants (196 females (71%), mean age 30.56, SD = 12.58) who underwent the new version of the scale. We performed factor analyses to test structural validity and compared four measurement models. Then, we investigated reliability and conducted a latent variable analysis to explore divergent validity.

Results

The CFA in the first study revealed a bifactor solution of the MISS. This structure was interpretable and provided an adequate fit for the data. The final version of the scale was reduced to forty-six items with globally good indices of adaptation. The scale also demonstrated acceptable reliability in terms of internal consistency through the McDonald's Hierarchical Omega. In the second study, we found that the bifactor structure was confirmed. Factor loadings inspection revealed that there was no justification to report only the separate scores for the subscales. We also found that the scale showed good internal consistency, but mixed evidence for divergent validity.

Conclusions

In the end, the Italian version of the MISS demonstrated good psychometric properties which will be discussed in detail below.

Intimate relationships and hypnosis: insecure adult attachment affects emotions and absorption during hypnosis

Introduction

Hypnosis research indicates that subjects are not equally hypnotizable. Most studies on hypnotizability focused on the relationships with personality or cognitive variables. At the same time, only a few proposed the contribution of the attachment style, defined as the result of the childhood relationship with the caregivers and influencing the adult relations.

Methods

In the present investigation, two studies were carried out to test the possible association between adult attachment and hypnotic responsivity. The adult attachment was assessed using the Experiences in Close Relationships-Revised (ECR-R) questionnaire, while hypnosis was assessed through the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A; Study 1) and the Phenomenology of Consciousness Inventory: Hypnotic Assessment Procedure (PCI-HAP; Study 2) in order to adopt a behavioral and a phenomenological approach, respectively.

Results

Analyses showed that attachment factors (anxiety and avoidance) were not associated with the level of hypnotizability, whereas it was associated with variations of consciousness during hypnosis, mainly internal dialogue, absorption and negative emotions. Overall, the insecure attachment styles yielded increased mind wandering and restlessness during hypnosis when compared to the secure style. The reason probably lies in the feeling of anxiety or danger of insecurely attached individuals when involved in intimate or confidential relationships.

Conclusion

These findings clarify a still poorly investigated aspect concerning the influence of attachment style on hypnotic experience and further highlight the need to consider inter-individual differences and the phenomenological perspective when assessing hypnosis and hypnotizability.

Hypnotizability Norms may not be Representative of the General Population: Potential Sample and Self-Selection Bias Considerations

The analysis of the methods sections of 66 normalization tests of hypnotizability scales reveals that out of 33,338 subjects, 58.57% were college and university students, and the majority of these were students of psychology. Of all subjects, 7.45% were younger school children, 27.63% were patients treated with hypnosis, and out of these, 85.26% were patients of 1 single therapist. Only 0.51% were trainees of dental or nursing schools, 0.13% were prisoners, and 5.71% were other adults. These figures suggest a sample-selection bias. As 83.08% of these subjects were told beforehand that they were to undergo a hypnosis study, a self-selection bias is also implied in the data. It can be presumed that those interested in hypnosis participated, whereas others who had no interest in hypnosis may have refrained. It is concluded that some of the published norms of hypnotizability tests may not be adequately representative of the general population. Many hypnosis studies, whether clinical or experimental, which are based on hypnotizability, may be afflicted by these biases.

German Norms of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) and Proposal of a 5-Item Short-Version (HGSHS-5:G)

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), is commonly used to test hypnotizability. There is still some controversy about what exactly hypnotizability is and whether and how it can be measured, especially by the HGSHS:A. Furthermore, a wider clinical use is limited, requiring a testing time of more than 1 hour. We analyzed the German HGSHS:A version for its factorial structure, item contribution, and item difficulty based on test data from six studies, including 1276 persons, to propose a shorter version of the HGSHS:A. We hereby present a 5-item version of the HGSHS:A (HGSHS-5:G), consisting of the challenge items, that was compared with an 11-item version (highly variable posthypnotic amnesia omitted). Age- and gender-specific norms was generated. The HGSHS-5: G showed high validity, reliability, and classification agreement. It reduces test time to 30 minutes thus facilitating wider use of hypnotizability testing.

Suggested deafness during hypnosis and simulation of hypnosis compared to a distraction and control condition: A study on subjective experience and cortical brain responses

Hypnosis is a powerful tool to affect the processing and perception of stimuli. Here, we investigated the effects of hypnosis on the processing of auditory stimuli, the time course of event-related-potentials (ERP; N1 and P3b amplitudes) and the activity of cortical sources of the P3b component. Forty-eight participants completed an auditory oddball paradigm composed of standard, distractor, and target stimuli during a hypnosis (HYP), a simulation of hypnosis (SIM), a distraction (DIS), and a control (CON) condition. During HYP, participants were suggested that an earplug would obstruct the perception of tones and during SIM they should pretend being hypnotized and obstructed to hear the tones. During DIS, participants' attention was withdrawn from the tones by focusing participants' attention onto a film. In each condition, subjects were asked to press a key whenever a target stimulus was presented. Behavioral data show that target hit rates and response time became significantly reduced during HYP and SIM and loudness ratings of tones were only reduced during HYP. Distraction from stimuli by the film was less effective in reducing target hit rate and tone loudness. Although, the N1 amplitude was not affected by the experimental conditions, the P3b amplitude was significantly reduced in HYP and SIM compared to CON and DIS. In addition, source localization results indicate that only a small number of neural sources organize the differences of tone processing between the control condition and the distraction, hypnosis, and simulation of hypnosis conditions. These sources belong to brain areas that control the focus of attention, the discrimination of auditory stimuli, and the organization of behavioral responses to targets. Our data confirm that deafness suggestions significantly change auditory processing and perception but complete deafness is hard to achieve during HYP. Therefore, the term 'deafness' may be misleading and should better be replaced by 'hypoacusis'.

Association of hypnotizability and deep sleep: any role for interoceptive sensibility?

The aim of the study was to investigate the possible association of hypnotizability and deep sleep (N3) duration, and whether the interoceptive sensibility influences this association. This was motivated by the proneness of highly hypnotizable individuals to easily change their psychophysiological state, i.e., from wakefulness to hypnosis and sleep, and by the positive association observed between hypnotizability and interoceptive sensibility. Forty-seven healthy participants previously enrolled in a polysomnographic night sleep study completed the questionnaire for Multidimensional Assessment of Interoceptive Awareness (MAIA) and underwent hypnotic assessment through the Stanford Hypnotic Susceptibility Scale, form A (SHSS,A). Results showed that N3 duration is not linearly correlated with hypnotizability. Controlling for a few MAIA scales did not modify the relation between hypnotizability and deep sleep. A polynomial relation indicates that N3 duration and N3 percentage of the total sleep time increase with hypnotizability in the low-to-medium range of hypnotizability and decrease in the medium-to-high range. In conclusion, hypnotic assessment predicts N3 duration and their association is not modified by interoceptive awareness/sensitivity.

The rubber hand illusion in hypnosis provides new insights into the sense of body ownership

Body ownership can be experimentally investigated with the rubber hand illusion (RHI), in which watching a rubber hand stroked synchronously with one’s own hidden hand induces a feeling of ownership over the rubber hand. The aim of this study was to investigate response to the RHI in high (N = 21) and low (N = 19) hypnotizable individuals in normal waking state and in hypnosis. Response to the RHI was measured via a question on the illusory feeling of ownership and with proprioceptive drift. The Highs expressed an overall feeling of more ownership over the rubber hand in both the normal waking state and hypnosis, although both groups gave higher ownership scores after synchronous than after asynchronous stroking and the difference between conditions was similar across groups. Conversely, the proprioceptive drift appeared to be differentially modulated by hypnosis and hypnotic suggestibility: it was increased in the Highs and decreased in the Lows after hypnosis induction. These findings hint at an interplay between hypnotic suggestibility and hypnosis in modulating response to the RHI. The selective breakdown of proprioceptive drift among the Lows suggests resistance to recalibrate one’s own limb in hypnosis.

High Motor Cortex Excitability in Highly Hypnotizable Individuals: A Favourable Factor for Neuroplasticity?

Hypnotizability is a psychophysiological trait associated with morphofunctional brain peculiarities and with several cognitive, sensorimotor and cardiovascular correlates. Behavioral and EEG studies indicate stronger functional equivalence (FE) between motor imagery and action in the individuals with high hypnotizability scores (Highs). We hypothesized that stronger FE leading to greater proneness to ideomotor behavior could be due to greater cortical excitability of the motor cortex. The aim of the study was to evaluate the motor cortical excitability through measurements of the muscle potentials (MEPs) evoked in the left abductor pollicis brevis by transcranial magnetic stimulation (TMS) of the right motor cortex in 10 Highs, 10 medium (Mediums) and 10 low hypnotizable individuals (Lows) classified according to the Stanford Hypnotic Susceptibility Scale, form A (SHSS). They were studied in basal conditions (B) and during motor imagery (MI). Results showed significant, negative correlations (i) between hypnotizability and MEPs Resting Motor Threshold (RMT) in basal conditions, and (ii) between hypnotizability and both MEPs RMT and suprathreshold (I_1mv) stimulation intensities during MI. ANOVA revealed significantly lower stimulation intensities in Highs than in Lows, with Mediums exhibiting intermediate values. Thus, the Highs' greater cortical excitability could sustain their greater FE and proneness to ideomotor behavior. In cognitive neuroscience these findings are relevant to the physiological interpretation of the response to sensorimotor suggestions by participants in the ordinary state of consciousness. In the clinical field they can predict the efficacy of mental training based on motor imagery and, possibly, the degree of imagery-induced cortical plasticity.

Effects of Prehypnotic Instructions on Hypnotizability and Relationships Between Hypnotizability, Absorption, and Empathy

Although hypnotizability exhibits high across-time and across-test consistencies, it is not clear (a) how different preambles to a hypnotic procedure (metasuggestions) influence responsiveness to suggestions and the strength of the association between two hypnotizability scales and (b) how hypnotizability relates to absorption and empathy. In Experiment 1, nonclinical participants (N = 152 women) were administered the Modified Tellegen Absorption Scale (MODTAS), Interpersonal Reactivity Index (IRI), Hypnotic Induction Profile (HIP), and Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C). In Experiment 2, nonclinical participants (N = 188; 105 women and 83 men) were administered the MODTAS, IRI, and Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A). The induction scores of the HIP (HIP-IND) and the SHSS:C scores showed a significantly stronger correlation when the HIP was introduced to the participants after hypnosis metasuggestion (HIP-H-IND) than after imagination metasuggestion (HIP-I-IND). Metasuggestion was a moderator of the association between HIP-IND and SHSS:C scores. Participants with low and medium, but not with high, hypnotizability levels on the SHSS:C showed significantly higher scores on the HIP-I-IND than on the HIP-H-IND. The strong correlations between the SHSS:C, HIP-H-IND, and HIP eye-roll (HIP-ER) scores indicate that both the HIP-H-IND and HIP-ER are robust measures of hypnotizability. Absorption and empathy were not significantly associated with hypnotizability. Women were more hypnotizable than men, as assessed by the HGSHS:A. The clinical relevance of metasuggestions, intended to increase responsiveness to suggestions, is discussed as a strategy to improve treatment outcomes.

HYPNOTIZABILITY-RELATED FAAH C385A POLYMORPHISM: POSSIBLE ENDOCANNABINOID CONTRIBUTION TO SUGGESTION-INDUCED ANALGESIA

Fatty acid amide hydrolase (FAAH) degrades the endogenous endocannabinoid (eCB) anandamide and might be involved in the response to suggestions of analgesia in subjects with high hypnotizability scores (highs). Since the A allele of the FAAH C385A polymorphism (rs324420) is associated with lower FAAH activity, it was studied in 21 highs, 66 low hypnotizable individuals (lows), and 172 individuals not selected for hypnotizability (controls) representing the general population. No significant difference was observed among groups, but the A allele frequency showed a significant trend to increase from lows to controls and from controls to highs. Since eCB small differences can be amplified by eCB interactions with other neurotransmitters, a contribution of the FAAH polymorphism to the highs' analgesia should not be excluded.

MECHANISMS OF HYPNOTIC ANALGESIA EXPLAINED BY FUNCTIONAL MAGNETIC RESONANCE (fMRI)

Hypnotic-focused analgesia (HFA) was produced in 20 highly hypnotizable subjects receiving nociceptive stimulations while undergoing functional magnetic resonance imaging (fMRI). The fMRI pattern in brain cortex activation while receiving a painful stimulus was recorded both during nonhypnosis and during HFA. The scanning protocol included the acquisition of a T1-weighted structural scan, 4 functional scans, a T2-weighted axial scan, and a fluid attenuated inversion recovery (FLAIR) scan. Total imaging time, including localization and structural image acquisitions, was approximately 60 minutes. Without HFA, the subjects reported subjective presence of pain, and the cortex primary sensory areas S1, S2, and S3 were activated. During HFA, the subjects reported complete absence of subjective pain and S1, S2, and S3 were deactivated. The findings suggest that HFA may prevent painful stimuli from reaching the sensory brain cortex, possibly through a gate-control mechanism.

UNITED KINGDOM NORMS FOR THE HARVARD GROUP SCALE OF HYPNOTIC SUSCEPTIBILITY, FORM A

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A), is widely used as a measure of suggestibility to screen participants for research purposes. To date, there have been a number of normative studies of the HGSHS:A, the majority of which originate from Western countries. The outcomes of these Western studies are summarized, and variations in methodologies are described and discussed. Also reported are the psychometric properties of the HGSHS:A in a large contemporary United Kingdom (UK) sample. Overall, these UK results are consistent with the earlier Western norms studies in terms of response distribution and item difficulty, with only minor differences. The continued use of HGSHS:A as a screening procedure is supported, particularly if corrected for response subjectivity/involuntariness and with revised amnesia scoring. The HGSHS:A is also important as a potential measure of the broader trait of direct verbal suggestibility.

Hypnosis and learning: Pilot study on a group of students

Background Milton Erickson was the first to introduce hypnosis as a form of therapy during the post-war period. Numerous studies have evaluated the effects of hypnosis on memory, focusing principally on post-hypnotic amnesia, post-hypnotic hypermnesia, faux memories and learning growth. The aim of the present study was to determine if hypnosis can influence visual-spatial memory by increasing its performance and learning; to do this, we chose to utilise the Corsi Test (backward and forward). Methods Three hundred second-year students enrolled in the psychology faculty at the University of Catania were informed of the research and its modalities, and an e-mail was sent to inquire if they wanted to participate in the experiment. Seventy female students took part in the research; 10 were excluded because they presented a high risk of being influenced under hypnosis. The 60 subjects in the research sample were randomly divided into two groups: the Experimental Group and Control Group. The protocol prescribed administration of the Corsi Test at Time 0 (start) followed by a resting phase of 30 min. The hypnotic state was subsequently introduced, and the Corsi Test was administered again. Results The results of the Corsi Test for the Experimental Group showed statistically significant results (p<0.0004 and p<0.0001), while the results obtained in the Control Group did not show any significance. Conclusions These results led us to believe that hypnosis has the capacity to induce a nervous plasticity that supports learning of visual-spatial memory.

Does hypnotic assessment predict the functional equivalence between motor imagery and action?

Motor imagery is influenced by individual and contextual factors. We investigated whether the psychophysiological trait of hypnotisability modulates its subjective experience and cortical correlates similarly to what was previously shown for head postures mental images. EEG was acquired in 18 high (highs) and 15 low (lows) hypnotizable subjects (Stanford Hypnotic Susceptibility Scale, A). The experimental conditions were: baseline, a complex arm/hand movement, visual (1st person) and kinesthetic imagery of the movement. After each imagery condition, participants scored the vividness and easeness of their performance and their ability to mantain the requested modality of imagery. Subjective reports, chronometric visual/kinesthetic indices, absolute beta and fronto-central midline alpha powers were analyzed. Findings confirmed earlier reports of better kinestetic imagery ability in highs than in lows and better visual than kinesthetic imagery in lows, as well as smaller restructuring of the cortical activity in highs than in lows, during all tasks. Also, they show that hypnotisability accounts for most of the correlations between brain regions for both alpha and beta changes. Thus, imagined and actual movements were less demanding processes in highs at subjective and cortical levels. Finally, hypnotic assessment assists to plan personalized mental training for neuro-rehabilitation and sports and predict their efficacy.

TAIWANESE NORMS FOR THE HARVARD GROUP SCALE OF HYPNOTIC SUSCEPTIBILITY, FORM A

Hypnotic susceptibility is a fundamental individual characteristic to consider in studies examining hypnosis. Although there is no existing normative data of group hypnotic susceptibility tests for the Mandarin-speaking Chinese population, the current study administered the Mandarin Chinese translation of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) to 242 subjects (137 females and 105 males). The results indicate that the normative properties-including the score distribution, item pass rates, and reliability-are comparable to 15 reference samples. In general, the Mandarin Chinese version of the HGSHS:A can be used as a viable and reliable instrument for prescreening subjects' hypnotizability in the Mandarin Chinese-speaking population in Taiwan.

Pain modulation as a function of hypnotizability: Diffuse noxious inhibitory control induced by cold pressor test vs explicit suggestions of analgesia

The aim of the present study was to compare the effects of explicit suggestions of analgesia and of the activation of the Diffuse Noxious Inhibitory Control (DNIC) by cold pressor test on pain perception and heart rate in healthy participants with high (highs, N=18), low (lows, N=18) and intermediate scores of hypnotizability (mediums, N=15) out of hypnosis. Pain reports and the stimulus-locked heart rate changes induced by electrical nociceptive stimulation of the left hand were studied in the absence of concomitant stimuli (Control), during suggestions of analgesia (SUGG, glove analgesia) and during cold pressor test used as a conditioning stimulus to the right hand (DNIC, water temperature=10-12°C) in the REAL session. Participants were submitted also to a SHAM session in which the DNIC water temperature was 30°C and the suggestions for analgesia were substituted with weather forecast information. Both suggestions and DNIC reduced pain significantly in all subjects; however, the percentage of reduction was significantly larger in highs (pain intensity=55% of the control condition) than in mediums (70%) and lows (80%) independently of the REAL/SHAM session and of the specific pain manipulation. Heart rate was not modulated consistently with pain experience. Findings indicate that both suggestions and DNIC influence pain experience as a function of hypnotizability and suggest that both sensory and cognitive mechanisms co-operate in DNIC induced analgesia.

Complementing the Latest APA Definition of Hypnosis: Sensory-Motor and Vascular Peculiarities Involved in Hypnotizability

The aim of this article is to complement the recently revised American Psychological Association (APA) definition of hypnotizability. It (a) lists a few differences in sensorimotor integration between subjects with high (highs) and low (lows) hypnotizability scores in the ordinary state of consciousness and in the absence of suggestions, (b) proposes that hypnotizability-related cerebellar peculiarities may account for them,

Pain modulation in waking and hypnosis in women: event-related potentials and sources of cortical activity

Using a strict subject selection procedure, we tested in High and Low Hypnotizable subjects (HHs and LHs) whether treatments of hypoalgesia and hyperalgesia, as compared to a relaxation-control, differentially affected subjective pain ratings and somatosensory event-related potentials (SERPs) during painful electric stimulation. Treatments were administered in waking and hypnosis conditions. LHs showed little differentiation in pain and distress ratings between hypoalgesia and hyperalgesia treatments, whereas HHs showed a greater spread in the instructed direction. HHs had larger prefrontal N140 and P200 waves of the SERPs during hypnotic hyperalgesia as compared to relaxation-control treatment. Importantly, HHs showed significant smaller frontocentral N140 and frontotemporal P200 waves during hypnotic hypoalgesia. LHs did not show significant differences for these SERP waves among treatments in both waking and hypnosis conditions. Source localization (sLORETA) method revealed significant activations of the bilateral primary somatosensory (BA3), middle frontal gyrus (BA6) and anterior cingulate cortices (BA24). Activity of these contralateral regions significantly correlated with subjective numerical pain scores for control treatment in waking condition. Moreover, multivariate regression analyses distinguished the contralateral BA3 as the only region reflecting a stable pattern of pain coding changes across all treatments in waking and hypnosis conditions. More direct testing showed that hypnosis reduced the strength of the association of pain modulation and brain activity changes at BA3. sLORETA in HHs revealed, for the N140 wave, that during hypnotic hyperalgesia, there was an increased activity within medial, supramarginal and superior frontal gyri, and cingulated gyrus (BA32), while for the P200 wave, activity was increased in the superior (BA22), middle (BA37), inferior temporal (BA19) gyri and superior parietal lobule (BA7). Hypnotic hypoalgesia in HHs, for N140 wave, showed reduced activity within medial and superior frontal gyri (BA9,8), paraippocampal gyrus (BA34), and postcentral gyrus (BA1), while for the P200, activity was reduced within middle and superior frontal gyri (BA9 and BA10), anterior cingulate (BA33), cuneus (BA19) and sub-lobar insula (BA13). These findings demonstrate that hypnotic suggestions can exert a top-down modulatory effect on attention/preconscious brain processes involved in pain perception.

Hungarian norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

Hungarian norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) are presented. The Hungarian translation of the HGSHS:A was administered under standard conditions to 434 participants (190 males, 244 females) of several professions. In addition to the traditional self-scoring, hypnotic behavior was also recorded by trained observers. Female participants proved to be more hypnotizable than males and so were psychology students and professionals as compared to nonpsychologists. Hypnotizability varied across different group sizes. The normative data-including means, standard deviations, and indicators of reliability-are comparable with previously published results. The authors conclude that measuring observer-scores increases the ecological validity of the scale. The Hungarian version of the HGSHS:A seems to be a reliable and valid measure of hypnotizability.

Norms of German adolescents for the Harvard Group Scale of Hypnotic Susceptibility, Form A

The Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) has not been explicitly tested on an adolescent population. In this study, the German version of the HGSHS:A was administered to 99 German adolescents aged 15 to 19. In contrast to other studies, the gender distribution was relatively balanced: 57% female and 43% male. Results were comparable to 14 earlier studies with regard to distribution, mean, and standard deviation. Some peculiarities in contrast to the 14 previous studies are pointed out. It is concluded that the HGSHS:A can be used as a valid and reliable instrument to measure hypnotic suggestibility in adolescent samples.

Hypnotizability and Catechol-O-Methyltransferase (COMT) polymorphysms in Italians

Higher brain dopamine content depending on lower activity of Catechol-O-Methyltransferase (COMT) in subjects with high hypnotizability scores (highs) has been considered responsible for their attentional characteristics. However, the results of the previous genetic studies on association between hypnotizability and the COMT single nucleotide polymorphism (SNP) rs4680 (Val¹⁵⁸Met) were inconsistent. Here, we used a selective genotyping approach to re-evaluate the association between hypnotizability and COMT in the context of a two-SNP haplotype analysis, considering not only the Val¹⁵⁸Met polymorphism, but also the closely located rs4818 SNP. An Italian sample of 53 highs, 49 low hypnotizable subjects (lows), and 57 controls, were genotyped for a segment of 805 bp of the COMT gene, including Val¹⁵⁸Met and the closely located rs4818 SNP. Our selective genotyping approach had 97.1% power to detect the previously reported strongest association at the significance level of 5%. We found no evidence of association at the SNP, haplotype, and diplotype levels. Thus, our results challenge the dopamine-based theory of hypnosis and indirectly support recent neuropsychological and neurophysiological findings reporting the lack of any association between hypnotizability and focused attention abilities.

The influence of time and gender on hungarian hypnotizability scores

In a between-lab study, a constant and steady shift was found in hypnotizability scores measured with standard scales. To investigate a time effect in a Hungarian (within-lab) sample, 613 subjects' scores on Stanford Hypnotic Susceptibility Scale, Forms A and B, 1898 subjects' self-scores, and 1713 subjects' observer-scores on the Harvard Group Scale of Hypnotic Susceptibility were analyzed. From the 1970s to 2010, a significant increase was observed in the SHSS:A and B scores of female subjects and the HGSHS:A scores of both genders. Females proved to be significantly more hypnotizable than males in a group setting but not in an individual context. Time and gender did not interact. The possible reasons for these effects on hypnotizability and the role of the testing context are discussed.

Disseminating hypnosis to health care settings: Applying the RE-AIM framework

Hypnosis is a brief intervention ready for wider dissemination in medical contexts. Overall, hypnosis remains underused despite evidence supporting its beneficial clinical impact. This review will evaluate the evidence supporting hypnosis for dissemination using guidelines formulated by Glasgow and colleagues (1999). Five dissemination dimensions will be considered: Reach, Efficacy, Adoption, Implementation, and Maintenance (RE-AIM).

REACH

In medical settings, hypnosis is capable of helping a diverse range of individuals with a wide variety of problems.

EFFICACY

There is evidence supporting the use of hypnosis for chronic pain, acute pain and emotional distress arising from medical procedures and conditions, cancer treatment-related side-effects and irritable bowel syndrome.

ADOPTION

Although hypnosis is currently not a part of mainstream clinical practices, evidence suggests that patients and healthcare providers are open to trying hypnosis, and may become more so when educated about what hypnosis can do.

IMPLEMENTATION

Hypnosis is a brief intervention capable of being administered effectively by healthcare providers.

MAINTENANCE

Given the low resource needs of hypnosis, opportunities for reimbursement, and the ability of the intervention to potentially help medical settings reduce costs, the intervention has the qualities necessary to be integrated into routine care in a self-sustaining way in medical settings. In sum, hypnosis is a promising candidate for further dissemination.

Portuguese norms for the harvard group scale of hypnotic susceptibility, form a

The Portuguese version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) was administered to 313 Portuguese college students. Score distribution, item pass rates, item analysis, and reliability of the HGSHS:A are presented and compared to earlier published reference samples. No differences were found between males and females. Reliability of the HGSHS:A Portuguese version was lower than that reported by most of the studies but within the range of the non-English versions. In general, Portuguese data are congruent with the reference samples and the Portuguese translation of the HGSHS:A. It appears to be a viable instrument for primary screening of hypnotic suggestibility in a Portuguese context.

Measured outcomes with hypnosis as an experimental tool in a cardiovascular physiology laboratory

The authors detail their multidisciplinary collaboration of cardiologists, physiologists, neurologists, psychologists, engineers, and statisticians in researching the effects of hypnosis on the cardiovascular system and their additions to that incomplete literature. The article details their results and provides guidelines for researchers interested in replicating their research on hypnosis' effect on the cardiovascular system.

Relaxation versus fractionation as hypnotic deepening: do they differ in physiological changes?

After rapid hypnotic induction, 12 healthy volunteers underwent hypnotic deepening with relaxation or with fractionation (without relaxation) in a random latin-square protocol. Electroencephalographic occipital alpha activity was measured, low-resolution brain electromagnetic tomography was performed, and hemodynamics (stroke volume, heart rate, cardiac output, mean arterial blood pressure, forearm arterial flow and resistance) were monitored in basal conditions and after deepening. After relaxation, both forearm flow (-18%) and blood pressure (-4%) decreased; forearm resistance remained unchanged. After fractionation, a forearm flow decrease comparable to that recorded after relaxation was observed, but blood pressure remained unchanged, leading to an increase of forearm resistance (+51%). Central hemodynamics did not change. Alpha activity increased in the precuneus after fractionation only. In conclusion, both relaxation and fractionation have vasoconstrictor effects, but fractionation is also associated with an increase in peripheral resistance.

On the objectivity of the scoring of Harvard Group Scale of Hypnotic Susceptibility

The authors analyzed the Harvard Group Scale of Hypnotic Susceptibility, Form A, scores of 1,887 subjects. In addition to the usual self-scoring, trained observers also scored the behavioral manifestations of the subjects according to the same standardized criteria during the sessions. Self- and observer-scoring proved to be internally consistent and highly correlated (r = .832). Item-by-item analysis, however, yielded notable differences. Subjects and observers scored items differently in about 20% of the cases; only 3 items showed no systematic bias toward pass or fail. Many subjects' hypnotizability level would be classified differently according to observer categorization (Cohen's Kappa = .563). We suggest reconsidering the "objectivity" of self-scoring.

Postural effects of imagined leg pain as a function of hypnotizability

It has been shown that, in subjects with high hypnotizability (Highs), imagined somatosensory stimulation can involuntarily activate the neural circuits involved in the modulation of reflex action. In this vein, aim of the study was to investigate whether the imagery of nociceptive stimulation in one leg may produce both subjective experience of pain and congruent postural adjustments during normal upright stance. The displacement of the centre of pressure (CoP) was studied during imagery of leg pain (LP) and during the control conditions of imagery of tactile stimulation of the same leg and of throat pain (TP) in 12 Highs and 12 low hypnotizable subjects (Lows). The results showed that the vividness of imagery was higher in Highs than in Lows for all tasks and that only Highs reported actually feeling pain during LP and TP. Congruently, during LP only Highs displaced their CoP towards the leg opposite to the one that was the object of painful imagery and increased their CoP mean velocity and area of excursion. Since the Highs' postural changes were not accounted for only by vividness of imagery and perceived pain intensity, high hypnotizability is apparently responsible for part of the postural effects of pain imagery.

The impact of hypnotic suggestibility in clinical care settings

Hypnotic suggestibility has been described as a powerful predictor of outcomes associated with hypnotic interventions. However, there have been no systematic approaches to quantifying this effect across the literature. This meta-analysis evaluates the magnitude of the effect of hypnotic suggestibility on hypnotic outcomes in clinical settings. PsycINFO and PubMed were searched from their inception through July 2009. Thirty-four effects from 10 studies and 283 participants are reported. Results revealed a statistically significant overall effect size in the small to medium range (r = .24; 95% Confidence Interval = -0.28 to 0.75), indicating that greater hypnotic suggestibility led to greater effects of hypnosis interventions. Hypnotic suggestibility accounted for 6% of the variance in outcomes. Smaller sample size studies, use of the SHCS, and pediatric samples tended to result in larger effect sizes. The authors question the usefulness of assessing hypnotic suggestibility in clinical contexts.

Polish norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

The Polish version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A; Shor & Orne, 1962) was administered to 1174 participants (968 women and 206 men). Polish data were compared with other norming studies. Point-biserial item-scale correlations ranged from r = .12 (posthypnotic suggestion item) to r = .49. The Kuder-Richardson correlation of .70 was within the range of the reference samples. Test-retest reliability coefficients were obtained from one group of participants tested twice in the same session (r = .69, p < .05), and another group 8 weeks apart (r = .58, p < .05). Females scored significantly higher than males.

Norms for the Korean version of the Harvard Group Scale of Hypnotic Susceptibility, Form A

The Korean Version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:K) was adapted and studied in order to determine Korean norms. In total, 271 subjects (175 males and 96 females) participated in the study. Comparisons are made between the Korean samples and previously published international samples. The normative data from the Korean sample on the HGSHS:K are generally congruent, including means and standard deviations, with data from international reference samples. However, the pass rate on the hallucination item on the Harvard Group Scale of Hypnotic Susceptibility, Form A, was significantly different from that of the American sample. Females showed higher overall scores than males.

Israeli norms for the Harvard Group Scale of Hypnotic Susceptibility, Form A

A Hebrew version of the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) was administered to 283 subjects. Results were compared with those obtained for the English original administered in the United States, Canada, and Australia, as well as with versions translated into Swedish, Romanian, Italian, Finnish, Danish, Spanish, and German. Mean scores were similar to the Canadian and Australian, though lower than the others. No differences were found between males and females. Pass rates for individual items were similar or lower than elsewhere. Item reliability was similar to the other non-English versions. The author speculates that the slightly lower scores obtained may be due to the larger group of subjects present in each session. Overall, the Israeli data are congruent with the reference samples.

Hypnosis prevents the cardiovascular response to cold pressor test

To highlight the effects of hypnotic focused analgesia (HFA), 20 healthy participants underwent a cold pressor test (CPT) in waking basal conditions (WBC) by keeping the right hand in icy water until tolerable (pain tolerance); subjective pain was quantified by visual scale immediately before extracting the hand from water. The test was then repeated while the participants were under hypnosis and underwent HFA suggestions. Cardiovascular parameters were continuously monitored. Pain tolerance was 121.5+/-96.1 sec in WBC and 411.0+/-186.7 sec during HFA (p < 0.0001), and visual rating score 7.75+/-2.29 and 2.45+/-2.98 (p < 0.0001), respectively. CPT-induced increase of total peripheral resistance was non significant during HFA and +21% (p < 0.01) in WBC. HFA therefore reduced both perception and the reflex cardiovascular consequences of pain as well. This indicates that hypnotic analgesia implies a decrease of sensitivity and/or a block of transmission of painful stimuli, with depression of the nervous reflex arc.

Local and systemic vasodilation following hypnotic suggestion of warm tub bathing

During hypnosis it is easy to induce hallucinations having, for the hypnotized subject, the characteristics and the concreteness of reality. This study was performed to put in evidence the physical effects of hypnotic suggestion of warm tub bathing. 18 volunteers screened for high hypnotizability were studied. They underwent suggestion of forearm in warm water (30 min), suggestion of body in warm water (30 min), and hypnosis without any thermal suggestion (30 min), while blood pressure, heart rate, body temperature, forearm flow and resistance, stroke volume, cardiac index and total peripheral resistance were monitored. During suggestion of forearm in warm water, local vasodilation was recorded, with decrease of forearm resistance (-18%, P<0.01) and increase of forearm blood flow (+43%, P<0.01) like in real local passive warming. During suggestion of whole-body in a warm water tub, there was a systemic vasodilation with decrease of total peripheral resistance (-29%, P<0.01) and increase of cardiac index (+54%, P<0.01), like in real total-body passive warming. Body temperature, arterial blood pressure and heart rate were unchanged. During simple hypnosis (sham procedure) no haemodynamic variations were observed. These results are in keeping with the possibility to induce through hypnotic suggestion of heat a physical pattern that is typical of hyperthermia, even without increase in body temperature.

Hypnotic susceptibility scales: are the mean scores increasing?

The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C), developed and named 37 years ago, is arguably the "gold standard" of hypnotic susceptibility scales. However, it has been the impression of several researchers that means obtained on the SHSS:C are higher now than in previous years. The authors comprehensively review studies using the SHSS:C over a 4-decade period. The findings demonstrate a significant linear trend between year and SHSS:C scores, with higher obtained means in more recent work. The authors also report a similar analysis of research with the Harvard Group Scale of Hypnotic Susceptibility, Form A. Although the mechanisms underlying this trend can only be speculated upon at present, these findings underscore the importance of using local control groups in research on hypnotizability.

The Stanford Hypnotic Susceptibility Scale, Form C: normative data of a Dutch student sample

Norms for the Dutch language version of the Standford Hypnotic Susceptibility Scale, Form C (SHSS:C; Weitzenhoffer & Hilgard, 1962) are presented. These norms are based upon a sample of 135 students at a Dutch university. Generally, the psychometric properties of the Dutch version of the SHSS:C are similar to other language versions. However, the mean score was somewhat lower than that found in the original norming studies at Stanford University.

Phenomenological experiences associated with hypnotic susceptibility

Following the administration of a Hungarian translation of the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C), 104 Hungarian subjects completed the Hungarian translation of the Phenomenology of Consciousness Inventory (PCI). Subjects had also been administered the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) about 1 week to 2 months before the SHSS:C. The pattern of correlations between hypnotizability (as measured by the HGSHS:A and the SHSS:C) and the 5 factors of the PCI was quite similar to that of previous work carried out using the English language versions on subjects in the United States. SHSS:C and HGSHS:A scores correlated significantly with the PCI factors of dissociated control, positive affect, and attention to internal processes factors. In addition, the SHSS:C score correlated significantly with the visual imagery factor, as found in previous work.

Italian norms for the Stanford Hypnotic Susceptibility Scale, Form C

This paper presents norms for an Italian translation of the Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C; Weitzenhoffer & Hilgard, 1962). Archival data on hypnosis research subjects recruited over a 10-year period of research on hypnosis were pooled, resulting in an aggregate sample of 356 participants (263 female and 93 male). Score distribution, item difficulty levels, and reliability of the SHSS:C were computed. Of this group, 218 subjects were administered the Harvard Group Scale of Hypnotic Susceptibility approximately 3 weeks prior to administration of the SHSS:C. The remaining 138 subjects received only the SHSS:C. Results suggest that the Italian version of the SHSS:C is a reliable and valid measure.