Dissociative tendencies and individual differences in high hypnotic suggestibility

Cognitive simulation along with neural adaptation explain effects of suggestions: a novel theoretical framework

Hypnosis is an effective intervention with proven efficacy that is employed in clinical settings and for investigating various cognitive processes. Despite their practical success, no consensus exists regarding the mechanisms underlying well-established hypnotic phenomena. Here, we suggest a new framework called the Simulation-Adaptation Theory of Hypnosis (SATH). SATH expands the predictive coding framework by focusing on (a) redundancy elimination in generative models using intrinsically generated prediction errors, (b) adaptation due to amplified or prolonged neural activity, and (c) using internally generated predictions as a venue for learning new associations. The core of our treatise is that simulating proprioceptive, interoceptive, and exteroceptive signals, along with the top-down attenuation of the precision of sensory prediction errors due to neural adaptation, can explain objective and subjective hypnotic phenomena. Based on these postulations, we offer mechanistic explanations for critical categories of direct verbal suggestions, including (1) direct-ideomotor, (2) challenge-ideomotor, (3) perceptual, and (4) cognitive suggestions. Notably, we argue that besides explaining objective responses, SATH accounts for the subjective effects of suggestions, i.e., the change in the sense of agency and reality. Finally, we discuss individual differences in hypnotizability and how SATH accommodates them. We believe that SATH is exhaustive and parsimonious in its scope, can explain a wide range of hypnotic phenomena without contradiction, and provides a host of testable predictions for future research.

Post-hypnotic suggestion improves confidence and speed of memory access with long-lasting effects

In our study, we use the post-hypnotic suggestion of easy remembering to improve memory with long-lasting effects. We tested 24 highly suggestible participants in an online study. Participants learned word lists and recalled them later in a recognition memory task. At the beginning of the study, participants were hypnotized and the post-hypnotic suggestion to remember easily was associated with a cue that participants used during the recognition memory task. In a control condition, the same participants used a neutral cue. One week later, participants repeated both conditions with new word lists. Participants were significantly faster and more confident in their recognition ratings in the easy-remembering condition compared to the control condition, and this effect persisted over one week. Crucially, the increased speed and confidence in the easy-remembering condition did not affect memory accuracy. That makes our hypnosis intervention promising for patients experiencing subjective memory impairments. APA PSYCINFO CODES: 2343 (Learning and Memory), 2380 (Consciousness States), 3351 (Clinical Hypnosis).

Hypnosis in psychotherapy, psychosomatics and medicine. A brief overview

Aspects of hypnosis and its application in psychotherapy, psychosomatics and medicine are examined and contextualized in the 250-year history of hypnosis. Imagination as an essential element of hypnotic treatments appeared as early as 1784 as an argument rejecting the theory of animal magnetism of Franz Anton Mesmer. In somnambulism of German romanticism, another proto-form of hypnosis after 1800, concepts of the mind-body problem were dealt with, which still characterize the understanding of unconscious mental processes today. Hypnosis was at the beginning of psychoanalysis, but was not pursued further by Sigmund Freud from 1900 onwards. Nevertheless, there were some hypnoanalytical approaches in the 20th century, as well as attempts to integrate hypnosis into behavior therapy. Techniques of imagination and relaxation combine both; in particular findings from cognitive psychology explain processes of both hypnosis and cognitive behavioral therapy. The influence of social psychology brought a new perspective to the debate about the nature of hypnosis, which continues to this day: is hypnosis to be understood as a special state of consciousness or is it a completely normal, mundane interaction? The experiments that were carried out to support one side or the other were also dependent on the hypnotizability of the subjects involved, as the more difficult hypnotic phenomena such as paralysis, hallucinations or identity delusions can only be demonstrated by highly hypnotizable subjects. The fact that these are not mere compliance reactions has now been proven by many studies using imaging techniques. But even those who are moderately hypnotizable benefit from hypnosis rituals. Variables postulated by socio-cognitive hypnosis researchers, such as motivation and expectation, are relevant, as is a good "hypnotic rapport." Practical application of hypnotherapy today is characterized by the innovative techniques and strategies developed by Milton H. Erickson. Research into the effectiveness of hypnosis in the field of psychotherapy and psychosomatics still leaves much to be done. The situation is different in the field of medical hypnosis, where there are considerably more studies with a satisfactory design and verifiable effects. However, the impact in practical application in everyday medical practice is still low. Newer developments such as virtual reality and artificial intelligence are being looked at with critical interest.

The relationship between transliminality, hypnotic and imaginative suggestibility, and other personality traits

To our knowledge, no study has directly examined the link between hypnotic response and the personality trait of transliminality (which is underpinned, for example, by magical ideation, mystical experience, fantasy proneness, absorption, hyperaesthesia). In order to further understand the correlates of suggestibility, the aim of the current project was to investigate whether transliminality is associated with hypnotic and imaginative suggestibility (considering: objective response, subjective response and involuntariness). Another aim was to assess the contribution of transliminality as a predictor of suggestibility when a range of previously studied personality trait measures were considered. Participants completed: the Revised Transliminality Scale, Tellegen Absorption Scale, Creative Experiences Questionnaire, and the Dissociative Experiences Scale II. To avoid context effects, where knowledge or measurement of one trait or ability might influence measurement of another, a separate standalone study was conducted where hypnotic and imaginative (without hypnosis) suggestibility screenings were carried out in-person in small groups using the modified Carleton University Responsiveness to Suggestion Scale. The merging of these two datasets enabled the analyses. Transliminality was weakly correlated with the imaginative suggestibility subjective response measure (r = 0.19). Likewise, weak correlations were found between transliminality and the hypnotic suggestibility response measures (objective, r = 0.21, subjective, r = 0.23, involuntariness, r = 0.24). The multiple regressions (forward selection) reflected the pattern of correlations, with no model for any of the variables, retaining more than a single significant predictor. In summary, this study combination, avoiding context effects, shows transliminality to be a weak predictor of response to suggestion.

Redefining hypnosis: A narrative review of theories to move towards an integrative model

Hypnosis is an ancient mind-body intervention that has regained interest with the surge of research in the last decade documenting its clinical validity. Yet, theoretical controversies and misconceptions prevail among theorists, clinicians, and the general public, impeding the understanding, acceptance, replication, and use of hypnosis. Providing adequate information, which dispels misconceptions and promotes more balanced views, is warranted to facilitate the implementation and adoption of hypnosis in clinical and research settings. This review re-examines the conceptualisation of hypnosis throughout history and the theoretical controversies surrounding it while highlighting their meeting points and clinical implications. Despite dichotomies, a broad agreement appears across theoretical approaches regarding hypnotic analgesia effects, key components, and vocabulary. Further, theories highlight key factors of hypnotic responding. For instance, social theories highlight social and contextual variables, whereas state theories highlight biopsychosocial mechanisms and individual factors. Based on theories, the terms hypnotherapy or clinical hypnosis are recommended to refer to the therapeutic use of hypnosis in psychotherapeutic and medical contexts, respectively. This review concludes with a model that integrates various theories and evidence and presents hypnosis as a complex multifaceted intervention encompassing multiple procedures, phenomena, and influencing factors. This review intends to deepen our understanding of hypnosis, and promote its more rapid adoption and adequate implementation in research and clinical contexts, in addition to steering research towards evidence-based hypnotic practice. The review can have important research and clinical implications by contributing to advancing knowledge regarding hypnotic procedures, phenomena, and influencing factors.

Hypnotizability-related risky experience and behavior

Risk is the probability of an adverse event. The proneness to take a risk and the risk taking behavior differ among the general population. Hypnotizability is a stable psychophysiological trait expressing the individual proneness to modify perception, memory and behavior following specific suggestions also in the ordinary state of consciousness. Some hypnotizability-related neurophysiological and behavioral correlates suggest that hypnotizability level, measured by standard scales classifying individuals as low (lows), medium (mediums) and high hypnotizable (highs) subjects, can be related to risk propensity and risk-taking. To study whether hypnotizability modulates risk propensity and behavior, we recruited healthy participants, classified through the Standford Hypnotic Susceptibility scale, form A, and compared lows' (n = 33), mediums' (n = 19) and highs'(n = 15) experiential and behavioral risk perception and propensity variables through the Domain-specific risk-taking scale and the Balloon Analogue Risk Task. MANOVA results indicated that different hypnotizability levels are not associated with different risky behavior and experience, except for higher expected financial benefits from risky behavior in lows. However, hypnotizability-related risk profiles were identified through correlational analyses. In fact, highs exhibited a negative association between risk perception and propensity to risk-taking, whereas mediums and lows displayed a positive association between risk propensity and expected benefit. In conclusion, the highs' profile indicates a more automatic behavior with respect to mediums and lows.

Brain Functional Correlates of Resting Hypnosis and Hypnotizability: A Review

This comprehensive review delves into the cognitive neuroscience of hypnosis and variations in hypnotizability by examining research employing functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and electroencephalography (EEG) methods. Key focus areas include functional brain imaging correlations in hypnosis, EEG band oscillations as indicators of hypnotic states, alterations in EEG functional connectivity during hypnosis and wakefulness, drawing critical conclusions, and suggesting future research directions. The reviewed functional connectivity findings support the notion that disruptions in the available integration between different components of the executive control network during hypnosis may correspond to altered subjective appraisals of the agency during the hypnotic response, as per dissociated and cold control theories of hypnosis. A promising exploration avenue involves investigating how frontal lobes' neurochemical and aperiodic components of the EEG activity at waking-rest are linked to individual differences in hypnotizability. Future studies investigating the effects of hypnosis on brain function should prioritize examining distinctive activation patterns across various neural networks.

Demystifying hypnosis: Unravelling facts, exploring the historical roots of myths, and discerning what is hypnosis

BACKGROUND AND PURPOSE

Hypnosis, a mind-body treatment dating back to early human history, has regained attention in the last decade, with research suggesting its effectiveness for varied physiological and psychological ailments such as distress, pain, and psychosomatic disorders. However, myths and misconceptions have prevailed among the general public and clinicians, hindering the adoption and acceptance of hypnosis. It is important to distinguish myths from facts and discern what is hypnosis and what is not to enhance the understanding, acceptance, and adoption of hypnotic interventions.

METHODS

This narrative review traces the history of myths surrounding hypnosis in contrast to the evolution of hypnosis as a treatment modality. In addition to comparing hypnosis to other interventions with similar procedures and features, the review unravels misconceptions that have impeded the adoption and acceptance of hypnosis in clinical and research settings and presents evidence to demystify this intervention.

RESULTS

This review examines the roots of myths while presenting historical facts and evidence that support hypnosis as a treatment modality and alleviate misconceptions depicting it as mystical. Further, the review distinguishes hypnotic and non-hypnotic interventions with overlapping procedures and phenomenological features to enhance our understanding of hypnotic techniques and phenomena.

CONCLUSION

This review enhances the understanding of hypnosis in historical, clinical, and research contexts by disproving related myths and misconceptions to promote the adoption of hypnosis in clinical and research contexts. Further, this review highlights knowledge gaps requiring further investigations to steer research toward an evidence-based practice of hypnosis and optimise multimodal therapies embedding hypnosis.

Point-of-Care Testing of Enzyme Polymorphisms for Predicting Hypnotizability and Postoperative Pain

Hypnotizability is a stable trait that moderates the benefit of hypnosis for treating pain, but limited availability of hypnotizability testing deters widespread use of hypnosis. Inexpensive genotyping of four single-nucleotide polymorphisms in the catechol-o-methyltransferase (COMT) gene was performed using giant magnetoresistive biosensors to determine if hypnotizable individuals can be identified for targeted hypnosis referrals. For individuals with the proposed optimal COMT diplotypes, 89.5% score highly on the Hypnotic Induction Profile (odds ratio, 6.12; 95% CI, 1.26-28.75), which identified 40.5% of the treatable population. Mean hypnotizability scores of the optimal group were significantly higher than the total population (P = 0.015; effect size = 0.60), an effect that was present in women (P = 0.0015; effect size = 0.83), but not in men (P = 0.28). In an exploratory cohort, optimal individuals also reported significantly higher postoperative pain scores (P = 0.00030; effect size = 1.93), indicating a greater need for treatment.

Comparative effects of hypnotic suggestion and imagery instruction on bodily awareness

Bodily awareness is informed by both sensory data and prior knowledge. Although misleading sensory signals have been repeatedly shown to affect bodily awareness, only scant attention has been given to the influence of cognitive variables. Hypnotic suggestion has recently been shown to impact visuospatial and sensorimotor representations of body-part size although the mechanisms subserving this effect are yet to be identified. Mental imagery might play a causal or facilitative role in this effect, as it has been shown to influence body awareness in previous studies. Nonetheless, current views ascribe only an epiphenomenal role to imagery in the implementation of hypnotic suggestions. This study compared the effects of hypnotic suggestion and imagery instruction for influencing the visuospatial and sensorimotor aspects of body-size representation. Both experimental manipulations produced significant increases (elongation) in both representations compared to baseline, although the effects were larger in the hypnotic suggestion condition. The effects of both manipulations were highly correlated across participants, suggesting overlapping mechanisms. Self-reports suggested that the use of voluntary imagery did not significantly contribute to the efficacy of either manipulation. Rather, top-down effects on body representations seem to be partly driven by response expectancies, spontaneous imagery, and hypnotic suggestibility in both conditions. These results are in line with current theories of suggestion and raise fundamental questions regarding the mechanisms driving the influence of cognition on body representations.

The response set theory of hypnosis reconsidered: toward an integrative model

Irving Kirsch is a leading figure in the field of psychological science who has advanced our understanding of hypnosis in key respects that have withstood the tests of time and replication. We honor his prodigious contributions over his distinguished career and extend his response expectancy theory in an integrative model that encompasses predictive coding. We review the construct of expectancies that he articulated and championed for decades and extended in response set theory. We propose novel hypotheses to align his innovative contributions with the most current findings in psychological science and to acknowledge the heuristic value of his work. We especially focus on (I) how the response set theory can be conceptualized in terms of the predictive coding model and (II) psycho-social constructs that need to be considered to better understand the effects of expectancies on hypnotic phenomena in an open and evidence-based integrative model of hypnosis.

Absorption and dissociation mediate the relationship between direct verbal suggestibility and impulsivity/compulsivity

Direct verbal suggestibility refers to the capacity for an individual to experience perceptual, motor, affective and cognitive changes in response to verbal suggestions. Suggestibility is characterized by pronounced, yet reliable, inter-individual differences. Previous research and theoretical considerations suggest that greater impulsivity and compulsivity is associated to higher suggestibility, but the characteristics and mediating factors of this association are poorly understood. Using established psychometric measures in an online sample, we found positive correlations between the domain comprising impulsivity, compulsivity and behavioural activation, and the domain of suggestibility, dissociation and absorption. We also observed that dissociation and absorption mediated the link between suggestibility and impulsivity, and between suggestibility and behavioural activation, respectively. These results confirm the positive link between suggestibility and the impulsivity/compulsivity domain and shed new light on the characterisation of traits associated with suggestibility.

Assessing responsiveness to direct verbal suggestions in depersonalization-derealization disorder

The dissociative disorders and germane conditions are reliably characterized by elevated responsiveness to direct verbal suggestions. However, it remains unclear whether atypical responsiveness to suggestion is similarly present in depersonalization-derealization disorder (DDD). 55 DDD patients and 36 healthy controls completed a standardised behavioural measure of direct verbal suggestibility that includes a correction for compliant responding (BSS-C), and psychometric measures of depersonalization-derealization (CDS), mindfulness (FFMQ), imagery vividness (VVIQ), and anxiety (GAD-7). Relative to controls, patients did not exhibit elevated suggestibility (g = 0.26, BF₁₀ = .11) but displayed significantly lower mindfulness (g = 1.38), and imagery vividness (g = 0.63), and significantly greater anxiety (g = 1.39). Although suggestibility did not correlate with severity of depersonalization-derealization symptoms in controls, r = -.03 [95% CI: -.36, .30], there was a weak tendency for a positive association in patients, r = .25, [95% CI: -.03, .48]. Exploratory analyses revealed that patients with more severe anomalous bodily experiences were also more responsive to suggestion, an effect not seen in controls. This study demonstrates that DDD is not characterized by elevated responsiveness to direct verbal suggestions. These results have implications for the aetiology and treatment of this condition, as well as its classification as a dissociative disorder in psychiatric nosology.

Hypnotic suggestibility in dissociative and related disorders: A meta-analysis

Elevated responsiveness to verbal suggestions is hypothesized to represent a predisposing factor for dissociative disorders (DDs) and related conditions. However, the magnitude of this effect has not been estimated in these populations nor has the potential moderating influence of methodological limitations on effect size variability across studies. This study assessed whether patients with DDs, trauma- and stressor-related disorders (TSDs), and functional neurological disorder (FND) display elevated hypnotic suggestibility. A systematic literature search identified 20 datasets. A random-effects meta-analysis revealed that patients displayed greater hypnotic suggestibility than controls, Hedges's g=0.92 [0.66, 1.18]. This effect was observed in all subgroups but was most pronounced in the DDs. Although there was some evidence for publication bias, a bias-corrected estimate of the group effect remained significant, g=0.57 [0.30, 0.85]. Moderation analyses did not yield evidence for a link between effect sizes and methodological limitations. These results demonstrate that DDs and related conditions are characterized by elevated hypnotic suggestibility and have implications for the mechanisms, risk factors, and treatment of dissociative psychopathology.

God Locus of Health Control, Paranormal Beliefs, and Hypnotizability

Belief in the paranormal (e.g., spirits, extrasensory perception, fortune telling, extraterrestrials) is common. Extraordinary and magical beliefs have been linked with hypnotizability. A total of 167 undergraduates completed measures of paranormal and magical beliefs, locus of control, absorption, fantasy proneness, expectancy about being hypnotized, and the God Locus of Health Control scale (GLHC) and were hypnotized with the HGSHS:A. High and medium hypnotizable participants more strongly agreed with statements reflecting paranormal and magical beliefs and the assertion that God directly controls their health, relative to those less responsive to hypnosis. Using stepwise regression, we found that expectations about hypnosis along with scores on the GLHC scale accounted for 26% and 30% of the variance in behavioral and subjective scores on the HGSHS:A, respectively. The authors discuss paranormal beliefs and the link between the GLHC and hypnotizability.

Dispositional Self-Consciousness and Hypnotizability

The abeyance of self-consciousness (SC) during hypnosis has been discussed as a central aspect of hypnosis, yet dispositional SC has been very rarely evaluated as a correlate of hypnotizability. In this study (N = 328), the authors administered the Harvard Group Scale of Hypnotic Susceptibility (HGSHS), the Inventory Scale of Hypnotic Depth (ISHD), and the Self-Consciousness Scale-Revised (SCS-R). Women tended to score higher than men on the HGSHS, besides experiencing greater ISHD automaticity. The Discontinuity (with everyday experiences) subscale of the ISHD correlated with the Public Self-Consciousness scale of the SCS-R and with the Private Self-Consciousness subscale (using simple, quadratic, and cubic regressions). Being concerned about the perception of others related to experiencing hypnosis as discontinuous with everyday life, which also related to being more introspective and interested in subjectivity at the middle range of scores. The article concludes with suggestions on how to pursue the implications of these results, including testing for nonlinear relations.

"Everything has been done at some time or another..." An Interview with Ernest Hilgard

Ernest R. Hilgard is not only one of the most important hypnosis theoreticians and researchers in history, but one the most eminent psychologists of the 20th century. This paper starts with a brief summary of his contributions to hypnosis, emphasizing his dissociation theory, and placing it within previous and later dissociation theories of hypnosis. I then transcribe an interview with him circa 1989, which I recorded with his authorization for later use, emphasizing dissociation in hypnosis. He also reminisced about historical figures in psychology.

Reality shifting: psychological features of an emergent online daydreaming culture

Reality shifting (RS) is a trendy mental activity that emerged abruptly following the flare-up of the COVID-19 pandemic in 2020 and seems to be practiced mainly by members of the post-millennial generation. RS, described as the experience of being able to transcend one's physical confines and visit alternate, mostly fictional, universes, is discussed by many on Internet platforms. One RS forum boasts over 40,000 members and RS clips on some social media platforms have been viewed over 1.7 billion times. The experience of shifting is reportedly facilitated by specific induction methods involving relaxation, concentration of attention, and autosuggestion. Some practitioners report a strong sense of presence in their desired realities, reified by some who believe in the concrete reality of the alternate world they shift to. One of the most popular alternate universes involves environments adopted from the Harry Potter book and film series. We describe the phenomenology of RS as reported online and then compare it to related phenomena such as hypnosis, tulpamancy, dissociation, immersive and maladaptive daydreaming, and lucid dreaming. We propose a theoretical model of interactive factors giving rise to RS, and conclude that it is an important, uninvestigated emerging phenomenon and propose future research directions.

Hypnotic predictors of agency: Responsiveness to specific suggestions in hypnosis is associated with involuntariness in fibromyalgia

Hypnosis is associated with alterations in the sense of agency which can play a role in its utilization as a nonpharmacological option for pain management. The goal of the current study was to examine the relationships between responsiveness to suggestions in hypnosis and alterations of the sense of agency among patients with fibromyalgia. Ninety-eight participants with fibromyalgia underwent two hypnotizability assessments followed by the Sense of Agency Rating Scale. Clinical pain measures were also collected. Involuntariness was predicted by responsiveness to control, ideomotor, and dissociation suggestions. Effortlessness was predicted by responsiveness to control and ideomotor suggestions, and age. Hypnotizability was associated with main clinical pain outcomes, but agency alterations were not. Results suggest a shared mechanism between responsiveness to specific suggestions and the sense of agency in hypnosis. We discuss theoretical and clinical implications for pain management and the need for further research.

No evidence for theta power as a marker of hypnotic state in highly hypnotizable subjects

EEG spectral-power density was analyzed in a group of nine highly hypnotizable subjects via ten frontal, central, parietal, and occipital electrodes under four conditions: 1) wake state, 2) neutral hypnosis, 3) hypnotic suggestion for altering perception of tones, and 4) post-hypnosis. Results indicate no theta-power changes between conditions, challenging previous findings that increased theta power is a marker of hypnosis. A decrease in gamma power under hypnotic suggestion and an almost significant decrease under neutral hypnosis were observed, compared to post-hypnosis. Anteroposterior power distribution remained stable over all conditions. The results are discussed and compared to earlier studies, which report heterogenous findings.

Shared cognitive mechanisms of hypnotizability with executive functioning and information salience

In recent years, evidence linked hypnotizability to the executive control and information salience networks, brain structures that play a role in cognitive conflict resolution and perseveration (insisting on applying a previously learned logical rule on a new set). Despite the growing body of neuroimaging evidence, the cognitive phenotype of hypnotizability is not well understood. We hypothesized that higher hypnotizability would correspond to lower perseveration and set-shifting. Seventy-two healthy adults were tested for hypnotizability and executive functions (perseveration and set-shifting). Multiple regression analyses were performed to test the relationship between hypnotizability and perseveration and set-shifting. Higher hypnotizability was associated with lower perseveration after accounting for age and education. Hypnotizability significantly predicted perseveration but not set-shifting. Our results indicate an inverse relationship between trait hypnotizability and perseveration, an executive function that utilizes regions of both the executive control and the salience systems. This suggests that hypnotizability may share a common cognitive mechanism with error evaluation and implementation of logical rules.

Multicomponent Theories of Hypnotizability: History and Prospects

This review addresses multicomponent theories of hypnotizability by focusing on 3 important exemplars from the history of hypnosis research: E. R. Hilgard's (1965) Hypnotic susceptibility; R. E. Shor's (1962) Three dimensions of hypnotic depth; and T.X. Barber's (1999) A comprehensive three-dimensional theory of hypnosis. Taken together, they illustrate the variety of hypnotic phenomena examined in research - overt responses, subjective experiences, and underlying processes - and the ways in which evidence about each has implied the existence of multiple underlying components. Particularly highlighted are the different ways in which the theories conceptualize the joint contribution of multiple individual differences. Also covered is relevant later work by other researchers as well as important issues remaining to be resolved.

A Critical Review of Standardized Measures of Hypnotic Suggestibility

The most well-established finding gleaned from decades of experimental hypnosis research is that individuals display marked variability in responsiveness to hypnotic suggestions. Insofar as this variability impacts both treatment outcome in therapeutic applications of hypnosis as well as responsiveness to suggestions in experimental contexts, it is imperative that clinicians and researchers use robust measures of hypnotic suggestibility. The current paper critically evaluates contemporary measures of hypnotic suggestibility. After reviewing the most widely used measures, we identify multiple properties of these instruments that result in the loss of valuable information, including binary scoring and single-trial sampling, and hinder their utility, such as the inclusion of suboptimal suggestion content. The scales are not well-suited for contemporary research questions and have outlived their usefulness. We conclude by outlining ways in which the measurement of hypnotic suggestibility can be advanced.

Can posthypnotic suggestions boost updating in working memory? Behavioral and ERP evidence

Updating is an essential executive function (EF), responsible for storing, retrieving, and substituting information in working memory (WM). Here we investigated whether posthypnotic suggestions (PHS) given to high-hypnotizable participants can enhance updating in WM and measured neural correlates of the observed effects by recording event-related brain potentials (ERP). In a tone-monitoring task different syllables were presented in random order, requiring a response to every fourth presentation of a given syllable. Experiment 1 (n = 19) established the relationship between performance and several ERP components across updating load (different numbers of syllables). In Experiment 2 (n = 18), a no-hypnosis (NH) and a hypnosis-plus-PHS session were administrated in counterbalanced order. Task instructions, presented at the beginning of the sessions, emphasized a cognitive strategy, demanding imagination of visual counters, a strategy that was also emphasized during PHS. PHS additionally contained suggestions stimulating cognitive simulation of the task, where participants were advised to apply the suggested strategy. Relative to the NH session, PHS enhanced WM performance with medium to large effect sizes. In ERPs, PHS increased the P2 and P3 components, indicating the proactive recruitment of control-related attention and updating-related cognitive control processes, respectively. PHS also reduced updating load effects in the posterior recognition component, suggesting diminished demands on WM buffers. These ERP findings suggest that PHS enhanced updating in WM by strengthening proactive control, which may have diminished the necessity for reactive control. Hence, the present results suggest that our PHS had worked like mental practice helping participants to develop an efficient and context-dependent trigger-action contingency. Consequentially, the present study provides a new framework for employing PHSs, which may be used as a basis for developing new training regimes for modifying WM or other EFs.

Hypnotised by Your Phone? Smartphone Addiction Correlates With Hypnotisability

Hypnosis and heavy smartphone use are both characterised by absorbed states in which one loses track of time and responds automatically to stimuli. In this pre-registered study, we tested whether there was a relationship between smartphone addiction and hypnotisability: one's tendency to follow suggestions under hypnosis. Over 11 public lectures, we hypnotised 641 student-aged participants; after the hypnosis session, participants completed the Smartphone Addiction Scale (Short Version). There was a positive correlation between hypnotisability and smartphone addiction (r = .17, 95% CI [.09, .24], p < .001) with a magnitude similar to standard predictors of hypnotisability. This correlation was small but unlikely spurious: it was positive in 10 of the 11 samples (including two from psychology courses) and persisted in a follow-up several months later. The addiction scores in this Canadian sample were unexpectedly high (M = 31.41) compared to other countries. We hypothesise that targeting the absorbed, time-distorted, and automatic use of smartphones may promote healthier phone habits.

Anomalous experiences are more prevalent among highly suggestible individuals who are also highly dissociative

Introduction: Predictive coding models propose that high hypnotic suggestibility confers a predisposition to hallucinate due to an elevated propensity to weight perceptual beliefs (priors) over sensory evidence. Multiple lines of research corroborate this prediction and demonstrate a link between hypnotic suggestibility and proneness to anomalous perceptual states. However, such effects might be moderated by dissociative tendencies, which seem to account for heterogeneity in high hypnotic suggestibility. We tested the prediction that the prevalence of anomalous experiences would be greater among highly suggestible individuals who are also highly dissociative.Methods: We compared high and low dissociative highly suggestible participants and low suggestible controls on multiple psychometric measures of anomalous experiences.Results: High dissociative highly suggestible participants reliably reported greater anomalous experiences than low dissociative highly suggestible participants and low suggestible controls, who did not significantly differ from each other.Conclusions: These results suggest a greater predisposition to experience anomalous perceptual states among high dissociative highly suggestible individuals.

The interoception and imagination loop in hypnotic phenomena

We tested a working hypothesis that the ideomotor and motor-control suggestions measured by current hypnotizability scales depend on the activation of an interoception-imagination processing loop. In three experiments, participants were exposed to an induction phase, Items 3 (mosquito hallucination) and 8 (arm immobilization) of the Stanford Hypnotic Susceptibility Scale, Form C, and a new version of Item 8 involving the additional activation of imaginative and interoception processes. We found that this modified version of Item 8 elicited greater responsiveness to suggestion, irrespective of its position in the sequence of hypnotic items. We argue that this interoception-imagination loop hypothesis provides a useful information processing analysis for understanding several hypnotic phenomena.

Cerebellar Structural Variations in Subjects with Different Hypnotizability

Hypnotizability-the proneness to accept suggestions and behave accordingly-has a number of physiological and behavioral correlates (postural, visuomotor, and pain control) which suggest a possible involvement of cerebellar function and/or structure. The present study was aimed at investigating the association between cerebellar macro- or micro-structural variations (analyzed through a voxel-based morphometry and a diffusion tensor imaging approach) and hypnotic susceptibility. We also estimated morphometric variations of cerebral gray matter structures, to support current evidence of hypnotizability-related differences in some cerebral areas. High (highs, N = 12), and low (lows, N = 37) hypnotizable healthy participants (according to the Stanford Hypnotic Susceptibility Scale, form A) were submitted to a high field (3 T) magnetic resonance imaging protocol. In comparison to lows, highs showed smaller gray matter volumes in left cerebellar lobules IV/V and VI at uncorrected level, with the results in left lobule IV/V maintained also at corrected level. Highs showed also gray matter volumes smaller than lows in right inferior temporal gyrus, middle and superior orbitofrontal cortex, parahippocampal gyrus, and supramarginal parietal gyrus, as well as in left gyrus rectus, insula, and middle temporal cortex at uncorrected level. Results of right inferior temporal gyrus survived also at corrected level. Analyses on micro-structural data failed to reveal any significant association. The here found morphological variations allow to extend the traditional cortico-centric view of hypnotizability to the cerebellar regions, suggesting that cerebellar peculiarities may sustain hypnotizability-related differences in sensorimotor integration and emotional control.

Trauma and anxious attachment influence the relationship between suggestibility and dissociation: a moderated-moderation analysis

INTRODUCTION

Hypnotic suggestibility is elevated in the dissociative disorders but the relationship between dissociative tendencies and suggestibility in the general population seems to be constrained by additional factors. The diathesis-stress (DS) model stipulates that suggestibility interacts with trauma exposure to augment the propensity for dissociative states whereas the dual pathway to suggestibility (DPS) model proposes two developmental routes involving either dissociation preceded by trauma, or a healthy cognitive profile characterised by superior imagination.

METHODS

This study sought to discriminate between these partially competing accounts and further considered the moderating role of anxious attachment. 209 participants completed psychometric measures of dissociative tendencies, trauma, and attachment, and a behavioural measure of suggestibility.

RESULTS

In support of the DS model, trauma moderated the relationship between suggestibility and dissociation and, as predicted by the DPS model, dissociation moderated the relationship between trauma and suggestibility. Anxious attachment additionally moderated both effects. Model comparisons indicated that the DS model consistently provided a superior fit to the data. Further analyses showed that secure attachment independently predicted suggestibility, thereby supporting the non-dissociative pathway in the DPS model.

CONCLUSIONS

These results suggest that high suggestibility confers vulnerability to dissociative states in individuals exposed to trauma and displaying an anxious attachment style.

Time perception and the experience of agency in meditation and hypnosis

Mindfulness meditation and hypnosis are related in opposing ways to awareness of intentions. The cold control theory of hypnosis proposes that hypnotic responding involves the experience of involuntariness while performing an actually intentional action. Hypnosis therefore relies upon inaccurate metacognition about intentional actions and experiences. Mindfulness meditation centrally involves awareness of intentions and is associated with improved metacognitive access to intentions. Therefore, mindfulness meditators and highly hypnotizable people may lie at opposite ends of a spectrum with regard to metacognitive access to intention‐related information. Here we review the theoretical background and evidence for differences in the metacognition of intentions in these groups, as revealed by chronometric measures of the awareness of voluntary action: the timing of an intention to move (Libet's “W” judgments) and the compressed perception of time between an intentional action and its outcome (“intentional binding”). We review these measures and critically evaluate their proposed connection to the experience of volition and sense of agency.

Reconsidering the autohypnotic model of the dissociative disorders

The dissociative disorders field and the hypnosis field currently reject the autohypnotic model of the dissociative disorders, largely because many correlational studies have shown hypnotizability and dissociation to be minimally related (r = .12). Curiously, it is also widely accepted that dissociative patients are highly hypnotizable. If dissociative patients are highly hypnotizable because only highly hypnotizable individuals can develop a dissociative disorder - as the author proposes - then the methodology of correlational studies of hypnotizability and dissociation in random clinical and community samples would necessarily be constitutively unable to detect, and statistically unable to reflect, that fact. That is, the autohypnotic, dissociative distancing of that small subset of highly hypnotizable individuals who repeatedly encountered intolerable circumstances is statistically lost among the data of (1) the highly hypnotizable subjects who do not dissociate and (2) subjects (of all levels of hypnotizability) who manifest other kinds of dissociation. The author proposes that, when highly hypnotizable individuals repeatedly engage in autohypnotic distancing from intolerable circumstances, they develop an overlearned, highly-motivated, automatized pattern of dissociative self-protection (i.e., a dissociative disorder). The author urges that theorists of hypnosis and the dissociative disorders explicitly include in their theories (a) the trait of high hypnotizability, (b) the phenomena of autohypnosis, and (c) the manifestations of systematized, autohypnotic pathology. Said differently, the author is suggesting that autohypnosis and autohypnotic pathology are unacknowledged nodes in the nomothetic networks of both hypnosis and dissociation.

Psychedelics and hypnosis: Commonalities and therapeutic implications

BACKGROUND

Recent research on psychedelics and hypnosis demonstrates the value of both methods in the treatment of a range of psychopathologies with overlapping applications and neurophenomenological features. The potential of harnessing the power of suggestion to influence the phenomenological response to psychedelics toward more therapeutic action has remained unexplored in recent research and thereby warrants empirical attention.

AIMS

Here we aim to elucidate the phenomenological and neurophysiological similarities and dissimilarities between psychedelic states and hypnosis in order to revisit how contemporary knowledge may inform their conjunct usage in psychotherapy.

METHODS

We review recent advances in phenomenological and neurophysiological research on psychedelics and hypnosis, and we summarize early investigations on the coupling of psychedelics and hypnosis in scientific and therapeutic contexts. Results/outcomes: We highlight commonalities and differences between psychedelics and hypnosis that point to the potential efficacy of combining the two in psychotherapy. We propose multiple research paths for coupling these two phenomena at different stages in the preparation, acute phase and follow-up of psychedelic-assisted psychotherapy in order to prepare, guide and integrate the psychedelic experience with the aim of enhancing therapeutic outcomes.

CONCLUSIONS/INTERPRETATION

Harnessing the power of suggestion to modulate response to psychedelics could enhance their therapeutic efficacy by helping to increase the likelihood of positive responses, including mystical-type experiences.

HYPNOTIZABILITY AND PAIN MODULATION: A Body-Mind Perspective

The study investigated whether the cardiac activity and cognitive-emotional traits sustained by the behavioral inhibition/activation system (BIS/BAS) may contribute to hypnotizability-related pain modulation. Nociceptive stimulation (cold-pressor test) was administered to healthy participants with high (highs) and low (lows) hypnotizability in the presence and absence of suggestions for analgesia. Results showed that heart rate increased abruptly at the beginning of nociceptive stimulation in all participants. Then, only in highs heart rate decreased for the entire duration of hand immersion. During stimulation with suggestions of analgesia, pain threshold negatively correlated with heart rate. BIS/BAS activity partially accounted for the observed hypnotizability-related differences in the relation between cardiac interoception and pain experience.

COMT Genotype and Sensory and Sensorimotor Gating in High and Low Hypnotizable Subjects

We investigated the association between hypnotizability, COMT polymorphism, P50 suppression ratio, and prepulse inhibition of acoustic startle response (ASR) in 21 high (HH) and 19 low (LH) hypnotizable subjects. The frequency of Met/Met carriers of COMT polymorphysm was higher in HH than in LH group (33.3% versus 10.6%, p = .049). Increased ASR amplitude and latency and decreased prepulse inhibition at 120 ms lead interval were found in the HH compared to the LH group. The effect of COMT genotype on prepulse inhibition was observed in LH group only. No between-group differences in P50 measures were found. The obtained results suppose the participation of dopamine system in mechanisms of hypnotizability and different allocation of attentional resources in HH and LH subjects.

The "hypnotic state" and eye movements: Less there than meets the eye?

Responsiveness to hypnotic procedures has been related to unusual eye behaviors for centuries. Kallio and collaborators claimed recently that they had found a reliable index for "the hypnotic state" through eye-tracking methods. Whether or not hypnotic responding involves a special state of consciousness has been part of a contentious debate in the field, so the potential validity of their claim would constitute a landmark. However, their conclusion was based on 1 highly hypnotizable individual compared with 14 controls who were not measured on hypnotizability. We sought to replicate their results with a sample screened for High (n = 16) or Low (n = 13) hypnotizability. We used a factorial 2 (high vs. low hypnotizability) x 2 (hypnosis vs. resting conditions) counterbalanced order design with these eye-tracking tasks: Fixation, Saccade, Optokinetic nystagmus (OKN), Smooth pursuit, and Antisaccade (the first three tasks has been used in Kallio et al.'s experiment). Highs reported being more deeply in hypnosis than Lows but only in the hypnotic condition, as expected. There were no significant main or interaction effects for the Fixation, OKN, or Smooth pursuit tasks. For the Saccade task both Highs and Lows had smaller saccades during hypnosis, and in the Antisaccade task both groups had slower Antisaccades during hypnosis. Although a couple of results suggest that a hypnotic condition may produce reduced eye motility, the lack of significant interactions (e.g., showing only Highs expressing a particular eye behavior during hypnosis) does not support the claim that eye behaviors (at least as measured with the techniques used) are an indicator of a "hypnotic state." Our results do not preclude the possibility that in a more spontaneous or different setting the experience of being hypnotized might relate to specific eye behaviors.

Inhibition of retrieval in hypnotic amnesia: dissociation by upper-alpha gating

Hypnotic amnesia is a functional dissociation from awareness during which information from specific neural processes is unavailable to consciousness. We test the proposal that changes in topographic patterns of cortical oscillations in upper-alpha (10–12 Hz) band selectively inhibit the recall of memories during hypnotic amnesia by blocking availability of locally processed information at specific points in retrieval. Participants were prescreened for high or low hypnotic susceptibility. Following hypnotic induction, participants were presented with a series of 60 face stimuli and were required to identify affective expressions. Participants received a suggestion for amnesia for these faces. They were then presented with a set of 30 old and 30 new faces and identified each as old or new. Amnesia suggestion was lifted and recall tested using the remaining 30 old faces and another 30 new faces. Exact Low Resolution Brain Electromagnetic Tomography source analyses are reported for 64 channel event-related electroencephalogram recorded from highs showing reversible amnesia to old faces. For high-susceptible participants, the amnesia suggestion significantly increased old faces wrongly identified while for low-susceptible participants amnesia suggestion increased the new faces wrongly identified. There were no differences between high- and low-susceptible participants following reversal of the suggestion. For previously seen faces which were wrongly identified, compared to new faces correctly identified, (late) evoked upper-alpha is significantly higher in right BA7 in a region implicated in top-down executive control to assist recall of visual information. Lagged nonlinear connectivity between cortical sources in upper-alpha in the same condition showed significantly increased connectivity between right BA34 (parahippocampal gyrus) and right BAs 7, 20 and 22. Integration between these regions is essential for recall of recent faces. During amnesia, spatial and temporal coordination of upper-alpha appears to suppress integrated functioning of these regions (hence recall). These patterns were absent after reversal of amnesia suggestion.

Suggestibility and signal detection performance in hallucination-prone students

INTRODUCTION

Auditory hallucinations are associated with signal detection biases. We examine the extent to which suggestions influence performance on a signal detection task (SDT) in highly hallucination-prone and low hallucination-prone students. We also explore the relationship between trait suggestibility, dissociation and hallucination proneness.

METHOD

In two experiments, students completed on-line measures of hallucination proneness (the revised Launay-Slade Hallucination Scale; LSHS-R), trait suggestibility (Inventory of Suggestibility) and dissociation (Dissociative Experiences Scale-II). Students in the upper and lower tertiles of the LSHS-R performed an auditory SDT. Prior to the task, suggestions were made pertaining to the number of expected targets (Experiment 1, N = 60: high vs. low suggestions; Experiment 2, N = 62, no suggestion vs. high suggestion vs. no voice suggestion).

RESULTS

Correlational and regression analyses indicated that trait suggestibility and dissociation predicted hallucination proneness. Highly hallucination-prone students showed a higher SDT bias in both studies. In Experiment 1, both bias scores were significantly affected by suggestions to the same degree. In Experiment 2, highly hallucination-prone students were more reactive to the high suggestion condition than the controls.

CONCLUSION

Suggestions may affect source-monitoring judgments, and this effect may be greater in those who have a predisposition towards hallucinatory experiences.

Relationship between hypnosis and personality trait in participants with high or low hypnotic susceptibility

BACKGROUND

The relationship between normal personality and hypnotic susceptibility is important for understanding mental processing and mental disorders, but it is less consistent in normal people or in patients with a psychiatric disorder. We have hypothesized that the correlation exists but varies in individuals with different levels of hypnotizability.

PARTICIPANTS AND METHODS

We invited 72 individuals with high (HIGH group) and 47 individuals with low (LOW group) hypnotic susceptibilities to undertake tests of NEO-PI-R and the Stanford Hypnotic Susceptibility Scale, Form C (SHSSC).

RESULTS

The HIGH group scored significantly higher than the LOW group did on openness to experience and its facet openness to feelings. In the LOW group, SHSSC total was positively predicted by openness to ideas; age regression was positively predicted by openness to experience and negatively predicted by extraversion; anosmia to ammonia was negatively predicted by agreeableness; and negative visual hallucination was positively predicted by openness to experience. In the HIGH group, hallucinated voice was positively predicted by openness to experience and negatively predicted by agreeableness, and posthypnotic amnesia was positively predicted by extraversion and negatively predicted by openness to experience.

CONCLUSION

The associations between normal personality traits and hypnotic susceptibility items were weak and different in the two groups, which imply that managing mental or somatoform disorders might be through adjusting hypnotizability and mobilizing personality functions.

Is high hypnotizability a necessary diathesis for pathological dissociation?

During the 19th century, high hypnotizability was considered to be a form of psychopathology that was inseparable from hysteria. Today, hypnotizability is considered to be a normal trait that has no meaningful relationship with psychopathology. Psychiatric patients generally manifest medium to low hypnotizability. Nevertheless, several psychiatric diagnoses are marked by an unexpectedly large proportion of patients with high hypnotizability. This is especially true of the diagnostic categories that were subsumed by the 19th-century concept of hysteria: dissociative identity disorder, somatization disorder, and complex conversion disorders. These hysteria-related modern diagnoses are also highly dissociative. A review and analysis of the literature regarding the relationship between hypnotizability and dissociation indicates that high hypnotizability is almost certainly a necessary diathesis for the development of a severe dissociative disorder. Such a diathesis has significant implications for (a) the psychiatric nosologies of the American Psychiatric Association and the World Health Organization, (b) the hypnosis field, and (c) the etiology and construct validity of dissociative identity disorder and other severe dissociative disorders. Specifically, the dissociative disorders (excepting depersonalization disorder, which is not classified as a dissociative disorder by the World Health Organization) are manifestations of hypnotic pathology.

Nuances and Uncertainties Regarding Hypnotic Inductions: Toward a Theoretically Informed Praxis

Although most definitions of hypnosis consider inductions as the initial stage in a hypnosis protocol, knowledge of inductions remains poor and uninformed by recent developments in theory and research. It is frequently argued that inductions play a critical role in hypnotic responding or, by contrast, are largely interchangeable and unimportant. Drawing on the literature on suggestibility, spontaneous phenomenology, neurophysiology, and cognition, this article argues that the value of inductions, as well as the potential value of inductions, is more nuanced and uncertain. Certain components of standard inductions appear to be efficacious in enhancing suggestibility, whereas others do not have any clear benefits. The impact of inductions on suggestibility seems to vary across suggestions and modes of assessment with the sources of this variability being unknown. Considering these effects, and the broader impact of inductions on spontaneous conscious states and cognition, through the lens of heterogeneity in high hypnotic suggestibility and componential models of hypnotic suggestibility may offer novel research avenues in this area. The article concludes by arguing for the practical and theory-driven optimization of inductions.

Dissociative Subtypes in Posttraumatic Stress Disorders and Hypnosis

Converging evidence suggests that heterogeneity in posttraumatic stress disorder (PTSD) arises from the presence of discrete subtypes of patients, one of which is characterized by elevated dissociative symptoms. A similar dissociative subtype has been observed among individuals displaying high hypnotic suggestibility. Here we highlight important parallels between these subtypes, drawing from research on a history of exposure to stressful life events and pathological symptomatology, cognitive functioning, hypnotic suggestibility, and functional neuroimaging and electrophysiology. Further clarification of these parallels can help elucidate the developmental paths and neurocognitive basis of heterogeneity in PTSD and high hypnotic suggestibility and refine the understanding and treatment of different subtypes of PTSD.

Patterns of hypnotic response, revisited

It has long been speculated that there are discrete patterns of responsiveness to hypnotic suggestions, perhaps paralleling the factor structure of hypnotizability. An earlier study by Brenneman and Kihlstrom (1986), employing cluster analysis, found evidence for 12 such profiles. A new study by Terhune (2015), employing latent profile analysis, found evidence for three such patterns among highly hypnotizable subjects, and a fourth comprising subjects of medium hypnotizability. Some differences between the two studies are described. Convincing identification of discrete "types" of high hypnotizability, such as dissociative and nondissociative, may require a larger dataset than is currently available, but also data pertaining directly to divisions in conscious awareness and experienced involuntariness.

Discrete response patterns in the upper range of hypnotic suggestibility: A latent profile analysis

High hypnotic suggestibility is a heterogeneous condition and there is accumulating evidence that highly suggestible individuals may be comprised of discrete subtypes with dissimilar cognitive and phenomenological profiles. This study applied latent profile analysis to response patterns on a diverse battery of difficult hypnotic suggestions in a sample of individuals in the upper range of hypnotic suggestibility. Comparisons among models indicated that a four-class model was optimal. One class was comprised of very highly suggestible (virtuoso) participants, two classes included highly suggestible participants who were alternately more responsive to inhibitory cognitive suggestions or posthypnotic amnesia suggestions, and the fourth class consisted primarily of medium suggestible participants. These results indicate that there are discrete response profiles in high hypnotic suggestibility. They further provide a number of insights regarding the optimization of hypnotic suggestibility measurement and have implications for the instrumental use of hypnosis for the modeling of different psychological conditions.

Are hypnosis and dissociation related? New evidence for a connection

The authors revisit the question of the existence of a relationship between hypnotizability and dissociative capacity. In the present study, the State Scale of Dissociation (SSD) replaced the commonly employed Dissociative Experiences Scale (DES) as a measure of dissociation, due to the latter capturing primarily pathological aspects of dissociation. Relationships between the Harvard Scale of Hypnotic Susceptibility, Form A (HGSHS:A), the SSD, and the Phenomenology of Consciousness Inventory (PCI) were assessed in the context of hypnosis. Robust results were found when comparing pre- to post-SSD scores, suggesting heightened nonpathological forms of dissociation are indeed related to hypnotizability. The appropriateness of the DES and similar trait-based measures for evaluating hypnotic phenomena is discussed as well as the relationships between PCI and SSD subscales.