High Hypnotizability Research Articles

The Role of Interoceptive Sensitivity and Hypnotizability in Motor Imagery.

Motor imagery (MI) requires the mental representation of the body, obtained by integrating exteroceptive and interoceptive information. This study aimed to investigate the role of interoceptive sensitivity (IS) in MI performed through visual and kinesthetic modalities by participants with low (lows, N = 26; SHSS: A, M + SD: 1.00 + 1.52), medium (mediums, N = 11; SHSS: A, 6.00 + 0.77) and high hypnotizability scores (highs, N = 16; SHSS:A, 9.75 + 1.24), as measured by the Stanford Hypnotic Susceptibility Scale: Form A. The three groups displayed different MI abilities and IS levels. The efficacy of MI was measured using the chronometric index and self-reported experience, while IS was measured using the Multidimensional Assessment of Interoceptive Awareness (MAIA) questionnaire. Alpha and beta power spectrum densities (PSDs) were extracted from the EEG signals acquired during baseline, actual movement and visually and kinesthetically imagined movements. The chronometric indices do not reveal significant differences between groups and imagery modalities. The self-report MI efficacy indicates better kinesthetic imagery in highs and mediums than in lows, and no modality difference among lows. The MAIA dimensions sustain the differences in subjective experience and almost all the EEG differences. The latter are slightly different in highs, mediums and lows. This is the first report of the major role played by IS in MI and strongly supports the theory of embodied cognition.

A neurophenomenological fMRI study of a spontaneous automatic writer and a hypnotic cohort

Purpose: To evaluate the neurophenomenology of automatic writing (AW) in a spontaneous automatic writer (NN) and four high hypnotizables (HH). Methods: During fMRI, NN and the HH were cued to perform spontaneous (NN) or induced (HH) AW, and a comparison task of copying complex symbols, and to rate their experience of control and agency. Results: Compared to copying, for all participants AW was associated with less sense of control and agency and decreased BOLD signal responses in brain regions implicated in the sense of agency (left premotor cortex and insula, right premotor cortex, and supplemental motor area), and increased BOLD signal responses in the left and right temporoparietal junctions and the occipital lobes. During AW, the HH differed from NN in widespread BOLD decreases across the brain and increases in frontal and parietal regions. Conclusions: Spontaneous and induced AW had similar effects on agency, but only partly overlapping effects on cortical activity.

Placebo or Nocebo Interventions as Affected by Hypnotic Susceptibility

The purpose of the present study was to examine placebo and nocebo effects under hypnotic analgesia in lowly hypnotizable (LH) and highly hypnotizable (HH) subjects. A placebo and nocebo, obtained in a two-step intervention (verbal expectation and conditioning), were studied in 12 LH and 12 HH subjects under hypnosis. Visual analog scales (VASs) of pain intensity were recorded in response to short, painful electrical stimuli. VAS scores of placebo-produced analgesia differed significantly from nocebo-produced hyperalgesia in the LH subjects. Placebo intervention combined with hypnotic analgesia in LH subjects led to an analgesic degree similar to that achieved in the HH subjects. Yet, no difference was detected between the placebo and the nocebo effects on the HH subjects. Expectations for placebo and nocebo were significantly higher in the LH subjects than in the HH subjects. It seems that the HH subjects were more “tuned” to an inner trait that made them less susceptible to contextual cues, and therefore, more resistant to placebo/nocebo interventions. The ability to achieve hypnotic analgesia in LH subjects to the degree reached in the HH subjects under combined placebo intervention and hypnosis induction is of clinical significance. Combining placebo intervention with the induction of hypnotic analgesia could markedly improve analgesia, regardless of the patients’ hypnotic susceptibility.

Hypnotizability May Relate to Interoceptive Ability to Accurately Perceive Sleep Depth: An Exploratory Study

ABSTRACT When individuals score high on hypnotizability, they usually report experiencing an altered state of consciousness, physiological changes, and attentional shifts during hypnotic induction procedures as well. We hypothesize that a better interoception of such internal changes is also relevant for accurate sleep perception. We compared subjects scoring high versus low on hypnotizability to the accuracy of their estimations of Sleep Onset Latency (SOL) time awake, and sleep depth and explored their objective sleep. We sampled seven studies performed in our sleep labs across a midday nap or a night resulting in n = 231 subjects (aged 30.11 (SD = 17.02) years, range 18–82 with 15.2% males). Hypnotizability did not influence the accuracy of the perception of time needed to fall asleep or time spent awake. However, the reported sleep depth correlated significantly with the measured amount of slow-wave sleep in high hypnotizables. This pattern appeared across a nap as well as a whole night’s sleep studies. We did not find any significant differences in objective sleep patterns depending on hypnotizability. Probably, high hypnotizables benefit from a better interoceptive ability for their perception of their sleep depth.

Electrodermal Orienting Response During Active-Alert Hypnosis: Do Verbal Suggestions Influence Automatic Attentional Processes?

ABSTRACT This study explored the influence of suggestions on differences in electrodermal laterality of the skin conductance orienting response (SCR). Thirty-two participants were randomly assigned to either permitting or excluding suggestions. During the dream task in the permitting condition the suggestion was: “You are aware of your surroundings and any distractions that might disturb your dream,” while in the excluding condition the wording was: “No outside stimulus will disturb your sleep.” Participants were presented with 12 standards and 2 deviant computer-generated tones during active-alert hypnosis and musical control conditions in a mixed within-between design. High hypnotizables produced higher SCRs after permissive compared to excluding suggestions during hypnosis, while low hypnotizables did the same in the control condition. Study limitations include some loss of data due to equipment failure and relative homogeneity of sample, therefore results cannot be considered definitive.

Cerebrovascular reactivity during visual stimulation: Does hypnotizability matter?

Hypnotizability is a trait associated with several physiological correlates including cardiovascular control. The present study aimed to investigate the posterior cerebral artery flow velocity (PCAv) in basal closed eyes (B) and during visual stimulation (VS) conditions in med-highs and med-lows. Twenty-four healthy volunteers were submitted to the hypnotic assessment through the Stanford Hypnotic Susceptibility Scale, form A which classified 13 low-to-medium (med-lows) and 10 high-to-medium (med-highs) hypnotizable participants. One subject scoring 6 out of 12 was excluded from the comparisons between groups. Arterial blood pressure, heart rate, and partial pressure of end-tidal CO2 were monitored during both B and VS conditions. Simultaneously, PCAv was assessed by transcranial Doppler. Cerebrovascular Reactivity (CVR) was computed as a percentage of the PCAv change occurring during VS with respect to B (ΔPCAv). During VS both groups increased their PCAv (mean ± SD: 7.9 ± 5.2 %) significantly with no significant group difference. However, among med-highs, CVR was negatively correlated with hypnotizability scores. Thus, higher hypnotizability may be associated with lower metabolic demand in response to VS only within med-highs hypnotizable participants.

Cerebral Blood Flow in Healthy Subjects with Different Hypnotizability Scores.

Hypnotizability is a cognitive trait associated with differences in the brachial artery flow-mediated dilatation of individuals with high hypnotizability (highs) and low hypnotizability scores (lows). The study investigated possible hypnotizability-related cerebrovascular differences. Among 24 healthy volunteers, the Stanford Hypnotic Susceptibility Scale Form A identified 13 medium-to-lows (med-lows), 11 medium-to-highs (med-highs), and 1 medium hypnotizable. Hypnotizability did not influence the significant changes produced by the trail making task (TMT), mental arithmetic task (MAT), hyperventilation (HVT), and rebreathing (RBT) on heart rate (HR), arterial blood pressure (ABP), and partial pressure of end-tidal CO2 (PETCO2), but moderated the correlations between the changes occurring during tasks with respect to basal conditions (Δ) in ABP and PETCO2 with middle cerebral artery flow velocity (MCAv). In HVT, med-lows exhibited a significant correlation between ΔMCAv and ΔPETCO2, and med-highs showed a significant correlation between ΔABP and ΔMCAv. Cerebrovascular reactivity (CVR) and conductance (ΔCVCi) were significantly correlated with ΔMCAv only in med-lows during HVT and RBT. For the first time, cerebrovascular reactivity related to hypnotizability was investigated, evidencing different correlations among hemodynamic variables in med-highs and med-lows.

Well-Being in Highly Hypnotizable Persons

ABSTRACT Both hypnotizability and well-being are relevant to health. This study aimed to investigate whether high hypnotizability was positively associated with well-being and whether the latter was related to the activity of the behavioral inhibition/approach system (BIS/BAS). ANOVA revealed significantly higher scores on the General Well-Being Index (PGWBI) in highly hypnotizable (highs, n = 31) compared with low hypnotizable participants (lows, n = 53), with medium hypnotizable participants (mediums, n = 41) exhibiting intermediate values. This finding was discussed in relation to other hypnotizability-related traits, such as morpho-functional brain characteristics, equivalence between imagery and perception, and interoceptive sensitivity. A secondary finding was a nonsignificant gender difference in scores on the PGWBI. The highs’ higher well-being could be considered a favorable prognostic factor for physical and mental health.

Semantic Adaptation and Validation of the Stanford Hypnotic Susceptibility Scale, Form C, in the Chilean Population

ABSTRACT One of the difficulties of evaluating hypnotizability in Chile is the limited existence of validated instruments. In this study, the Mexican version of Stanford Hypnotic Susceptibility Scale, Form C, was semantically adapted and validated. A descriptive cross-sectional study was carried out in 102 Chilean university students. The content validation was performed by 3 experts; the internal consistency was evaluated with KR-20. The difficulty of the items was measured with a difficulty index. The majority of the students were classified with high hypnotizability. The mean score obtained was 7.41 (SD = 1.84). The internal consistency was acceptable (KR-20 = 0.73). The item with the least difficulty was arm lowering, whereas the auditory hallucination was the item with the greatest difficulty. The survey showed metric properties to be considered as a valid and reliable instrument to measure the level of hypnotizability in the Chilean population.

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.

Electrodermal Correlates of Hypnosis: Current Developments

Hypnosis has proven to be an effective treatment in disorders that affect the autonomic nervous system (ANS). However, the studies investigating the nature of its effect on the ANS have reported contradictory results. Measurement of electrodermal activity (EDA) is an objective way to assess the activity of the sympathetic branch of the ANS. We aim to elucidate the effects of hypnosis on EDA. Here, we report the results of two studies, both investigating the psychophysiological effects of hypnosis.In the first experiment, subjects engaged in an HGSHS:A group hypnosis session to measure their hypnotizability. EDA was measured bilaterally from their wrists. We found a significant reduction in EDA levels and the number of nonspecific responses during the hypnotic induction phase. This effect was observed in all three hypnotizability groups—high, medium, and low hypnotizables. A three-way interaction confirmed that EDA patterns on the left and right sides were characteristically different in these three groups. Left-side dominance was typical in high hypnotizables, whereas low hypnotizables were characteristically right-sided. EDA levels of the two sides remained synchronous in medium hypnotizables. During the suggestion phase, we found significant differences in EDA levels depending on the test suggestions, modulated by hypnotizability. A suggestion, harder to respond to, elicited higher arousal in high hypnotizables as compared to low hypnotizables. In the second experiment, we performed five consecutive hypnosis sessions to confirm the reproducibility of the most prominent effect found in Study 1—a gradual decrease in the level of skin conductance during hypnotic induction. We also confirmed that this effect is independent of the hypnotizability level. We conclude that arousal is bilaterally reduced during hypnosis induction, which is persistent across different levels of hypnotizability. At the same time, lateral differences define unique EDA patterns in the induction phase, characterizing high, medium, and low hypnotizables.

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 (I1mv) 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.

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

ABSTRACT 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.

CHANGES IN OXYTOCIN AND CORTISOL IN ACTIVE-ALERT HYPNOSIS: Hormonal Changes Benefiting Low Hypnotizable Participants

It is increasingly clear that oxytocin and cortisol play an intricate role in the regulation of behavior and emotions impacting health, relationships, and well-being. Their long-term, cross-generational effect makes them an important focus of the present study. This exploratory research examined changes in oxytocin and cortisol levels and their correlations with different phenomenological measures in both hypnotist and subject during active-alert hypnosis. The level of oxytocin increased whereas the level of cortisol decreased in the hypnotist. When comparing the oxytocin changes of subjects with their hypnotizability, those with low hypnotizability scores experienced an increase in oxytocin, and those with medium and high hypnotizability scores showed no change or decrease. This could explain why clients’ hypnotizability is not considered an important factor during hypnotherapy.

Investigation of the Effect of Hypnotic Anesthesia on Nerve Conduction Velocity (NCV).

BackgroundHypnosis is a psychological method used for treatment of different types of disorders and illnesses. This technique is also used in surgical interventions. Many studies proved the efficacy of hypnosis in medical treatment. However, the mechanism of hypnosis is unclear for scientists. To find out if the peripheral nervous system has a role in hypnotic anesthesia, we aimed to investigate the effect of hypnotic anesthesia on nerve conduction velocity (NCV).MethodsIn this study, healthy volunteers with high hypnotizability entered the study. First, The NCV test was performed in both hands of participants and then they all underwent hypnosis. Hypnotic anesthesia was induced in the right hand of all subjects followed by painful stimuli in their hand by vascular clasping. Then, the NCV test was repeated in both hands again. Data were analyzed by SPSS version16.ResultsThe group study consisted of 13 (65%) women and 7 (35%) men with their age ranging between 14 to 52 years. According to the results, the mean values of sensory latency, and NCV changed from 3.225 ms and 54.355 m/s before hypnotic anesthesia to 3.32 ms and 55.3 m/s after hypnotic anesthesia in right hand, respectively. Results showed that there was a significant difference between data before and after hypnotic induction (P < 0.001). The covariance test also indicated a significant difference between the data obtained from both hands (P < 0.001).ConclusionsIn contrast to our hypothesis, the NCV test showed an increase after the hypnotic anesthesia. However, increase in NCV did not lead to experience pain after the painful stimuli. It seems that central nervous system should be involved in this process.

REVISITING THE SAFE PLACE:Method and Regulatory Aspects in Psychotherapy when Easing Allostatic Overload in Traumatized Patients

Safe-place inductions are considered important altered states of consciousness (ASC) to be (re)installed during trauma-informed psychotherapy. Coregulation aimed at changing implicit relational knowing and increasing integration and coherence through relational work and hypnotic techniques is crucial, as clients’ abilities to self-soothe and regulate have become seriously impaired. Thus, resource-oriented metaphors as inner strength imagery is advocated. Also, methods such as creative-arts therapy and neurofeedback will induce ASCs, as most methods used with complex traumatized clients, due to their high hypnotizability. When positive or soothing imagery or relationally held suggestions for changed attentional focus are added to both psychodynamic psychotherapy and CBT, a hetero-hypnosis will be induced—a prerequisite for phase-specific trauma therapy aimed at changing inner schemas and scripts.

ENHANCING IMPLICIT LEARNING WITH POSTHYPNOTIC SUGGESTION: An ERP Study

Can posthypnotic suggestion (PHS) enhance cognitive abilities? The authors tested behaviorally and with event-related potentials (ERP) if sequential learning (SL), the ability to learn statistical regularities, can be enhanced with PHS. Thirty adults were assessed with the Stanford Hypnotic Susceptibility Scale (Form C) and an auditory SL task. Before this task, half the sample received a PHS to enhance SL, and the other half received the same suggestion under normal waking state. Response times and ERPs indicated a strong effect of PHS. Compared to the control group, PHS inverted, attenuated, or left unaffected the response time SL effect in low, medium, and high hypnotizability participants, respectively. These results suggest that PHS cannot be used to enhance SL.

Reconsidering the autohypnotic model of the dissociative disorders

ABSTRACTThe 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.

Hypnotizability and the Peripersonal Space

High hypnotizability is associated with left-sided cerebral asymmetry, which could influence measurement of the Peripersonal Space (PPS). Right-handed participants with high (highs, n = 20), medium (mediums, n = 9), and low hypnotizability scores (lows, n = 20) performed the line bisection test on a computer screen automatically displaced at distances of 30, 60, and 90 cm from the subjects’ eyes. Highs’ results showed rightward bias of the bisection (Relative Error, RE) for all presentation distances. In contrast, in lows RE was displaced leftward at 30 cm and exhibited a progressive rightward shift at 60 and 90 cm, as occurs in the general population. Mediums’ RE values were intermediate between highs’ and lows’ values. Bisection Times (BT) were significantly longer in highs/mediums than in lows. Findings indicate that the highs’ bisection identifies PPS as if it was extrapersonal, but further studies should assess its functional characteristics. The highs/mediums longer BT suggest less efficient sensorimotor performance.

A Neutral Control Condition for Hypnosis Experiments: “Wiki” Text

A new control condition called Wiki is introduced. Key themes of each test suggestion of the Stanford Hypnotic Susceptibility Scale, Form C, were matched by a corresponding extract from Wikipedia.org. The authors compared phenomenological reports of participants across 4 conditions: hypnosis split into high and low hypnotizable subgroups, music, and Wiki condition, using the Phenomenology of Consciousness Inventory. High hypnotizables undergoing hypnosis reported higher altered experience and altered states of awareness than individuals in the Wiki condition, supporting the authors’ hypothesis that the Wiki condition does not evoke an altered state of consciousness (internal dialogue, volitional control, and self-awareness did not differ). Wiki might be a viable control condition in hypnosis research given further examination.