High Hypnotizability Research Articles

Effects of Hypnosis on Regression to Primary-Process Thinking

The authors tested the hypothesis that hypnotic age regression produces a shift from secondary- to primary-thought processing in hypnotizable participants. Thirty participants were tested for hypnotizability using the Elkins Scale of Hypnotizability (EHS). Participants were exposed to a tailored hypnotic arm-levitation induction and a hypnotic suggestion to age regress to 5 years of age and to have a dream. Primary-process thinking was assessed using the Primary-Process Thinking Scale. An independent t test with 2 levels of hypnotizability (middle and high) showed high hypnotizables demonstrated higher ratings of primary thought processing than those in the middle group.

Brain Activity and Functional Connectivity Associated with Hypnosis.

Hypnosis has proven clinical utility, yet changes in brain activity underlying the hypnotic state have not yet been fully identified. Previous research suggests that hypnosis is associated with decreased default mode network (DMN) activity and that high hypnotizability is associated with greater functional connectivity between the executive control network (ECN) and the salience network (SN). We used functional magnetic resonance imaging to investigate activity and functional connectivity among these three networks in hypnosis. We selected 57 of 545 healthy subjects with very high or low hypnotizability using two hypnotizability scales. All subjects underwent four conditions in the scanner: rest, memory retrieval, and two different hypnosis experiences guided by standard pre-recorded instructions in counterbalanced order. Seeds for the ECN, SN, and DMN were left and right dorsolateral prefrontal cortex, dorsal anterior cingulatecortex (dACC), and posterior cingulate cortex (PCC), respectively. During hypnosis there was reduced activity in the dACC, increased functional connectivity between the dorsolateral prefrontal cortex (DLPFC;ECN) and the insula in the SN, and reduced connectivity between the ECN (DLPFC) and the DMN (PCC). These changes in neural activity underlie the focused attention, enhanced somatic and emotional control, and lack of self-consciousness that characterizes hypnosis.

Asymmetric Tactile Foot Stimulation: How Postural Studies May Suggest New Views of Hypnotizability

Earlier studies have shown hypnotizability-related postural effects of visual suppression and of leg and neck proprioceptive alteration. This study completes this investigation by demonstrating the postural effects of asymmetric tactile foot stimulation in standing participants with different hypnotizability scores. During this stimulation, body sway changed in medium-to-high more than in low-to-medium hypnotizable participants. Findings support the view that high hypnotizability is associated with higher vulnerability of posture to sensory alteration; together with earlier results, they suggest a role of the cerebellum in the observed hypnotizability-related differences and prompt investigation of cerebral structures and factors potentially responsible for both the cognitive and physiological aspects of hypnotizability.

Attentional Dissociation in Hypnosis And Neural Connectivity: Preliminary Evidence from Bilateral Electrodermal Activity

According to recent findings, interhemispheric interactions and information connectivity represent crucial mechanisms used in processing information across various sensory modalities. To study these interactions, the authors measured bilateral electrodermal activity (EDA) in 33 psychiatric outpatients. The results show that, during congruent Stroop stimuli in hypnosis, the patients with higher hypnotizability manifest a decreased level of interhemispheric information transfer measured by pointwise transinformation (PTI) that was calculated from left and right EDA records. These results show that specific shifts of attentional focus during hypnosis are related to changes of interhemispheric interactions that may be reflected in neural connectivity calculated from the bilateral EDA measurement. This attentional shift may cause dissociated attentional control disturbing integrative functions of consciousness and contextual experiences.

Do actors possess traits associated with high hypnotizability?

Do actors possess traits associated with high hypnotizability?

The relation of hypnotizability and dissociation to everyday mentation: An experience-sampling study.

Research has found that individuals varying in hypnotizability and dissociation respond differently to questionnaires and procedures geared to affect their state of consciousness, but their stream of consciousness in everyday life has not been investigated. We evaluated the everyday mentation of students (N 46) in a 2 (High vs. Low Hypnotizability) 2 (High vs. Low Dissociative) design through experience sampling with personal digital assistants (PDAs). The PDAs prompted volunteers randomly 8 times per day during 5 days and included questions about attention, type of mental activity, and mood, among others, which resulted in 5 factors: focus/absorption, daydreaming, negative affect, control/awareness, and detachment. High control/ awareness correlated with high focus/absorption, low negative affect, and low detachment. Detachment correlated also with daydreaming. As predicted, high dissociatives reported less control but more detachment and negative affect than low dissociatives. High hypnotizables (Highs) did not report more focus/absorption than low hypnotizables (Lows) but endorsed more daydreaming and negative affect. Highs reported more thoughts than Lows, and Lows reported more sensory impressions than Highs. Hypnotizability and dissociation also interacted: Low dissociatives/Lows reported less daydreaming than the others, and high dissociatives/Lows experienced less control than the other 3 groups combined. Participants reported less control/awareness during daydreaming, with high dissociatives/Highs showing a larger decrement than the others. Most mentations referred to thoughts or sensory impressions; the former were characterized by more negative affect than the latter. In general, individuals felt more dysphoric when (Less)

High Hypnotizability Impairs the Cerebellar Control of Pain

In the general population, transcranial anodal direct current stimulation of the cerebellum (ctDCS) reduces pain intensity and the amplitude of nociceptive laser evoked potentials (LEPs), whereas cathodal ctDCS elicits opposite effects. Since behavioral findings suggest that the cerebellar activity of highly hypnotizable individuals (highs) differs from the general population, we investigated whether hypnotizability-related differences occur in the modulation of pain by ctDCS. Sixteen healthy highs (according to the Stanford Hypnotic Susceptibility Scale, form A) and 16 participants not selected according to hypnotizability (controls) volunteered to undergo laser nociceptive stimulation of the dorsum of the left hand before and after anodal or cathodal ctDCS. LEPs amplitudes and latencies and the subjective pain experience (Numerical Rating Scale) were analyzed. Smaller LEP amplitudes and longer latencies were observed in highs with respect to controls independently of stimulation. After anodal and cathodal cerebellar stimulation, controls reported lower and higher pain than before it, respectively. In contrast, highs did not report significant changes in the perceived pain after both stimulations. They increased significantly their N2/P2 amplitude after anodal ctDCS and did not exhibit any significant change after cathodal tDCS, whereas controls decreased the N1 and N2P2 amplitude and increased their latency after anodal cerebellar stimulation and did the opposite after cathodal ctDCS. In conclusion, the study showed impaired cerebellar pain modulation and suggested altered cerebral cortical representation of pain in subjects with high hypnotizability scores.

Hypnosis and Empathy: A Complex Relationship

This article takes its inspiration from Wickramasekera II’s empathic involvement theory of hypnosis. That model illuminates the mutual territory of hypnosis and empathy—common to much interaction between hypnotist and subject, and to the internal process of subjects as they enact suggestions of the hypnotist. However, the present article suggests that the overlap is not as ubiquitous as the empathic involvement theory asserts. Other aspects of hypnosis involve disengagement from real persons in the environment and dissociating from other ego states of the self. Amnesia and certain uses of focused attention in the hypnotic context run counter to empathy. The fantasizer type of high hypnotizables experiences hypnosis more empathically than do the equally hypnotizable dissociater type. This article also explores the relationship of hypnosis and empathy to other related states, including meditation, dreaming, and psychedelic drugs. The conclusion is that empathy is an important component of many hypnotic phenomena, but that the relationship is as partial and complex as the manner in which other traits, such as imagery ability and dissociation, map onto hypnosis.

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.

High hypnotizability reverses the effects of the cerebellar direct transcutaneous stimulation (tDCS) on pain

Anodal and cathodal cerebellar stimulation in highly hypnotizable healthy individuals. Laser nociceptive stimulation. Anodal stimulation modulates pain perception and LEPs amplitude in a direction opposite to that observed in the general population.

Chaos–chaos transition of left hemisphere EEGs during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility

A recent study, recurrence quantification analysis of EEG signals during standard tasks of Waterloo-Stanford Group Scale of hypnotic susceptibility investigated recurrence quantifiers (RQs) of hypnotic electroencephalograph (EEG) signals recorded after hypnotic induction while subjects were doing standard tasks of Waterloo-Stanford Group Scale (WSGS) of hypnotic susceptibility to distinguish subjects of different hypnotizability levels. Following the same analysis, the current study determines the capability of different RQs to distinguish subjects of low, medium and high hypnotizability level and studies the influence of hypnotizability level on underlying dynamic of tasks. Besides, EEG channels were sorted according to the number of their RQs, which differed significantly among subjects of different hypnotizability levels. Another valuable result was determination of major brain regions in observing significant differences in various task types (ideomotors, hallucination, challenge and memory).

Carriers of the COMT Met/Met Allele Have Higher Degrees of Hypnotizability, Provided That They Have Good Attentional Control: A Case of Gene–Trait Interaction

Genetic factors may explain part of the interindividual variability in hypnotizability. A new avenue that may provide more comprehensive understanding of the phenotypic effects of genetic variations is the study of gene–trait interaction. In this study, the authors investigate the relationship of the dopamine-related COMT and the serotonin-related 5-HTTLPR polymorphisms to hypnotizability by taking individual differences in executive attention into account. Homozygosity for the COMT Met allele, putatively linked to the capability or proneness to dissociate from reality, was associated with high hypnotizability only if paired with high-attention ability. The finding can be integrated into hypnosis theory and represents a case of gene–trait interaction suggesting that investigating the effects of a gene in the context of relevant psychological traits may further elucidate gene-brain-behavior relationships.

Hypnotizability, Personality Style, and Attachment: An Exploratory Study, Part 1—General Results

This article is an exploratory study investigating the relationship between hypnotizability, personality style, and attachment. Data were collected from 99 students by means of the Harvard Group Scale of Hypnotic Susceptibility, Form A; Personality Styles and Disorders Inventory; and Relationship Scale Questionnaire. Results suggest that individual personality styles accounted for a significant amount of variance in hypnotizability in: (a) the whole sample, (b) the securely attached, and (c) the insecurely attached. High hypnotizables among both the whole sample and securely attached individuals shared the unselfish/self-sacrificing personality style as a main predictor of hypnotizability and displayed elevated scores for the charming/histrionic and the optimistic/rhapsodic personality style. Furthermore, two groups were identified among the high hypnotizables that differed mainly according to attachment style: one consists of securely attached, charming/histrionic, and optimistic/rhapsodic people, who are best described by socio-cognitive theories. The other is composed of insecurely attached intuitive/schizotypal people, who are better depicted by dissociation theories.

Hypnotizability, Personality Style, and Attachment: An Exploratory Study, Part 2—Results With Particular Focus on Sex

The relationship between hypnotizability, personality style, and attachment was examined according to sex in 99 student participants. No specific differences for personality and hypnotizability were found in the highly hypnotizable participants according to sex. Similarly, no differences were found between high, medium, and low hypnotizable females, though differences were found among males. For males, the best predictor of hypnotizability was the unselfish/self-sacrificing personality style, which explained 40% of variance. This was in contrast to low hypnotizable males, who were less spontaneous/borderline, self-critical/avoidant, unselfish/self-sacrificing, but more assertive/antisocial. In comparison with females, low hypnotizable males were less intuitive/schizotypal and less loyal/dependent. Within the whole sample and among securely attached high hypnotizables, two peaks were observed for charming/histrionic and optimistic/rhapsodic styles, which suggests a “prone to hypnosis” personality style. Such people are optimistic and charming, and tend to be securely attached. This may suggest a high self-selection bias in hypnosis experiments and potentially creates confounds for the majority of such studies.

New views of hypnotizability.

New views of hypnotizability.

Effects of Hypnotic Analgesia and Virtual Reality on the Reduction of Experimental Pain Among High and Low Hypnotizables

This research compared a no-treatment control condition and 3 experimentally induced pain treatment conditions: (a) virtual reality distraction (VRD), (b) hypnotic analgesia (HA), and (c) HA + VRD in relieving finger-pressure pain. After receiving baseline pain stimulus, each participant received hypnosis or no hypnosis, followed by VRD or no VRD during another pain stimulus. The data analysis indicated that, overall, all 3 treatments were more effective compared to the control group, irrespective of whether it involved hypnotic analgesia, virtual reality distraction, or both (hypnosis and virtual reality). Nevertheless, the participants responded differently to the pain treatment, depending on the hypnotizability level. High hypnotizables reported hypnotic analgesia, but low hypnotizables did not show hypnotic analgesia. VR distraction reduced pain regardless of hypnotizability.

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.

Are Highly Hypnotizable People Naturally Aware Of Their Hypnotic Talents? Implications for Human Potentialities 1

This article investigated the degree to which high hypnotizables are aware of their capability and assessed their ability to produce it without guidance from a hypnotist. Qualitative data suggest that most participants reported being surprised by their hypnotic responsiveness and the realness of the suggestions. Quantitative data tended to support this trend, in which participants had higher overall responsiveness scores, both objectively and subjectively, when the suggestions were given by a hypnotist compared to self-hypnosis. Though some were able to self-produce some hypnotic phenomena, all participants reported that it was easier to experience the suggested effects when given by the hypnotist. An explanation accounting for this finding, implications for future research, and limitations of the study are also provided.

Subjects’ hypnotizability level affects somatosensory evoked potentials to non-painful and painful stimuli

ObjectiveWe evaluated the working hypothesis that the EEG activity associated to non-painful and painful stimuli in condition of waking state (no hypnotic procedure) was related to the hypnotizability level. MethodsHypnotizability level was measured in 16 healthy subjects through the Italian version of the Stanford Hypnotic Susceptibility Scale (SHSS, score: 0–12). EEG data (56 electrodes) were recorded during non-painful and painful electrical stimuli applied to the left index finger. Cortical activity (vertex N1–P2 complex) was compared in subjects with low hypnotizability level (N=8, SHSS:0–6) vs. subjects with high hypnotizability level (N=8, SHSS:7–12). ResultsThe amplitude of the N1–P2 complex was lower in the High-hypnotizability compared to the Low-hypnotizability group over primary sensorimotor cortex (C3 and C4 electrodes) and centro-parietal midline areas (Cz and Pz electrodes) for non-painful and painful stimuli. The SHSS showed a statistically significant negative correlation with the vertex N1–P2 complex at C3 and Cz (r=−0.5, p<0.05) electrodes for non-painful stimuli. ConclusionCompared to the Low-hypnotizability subjects, High-hypnotizability subjects showed a reduced cortical activity related to non-painful and painful stimuli. SignificanceThe results suggest a relationship between hypnotizability and cortical activity related to non-painful and painful stimuli in the condition of waking state (no hypnotic effect).

Body sway modulation by hypnotizability and gender during low and high demanding postural conditions.

The cognitive trait of hypnotizability, associated with the proneness to accept suggestions, exhibits several physiological correlates including the modulation of sensorimotor integration and, in particular, of postural control. In this respect, we have shown that, at eyes closure, healthy subjects with high hypnotizability scores (highs) having their feet 2 cm apart show larger and faster body sway with respect to low hypnotizable individuals (lows). The aim of the present study was to investigate whether hypnotizability modulates body sway during slightly more demanding and very difficult postural conditions such as feet together bipedal posture and one legged stance, respectively. The Center of Pressure (CoP) Area, mean Velocity, the CoP mean position (Xmean, Ymean) and its variability (SDx, SDy) in the frontal and sagittal planes were acquired in 18 highs (9 females) and 18 lows (9 females). Results showed that the previously observed lows' smaller and slower body sway was not present any longer. Nonetheless, hypnotizability interacted with gender in the modulation of the variability of the CoP movement in the frontal plane during both the bipedal feet together posture and one legged stance, as significant gender differences were observed only among lows. In conclusion, results confirm a role of hypnotizability in sensorimotor integration and support the relevance of hypnotic assessment in clinical settings, as hypnotizability may be responsible for part of the postural variability.