Hypnotic Responsiveness Research Articles

Variations in the sense of agency during hypnotic responding: Insights from latent profile analysis.

The primary phenomenological feature of a response to hypnotic suggestion is the perception that a person is not the author of their actions and experiences. This distortion in volition during hypnotic responding, known as the classic suggestion effect, has the potential to illuminate the neurocognitive mechanisms underlying hypnosis and inform broader models of agency. Here, we sought to clarify interindividual differences in the patterns of agency that participants experience during hypnosis. We applied latent profile analysis, a finite mixture modeling method for partitioning participants into homogeneous classes, to participants’ responses to a standardized behavioral measure of hypnotic suggestibility and an experiential measure of sense of agency during hypnotic responding. The best fitting model suggested that there were 4 discrete response patterns: a low suggestible class, 2 medium suggestible classes, and 1 highly suggestible class. The 2 medium suggestible classes displayed nearly equivalent patterns of behavioral hypnotic responding but diverged in their experience of agency during hypnotic responding: 1 class experienced greater involuntariness during responding, whereas the other experienced greater effortlessness during responding. These results reinforce previous research highlighting differential patterns of hypnotic responding and complement work suggesting that there may be 2 or more phenomenologically distinct modes of hypnotic responding. They also have a number of implications for the measurement of hypnotic responding and for the use of low and medium suggestible individuals in experimental hypnosis research designs.

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.

What Can a Hypnotic Induction Do?

In contrast to how recent definitions of hypnosis describe the induction, a work-sample perspective is advocated that characterizes the induction as an initial, stage-setting phase encompassing everything in a hypnotic session up to the first hypnotic suggestion of particular relevance to the therapeutic or research goals at hand. Four major ways are then discussed in which the induction could affect subsequent hypnotic responses: It may provide information about how subsequent behaviors are to be enacted; it may provide cues about the nature of the interpersonal interaction to be expected in hypnosis; it may provide meta-suggestions, defined as suggestive statements intended to enhance responses to subsequent hypnotic suggestions; and it may provide a clear transition to help allow new behaviors and experiences to emerge. Several ideas for future research are advanced, such as mapping hypnosis style onto the interpersonal circumplex, evaluating whether attentional-state changes measured at the end of the induction actually mediate subsequent hypnotic responsiveness, and systematically examining the impact of ritual-like aspects of inductions.

Role of Beliefs About Hypnotic States as a Moderator Variable: A Reexamination of the Relationship Between Reactance and Hypnotizability

The hypothesis that beliefs about hypnosis determine the amount of psychological reactance aroused was tested. Participants were administered a measure of trait reactance to therapist directives (Therapeutic Reactance Scale; TRS), the Beliefs about Hypnotic State Questionnaire (BHSQ–R), and behavioral and subjective scales concerning hypnotic response. Hierarchical multiple regressions revealed significant interactions between BHSQ–R subscales and TRS. The findings suggest that the arousal of psychological reactance to hypnosis is determined by individuals’ trait reactance levels acting together with their interpretations of the hypnotic situation. The role of beliefs about hypnotic states as a moderator of the relationship between personality and hypnotizability was discussed.

Metacognition of intentions in mindfulness and hypnosis.

In a famous series of experiments, Libet investigated the subjective timing of awareness of an intention to move, a task that can be considered a metacognitive judgement. The ability to strategically produce inaccurate metacognitions about intentions has been postulated to be central to the changes in judgements of agency common to all hypnotic responding. Therefore, differences in hypnotisability may be reflected in Libet’s measure. Specifically, the ability to sustain inaccurate judgements of agency displayed by highly hypnotisable people may result from their having coarser higher order representations of intentions. They, therefore, should report a delayed time of intention relative to less hypnotisable individuals. Conversely, mindfulness practice aims at accurate metacognition, including of intentions, and may lead to the development of finer grained higher order representations of intending. Thus, the long-term practice of mindfulness may produce an earlier judgement of the time of an intention. We tested these groups using Libet’s task, and found that, consistent with predictions, highly hypnotisable people reported a later time of intention than less hypnotisable people and meditators an earlier time than non-meditators. In a further two studies, we replicated the finding that hypnotisable people report later awareness of a motor intention and additionally found a negative relationship between trait mindfulness and this measure. Based on these findings, we argue that hypnotic response and meditation involve opposite processes.

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.

Diurnal Variations in Hypnotic Responsiveness: Is There an Optimal Time to Be Hypnotized?

With a sample of nearly 700 undergraduate students, the authors found support for diurnal variations in hypnotic responsiveness. Administering the Harvard Group Scale of Hypnotic Susceptibility, Form A (HGSHS:A) in the morning or evening resulted in higher average scores than from afternoon sessions. The authors replicated this finding using a second independent sample. In the primary study, participants indicated the time of day that they are most alert. Matching self-reported preferred time of the day with HGSHS:A administration time did not improve hypnotic responsiveness. Considering this as well as past research, the authors argue that mid-morning may be the optimal time to be hypnotized and afternoon the least favorable.

Expectancies and Hypnotic Responsiveness: An Experimental-Design Flaw Revealed

Recent research suggests that expectancies about being hypnotized have a determinant role in the hypnotic experience. The authors analyzed the relationship between expectancies and the phenomenology of hypnosis using the Phenomenology of Consciousness Inventory and Hypnotic Assessment Procedure. Participants (115) were assigned either to the imagination (hypnosis labeled as imagination) or the hypnosis conditions. Results revealed only a minor influence of expectancies and none on the label “hypnosis” across all variables. These findings indicate that the methodology commonly used to study the influence of expectancies on hypnotic responsiveness and phenomenology might represent a flaw in favor of a causal relationship between expectancies and hypnotic experience.

Brain Oscillations, Hypnosis, and Hypnotizability

This article summarizes the state-of-science knowledge regarding the associations between hypnosis and brain oscillations. Brain oscillations represent the combined electrical activity of neuronal assemblies, usually measured as specific frequencies representing slower (delta, theta, alpha) and faster (beta, gamma) oscillations. Hypnosis has been most closely linked to power in the theta band and changes in gamma activity. These oscillations are thought to play a critical role in both the recording and recall of declarative memory and emotional limbic circuits. The authors propose that this role may be the mechanistic link between theta (and perhaps gamma) oscillations and hypnosis, specifically, that the increases in theta oscillations and changes in gamma activity observed with hypnosis may underlie some hypnotic responses. If these hypotheses are supported, they have important implications for both understanding the effects of hypnosis and for enhancing response to hypnotic treatments.

Análisis factorial confirmatorio de la escala Valencia de actitudes y creencias hacia la hipnosis (versión cliente revisada), en una muestra española

Title: Confirmatory factor analysis of the valencia scale of attitudes and be- liefs toward hypnosis (revised client version), with a spanish sample. Abstract: Several approaches to hypnosis have highlighted the importance of attitudes and beliefs on it to promote hypnotic responses, their power to predict the efficacy of interventions that include hypnosis, as well as to generate or prevent iatrogenic reactions in patients. The goal of this study is to investigate the new variation of the Valencia Scale of Attitudes and Beliefs toward Hypnosis Client version, written in Castilian. The scale was analyzed using confirmatory methodology to obtain its factor structure and psychometric properties, in order to confirm the results of previous ex- ploratory and confirmatory research, with samples from different coun- tries. A sample of 1.678 Spanish university students was used this time. Data show an eight factors structure (Fear, Memory, Help, Control, Col- laboration, Interest, Magic and Marginal), and an appropriate internal con- sistency and test-retest reliability. Results are similar to those found in pre- vious exploratory and confirmatory factorial analysis conducted in different countries.

New views of hypnotizability.

New views of hypnotizability.

Adenylyl cylases 1 and 8 mediate select striatal-dependent behaviors and sensitivity to ethanol stimulation in the adolescent period following acute neonatal ethanol exposure

Neonatal alcohol exposure in rodents causes dramatic neurodegenerative effects throughout the developing nervous system, particularly in the striatum, acutely after exposure. These acute neurodegenerative effects are augmented in mice lacking adenylyl cyclases 1 and 8 (AC1/8) as neonatal mice with a genetic deletion of both AC isoforms (DKO) have increased vulnerability to ethanol-induced striatal neurotoxicity compared to wild type (WT) controls. While neonatal ethanol exposure is known to negatively impact cognitive behaviors, such as executive functioning and working memory in adolescent and adult animals, the threshold of ethanol exposure required to impinge upon developmental behaviors in mice has not been extensively examined. Therefore, the purpose of this study was to determine the behavioral effects of neonatal ethanol exposure using various striatal-dependent developmental benchmarks and to assess the impact of AC1/8 deletion on this developmental progression. WT and DKO mice were treated with 2.5g/kg ethanol or saline on postnatal day (P)6 and later subjected to the wire suspension, negative geotaxis, postural reflex, grid hang, tail suspension and accelerating rotarod tests at various time points. At P30, mice were evaluated for their hypnotic responses to 4.0g/kg ethanol by using the loss of righting reflex assay and ethanol-induced stimulation of locomotor activity after 2.0g/kg ethanol.Ethanol exposure significantly impaired DKO performance in the negative geotaxis test while genetic deletion of AC1/8 alone increased grid hang time and decreased immobility time in the tail suspension test with a concomitant increase in hindlimb clasping behavior. Locomotor stimulation was significantly increased in animals that received ethanol as neonates, peaking significantly in ethanol-treated DKO mice compared to ethanol-treated WT controls, while sedation duration following high-dose ethanol challenge was unaffected.These data indicate that the maturational parameters examined in the current study may not be sensitive enough to detect effects of a single ethanol exposure during the brain growth spurt period. Genetic deletion of AC1/8 reveals a role for these cylases in attenuating ethanol-induced behavioral effects in the neonatally-exposed adolescent.

A Causal Model Explaining the Relationships Governing Beliefs, Attitudes, and Hypnotic Responsiveness

The author developed a new scale aimed at measuring beliefs about “hypnotic states” and investigated the influence of such beliefs and attitudes on hypnotic responses in a large sample of Japanese undergraduate students. Exploratory factor analysis of this new questionnaire examining beliefs about hypnotic states yielded four factors: Dissociative or Depersonalized Experience, Loss of Self-Control, Therapeutic Expectation, and Arousing Extraordinary Ability. The results of structural equation modeling showed that Therapeutic Expectation and Arousing Extraordinary Ability influenced hypnotizability through attitudes toward hypnosis, while also directly affecting subjective experiences without mediating attitudes. Present findings suggest that it is more effective to enhance therapeutic expectations than to correct misconceptions about hypnotic states in modification of patients’ beliefs before initiating treatment.

Hypnosis for insomnia: an exaggerated myth or an underrated intervention?

Hypnosis is one of the oldest forms of complementary and alternative medicine as well as a psychological intervention. Derived from its Greek origin, the term was once mythically associated with sleep. Because hypnosis is commonly more related to relaxation and imagery under suggestion, the approach may be helpful to improve insomnia by reducing hyperarousal. This presentation discusses its components, effectiveness and potential for treating insomnia. Review of literature on the nature, characteristics and components and measurements of hypnosis and critical appraisal of 6 randomized controlled trials (RCTs) from 1970s to 2000s identified from keywords search in databases on the components, treatment regime of hypnosis as well as study design, methodology and limitations. Despite lacking a unique definition, some characteristics of hypnosis such as lack of voluntary initiation and a fading of generalized reality orientation are recognized. Hypnotic responses are often assessed by behavioural scales or self-reported inventories. Another practice to operationalize hypnosis is the use of hypnotizability scales to measure the extent a subject responds to standardized suggestions presented after a standardized hypnotic induction procedure. The appraisal of the studies found that methodological quality of the included studies was low. Limitations include imprecise enrollment criteria and diagnostic procedure, unclear randomization and allocation concealment methods, inadequate outcome assessment and descriptions of withdrawal and dropouts, and lack of adverse event monitoring. None of the reviewed RCTs have assessed the hypnotic responses or the success of blinding of participants, though some argue that blinding is not possible in hypnosis. Despite low quality, most RCTs reported that a significant improvement in sleep parameters could be achieved in 4 weekly sessions or less and no adverse events were reported. Although the overall results suggested that hypnosis treatment was safe and efficacious for treating insomnia, due to the methodological limitations, the generalizabilty of the positive findings remained questionable. Future studies with larger sample size, better study design and methodological quality are needed to ascertain the efficacy of hypnosis for insomnia. This presentation is part of my research project for PhD candidature at the Department of Psychiatry, University of Hong Kong.

Placebo versus “Standard” Hypnosis Rationale: Attitudes, Expectancies, Hypnotic Responses, and Experiences

In this study participants were provided with either the standard rationale that accompanies the Harvard Group Scale of Hypnotic Susceptibility: A (Shor & Orne, 1962) or a rationale that presented hypnosis as a nondeceptive placebo, consistent with Kirsch's (1994) sociocognitive perspective of hypnosis. The effects of the placebo and standard rationales were highly comparable with respect to hypnotic attitudes; prehypnotic expectancies; objective, subjective, and involuntariness measures of hypnotic responding; as well as a variety of subjective experiences during hypnosis, as measured by the Phenomenology of Consciousness Inventory (Pekala, 1982). Differences among correlations were not evident when measures were compared across groups. However, indices of hypnotic responding were correlated with attitudes in the hypnosis but not the placebo condition, and, generally speaking, the link between subjective experiences during hypnosis and measures of hypnotic responding were more reliable in the placebo than the hypnosis group. Researcher findings are neutral with respect to providing support for altered state versus sociocognitive models of hypnosis.

Alcohol increases hypnotic susceptibility

One approach to hypnosis suggests that for hypnotic experience to occur frontal lobe activity must be attenuated. For example, cold control theory posits that a lack of awareness of intentions is responsible for the experience of involuntariness and/or the subjective reality of hypnotic suggestions. The mid-dorso-lateral prefrontal cortex and the ACC are candidate regions for such awareness. Alcohol impairs frontal lobe executive function. This study examined whether alcohol affects hypnotisability. We administered 0.8 mg/kg of alcohol or a placebo to 32 medium susceptible participants. They were subsequently hypnotised and given hypnotic suggestions. All participants believed they had received some alcohol. Participants in the alcohol condition were more susceptible to hypnotic suggestions than participants in the placebo condition. Impaired frontal lobe activity facilitates hypnotic responding, which supports theories postulating that attenuation of executive function facilitates hypnotic response, and contradicts theories postulating that hypnotic response involves enhanced inhibitory, attentional or other executive function.

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.

Impulsivity, self-control, and hypnotic suggestibility

Hypnotic responding might be due to attenuated frontal lobe functioning after the hypnotic induction. Little is known about whether personality traits linked with frontal functioning are associated with responsiveness to hypnotic suggestions. We assessed whether hypnotic suggestibility is related to the traits of self-control and impulsivity in 154 participants who completed the Brief Self-Control Scale, the Self-Regulation Scale, the Barratt Impulsiveness Scale (BIS-11), and the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A). BIS-11 non-planning impulsivity correlated positively with HGSHS:A (Bonferroni-corrected). Furthermore, in the best model emerging from a stepwise multiple regression, both non-planning impulsivity and self-control positively predicted hypnotic suggestibility, and there was an interaction of BIS-11 motor impulsivity with gender. For men only, motor impulsivity tended to predict hypnotic suggestibility. Hypnotic suggestibility is associated with personality traits linked with frontal functioning, and hypnotic responding in men and women might differ.

The association between the oxytocin receptor gene (OXTR) and hypnotizability

Hypnosis has puzzled scientists for centuries, and particularly the reason why some people are prone to engaging in suggested experiences discordant with external reality. Absorption in internal experience is one key component of the hypnotic response. The neuropeptide oxytocin has been posited to heighten sensitivity to external cues, and it is possible that individual differences in oxytocin-related capacity to engage in external or internal experiences influences hypnotic response. To test this proposal, 185 Caucasian individuals provided saliva samples for analysis of polymorphisms in the oxytocin receptor gene, COMT, and independently completed standardized measures of hypnotizability and absorption. Participants with the GG genotype at rs53576 were characterized by lower hypnotizability and absorption scores than those with the A allele; there was no association between hyponotizability and COMT. These findings provide initial evidence that the capacity to respond to suggestions for altered internal experience is influenced by the oxytocin receptor gene, and is consistent with evidence that oxytocin plays an important role in modulating the extent to which people engage with external versus internal experiences.

Bidirectional Regulation of Intravenous General Anesthetic Actions by α3-containing γ-aminobutyric AcidAReceptors

γ-aminobutyric acid A (GABAA) receptors mediate the actions of several intravenous general anesthetics. However, the contribution of α3-containing GABAA receptors to the action of these drugs is unknown. The authors compared anesthetic endpoints (hypnosis, immobility, hypothermia) in response to various intravenous anesthetics in mice lacking the α3 subunit of the GABAA receptor (α3 knockout) and in wild-type mice. Furthermore, the authors generated and analyzed conditional mutant mice expressing the GABAA receptor α3 subunit exclusively in noradrenergic neurons. α3 knockout mice displayed decreased hypnotic and hypothermic responses to etomidate and midazolam, but an increased response to pentobarbital. The hypnotic response to ketamine was unaltered, whereas the hypothermic response was increased. In contrast, the hypnotic but not the hypothermic response to medetomidine was increased. The combination of ketamine/xylazine displayed increased hypnotic, immobilizing, and hypothermic effects in α3 knockout mice. Mice expressing the α3 subunit exclusively in noradrenergic neurons were generated to assess whether the lack of α3 subunits on noradrenergic neurons may be responsible for this effect. In these mice, the increases of the hypnotic and immobilizing actions induced by ketamine/xylazine were largely absent, whereas the increase in the hypothermic action was still present. α3-containing GABAA receptors bidirectionally regulate essential anesthetic actions: they mediate anesthetic actions of etomidate and midazolam, known to selectively act at GABAA receptors, and they negatively constrain anesthetic actions of compounds with targets partly or exclusively distinct from GABAA receptors such as medetomidine, ketamine, and pentobarbital. Furthermore, our results indicate that α3-containing GABAA receptors on noradrenergic neurons may contribute to this constraint.