Can hypnotic suggestibility be measured online?

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

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

Hypnotic suggestion modulates visual recognition of negative words depending on word arousal

This study examined whether and how emotional hypnotic suggestions modulate the visual recognition of negative words. We investigated the influence of hypnotic suggestions aimed at modifying emotional reactivity on the arousal effect in negative words. High and low suggestible individuals performed a go/no-go lexical decision task in three intra-individual conditions: with a suggestion to increase emotional reactivity, with a suggestion to decrease emotional reactivity and without hypnotic suggestion. Results showed that hypnotic suggestions modulated the arousal facilitation effect differently depending on the level of suggestibility of the participants. In high suggestible individuals, response times for low-arousal negative words varied oppositely according to the suggestion administered, while no modulations were retrieved for high-arousal ones. In contrast, no suggestion effects were found for low suggestible participants. Altogether, these findings suggest a higher influence of hypnotic suggestions on emotional words that require longer processing times in high suggestible individuals.

French Norms for the Online Sussex-Waterloo Scale of Hypnotizability

This article presents French norms for the online version of the Sussex-Waterloo Scale of Hypnotizability. This scale is an online adaptation of the well-established Waterloo-Stanford Group C Scale of Hypnotic Susceptibility: with both behavioral and subjective scores. Insofar as hypnotizability (the ability to respond to suggestions in a hypnotic context) varies substantially in the general population and remains generally stable throughout life, it is important to measure it in experiments using hypnotic suggestion. However, these scales are time consuming, as they often require multiple sessions to achieve a suitable sample size for subsequent participant screening. One promising route for overcoming this inconvenience is to perform hypnotizability assessment online. The Sussex-Waterloo Scale of Hypnotizability is the first to have demonstrated the viability of online measurement. The authors demonstrate that their translation of this scale yields similar statistics.

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

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.

Current neuroscientific research database findings of brain activity changes after hypnosis

Using multi-modal brain imaging techniques we found pronounced changes in neuronal activity after hypnotic trance induction whereby state changes seem to occur synchronously with the specific induction instructions. In clinical patients, hypnosis proved to be a powerful method in inhibiting the reaction of the fear circuitry structures. The aim of the present paper is to critically discuss the limitations of the current neuroscientific research database in the light of a debate in defining relevant hypnotic constructs and to suggest ideas for future research projects. We discuss the role of hypnotic suggestibility (HS), the impact of hypnotic inductions and the importance of the depth of hypnotic trance. We argue that future research on brain imaging studies on the effects of hypnosis and hypnotherapy should focus on the analysis of individual cross-network activation patterns. A most promising approach is to simultaneously include physiological parameters linked to cognitive, somatic, and behavioral effects.

Testing Hypnotizability by Phone: Development and Validation of the Remote Hypnotic Induction Profile (rHIP)

Standard hypnotizability scales require physical contact or direct observation by tester and participant. The authors addressed this limitation by developing and testing the remote Hypnotic Induction Profile (rHIP), a hypnotizability test derived from the Hypnotic Induction Profile that is completed by telephone. To assess the validity of the rHIP, 56 volunteers naïve to hypnotizability testing completed both the HIP and the rHIP, with order of testing randomized. Results indicate a strong correlation between HIP and rHIP scores, r _s =.71(0.53-0.84), p <.0001, and good concordance, difference =.03(-0.53, 0.59), p =.91, independent of testing order. The rHIP had few complications. Possible advantages of using the rHIP include improving patient expectancy prior to scheduling a hypnosis session, increasing access to hypnotizability testing for remote interventions, and obviating resource-intensive in-person hypnotizability screening for trials that exclude subjects with certain scores.

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.

The Hypnotic Induction Profile (HIP) in Clinical Practice and Research

The Hypnotic Induction Profile (HIP) was developed as a brief, yet thorough, assessment of a person's level of trait hypnotizability and their potential to experience a hypnotic state. The HIP quantitatively and qualitatively measures hynotizability by evaluating biological and sensorimotor experiences designed to assess 3 fundamental observable and measurable components of hypnosis: absorption, dissociation, and suggestibility through a guided assessment that takes 5 to 10 minutes. From conception, the HIP has been utilized in clinical settings to assess appropriateness for the use of hypnosis in treatment planning and research protocols to stratify research participants. The brevity, accessibility, and reliability of the HIP have allowed it to adapt, not only across settings but through media platforms as technology and remote delivery become increasingly incorporated in the field of hypnosis.

Trait phenomenological control predicts experience of mirror synaesthesia and the rubber hand illusion

In hypnotic responding, expectancies arising from imaginative suggestion drive striking experiential changes (e.g., hallucinations) - which are experienced as involuntary - according to a normally distributed and stable trait ability (hypnotisability). Such experiences can be triggered by implicit suggestion and occur outside the hypnotic context. In large sample studies (of 156, 404 and 353 participants), we report substantial relationships between hypnotisability and experimental measures of experiential change in mirror-sensory synaesthesia and the rubber hand illusion comparable to relationships between hypnotisability and individual hypnosis scale items. The control of phenomenology to meet expectancies arising from perceived task requirements can account for experiential change in psychological experiments.

Mechanisms of the breathing contribution to bodily self-consciousness in healthy humans: Lessons from machine-assisted breathing?

Previous studies investigated bodily self-consciousness (BSC) by experimentally exposing subjects to multisensory conflicts (i.e., visuo-tactile, audio-tactile, visuo-cardiac) in virtual reality (VR) that involve the participant's torso in a paradigm known as the full-body illusion (FBI). Using a modified FBI paradigm, we found that synchrony of visuo-respiratory stimulation (i.e., a flashing outline surrounding an avatar in VR; the flash intensity depending on breathing), is also able to modulate BSC by increasing self-location and breathing agency toward the virtual body. Our aim was to investigate such visuo-respiratory effects and determine whether respiratory motor commands contributes to BSC, using non-invasive mechanical ventilation (i.e., machine-delivered breathing). Seventeen healthy participants took part in a visuo-respiratory FBI paradigm and performed the FBI during two breathing conditions: (a) "active breathing" (i.e., participants actively initiate machine-delivered breaths) and (b) "passive breathing" (i.e., breaths' timing was determined by the machine). Respiration rate, tidal volume, and their variability were recorded. In line with previous results, participants experienced subjective changes in self-location, breathing agency, and self-identification toward the avatar's body, when presented with synchronous visuo-respiratory stimulation. Moreover, drift in self-location was reduced and tidal volume variability were increased by asynchronous visuo-respiratory stimulations. Such effects were not modulated by breathing control manipulations. Our results extend previous FBI findings showing that visuo-respiratory stimulation affects BSC, independently from breathing motor command initiation. Also, variability of respiratory parameters was influenced by visuo-respiratory feedback and might reduce breathing discomfort. Further exploration of such findings might inform the development of respiratory therapeutic tools using VR in patients.