Nina Zech

Introduction: Mind-body interventions (MBIs) increasingly used in health care include alterations in the ordinary state of consciousness that might be essential for their effects on psychological and physical patterns encoded in the unconscious. Little is known about the effects of repeated practice or the time of the repetitions. Methods: EEG-derived Bispectral-Index (BIS) is clinically used to monitor anesthetic depth, a deviation from the normal waking consciousness. We used BIS-monitoring in six participants who repeated a MBI ten times within 3–4 days at different times of day. Results: BIS values decreased significantly from an awake baseline of 97.5 to a mean of 83.2, showing a magnitude of reduction similar to that observed during the standardized hypnosis induction of a suggestibility test. Marked drops in BIS occurred during the breaks before and after the four tasks of the MBI and within certain tasks. There was a steady decline in BIS during the 30-min MBI, and some deepening with increasing exercise. Changes in BIS were significantly more pronounced when the MBI was performed at midday compared to mornings, particularly in individuals with an eveningness chronotype. Discussion: The reproducibly observed decrease of BIS during the MBI we take as surrogate for involved trance states in support of the hypothesis that this facilitates access to the unconscious and modulation of physiological and psychological programs encoded there. The within-subject variability in the corresponding EEG-derived BIS with repetitions of the MBI is unexpectedly high, although still lower than between-subject variability. Some improvement was observed with repeated practice, although not in a linear relationship. The dependence of these effects on time of day warrants further investigation.

Introduction: Mind–body interventions are increasingly used in health care, both for physical and for psychological therapy. With directing the focus to the body and inner experiences they include elements of trance induction and hypnosis. The scope of this experimental study was to test the hypothesis that a non-ordinary state of consciousness may occur during a mind–body intervention with changes in electrical brain activity similar to a hypnotic induction. Methods: Bispectral Index an EEG-derived parameter used in anesthesia, was monitored during a test of hypnotic susceptibility including a trance induction, and during a mind–body intervention modified from the Feldenkrais method. 54 adult volunteers were tested with a short version of the Harvard Group Scale of Hypnotic Susceptibility (HGSHS-5) and the instructions for a mind–body intervention from a 30-min audio file. The latter consists of an introduction, reflections on posture and sensations, and four suggested tasks with body movements and variations followed by a break each time. Contributing factors, namely age, sex, suggestibility and daytime, were analyzed by multifactorial analysis and linear regression. Results: BIS significantly decreased from an awake value of 97.5 to values of 88–92, similar in extent to the hypnosis induction of the test for HGSHS-5. Besides a general decline with duration significant drops were observed with every break. None of the tested potential influencing factors had significant impact. Conclusion: Measurable changes in electrophysical brain activity can be detected during a mind–body intervention as a surrogate marker of a state of non-ordinary consciousness. The high relevance arises from the fact that inclusion of the unconscious is essential for initiating beneficial changes in psychological and physical patterns, as these patterns are encoded and maintained there. The EEG reactions and aspects of a focus shift toward inside, body scan and confusion bring it close to hypnotic trance and provide new and objective research approaches.

Introduction: The HGSHS:A is one of the most commonly used measures of hypnotic suggestibility. However, this test suffers from low feasibility due to a time requirement exceeding 1 h, and from a questionable representation of the normal population. Recently, a short version of HGSHS-5:G was developed and published, and now the first results are available. The scope of this investigation was to verify the assumption of equally positioned and normally distributed scores, resulting in equally sized suggestibility groups in a number of different studies with full or short versions of HGSHS, and to compare the results of the 11-item score with the 5-item score, the latter being calculated from either the full version or the short version test.Methods: Data from 21 studies with testing for HGSHS were analyzed, 15 using the HGSHS:A full version and six using the HGSHS-5:G short version, for a total of 2,529 data sets. Position and distribution of both the 11-item score and the 5-item score were tested. Linear regression analysis was used to compare the two scores, as well as cross-table and weighted Cohen’s kappa to determine the match of grouping into low and high suggestibility. To evaluate contributing factors to the observed differences in the study results, a multifactorial analysis of variance was performed.Results: In the different studies, position and distribution of scores, as well as group sizes for low and high suggestibles, varied. All score distributions were found to be non-normal and shifted to the right from the middle score; the shift was more extensive with the 11-item score. The correlation between both scores calculated from full version tests was moderate (R² = 0.69), as was the match of suggestibility grouping (κ = 0.58). Studies using the short version involving less student-dominated populations showed sufficient agreement with the full version, but lower scores were caused by an increase in the zero score.Conclusion: A normal population is not represented in most applications of HGSHS, and grouping into low and high suggestibles varies, mainly due to different positions of score distributions. A direct comparison of full and short versions of HGSHS tested in the same subjects is still missing.

Introduction: Hypnotic trance can be defined as a non-ordinary state of consciousness that is accompanied by a number of neurophysiological changes, including brain electrophysiology. In addition to subjective measures, corresponding objective parameters are needed in experimental and clinical hypnosis research but are complex, impractical, or unspecific. A similar challenge exists for the measurement and monitoring of drug-induced hypnosis, namely general anesthesia. The observation of changes in EEG induced by narcotics has led to the development of monitors for the depth of anesthesia based on EEG parameters. We investigated whether two such monitors react to the induction and maintenance of hypnosis during a highly standardized procedure.Methods: A total of 56 volunteers were monitored for the bispectral index (BIS) and cerebral state index (CSI) (range 0–100, >95 considered “awake”) during the Harvard Group Scale of Hypnotic Susceptibility test. For this test, trance is induced by a taped text and followed by 12 tasks performed under hypnosis. In contrast to random forms of hypnosis, this represents a standardized, worldwide-established condition. According to the resulting score, participants were classified into suggestibility groups in order to evaluate whether the electrophysiological measurements of BIS and CIS indices differ between high and low suggestible persons. Furthermore, participants were asked to rate their hypnotic depth (HD, 1–10) at every task of the test.Results: Scores dropped significantly from a mean of 97.7 to 86.4 for BIS and from 94.6 to 77.7 for CSI with the induction of hypnosis to stay throughout hypnosis at levels of approximately 88.6 or 82.9, respectively. Results did not differ between high- and low-suggestible participants. The means of the subjective score of hypnotic depth and of the electrophysiological measurements showed a similar course. However, no correlation was found between BIS or CSI values and scores of hypnotic depths.Conclusion: Monitors for depth of anesthesia respond to changes in consciousness, including trance states of hypnosis. However, specificity is unclear. Practically, in hypnosis research with the exclusion of drug effects or sleep, these monitors might be helpful to test and compare the efficacy of induction texts and to detect disturbances of trance state.

Introduction: In the context of giving risk information for obtaining informed consent, it is not easy to comply with the ethical principle of “primum nihil nocere.” Carelessness, ignorance of nocebo effects and a misunderstood striving for legal certainty can lead doctors to comprehensive and brutal risk information. It is known that talking about risks and side effects can even trigger those and result in distress and nonadherence to medication or therapy.Methods: Recently, we have reported on significant clinically relevant effects of verbal and non-verbal suggestions on maximal muscular arm strength in healthy volunteers and in patients at two time points before surgery. Maximal strength during arm abduction was measured by dynamometry of the deltoid muscle group. Suggestions from clinical everyday life were formulated as presumed negative and neutral versions.Results: Here, we report on the effects of two versions of risk information in 45 patients. After sole mentioning risks of a puncture for the placement of a pain catheter, the maximal arm muscle strength was significantly reduced to 83% of baseline several days (T1), and to 84% the evening before surgery (T2). Strength was not significantly decreased and close to baseline at T1 and T2 when risks and benefits of a pain catheter were combined in one sentence. The difference between both versions was significant. With persistent normal distribution of values, the effect was due to uniform reactions of many patients, not to strong reactions of a few. High suggestibility and increase of anxiety with approaching surgery were identified as influencing factors for the neutralizing effect of modified wording.Conclusion: We not only suggest an alternative formulation for risk information to avoid nocebo effects but present an objective method to quantify and compare effects of different wordings. Thereby, we provide evidence that concurrently given positive aspects can neutralize negative effects during medical interview.

Introduction: The effects of specific suggestions are usually studied by measuring parameters that are directly addressed by these suggestions. We recently proposed the use of a uniform, unrelated, and objective measure like maximal muscle strength that allows comparison of suggestions to avoid nocebo effects and thus to improve communication. Since reduced breathing strength might impair respiration and increase the risk of post-operative pulmonary complications, the aim of the present study was to evaluate the effects of the suggestions on respiratory muscle power. Both the identification and neutralization of negative suggestions in the clinical context and stimulating suggestions could improve breathing force, a predictor of physical fitness and convalescence.Methods: In 50 healthy, adult volunteers, respiratory muscle strength was measured by maximal inspiratory and expiratory pressures, as well as by maximal inspiratory and expiratory flows. Baseline was compared to values after application of eleven suggestions, five out of clinical context, including memory of negative or positive past, risk information for informed consent, and a non-verbal suggestion. Six stimulating suggestions included self-affirmation, empowering words, a heroic mirror image, and an imagination.Results: All suggestions showed an impact on respiratory muscle strength, indicating placebo and nocebo effects. No single parameter could represent the breathing force in its complexity, however, trends and different specific aspects of it were measured. The strongest reaction was observed with the recall of a previous negative situation resulting in a reduction in expiratory flow to 96.1% of baseline (p = 0.041). After risk information, a decrease was observed in three of the parameters, with the highest extend in expiratory pressure by 4.4%. This nocebo effect was neutralized by adding positive aspects to the risk information. Every intended strengthening suggestion resulted in statistically significant increases of at least one parameter, with changes of up to 10% (e.g., MEP 110.3%, p = 0.001), indicating placebo effects. Here, expiration was more affected than inspiration. Sex was the only influencing factor reaching statistical significance, with stronger reactions in women.Conclusion: Respiratory muscle strength proved to be sensitive to suggestions with clinical context, as well as suggestions intended for stimulation. With this objective measurement, evaluation, and comparison of different suggestions is possible to help avoid nocebo effects. The demonstrated effect of supporting suggestions can be followed up and used in clinical practice.