Autonomic and psychological responses to an acute psychological stressor and relaxation: the influence of hypnotizability and absorption

Physiological Correlates of Hypnotizability: Hypnotic Behaviour and Prognostic Role in Medicine

Studies in the field of experimental hypnosis highlighted the role of hypnotizability in the physiological variability of the general population. It is associated, in fact, with a few differences which are observable in the ordinary state of consciousness and in the absence of suggestions. The aim of the present scoping review is summarizing them and indicate their relevance to the neural mechanisms of hypnosis and to the prognosis and treatment of a few medical conditions. Individuals with high, medium and low hypnotizability scores display different cerebral functional differences-i.e., functional equivalence between imagery and perception/action, excitability of the motor cortex, interoceptive accuracy-possibly related to brain structural and functional characteristics, and different control of blood supply at peripheral and cerebral level, likely due to different availability of endothelial nitric oxide. These differences are reviewed to support the idea of their participation in hypnotic behaviour and to indicate their prognostic and therapeutic usefulness in a few medical conditions.

Association of hypnotizability and deep sleep: any role for interoceptive sensibility?

The aim of the study was to investigate the possible association of hypnotizability and deep sleep (N3) duration, and whether the interoceptive sensibility influences this association. This was motivated by the proneness of highly hypnotizable individuals to easily change their psychophysiological state, i.e., from wakefulness to hypnosis and sleep, and by the positive association observed between hypnotizability and interoceptive sensibility. Forty-seven healthy participants previously enrolled in a polysomnographic night sleep study completed the questionnaire for Multidimensional Assessment of Interoceptive Awareness (MAIA) and underwent hypnotic assessment through the Stanford Hypnotic Susceptibility Scale, form A (SHSS,A). Results showed that N3 duration is not linearly correlated with hypnotizability. Controlling for a few MAIA scales did not modify the relation between hypnotizability and deep sleep. A polynomial relation indicates that N3 duration and N3 percentage of the total sleep time increase with hypnotizability in the low-to-medium range of hypnotizability and decrease in the medium-to-high range. In conclusion, hypnotic assessment predicts N3 duration and their association is not modified by interoceptive awareness/sensitivity.

Meta-analysis of digital game and study characteristics eliciting physiological stress responses

Digital games have been used as stressors in a range of disciplines for decades. Nonetheless, the underlying characteristics of these stressors and the study in which the stressor was applied are generally not recognized for their moderating effect on the measured physiological stress responses. We have therefore conducted a meta-analysis that analyzes the effects of characteristics of digital game stressors and study design on heart rate, systolic and diastolic blood pressure, in studies carried out from 1976 to 2012. In order to assess the differing quality between study designs, a new scale is developed and presented, coined reliability of effect size. The results show specific and consistent moderating functions of both game and study characteristics, on average accounting for around 43%, and in certain cases up to 57% of the variance found in physiological stress responses. Possible cognitive and physiological processes underlying these moderating functions are discussed, and a new model integrating these processes with the moderating functions is presented. These findings indicate that a digital game stressor does not act as a stressor by virtue of being a game, but rather derives its stressor function from its characteristics and the methodology in which it is used. This finding, together with the size of the associated moderations, indicates the need for a standardization of digital game stressors.

Hearth and Campfire Influences on Arterial Blood Pressure: Defraying the Costs of the Social Brain through Fireside Relaxation

The importance of fire in human evolutionary history is widely acknowledged but the extent not fully explored. Fires involve flickering light, crackling sounds, warmth, and a distinctive smell. For early humans, fire likely extended the day, provided heat, helped with hunting, warded off predators and insects, illuminated dark places, and facilitated cooking. Campfires also may have provided social nexus and relaxation effects that could have enhanced prosocial behavior. According to this hypothesis, calmer, more tolerant people would have benefited in the social milieu via fireside interactions relative to individuals less susceptible to relaxation response. Using a randomized crossover design that disaggregated fire's sensory properties, pre-posttest blood pressure measures were compared among 226 adults across three studies with respect to viewing simulated muted-fire, fire-with-sound, and control conditions, in addition to tests for interactions with hypnotizability, absorption, and prosociality. Results indicated consistent blood pressure decreases in the fire-with-sound condition, particularly with a longer duration of stimulus, and enhancing effects of absorption and prosociality. Findings confirm that hearth and campfires induce relaxation as part of a multisensory, absorptive, and social experience. Enhancements to relaxation capacities in the human social brain likely took place via feedback involving these and other variables.

Watching neutral and threatening movies: subjective experience and autonomic responses in subjects with different hypnotizability levels

Subjects with high hypnotizability scores (Highs) have been considered more prone to experience negative affect and more vulnerable to its autonomic effects with respect to low hypnotizable individuals (Lows). The aim of the study was to analyze the subjective experience, tonic skin conductance (SC), respiratory frequency (RF), heart rate (HR) and heart rate variability (HRV) of healthy Highs and Lows during a long-lasting, emotionally neutral task (Session R, 46 subjects) and a moderately threatening one (Session T, 35 subjects). At the end of the relaxing Session R, all participants reported an increased relaxation. At the end of the threatening Session T, only 20 subjects reported a decreased relaxation (effective T: eT subsample). Highs and Lows of this subsample reported a similarly reduced relaxation and showed a similarly increased skin conductance. HR and HRV did not differ between the two sessions and between Highs and Lows. Among the subjects not reporting decreased relaxation at the end of Session T (ineffective T: iT subsample, n=15), relaxation was deeper and associated with lower skin conductance in Highs, although HR and HRV did not differ between Highs and Lows. All together, the results do not support the hypothesis of higher proneness of Highs to experience negative affect and to exhibit the autonomic correlates of negative emotion.

Attention to bodily sensations and symptom perception in individuals with idiopathic environmental intolerance

INTRODUCTION

Idiopathic environmental intolerance (IEI) is characterized by non-specific symptoms attributed to exposure to environmental odours or chemicals at levels below those known to induce adverse health effects. A clarification of whether psychological processes involved in sensory perceptions are associated with IEI would add to our understanding of this complex disorder.

PURPOSE

To examine if measures of somato-sensory amplification, autonomic perception and absorption are associated with IEI.

METHODS

The study included individuals with self-reported or physician-diagnosed IEI. Participants (n = 732) completed questionnaires that included items on descriptive variables of IEI, the Somato-Sensory Amplification Scale (SSAS), the Autonomic Perception Questionnaire (APQ), the Tellegen Absorption Scale (TAS) and a Negative Affectivity Scale (NAS).

RESULTS

Multiple, hierarchical linear regression analyses revealed significant positive associations between SSAS, APQ, and IEI, while small and inverse associations were seen between TAS and IEI.

CONCLUSIONS

The association with SSAS and APQ suggests that perceptual personality characteristics are important in understanding this disorder.

Chemotherapy-induced nausea, vomiting, and fatigue--the role of individual differences related to sensory perception and autonomic reactivity

BACKGROUND

In spite of antiemetics, postchemotherapy side effects continue to be common and may affect compliance to cancer treatment. Among the known factors associated with increased symptom severity are: younger age, treatment toxicity, expected severity, and distress, but little is still known about the role of other factors. The aim of our study was to investigate the role of individual differences related to sensory perception for posttreatment side effects.

METHODS

Hundred and twenty-five women receiving adjuvant chemotherapy for breast cancer completed measures of absorption, autonomic perception, somatosensory amplification, trait anxiety, and expected severity at baseline. Pretreatment distress and posttreatment nausea, vomiting, and fatigue were assessed at the 1st, 4th, 6th and last cycles of chemotherapy.

RESULTS

While univariate analyses showed several factors to be associated with side effects, only absorption and pretreatment distress remained independent predictors of nausea and fatigue when controlling for the remaining factors. Posttreatment vomiting was only predicted by expected severity of vomiting.

CONCLUSION

Chemotherapy-induced side effects are related to increased autonomic nervous system activity, and absorption has been associated with increased autonomic nervous system reactivity to stress. The results suggest that individuals with high absorption may be at greater risk for developing side effects. Improved precision in identifying patients at risk of experiencing more severe side effects after cancer treatment will increase the ability to target treatments aimed at reducing these side effects.

Anticipatory Nausea: The Role of Individual Differences Related to Sensory Perception and Autonomic Reactivity

BACKGROUND

Anticipatory nausea (AN) during chemotherapy has been difficult to control with conventional antiemetics. AN can lead cancer patients to delay or discontinue chemotherapy, possibly compromising the treatment.

PURPOSE

The aim is to investigate the possible influence on the development of AN of individual differences in absorption, somato-sensory amplification, and autonomic perception-measures theorized to be related to sensory perception and autonomic reactivity.

METHODS

Prior to treatment, 125 women (M age = 48.5 years) undergoing adjuvant chemotherapy for breast cancer rated their expected severity of side effects and completed the Tellegen Absorption Scale, the Somato-Sensory Amplification Scale, and the Autonomic Perception Questionnaire. AN, as well as anticipatory vomiting (AV), distress, and worry/anxiety, were measured prior to the fourth, sixth, and last cycle of chemotherapy. Posttreatment nausea (PN), vomiting, and fatigue were measured after the first, fourth, sixth, and last cycle.

RESULTS

34% of the women reported AN before 1 or more cycles. When controlling for treatment characteristics and other known predictors, AN was significantly associated with high absorption in addition to severity of PN, pretreatment worry/anxiety, and not receiving radiotherapy between chemotherapy sessions. AV was not associated with any of the variables investigated. Our data suggest that the association is strongest in the early phases of treatment.

CONCLUSIONS

Our results partly confirm the results of a previous study showing absorption and autonomic perception as predictors of anticipatory side effects in cancer patients receiving chemotherapy. Individuals high in absorption may be more autonomically reactive to aversive stimuli and, subsequently, more conditionable. Additional radiotherapy could be a competing stimulus, reducing the conditioning of chemotherapy-related nausea. Further studies investigating possible psycho-physiological mechanisms in the development of AN are needed.

Effect of self-hypnosis on hay fever symptoms - a randomised controlled intervention study

BACKGROUND

Many people suffer from hay fever symptoms. Hypnosis has proved to be a useful adjunct in the treatment of conditions where allergic phenomena have an important role.

METHODS

Randomised parallel group study over an observation period of two consecutive pollen seasons. Outcome data include nasal flow under hypnosis, pollinosis symptoms from diaries and retrospective assessments, restrictions in well-being and use of anti-allergic medication. We investigated 79 patients with a mean age of 34 years (range 19-54 years; 41 males), with moderate to severe allergic rhinitis to grass or birch pollen of at least 2 years duration and mild allergic asthma. The intervention consisted of teaching self-hypnosis during a mean of 2.4 sessions (SD 1.7; range 2-5 sessions) and continuation of standard anti-allergic pharmacological treatment.

RESULTS

Of 79 randomised patients, 66 completed one, and 52 completed two seasons. Retrospective VAS scores yielded significant improvements in year 1 in patients who had learned self-hypnosis: pollinosis symptoms -29.2 (VAS score, range 0-100; SD 25.4; p < 0.001), restriction of well-being -26.2 (VAS score, range 0-100; SD 28.7; p < 0.001. In year 2, the control group improved significantly having learned self-hypnosis as well: pollinosis symptoms -24.8 (SD 29.1; p < 0.001), restriction of well-being -23.7 (SD 30.0; p < 0.001). Daily self-reports of subjects who learnt self-hypnosis do not show a significant improvement. The hazard ratio of reaching a critical flow of 70% in nasal provocation tests was 0.333 (95% CI 0.157-0.741) after having learnt and applied self-hypnosis.

Sensed presence and mystical experiences are predicted by suggestibility, not by the application of transcranial weak complex magnetic fields

Transcranial magnetic stimulation (TMS) with weak (micro Tesla) complex waveform fields have been claimed to evoke the sensed presence of a sentient being in up to 80% in the general population. These findings have had a questionable neurophysiological foundation as the fields are approximately six orders of magnitude weaker than ordinary TMS fields. Also, no independent replication has been reported. To replicate and extend previous findings, we performed a double-blind experiment (N=89), with a sham-field control group. Personality characteristics indicating suggestibility (absorption, signs of abnormal temporal lobe activity, and a "new age"-lifestyle orientation) were used as predictors. Sensed presence, mystical, and other somatosensory experiences previously reported from the magnetic field stimulation were outcome measures. We found no evidence for any effects of the magnetic fields, neither in the entire group, nor in individuals high in suggestibility. Because the personality characteristics significantly predicted outcomes, suggestibility may account for previously reported effects. Our results strongly question the earlier claims of experiential effects of weak magnetic fields.

Hypnotic modulation of flow-mediated endothelial response to mental stress

Post-ischaemic flow mediated dilation of peripheral arteries (FMD) is transiently reduced during mental stress. This experiment was aimed at assessing whether hypnosis, which is a powerful relaxation technique, modulated the FMD response to mental stress in subjects with different hypnotic susceptibility. Results showed that hypnotic relaxation prevented the expected stress-related reduction of FMD only in highly hypnotizable subjects, suggesting a protective role of hypnotisability against vascular damage.

Electroencephalographic Cordance Patterns Distinguish Exceptional Clinical Responders with Fibromyalgia to Individualized Homeopathic Medicines

OBJECTIVES

To characterize initial central nervous system responses to olfactory administration of homeopathic remedies as biomarkers for subsequently exceptional, simillimum-like clinical outcomes at a systemic level (i.e., both locally and globally).

DESIGN

Double-blinded, randomized, placebo-controlled clinical trial.

SETTING

A private homeopathic clinic in Phoenix, AZ, and a university laboratory in Tucson, AZ.

PATIENTS

Sixty-two (62) persons with physician-confirmed fibromyalgia (FM) (mean age, 49 years; 94% women) enrolled; 53 completed the 3-month assessment visit. Exceptional responders (n = 6, 23% of active treatment group; none on placebo) were those with improvements in the top one-third for both tender point pain and global health ratings after 3 months.

INTERVENTION

Patients took daily oral doses of treatment solution in LM (1/50,000 dilution) potency (active group received individualized remedy; placebo group received plain solvent). Dependent measures: Baseline and 3-month difference scores for initial prefrontal electroencephalographic alpha frequency cordance (EEG-C, a correlate of functional brain activity) during 16 pairs of randomized, double-blinded bottle sniffs (treatment minus control solutions).

RESULTS

Exceptional responders versus other patients exhibited significantly more negative initial EEG-C difference scores at prefrontal sites. Right prefrontal cordance findings correlated with subsequently reduced pain (r = 0.85, p = 0.03), better global health (r =-0.73, p = 0.10), and trait absorption (genetically determined ability to focus attention selectively and fully) (r = 0.91, p = 0.012).

CONCLUSIONS

These observations suggest prefrontal EEG-C as an early biomarker of individualized homeopathic medicine effects in patients with FM who later exhibit exceptional outcomes. Prefrontal cortex controls executive function, including ability to redirect attention. Interactions between executive function, absorption, and the simillimum remedy could facilitate exceptional responses.

Individual Differences in Response to Randomly Assigned Active Individualized Homeopathic and Placebo Treatment in Fibromyalgia: Implications of a Double-Blinded Optional Crossover Design

OBJECTIVE

To assess individual difference characteristics of subgroups of patients with fibromyalgia (FM) patients with respect to the decision to stay in or switch from randomly-assigned verum or placebo treatment during an optional crossover phase of a double-blinded homeopathy study.

DESIGN

Double-blinded, randomized, placebo-controlled, optional crossover clinical trial.

PARTICIPANTS

Fifty-three (53) community-recruited patients with FM entered the optional crossover phase.

INTERVENTION

Two homeopaths jointly selected an individualized homeopathic remedy for all patients. The pharmacy dispensed either verum LM remedy or indistinguishable placebo in accord with randomized assignment for 4 months and the patient's optional crossover decision for an additional 2 months.

OUTCOME MEASURES

Patients completed a battery of baseline state/trait questionnaires, including mood, childhood neglect and abuse, and trait absorption. They rated global health (whole person-centered) and tender point pain on physical examination (disease-specific) at baseline, 3 months, and 6 months.

RESULTS

Rates of optional crossover from verum to placebo or placebo to verum were comparable (p = 0.6; 31%, and 41%, respectively). The switch subgroups had greater baseline psychologic issues (emotional neglect in placebo-switch; depression and anger in verum-switch). The verum-stay subgroup scored highest on treatment helpfulness and included all six exceptional responders who fell, prior to crossover, into the top terciles for improvement in both global health and pain. Patients staying in their randomly assigned groups, active or placebo (n = 34), scored significantly higher in trait absorption than did those who switched groups (n = 19).

CONCLUSION

Individual difference factors may predict better and poorer responders with FM to specific and nonspecific effects of homeopathic and placebo treatment.

Autonomic and EEG correlates of emotional imagery in subjects with different hypnotic susceptibility

The autonomic and EEG correlates of the response to a cognitive unpleasant stimulation (US) verbally administered to awake hypnotizable and non hypnotizable subjects were studied. They were compared with the values obtained during a resting condition immediately preceding the stimulus and with those produced by a cognitive neutral stimulation (NS), also administered after a basal resting period. Results showed hypnotic trait effects on skin resistance, heart and respiratory rate as well as on EEG theta, alpha, beta and gamma relative power changes. The autonomic and EEG patterns observed indicated different strategies in the task execution for hypnotizable and non hypnotizable subjects and a discrepancy between the autonomic and EEG changes associated to the US in susceptible subjects. Results support dissociation theories of hypnosis and suggest for hypnotizable persons an active mechanism of protection against cardiac hazard.

Autonomic reactivity to cognitive and emotional stress of low, medium, and high hypnotizable healthy subjects: testing predictions from the high risk model of threat perception

This study tested hypotheses derived from Wickramasekera's High Risk Model of Threat Perception (HRMTP) by comparing autonomic and affective responses to a cognitive and an emotional stress task in high, medium, and low hypnotizables. Electrodermal activity (EDA) was used as a measure of sympathetic activity, and the high frequency (HF) spectral component of heart rate variability as a measure of parasympathetic activity. High hypnotizables exhibited greater EDA at baseline and slower EDA recovery following both tasks than did medium and lows. Medium hypnotizables responded with greater decreases in normalized HF power than did highs and lows during the emotional stress task. The results suggest diminished EDA variability in high hypnotizables and the potential for HF power as an indicator of autonomic dysregulation in low and high hypnotizables, compared to mediums. The results are discussed in relation to predictions based on the HRMTP.

Rosacea: current thoughts on origin

Rosacea is a clinical pattern beginning and evolving in the genetically susceptible individual in response to a host of exposures. It produces a variety of clinical presentations, which vary over time and with age. Recently, many specific mediators of rosacea development have been described. A primary genetic cause for rosacea is suggested as single genes often control such mediators: enzymes, neuroendocrine transmitters, and cytokines are found in pathways to rosacea signs and symptoms. Currently, neither a specific cause nor a laboratory indicator of rosacea has been suggested. However, broadening interest in rosacea portends future increase in knowledge.