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

Wearable Multisensor Ring-Shaped Probe for Assessing Stress and Blood Oxygenation: Design and Preliminary Measurements

The increasing interest in innovative solutions for health and physiological monitoring has recently fostered the development of smaller biomedical devices. These devices are capable of recording an increasingly large number of biosignals simultaneously, while maximizing the user's comfort. In this study, we have designed and realized a novel wearable multisensor ring-shaped probe that enables synchronous, real-time acquisition of photoplethysmographic (PPG) and galvanic skin response (GSR) signals. The device integrates both the PPG and GSR sensors onto a single probe that can be easily placed on the finger, thereby minimizing the device footprint and overall size. The system enables the extraction of various physiological indices, including heart rate (HR) and its variability, oxygen saturation (SpO₂), and GSR levels, as well as their dynamic changes over time, to facilitate the detection of different physiological states, e.g., rest and stress. After a preliminary SpO₂ calibration procedure, measurements have been carried out in laboratory on healthy subjects to demonstrate the feasibility of using our system to detect rapid changes in HR, skin conductance, and SpO₂ across various physiological conditions (i.e., rest, sudden stress-like situation and breath holding). The early findings encourage the use of the device in daily-life conditions for real-time monitoring of different physiological states.

BILATERAL ELECTRODERMAL ACTIVITY IN THE ACTIVE-ALERT HYPNOTIC INDUCTION

Shifts in hemispheric dominance were previously proposed to play a role in hypnosis. Participants (N = 32) were exposed to an active-alert hypnosis induction and a music-control condition while electrodermal activity was registered bilaterally, providing information on alterations in hemispheric dominance. The results suggest that highly hypnotizable participants show a shift to right-sided and low hypnotizable participants demonstrated a shift to left-sided electrodermal dominance in response to the induction, whereas no change in laterality is present in the control condition. Additionally, the authors found that self-reported hypnosis experiences were also associated with a shift in laterality. These results underline the importance of the shift to right hemispheric activity in hypnosis and underscore the importance of hemispheric changes in shaping subjective experience.

Alterations in electrodermal activity and cardiac parasympathetic tone during hypnosis

Exploring autonomic nervous system (ANS) changes during hypnosis is critical for understanding the nature and extent of the hypnotic phenomenon and for identifying the mechanisms underlying the effects of hypnosis in different medical conditions. To assess ANS changes during hypnosis, electrodermal activity and pulse rate variability (PRV) were measured in 121 young adults. Participants either received hypnotic induction (hypnosis condition) or listened to music (control condition), and both groups were exposed to test suggestions. Blocks of silence and experimental sound stimuli were presented at baseline, after induction, and after de-induction. Skin conductance level (SCL) and high frequency (HF) power of PRV measured at each phase were compared between groups. Hypnosis decreased SCL compared to the control condition; however, there were no group differences in HF power. Furthermore, hypnotic suggestibility did not moderate ANS changes in the hypnosis group. These findings indicate that hypnosis reduces tonic sympathetic nervous system activity, which might explain why hypnosis is effective in the treatment of disorders with strong sympathetic nervous system involvement, such as rheumatoid arthritis, hot flashes, hypertension, and chronic pain. Further studies with different control conditions are required to examine the specificity of the sympathetic effects of hypnosis.

The role of tactile support in arm levitation

How many persons need tactile support à la Milton H. Erickson to achieve arm levitation during hypnosis? How do these differ from those who do not need it? Hypnotic arm levitation was suggested three times consecutively to 30 medium suggestible students. Sixteen succeeded without any tactile support; 7 needed it one or two times; 5 needed it every time; and 2 achieved no arm levitation at all. Participants without any tactile support went more quickly into deeper hypnosis, experienced more involuntariness, less effort, and had higher electrodermal activity. This greater physiological activity seems necessary for hypnotic arm levitation as a form of "attentive hypnosis" in contrast to "relaxation hypnosis." A change in verbal suggestion from "imagine a helium balloon" to "leave levitation to your unconscious mind" revealed no differences. Several issues resulting from this exploratory arm levitation study are discussed. The idea of different proprioceptive-kinesthetic abilities is introduced and the profound need of co-creating an individual suggestion is emphasized.

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.

State-space grid analysis: applications for clinical whole systems complementary and alternative medicine research

This paper presents state space grids (SSGs) as a mathematically less intensive methodology for process-oriented research beyond traditional qualitative and quantitative approaches in whole systems of complementary and alternative medicine (WS-CAM). SSGs, originally applied in developmental psychology research, offer a logical, flexible, and accessible tool for capturing emergent changes in the temporal dynamics of patient behaviors, manifestations of resilience, and outcomes. The SSG method generates a two-dimensional visualization and quantification of the inter-relationships between variables on a moment-to-moment basis. SSGs can describe dyadic interactive behavior in real time and, followed longitudinally, allow evaluation of how change occurs over extended time periods. Practice theories of WS-CAM encompass the holistic health concept of whole-person outcomes, including nonlinear pathways to complex, multidimensional changes. Understanding how the patient as a living system arrives at these outcomes requires studying the process of healing, e.g., sudden abrupt worsening and/or improvements, 'healing crises', and 'unstuckness', from which the multiple inter-personal and intra-personal outcomes emerge. SSGs can document the indirect, emergent dynamic effects of interventions, transitional phases, and the mutual interaction of patient and environment that underlie the healing process. Two WS-CAM research exemplars are provided to demonstrate the feasibility of using SSGs in both dyadic and within-patient contexts, and to illustrate the possibilities for clinically relevant, process-focused hypotheses. This type of research has the potential to help clinicians select, modify and optimize treatment plans earlier in the course of care and produce more successful outcomes for more patients.

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.

Heart rate variability as a measure of autonomic regulation of cardiac activity for assessing stress and welfare in farm animals -- a review

Measurement of heart rate variability (HRV) is a non-invasive technique that can be used to investigate the functioning of the autonomic nervous system, especially the balance between sympathetic and vagal activity. It has been proven to be very useful in humans for both research and clinical studies concerned with cardiovascular diseases, diabetic autonomic dysfunction, hypertension and psychiatric and psychological disorders. Over the past decade, HRV has been used increasingly in animal research to analyse changes in sympathovagal balance related to diseases, psychological and environmental stressors or individual characteristics such as temperament and coping strategies. This paper discusses current and past HRV research in farm animals. First, it describes how cardiac activity is regulated and the relationships between HRV, sympathovagal balance and stress and animal welfare. Then it proceeds to outline the types of equipment and methodological approaches that have been adapted and developed to measure inter-beats intervals (IBI) and estimate HRV in farm animals. Finally, it discusses experiments and conclusions derived from the measurement of HRV in pigs, cattle, horses, sheep, goats and poultry. Emphasis has been placed on deriving recommendations for future research investigating HRV, including approaches for measuring and analysing IBI data. Data from earlier research demonstrate that HRV is a promising approach for evaluating stress and emotional states in animals. It has the potential to contribute much to our understanding and assessment of the underlying neurophysiological processes of stress responses and different welfare states in farm animals.

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.

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.

The influence of rumination and defensiveness on negative affect in response to experimental stress

Previous experiments investigating the influence of rumination on negative affect have often manipulated the timing and content of rumination, which may be problematic as rumination is phenomenologically experienced as uncontrollable. In the present experiment, rumination was not manipulated, but measured as an individual tendency before the experiment. Furthermore, it was tested whether defensiveness would reduce the higher degree of negative affect often associated with rumination. Fifty-six participants completed questionnaires measuring rumination and defensiveness and participated in a phrase completion task, rating negative affect before and after the task. Correlational analyses showed that rumination was positively associated (p < 0.05) with affect responses (r range = 0.35-0.61), whereas defensiveness was negatively associated with affect responses (r range =-0.27-0.32). Four groups of high and low rumination and defensiveness scorers were created using median splits. An ANOVA showed that scoring high on defensiveness did not reduce the negative affect experienced by high ruminating participants.