Cardiac autonomic reactivity and salivary cortisol in men and women exposed to social stressors: relationship with individual ethological profile

Research prospect of human salivary cortisol: a bibliometric analysis

Background

Salivary cortisol has garnered increasing attention; the aim of this study was to employ bibliometric analysis to identify key papers in this research field and to explore its current status and trends.

Methods

Data were sourced from Clarivate Analytics' Web of Science core database, utilizing the search terms 'TS = ('Salivary cortisol') AND (Human) NOT (animal)'. All articles published from January 1, 2004, to September 30, 2024, were included.

Results

A total of 876 articles were identified. The United States has made a significant contribution to this field, with the highest number of publications at 291. The University of California system leads this research area, having published 40 articles. Professor Clemens Kirschbaum has authored 21 articles in this domain. The journal Psychoneuroendocrinology published the largest number of articles, totaling 99, which accounts for 11.3% of the overall articles. Additionally, Psychoneur-oendocrinology was the most cited journal, with 3,681 citations. High-frequency keywords reveal the developmental status and future trends of human salivary cortisol. As a biomarker and signaling molecule, salivary cortisol is closely linked to human gender, personality, psychology, and physiology. We identified that "mental health," "circadian rhythm," and "assay" may become focal points of interest in the coming years.

Conclusion

Global publications related to human salivary cortisol were systematically reviewed. CiteSpace and VOSviewer were utilized to analyze their bibliometric characteristics, identify the most cited articles in the field, and determine the leading countries, authors, and institutions, along with the interconnections among them. This analysis aims to elucidate the current status, hotspots, and trends in global research, while providing future development directions for scientific inquiry and medical practitioners.

Continuous real-time assessment of acute cognitive stress from cardiac mechanical signals captured by a skin-like patch

The inability to objectively quantify cognitive stress in real-time with wearable devices is a crucial unsolved problem with serious negative consequences for dementia and mental disability patients and those seeking to improve their quality of life. Here, we introduce a skin-like, wireless sternal patch that captures changes in cardiac mechanics due to stress manifesting in the seismocardiogram (SCG) signals. Judicious optimization of the device's micro-structured interconnections and elastomer integration yields a device that sufficiently matches the skin's mechanics, robustly yet gently adheres to the skin without aggressive tapes, and captures planar and longitudinal SCG waves well. The device transmits SCG beats in real-time to a user's device, where derived features relate to the heartbeat's mechanical morphology. The signals are assessed by a series of features in a support vector machine regressor. Controlled studies, compared to gold standard cortisol and following the validated imaging test, show an R-squared correlation of 0.79 between the stress prediction and cortisol change, significantly improving over prior works. Likewise, the system demonstrates excellent robustness to external temperature and physical recovery status while showing excellent accuracy and wearability in full-day use.

Atypical Response to Affective Touch in Children with Autism: Multi-Parametric Exploration of the Autonomic System

This study aimed at evaluating the autonomic response to pleasant affective touch in children with Autism Spectrum Disorders (ASD) and age-matched typically developing (TD) peers, thanks to multiple autonomic nervous system (ANS) parameters and by contrasting CT (C-tactile fibers) high- vs. low-density territory stimulations. We measured pupil diameter, skin conductance, and heart rate during gentle stroking of two skin territories (CT high- and low-density, respectively, forearm and palm of the hand) in thirty 6-12-year-old TD children and twenty ASD children. TD children showed an increase in pupil diameter and skin conductance associated with a heart rate deceleration in response to tactile stimulations at the two locations. Only the pupil was influenced by the stimulated location, with a later dilation peak following CT low-density territory stimulation. Globally, ASD children exhibited reduced autonomic responses, as well as different ANS baseline values compared to TD children. These atypical ANS responses to pleasant touch in ASD children were not specific to CT-fiber stimulation. Overall, these results point towards both basal autonomic dysregulation and lower tactile autonomic evoked responses in ASD, possibly reflecting lower arousal and related to social disengagement.

Cardiovascular reactivity during sadness induction predicts inhibitory control performance

Higher negative affectivity has an association with decreased executive function and cognitive control. Heart rate variability (HRV) serves as an index of cardiac vagal regulation differences in the autonomic nervous system for both cognition and emotion. The current study investigates this association using a classic as well as emotional antisaccade paradigm to study inhibitory control performance. Ninety participants completed affective questionnaires (Beck Depression Inventory-II, and Mood Scale), a 6-minute baseline electrocardiogram, and two different antisaccade tasks. After the baseline, subjects were presented with a video sequence with either neutral, sad, or emotionally arousing content. By subtracting the baseline from the video sequence, we computed HRV reactivity and tested whether the reactivity score could predict inhibitory control performance. We hypothesized that this would be the case in both the sadness and arousal group, but not in the neutral one. Furthermore, we awaited significant performance differences between experimental groups. Contrary to our assumption, inhibitory control performance did not differ between experimental groups. Moreover, there was no significant relation between affective measures and task performance. Nevertheless, cardiovascular reactivity in terms of HRV was predictive of error rates in both antisaccade tasks in the sadness group. We could find this effect neither in the neutral nor in the arousal group. In addition, BDI scores moderated the effect in the emotional task. Results indicate that emotional reactivity to a sad video stimulus as indexed by HRV as well as the interaction with current emotional state predict inhibitory control performance.

Osteopathic Manipulative Treatment Regulates Autonomic Markers in Preterm Infants: A Randomized Clinical Trial

Osteopathic manipulative treatment (OMT) has been found to be effective in the context of premature infants. Nonetheless, no studies have investigated the immediate effects of OMT on heart rate variability (HRV). As altered HRV reflects poor or worsening newborn's clinical conditions and neurodevelopment, should OMT improve HRV fluctuations, it could become a relevant intervention for improving the care of preterm newborns. Therefore, this study aimed to evaluate whether OMT could affect HRV. The study was carried out at the Buzzi Hospital in Milan. From the neonatal intensive care unit, ninety-six preterm infants (41 males) were enrolled and were randomly assigned to one of two treatment groups: OMT or Static Touch. The infants were born at 33.5 weeks (±4.3) and had a mean birth weight of 2067 g (±929). The study had as primary outcome the change in the beat-to-beat variance in heart rate measured through root mean square of consecutive RR interval differences (RMSSD); other metrics were used as secondary and exploratory analyses. Despite the lack of statistically significant results regarding the primary outcomeand some study limitations, compared to static touch, OMT seemed to favor a parasympathetic modulation and improved HRV, which could reflect improvement in newborn's clinical conditions and development.

The psychophysiological correlates of cognitive dissonance

This preregistered study uses a combination of physiological measures to explore both the activation and reduction components of cognitive dissonance theory. More precisely, we use skin conductance to identify dissonance arousal, a short-term affective response to counter-attitudinal stimuli, and then use heart rate variability to measure dissonance reduction, which reflects longer-term patterns of emotional regulation and information processing. Our preliminary tests find weak evidence of dissonance arousal and no evidence of dissonance reduction using this physiological approach. We consequently reconsider (albeit optimistically) the use of physiology in future work on cognitive dissonance. We also discuss the implications of our findings for selective exposure and motivated reasoning.

Subjective and objective demands on different types of differential stress inventory

PURPOSE

To validate the differential stress inventory (DSI) by evaluating the objective and subjective stress differences in the five DSI types in the occupational setting.

METHODS

A total of 119 German participants working as medical assistants (n = 40) or in a bank (n = 79) were recruited. They completed the Maslach Burnout Inventory-General Survey, the DSI, and wore ECG measuring devices for 24 h to measure heart rate variability. The DSI was used to group people into one of five types according to how they perceived and coped with stress: normal, overstressed, stress-resistant, low stress/high coping, or high stress/high coping.

RESULTS

The overstressed type had significantly more burnout symptoms than the other types. The high stress/high coping type also had more symptoms of emotional exhaustion and total burnout compared to the other types, while the low stress/high coping and the stress-resistant types generally had the lowest levels of burnout. There were no differences on the HRV parameters among the DSI types.

CONCLUSION

Categorising people into types like in the DSI can help make workers aware of unhealthy stress and coping patterns before they turn into more severe pathology. Proper application and targeted preventive measures can save the individual's health and the company's budget. While the DSI picked up on differences in burnout symptoms as a long-term consequence of stress, there is evidence that it cannot pick up on short-term stress or physical stress as measured by HRV from the 24 h recording.

Behavioral and physiological stress responses: Within-person concordance during pregnancy

During pregnancy, a woman's emotions can have longstanding implications for both her own and her child's health. Within-person emotional concordance refers to the simultaneous measurement of emotional responses across multiple levels of analysis. This method may provide insight into how pregnant women experience emotions in response to stress. We enrolled 162 pregnant women and assessed concordance through autonomic physiology (electrodermal activity [EDA], respiratory sinus arrhythmia [RSA]), and coded behavior (Prosocial, Flight, Displacement) during the Trier Social Stress Test-Speech. We used multilevel models to examine behavioral-physiological concordance and whether self-reported emotion dysregulation moderated these effects. Participants exhibited EDA-Prosocial concordance, suggesting that prosocial behavior may be a marker of stress. Emotion dysregulation did not moderate concordance. These findings provide novel information about behavioral coping to stress in pregnancy. Given the importance of observed behavior in the maintenance and treatment of psychopathology, these findings may provide a launchpad for future perinatal intervention research.

Psychobiological evidence of the stress resilience fostering properties of a cosmetic routine

Everyday life psychosocial stressors contribute to poor health and disease vulnerabilty. Means alternative to pharmacotherapy that are able to foster stress resilience are more and more under the magnifying glass of biomedical research. The aim of this study was to test stress resilience fostering properties of the self-administration of a cosmetic product enriched with essential oils. On day 0, fourty women, 25-50 years old, self-administered both the enriched cosmetic product (ECP) and a placebo one (PCP). Then, women were randomized for daily self-administration (from day 1 to 28) of either ECP (n = 20) or PCP (n = 20). On day 29, subjects underwent a psychosocial stress test (PST). Autonomic (heart rate and its variability) and neuroendocrine (salivary cortisol) parameters were assessed both on day 0 and 29. All subjects filled a number of psychological questionnaires in order to quantify anxiety, perceived stress, and mood profile, and were videorecorded during PST for non-verbal behavior evaluation. A single application of ECP produced an acute potentiation of cardiac parasympathetic modulation, which was not observed when placebo was used. Prolonged self-administration of ECP induced: (i) a dampening of the cortisol rise produced by PST, (ii) a reduction of state anxiety, (iii) a favorable change in mood profile, and (iv) a reduction of non-verbal behavior patterns that signal anxiety, motivational conflict and avoidance. In conclusion, this study suggests that the self-administration of a cosmetic cream enriched with essential oils should be considered as a stress resilience fostering strategy due to its favorable physiological, neuroendocrine and psychological effects.

Are there non-verbal signals of guilt?

Guilt is a complex emotion with a potentially important social function of stimulating cooperative behaviours towards and from others, but whether the feeling of guilt is associated with a recognisable pattern of nonverbal behaviour is unknown. We examined the production and perception of guilt in two different studies, with a total of 238 participants with various places of origin. Guilt was induced experimentally, eliciting patterns of movement that were associated with both the participants' self-reported feelings of guilt and judges' impressions of their guilt. Guilt was most closely associated with frowning and neck touching. While there were differences between self-reported guilt and perception of guilt the findings suggest that there are consistent patterns that could be considered a non-verbal signal of guilt in humans.

The Relationship between Different Types of Alarm Sounds and Children's Perceived Risk Based on Their Physiological Responses

Due to differences in cognitive ability and physiological development, the evacuation characteristics of children are different from those of adults. This study proposes a novel method of using wearable sensors to collect data (e.g., electrodermal activity, EDA; heart rate variability, HRV) on children’s physiological responses, and to continuously and quantitatively evaluate the effects of different types of alarm sounds during the evacuation of children. In order to determine the optimum alarm for children, an on-site experiment was conducted in a kindergarten to collect physiological data for responses to different types of alarm sounds during the evacuation of 42 children of different ages. The results showed that: (1) The alarm sounds led to changes in physiological indicators of children aged 3–6 years, and the effects of different types of alarm sounds on EDA and HRV activities were significantly different (p < 0.05). Skin conductance (SC), skin conductance tonic (SCT) and skin conductance level (SCL) can be used as the main indicators for analysing EDA of children in this experiment (p < 0.05), and the indicators of ultralow frequency (ULF) and very low frequency (VLF) for HRV were not affected by the type of alarm sounds (p > 0.05). (2) Unlike adults, kindergarten children were more susceptible to the warning siren. The combined voice and warning alarm had optimal effects in stimulating children to perceive risk. (3) For children aged 3–6 years, gender had a significant impact on children’s reception to evacuation sound signals (p < 0.05): Girls are more sensitive than boys in receiving evacuation sound signals, similar to findings of studies of risk perception of adult males and females. In addition, the higher the age, the greater the sensitivity to evacuation sound signals, which accords with results of previous studies on the evacuation dynamics of children.

Maternal prenatal and early postnatal distress and child stress responses at age 6

Individuals differ in their physiological and behavioral stress responses. Alterations in these responses have been associated with mental and physical health. Therefore, it is important to understand how stress responses develop. This study investigated whether in a healthy, non-risk population, 6-year-old's physiological (cortisol) and behavioral (gazing) stress responses were associated with stress early in the child's life, in the form of maternal prenatal and early postnatal distress. Additionally, associations between the two stress responses were studied. At age 6, children (n = 149; M_age = 6.09; 70 girls) in a longitudinal project that started prenatally (n = 193), participated in a social evaluative stress test (Children's Reactions to Evaluation Stress Test, CREST) in front of a judge. To operationalize physiological stress responses six cortisol saliva samples were collected and cortisol stress reactivity and total stress cortisol scores were calculated. To operationalize behavioral stress responses, gazing at the judge during the stress test was observed. Maternal prenatal distress (week 37) was measured using questionnaires and physiological measures, that is, cortisol saliva samples. Early postnatal maternal distress (first 6 months) was measured using questionnaires. Results of hierarchical regression analyses indicated that less maternal prenatal fear of giving birth, higher maternal prenatal evening cortisol concentrations, and more maternal feelings of anxiety in the first 6 postnatal months were all uniquely associated with higher total stress cortisol concentrations in children at age 6. Additionally, correlations indicated that children with higher cortisol stress reactivity gazed less in the direction of the judge. Results indicate that maternal prenatal and early postnatal distress are associated with children's later hypothalamic-pituitary-adrenal-axis functioning and that in children gazing and physiological stress reactivity are related. Lay summary We examined whether maternal stress and anxiety during pregnancy, as measured by means of maternal self-reports and saliva cortisol samples, as well as maternal stress and anxiety in the first 6 months of the child's life, measured using maternal self-reports, were associated with children's physiological (cortisol) and behavioral (gazing) responses during a stressful laboratory situation at the age of 6. Results showed that mothers with higher levels of distress in late pregnancy and/or the early postnatal period had children with higher cortisol concentrations during the stressful situation. This suggests that maternal prenatal and early postnatal distress are associated with children's later hypothalamic-pituitary-adrenal-axis functioning.

Psychological characteristics and physiological reactivity to acute stress in mothers of children with autism spectrum disorder

Stress related to parenting a child with autism spectrum disorder can differently affect caregiver's physiological reactivity to acute stress. Here, parental stress levels, psychological characteristics, and coping strategies were assessed alongside measures of heart rate, heart rate variability, and cortisol during a psychosocial stress test in mothers of children with ASD (M-ASD, n = 15) and mothers of typically developing children (n = 15). M-ASD reported significantly higher levels of parental stress, anxiety, negative affectivity, social inhibition, and a larger preference for avoidance strategies. M-ASD showed larger heart rate and cortisol responses to the psychosocial stress test. A positive relationship was found between parental stress levels and the magnitude of the cortisol stress response in both groups. The present findings indicate exaggerated physiological reactivity to acute psychosocial stress in M-ASD and prompt further research to explore the role of individual differences in mediating the effects of parental stress on physiological stress responses.

The moderating effect of heart rate variability on the relationship between alpha asymmetry and depressive symptoms

Electroencephalographic (EEG) research has suggested relatively reduced brain activity in the left frontal and right posterior region trait-markers of depression. However, inconsistent results have been reported. Based on previous studies reporting the heart rate variability (HRV) as an index of emotional regulation, this study makes a novel investigation of the role of heart rate variability (HRV) as a moderator in the relationship between frontal and parietal alpha asymmetry and depression. Resting EEG (eyes open) was recorded in 38 patients with MDD and 34 healthy subjects. Frontal and parietal alpha asymmetries were calculated at total (8–12 Hz), high (10–12 Hz), and low (8–10 Hz) alpha frequency bands. Three vagally mediated HRV (vmHRV) components (LF, HF, and the LF/HF ratio) were calculated in the frequency domain. Relatively greater right parietal alpha activity significantly predicted the severity of depression only when HF was low (or the LF/HF ratio was high) at low alpha frequency band. The interaction effect of parietal alpha asymmetry and vmHRV remained significant after including anxiety score as a covariate. No moderation effect of vmHRV was found for frontal sites and other frequency bands, as well as healthy subjects. These findings suggest that vmHRV moderates the association between parietal alpha asymmetry at low frequency band and depression for MDD patients. We suggest that the interaction between parietal alpha asymmetry and vmHRV may be a biomarker of MDD.

Assessing Performance on an Evaluated Speaking Task

Abstract. Coping with social stress involves cognitive perceptions and the activation of several physiological mechanisms. Our main purpose was to examine how psychological factors such as cognitive appraisal, and particularly self-efficacy, may affect psychophysiological reactivity to social stress and young people’s performance on an evaluated speaking task. Thirty-five university students (18 men and 17 women) were exposed to the Trier Social Stress Test (TSST) and a control condition in a counterbalanced order. Self-efficacy, several dimensions of trait anxiety related to social evaluation, and changes in state anxiety were assessed. Additionally, heart rate and heart rate variability (HRV) were analyzed by means of R-R and r-MSSD parameters, respectively. The results indicate that a positive self-assessment of their own ability to overcome a social threat was related to the predominance of vagal tone and better performance. However, cardiac reactivity was not related to the quality of the performance displayed. In addition, some dimensions of trait anxiety, such as cognitive anxiety and test evaluation anxiety, were negatively associated with self-efficacy and performance. These findings emphasize the relevance of self-efficacy, a key component of cognitive appraisal, in explaining psychophysiological reactivity to social stress. Furthermore, they highlight the importance of some personality characteristics, such as social evaluation anxiety, in explaining performance in specifically related stressful situations, regardless of autonomic activation.

The Role of Baseline Vagal Tone in Dealing with a Stressor during Face to Face and Computer-Based Social Interactions

Facing a stressor involves a cardiac vagal tone response and a feedback effect produced by social interaction in visceral regulation. This study evaluated the contribution of baseline vagal tone and of social engagement system (SES) functioning on the ability to deal with a stressor. Participants (n = 70) were grouped into a minimized social interaction condition (procedure administered through a PC) and a social interaction condition (procedure administered by an experimenter). The State Trait Anxiety Inventory, the Social Interaction Anxiety Scale, the Emotion Regulation Questionnaire and a debriefing questionnaire were completed by the subjects. The baseline vagal tone was registered during the baseline, stressor and recovery phases. The collected results highlighted a significant effect of the baseline vagal tone on vagal suppression. No effect of minimized vs. social interaction conditions on cardiac vagal tone during stressor and recovery phases was detected. Cardiac vagal tone and the results of the questionnaires appear to be not correlated. The study highlighted the main role of baseline vagal tone on visceral regulation. Some remarks on SES to be deepen in further research were raised.

Hidden Signals-The History and Methods of Heart Rate Variability

The understanding of heart rate variability (HRV) has increased parallel with the development of modern physiology. Discovered probably first in 1847 by Ludwig, clinical applications evolved in the second part of the twentieth century. Today HRV is mostly used in cardiology and research settings. In general, HRV can be measured over shorter (e.g., 5-10 min) or longer (12 or 24 h) periods. Since 1996, most measurements and calculations are made according to the standard of the Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. As the first step, the series of times between successive R-peaks in the ECG are in milliseconds. It is crucial, however, to identify and remove extrasystoles and artifacts according to standard protocols. The series of QRS distances between successive heartbeats can be analyzed with simple or more sophisticated algorithms, beginning with standard deviation (SDNN) or by the square root of the mean of the sum of squares of differences between adjacent normal RR (rMSSD). Short-term HRV is frequently analyzed with the help of a non-parametric fast Fourier transformation quantifying the different frequency bands during the measurement period. In the last decades, various non-linear algorithms have been presented, such as different entropy and fractal measures or wavelet analysis. Although most of them have a strong theoretical foundation, their clinical relevance is still debated.

Cortisol Levels and Autonomic Control of Heart Rate in Healthy Subjects

Introduction: There is an increase in level of stress in the general population because of the social, personal and professional demands. Currently, there are only simple tools that can safely measure this stress such as levels of cortisol and heart rate variability (HRV). Objective: To analyze the relationship between salivary cortisol and the cardiac autonomic modulation. Methods: A total of fifty-one male and female subjects between 18 and 40 years old were evaluated. Saliva collection was achieved for the salivary cortisol dosage. The collection was performed through the SalivetteR tube. After this collection, the median cortisol levels (0.24 ug/dl) were analyzed and the volunteers were divided into two groups: i) cortisol below the mediane ii) cortisol above the median. After this division, each group consisted of 25 volunteers and then was verified the following information: age, gender, weight, height, body mass index (BMI), blood pressure. Shortly thereafter was assessment of cardiac autonomic modulation por meio da HRV. The Polar RS800cx heart rate receiver was placed on the chest of the volunteers, in the vicinity of the distal third of the sternum. The volunteers were instructed to remain in rest with spontaneous breathing in dorsal position for 20 minutes. HRV analysis included geometric, time and frequency domain indices. Results: There were no statistical differences for the two groups regarding systolic and diastolic blood pressure, heart rate, RR intervals or linear and frequency indices for the volunteers. In addition, also there was no correlation the cortisol with the analyzed variables (SAP, p=0.460; DAP, p = 0.270; HR, p = 0.360; RR, p = 0.380; SDNN, p = 0.510; rMSSD, p = 0.660; pNN50, p = 0.820; RRtri, p = 0.170; TINN, p = 0.470; SD1, p = 0.650; SD2, p = 0.500; LF [ms2], p = 0.880; LF [nu], p = 0.970; HF [ms2], p = 0.870; HF [nu], p = 0.960; LF/HF, p = 0.380 Conclusion: Heart rate variability autonomic control was unchanged in healthy subjects with physiological distribution of salivary cortisol levels. There was no association between normal salivary cortisol and resting autonomic regulation of heart rate.

Single Osteopathic Manipulative Therapy Session Dampens Acute Autonomic and Neuroendocrine Responses to Mental Stress in Healthy Male Participants

Context

The efficacy of osteopathic manipulative therapy (OMTh; manipulative care provided by foreign-trained osteopaths) is supported by observational data and patient feedback, but there is still a need for objective, quantitative biomarkers that allow measurement of the underlying mechanisms. No study exploring the protective potential of OMTh for mental stress has been published, to the authors’ knowledge.

Objectives

To explore the modulating effect of OMTh on autonomic neural regulation of the heart and verifiy its ability to influence the activity of the hypothalmic-pituitary-adrenocortical axis.

Methods

Healthy young adult men who had never received OMTh were exposed to either a brief protocol using craniosacral techniques or sham therapy (control) involving the same anatomical areas. A laboratory stress episode consisting of a 5-minute arithmetic task participants were required to perform in front of a committee preceded the therapy sessions. Continuous electrocardiograph recordings were done before, during, and after the stress episode. Heart rate and frequency-domain parameters of heart rate variability (specifically, high-frequency component power in normalized units and the ratio of low-frequency to high-frequency power) were measured to quantify the activity of the parasympathetic nervous system and the state of sympathovagal balance at the level of the heart, respectively. Saliva samples were also collected at points throughout the study to determine cortisol levels.

Results

Osteopathic manipulative therapy reduced the overall chronotropic effect of the stressor (t=−2.9, P<.05) and counteracted the vagal withdrawal and the shift of autonomic balance toward sympathetic prevalence (t=−2.8, P<.05) that were observed in control participants. Moreover, OMTh participants had a much lower overall cortisol level during the mental stressor compared with control participants (t=−2.3, P<.05). Participants in the OMTh group did not show the statistically significant reduction in the amplitude of the cortisol awakening response observed in their control counterparts after the stress episode (control: t=2.7, P<.05; OMT: P=.83).

Conclusion

The application of a single OMTh session to healthy participants induced a faster recovery of heart rate and sympathovagal balance after an acute mental stressor by substantially dampening parasympathetic withdrawal and sympathetic prevalence. The OMTh session also prevented the typical increase in cortisol levels observed immediately after a brief mental challenge.

Experiential learning as preparation for leadership

Purpose

The purpose of this paper is to explore whether challenging experiences on development programmes would simulate leadership challenges and therefore stimulate the body’s autonomic nervous system response. The authors also aimed to determine whether increase in autonomic arousal would be related to learning, and/or moderated by personality variables.

Design/methodology/approach

The research used heart rate (HR) monitors to measure HR continuously over a two-day simulated learning experience. This was used to calculate autonomic arousal which was taken to be the difference between resting HR measured during sleep and HR during critical incidents (CIs) (HR). The authors correlated this with self-reports of learning immediately after, and one month after, the programme to assess the impact of autonomic arousal on perceived learning, as well as with variety of psychometric measures.

Findings

The research found significant correlations between (HR) during CIs and perceived learning which were not related to personality type. The research also found a significant correlation between (HR) and learning during a control event for individuals with “approach” personalities.

Research limitations/implications

Whilst a significant result was found, the sample size of 28 was small. The research also did not empirically assess the valence or intensity of the emotions experienced, and used only a self-report measure of learning. Future research should replicate the findings with a larger sample size, attempt to measure these emotional dimensions, as well as obtain perceptions of learning from direct reports and line managers.

Practical implications

The findings from the research help clarify the mechanisms involved in the effectiveness of experiential learning, and contribute to the understanding of the influence of personality type on perceived learning from experiential methodologies. Such understanding has implications for business schools and learning and development professionals, suggesting that development experiences that challenge leaders are likely to result in learning that is longer lasting.

Originality/value

The research extends the literature regarding the value of learning through experience, the role of autonomic arousal on learning, and the impact of negative emotions on cognition. The research makes a unique contribution by exploring the impact of experience on arousal and learning in a simulated learning experience and over time, by demonstrating that simulated experiences induce emotional and physiological responses, and that these experiences are associated with increased learning.

Changes in Heart Rate Variability Recorded in Natural Situation with T-Shirt Integrated Sensors and Level of Observed Behavioral Excitation: A Pilot Study of Patients with Intellectual Disabilities and Psychiatric Disorders

BACKGROUND

The present study investigates the possibilities of using heart rate variability (HRV) parameters as physiological markers that precede increase in observed behavioral excitation of intellectually disabled individuals. The ability to recognize or predict such patterns, especially in patients showing unpredictable reactions and language deficiencies, might be a major step forward in clinical research.

METHOD

Thirteen volunteers with intellectual disabilities, who had suffered of at least one event of overt aggression in the preceding 3 months, participated to the study. The protocol consists in the acquisition of continuous electrocardiogram (ECG) throughout approximately two times of 8 h in natural situation, using a T-shirt integrated with sensors. Simultaneously, an observer evaluates the patient's level of overt excitation from calm (level 1) to extremely tense (level 5) and send online via Bluetooth these triggers into the ECG signals. The HRV indexes were then estimated offline on the basis of the inter-beat intervals recorded by the ECG, independently for the 30 min preceding each behavioral tension marking point, averaged, and compared through non-parametric Wilcoxon matched-pairs test. Of these, the RMSSD and LF/HF calculations were used to observe the fluctuations of inhibitory activity and cardiovagal balance through different tension states.

RESULTS

Seven individuals have sufficient reliable data for analysis. They have reached at least a level 3 of behavioral excitation (moderately tense) or more (very to extremely tense, level 4 and 5) and have been retained for further analysis. In sum, a total of 197 periods of tension were kept, made up of 46 periods of slight excitation (level 2), 18 of moderate excitation (level 3), 10 of high excitation (level 4), and 5 of extreme agitation (level 5). Variations in the HRV as a function of degree of excitation are observed for RMSSD index only (inhibitory parasympathetic activity). The changes from calm to increasing levels of excitation are characterized by a significant downfall in RMSSD index when patients were evaluated to be in a very high level of tension (level 4).

CONCLUSION

The presence of precursors to agitation, reflected in the falling-off of parasympathetic activity, offers potentially interesting prospects for therapeutic development.

Anxiety and physiological responses to the Trier Social Stress Test for Children in adolescents with cyclic vomiting syndrome

This study compared anxiety and physiological responses during the Trier Social Stress Test for Children (TSST-C) in adolescents. 38 subjects (26 females) were enrolled: 11 cyclic vomiting syndrome (CVS), 11 anxiety, and 16 controls. Salivary cortisol, α-amylase and heart rate variability (HRV) were assessed during the TSST-C. Anxiety was measured by the Screen for Childhood Anxiety Related Emotional Disorders (SCARED), Anxiety Disorders Interview Schedule, and State-Trait Anxiety Inventory for Children (STAI-C). 11 anxiety and 7 CVS subjects had ≥1 anxiety disorder. 82% in the anxiety and CVS groups met criteria for an anxiety disorder on the SCARED. Combining groups, cortisol increased from baseline to recovery during the TSST-C (p=0.0004) and the stressor to recovery (p=0.005). α-amylase did not differ during the TSST-C for the total sample, but increased for anxiety compared to controls from baseline to recovery (p=0.01). HRV decreased during the stressor (p=0.0001) and increased at recovery (p=0.004). No associations were found between biomarkers and trait anxiety. Associations were found between baseline HRV and pre-test state anxiety (r=-0.406, p=0.012) and between recovery HRV and post-test state anxiety (r=-0.501, p=0.002) for the total sample. Anxiety is prevalent in CVS warranting screening. HRV may serve as a biomarker for evaluating stress as a potential trigger for CVS episodes. State but not trait anxiety was associated with changes in HRV, suggesting acute anxiety may be more relevant in linking stress and CVS episodes.

Salivary cortisol and behavioral response to social evaluative threat in adolescents with autism spectrum disorder

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social behavior. One possible explanation for social communication deficits in ASD could be differences in biological systems that support responses to environmental stimuli. If so, it is unclear if differences in the arousal response to social stimuli in ASD are due to reduced interest in social information, or to an increased stress response. The hypothalamic pituitary adrenal axis facilitates arousal and the stress response to sensory input, including social stimuli. Previous research shows blunted cortisol response to social evaluative threat in children with ASD. The majority of prior work has focused on children with ASD, but adolescents with ASD are understudied. The adolescent period is of interest, as this developmental epoch is associated with increased salience of social evaluative threat in typically developing (TD) populations. In this study, we employed the Trier Social Stress Test (TSST), a laboratory paradigm that involves exposure to social evaluative threat, to study the cortisol and behavioral response to social evaluative threat in ASD and TD adolescents. Salivary cortisol data were collected at six time points before and after the TSST. Behavioral data were collected using video recordings of the TSST, which were then operationalized and coded. Paired sample t-tests were used to calculate within-group cortisol response to the TSST. Cortisol significantly increased in response to the TSST in the TD group but not the ASD group. The TD group showed a trend for more self-soothing behaviors during the stressor than the ASD group. The lack of a cortisol response to the TSST in the ASD group suggests that the TSST is not interpreted as stressful or salient for ASD adolescents. Autism Res 2017, 10: 346-358. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.

How are neuroticism and depression related to the psychophysiological stress response to acute stress in healthy older people?

Neuroticism and depressive symptomatology have been related to a heightened and diminished physiological stress response, which may partly explain their negative relationship with health and wellbeing. Identifying factors that may increase disease vulnerability is especially relevant in older people, whose physiological systems decline. With this in mind, we investigated the influence of neuroticism and depression on the psychophysiological stress response in healthy older people (from 55 to 76years old). A total of 36 volunteers were exposed to a stressful task (Trier Social Stress Test, TSST), while 35 volunteers performed a control non-stressful task. The physiological stress response was assessed through measures of cortisol, alpha-amylase, heart rate (HR). Our results showed that, neuroticism was not related to physiological stress response. However, depression was related to higher cortisol response and lower HR reactivity in the stress condition. In summary, emotional states such as depressive mood seem to amplify the cortisol stress response and reduce the cardiovascular response, whereas more stable dispositions such as neuroticism did not affect stress response in older people. These findings confirm, in healthy older people, the adverse effects of depression, acting on different subsystems of the stress response.

Neuroticism and stress: the role of displacement behavior

BACKGROUND AND OBJECTIVES

Neuroticism is linked with an impaired ability to cope with stress and is an important risk factor for stress-related disorders. Hence, there is interest in exploring the behavioral correlates of neuroticism and how such behaviors may moderate the link between neuroticism and the response to stress. Displacement behavior - activity such as face touching and scratching - is important to investigate in this respect, as recent studies indicate that such behavior is linked to negative emotional states and has an important stress coping function. Here, we explored the relationship between neuroticism, displacement behavior, and stress in a healthy population of men.

DESIGN

This was a cross-sectional, quasiexperimentally controlled study.

METHODS

We assessed participants' levels of neuroticism, and then during a Trier Social Stress Test quantified displacement behavior, physiological, and cognitive indices of the stress response; after the test we measured the self-reported experience of stress.

RESULTS

Displacement behavior was negatively correlated with self-reported experience, physiological, and cognitive measures of stress and moderated the relationships between neuroticism, self-reported experience, and cognitive index of stress.

CONCLUSIONS

Our results suggest displacement behavior plays an important role in shaping the link between neuroticism and the response to stress.

Coping with an acute psychosocial challenge: behavioral and physiological responses in young women

Despite the relevance of behavior in understanding individual differences in the strategies used to cope with stressors, behavioral responses and their relationships with psychobiological changes have received little attention. In this study on young women, we aimed at analyzing the associations among different components of the stress response and behavioral coping using a laboratory psychosocial stressor. The Ethological Coding System for Interviews, as well as neuroendocrine, autonomic and mood parameters, were used to measure the stress response in 34 young women (17 free-cycling women in their early follicular phase and 17 oral contraceptive users) subjected to the Trier Social Stress Test (TSST) and a control condition in a crossover design. No significant differences in cardiac autonomic, negative mood and anxiety responses to the stressor were observed between the two groups of women. However, women in the follicular phase showed a higher cortisol response and a larger decrease in positive mood during the social stress episode, as well as greater anxiety overall. Interestingly, the amount of displacement behavior exhibited during the speaking task of the TSST was positively related to anxiety levels preceding the test, but negatively related to baseline and stress response values of heart rate. Moreover, the amount of submissive behavior was negatively related to basal cortisol levels. Finally, eye contact and low-aggressiveness behaviors were associated with a worsening in mood. Overall, these findings emphasize the close relationship between coping behavior and psychobiological reactions, as well as the role of individual variations in the strategy of coping with a psychosocial stressor.

The power of clinicians' affective communication: how reassurance about non-abandonment can reduce patients' physiological arousal and increase information recall in bad news consultations. An experimental study using analogue patients

OBJECTIVE

The diagnosis of incurable cancer may evoke physiological arousal in patients. Physiological arousal can negatively impact patients' recall of information provided in the medical consultation. We aim to investigate whether clinicians' affective communication during a bad news consultation will decrease patients' physiological arousal and will improve recall.

METHODS

Healthy women (N=50), acting as analogue patients, were randomly assigned to watch one out of the two versions of a scripted video-vignette of a bad news consultation in which clinician's communication differed: standard vs. affective communication. Participants' skin conductance levels were obtained during video-watching, and afterwards their recall was assessed.

RESULTS

While the diagnosis increased skin conductance levels in all analogue patients, skin conductance levels during the remainder of the consultation decreased more in the affective communication condition than in the standard condition. Analogue patients' recall was significantly higher in the affective condition.

CONCLUSION

Breaking bad news evokes physiological arousal. Affective communication can decrease this evoked physiological arousal and might be partly responsible for analogue patients' enhanced information recall.

PRACTICE IMPLICATIONS

Although our findings need to be translated to clinical patients, they suggest that clinicians need to deal with patients' emotions before providing additional medical information.

The relation between gaze aversion and cortisol reactivity in middle childhood

The present study sought to investigate the relation between ethological observations of children's gaze aversion during a psychosocial stress task and their cortisol reactivity to the task, and how this relation might be moderated by how stressful the children perceived the stress task to be. Videos of 140 children (74 girls; Mage=10.60years) performing a psychosocial stress task in front of a jury were coded for displays of the children's gaze aversion from the jury, and saliva samples were taken to determine their cortisol reactivity. A questionnaire assessed the children's level of perceived stress. Results showed higher cortisol reactivity in children who perceived the task as more stressful. Furthermore, a quadratic relation between gaze aversion and cortisol was found which depended on the level of perceived stress: for children with low levels of perceived stress, cortisol reactivity was lowest with intermediate levels of gaze aversion, whereas for children with high levels of perceived stress cortisol reactivity was highest at intermediate levels of gaze aversion. The results suggest a modest association between subjective and physiological stress responses in 9- to 11-year-olds, and indicate that gaze aversion may play only a minor role as a behavioural coping strategy at this age.

Oxytocin and psychotherapy: a pilot study of its physiological, behavioral and subjective effects in males with depression

Individual psychotherapy is an important treatment for a number of psychiatric conditions and involves a unique form of human attachment. This raises the question of whether oxytocin (OT), the paradigmatic "attachment hormone", may have benefits in this context. In this randomized, double-blind, crossover trial, we gave male psychiatric outpatients with major depressive disorder 40 IU intranasal OT or placebo before a videotaped session with a therapist and measured a number of subjective, physiological, and behavioral parameters. We report three main findings. Surprisingly - in contrast to prior reports of OT's anxiolytic properties - we found OT caused an increase in anxiety over the course of the therapy session. Secondly, though it had no main effect on cortisol, eye contact, or overall behavior, we did find that OT caused a decrease in nonverbal behaviors that cut off social contact, after controlling for level of depressive symptoms. Lastly, we replicated prior findings that OT improves social cognition (performance on the reading the mind in the eyes test (RMET)), albeit in a depressed patient group. These results inform future studies of oxytocin and psychotherapy and suggest that in certain clinical populations and contexts, OT has heterogeneous subjective effects which may include acute anxiogenesis. Moreover, the similarity of some of these acute effects to those of single-dose serotonergic antidepressants raises interesting questions about the potential antidepressant benefits of chronic OT administration.

Children's heart rate variability as stress indicator: association with reported stress and cortisol

Stress is a complex phenomenon coordinated by two main neural systems: the hypothalamic-pituitary-adrenal system with cortisol as classical stress biomarker and the autonomic nervous system with heart rate variability (HRV) as recently suggested stress marker. To test low HRV (5 minute measurements) as stress indicator in young children (5-10 y), associations with self-reported chronic stress aspects (events, emotions and problems) (N=334) and salivary cortisol (N=293) were performed. Peer problems, anger, anxiety and sadness were associated with lower root mean square of successive differences (RMSSD) and high frequency power (i.e. lower parasympathetic activity). Anxiety and anger were also related to a higher low frequency to high frequency ratio. Using multilevel modelling, higher cortisol levels, a larger cortisol awakening response and steeper diurnal decline were also associated with these HRV patterns of lower parasympathetic activity.

CONCLUSION

Low HRV (lower parasympathetic activity) might serve as stress indicator in children.

Displacement behaviour regulates the experience of stress in men

Behavioural coping strategies represent a key means by which people regulate their stress levels. Attention has recently focused on the potential role in coping of 'displacement behaviour' - activities such as scratching, lip biting and face touching. Increased levels of displacement behaviour are associated with feelings of anxiety and stress; however, the extent to which displacement behaviour, as a short-term behavioural response to emotionally challenging stimuli, influences the subsequent experience of stress remains poorly understood. The aim of this study was to investigate the potential role of displacement behaviour in coping with stress. In a study population of 42 healthy adult men (mean age = 28.09 years, SD = 7.98), we quantified displacement behaviour during a Trier Social Stress Test (TSST), and used self-report questionnaires to assess trait and state anxiety before the TSST, and the experience of stress afterwards. We predicted displacement behaviour would diminish the negative impact of the stressful situation, and hence be associated with lower post-TSST stress levels. Furthermore, we predicted displacement behaviour would mediate the link between state and trait anxiety on the one hand and the experience of stress on the other. Results showed the rate of displacement behaviour was positively correlated with state anxiety but unrelated to trait anxiety, and negatively correlated with the self-reported experience of stress, in agreement with the idea that displacement behaviour has a crucial impact on regulation of stress. Moreover, serial mediation analyses using a bias-corrected bootstrapping approach indicated displacement behaviour mediated the relationship between state anxiety and the experience of stress, and that state anxiety and displacement behaviour - in combination, respectively - mediated the link between trait anxiety and experience of stress. These results shed important new light on the function of displacement behaviour, and highlight promising new avenues for research into emotional expression and stress regulation.

Displacement behaviour is associated with reduced stress levels among men but not women

Sex differences in the ability to cope with stress may contribute to the higher prevalence of stress-related disorders among women compared to men. We recently provided evidence that displacement behaviour--activities such as scratching and face touching--represents an important strategy for coping with stressful situations: in a healthy population of men, displacement behaviour during a social stress test attenuated the relationship between anxiety experienced prior to this test, and the subsequent self-reported experience of stress. Here, we extend this work to look at physiological and cognitive (in addition to self-reported) measures of stress, and study both men and women in order to investigate whether sex moderates the link between displacement behaviour and the response to stress. In a healthy study population, we quantified displacement behaviour, heart rate and cognitive performance during the Trier Social Stress Test, and used self-report questionnaires to assess the experience of stress afterwards. Men engaged in displacement behaviour about twice as often as women, and subsequently reported lower levels of stress. Bivariate correlations revealed that for men, higher rates of displacement behaviour were associated with decreased self-reported stress, fewer mistakes in the cognitive task and a trend towards lower heart rate; no relationships between displacement behaviour and stress measures were found for women. Moreover, moderation analyses revealed that high rates of displacement behaviour were associated with lower stress levels in men but not in women, and that high displacement behaviour rates were associated with poorer cognitive performance in women, but not men. These results point to an important sex difference in coping strategies, and highlight new avenues for research into sex biases in stress-related disorders.

Expensive egos: narcissistic males have higher cortisol

Background

Narcissism is characterized by grandiosity, low empathy, and entitlement. There has been limited research regarding the hormonal correlates of narcissism, despite the potential health implications. This study examined the role of participant narcissism and sex on basal cortisol concentrations in an undergraduate population.

Methods and Findings

Participants were 106 undergraduate students (79 females, 27 males, mean age 20.1 years) from one Midwestern and one Southwestern American university. Narcissism was assessed using the Narcissistic Personality Inventory, and basal cortisol concentrations were collected from saliva samples in a laboratory setting. Regression analyses examined the effect of narcissism and sex on cortisol (log). There were no sex differences in basal cortisol, F(1,97) = .20, p = .65, and narcissism scores, F(1,97) = .00, p = .99. Stepwise linear regression models of sex and narcissism and their interaction predicting cortisol concentrations showed no main effects when including covariates, but a significant interaction, β = .27, p = .04. Narcissism was not related to cortisol in females, but significantly predicted cortisol in males. Examining the effect of unhealthy versus healthy narcissism on cortisol found that unhealthy narcissism was marginally related to cortisol in females, β = .27, p = .06, but significantly predicted higher basal cortisol in males, β = .72, p = .01, even when controlling for potential confounds. No relationship was found between sex, narcissism, or their interaction on self-reported stress.

Conclusions

Our findings suggest that the HPA axis is chronically activated in males with unhealthy narcissism. This constant activation of the HPA axis may have important health implications.

Behavioral and physiological correlates of stress related to examination performance in college chemistry students

This study was designed to assess physiological and behavioral correlates of academic stress during a college course in organic chemistry in the USA. Participants (45 females, 46 males, mean age 19.88 years) were screened for their basal hypothalamic-pituitary-adrenocortical activity using saliva samples collected at the beginning of the course and after each major test. Displacement activities (DAs) were observed during each test by videotaping students' behavior when they were taking the tests. These variables were then used as predictors of the students' achievement as measured by their grade point average (GPA) scores, American College Testing (ACT) scores, and their final grade in the class. Ninety-one students, enrolled in Organic Chemistry I at Marshall University during the summer of 2009, were recruited for this study. It was found that individual differences in the physiological stress responses are a factor in predicting the students' ability to pass a challenging class. A logistic model built on GPA, DAs during stress, and salivary hormone (cortisol and dehydroepiandrosterone) concentrations was able to correctly classify almost 90% of the students passing the class. The same model was not nearly as successful in determining the possible factors behind failing the class, because the classification success was just 52%, a figure close to chance. We conclude that a clear set of characteristics related to the students' ability and resilience to psychological stress are necessary to succeed in a challenging class. The reason behind dropping or failing a class could be less defined. These data indicated that investigating the physiological and behavioral propensities associated with psychological stress can help us better understand an individual's coping responses to a long-term challenging situation.

Heart rate variability in response to affective scenes in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is characterized by psychophysiological abnormalities, such as an altered baseline heart rate and either hyper- or hyporeactivity to a wide range of stimuli, implying dysfunctional arousal regulation. Heart rate variability (HRV) has been established as an important marker of arousal regulatory ability. The aim of the present study was to examine HRV in PTSD under different affective conditions and to explore the role of potential moderating factors. To meet this purpose, videos of varying emotional valence were presented to trauma-exposed participants with PTSD (n=26), trauma-exposed participants without PTSD (n=26), as well as non-trauma-exposed controls (n=18) while HRV was recorded. The PTSD group showed lower HRV than non-trauma-exposed controls at baseline (corrected for age) and throughout different affective conditions implying decreased parasympathetic activity and an inflexible response regulation. There was a negative relationship between HRV and self-report of both depression and state dissociation.

Saliva as an analytical matrix: state of the art and application for biomonitoring

Analytical tests to measure chemicals in saliva can be employed for numerous analytes, endogenous compounds or xenobiotics. The objective was to determine which chemicals can be analysed with this matrix, which analytical methods are applicable, and what application is possible for biomonitoring. We reviewed the literature using three databases, MEDLINE, PubMed and Scopus, collecting articles on different kinds of analysis in saliva. Studies were principally about molecules of clinical interest, xenobiotics, especially drugs of abuse, and chemicals used at workplaces; some substances show no relevant correlation with exposure data while others seems to be of particular interest for systematic use for biomonitoring. Currently, saliva is used far less than other biological fluids but its use for biomonitoring of exposure to chemicals might open up new areas for research and would certainly simplify the collection of biological samples.

The role of DHEA in relation to problem solving and academic performance

Dehydroepiandrosterone (DHEA) has been correlated with lower susceptibility to anxiety and mood disturbance. Since coping styles have been shown to be a critical component of academic achievement, we aimed to assess the relationship between DHEA and coping mechanisms in college students. Participants were recruited and tested twice, one week apart. Cardiovascular measurements and saliva samples were taken for each participant. The behavioral task consisted of a set of anagrams of increasing difficulty (possible to impossible). American College Testing (ACT) scores, number of college courses failed and dropped along with current grade point average (GPA) were recorded. Results indicated that successfully coping with challenging tasks is a function of behavioral flexibility and physiological neuroprotection. When presented with challenging tasks, individuals who vary their behavioral response to fit the task's demands have the lowest probability of failing the task. The same individuals also have higher levels of resiliency hormones, demonstrated by a lower ratio of cortisol versus DHEA levels.

Cardiovascular, hormonal, and emotional responses to the TSST in relation to sex and menstrual cycle phase

The prevalence of stress disorders differs between men and women. An understanding of how men and women vary in acute stress responses may help to understand these sex differences. We compared responses to the TSST and a control task in healthy men (N=28) and women tested in two phases (Follicular N=29, Luteal N=23) of the menstrual cycle. Men exhibited greater cortisol responses to stress than women in either phase. Luteal women exhibited the greatest subjective and allopregnanolone responses to stress, whereas follicular women exhibited blunted noradrenaline responses. Partial correlations controlling for group differences revealed that individuals who were most sensitive to the subjective effects of stress exhibited the largest salivary cortisol, noradrenaline, and allopregnanolone responses and the smallest progesterone responses to stress. We discuss our findings in the context of sex differences in the prevalence of stress-linked disorders.

Effect of lecturing to 200 students on heart rate variability and alpha-amylase activity

The aim of this study was to examine cardiovascular [heart rate variability (HRV)] and autonomic nervous system activation (by evaluating salivary alpha-amylase activity) that occur in professors both to, and after, the delivery of a lecture to 200 students and to determine whether gender is an influencing factor upon response. Fifty-two participants (26 women and 26 men) collected eight unstimulated saliva samples on 2 days (one a working day on which the lecture was given, the other a non-work or rest day). They also completed the Trait version of the State-Trait Anxiety Inventory (STAI) to assess their dispositional anxiety on the rest day and the State section of the STAI 15 min before and 10 min after their lecture, repeated at the same hour on the control (rest) day. The Perceived Stress Scale (PSS) was also recorded 15 min before the lecture. Continuous RR intervals were recorded before and after the lecture and the following HRV parameters were calculated: total spectral power (P (TOT)); the spectral power of the low frequency component (P (LF)); the high frequency component (P (HF)); and the ratio LF/HF. A reduction (P < 0.05) in the HF and HFnu component of HRV and an increase in the LH/HF ratio (P < 0.05) were observed at the end of the lecture. AA activity measured on the teaching day was significantly higher than that noted on the resting day. Lecturing resulted in a significant increase in the secretion of the stress marker alpha-amylase. Men and women did not differ in trait and state anxiety and no gender differences for HRV or AA activity were found.

Repeated amphetamine administration in rats revealed consistency across days and a complete dissociation between locomotor and hypothalamic-pituitary-adrenal axis effects of the drug

RATIONALE

Most drugs of abuse stimulate both locomotor activity and the hypothalamic-pituitary-adrenal (HPA) axis, but the relationship between the two responses within the same subjects and their reliabilities has been scarcely studied. Our objectives were to study: (1) the consistency and stability across time of locomotor and HPA activation induced by repeated d-amphetamine (AMPH); (2) the relationship between locomotor and hormonal responses to AMPH; and (3) the relationship between novelty-induced activity and both types of responses to the drug.

METHODS

Male adult rats were exposed to a novel environment to study the locomotor response. Later, they were injected with AMPH (2 mg/kg, sc) for 5 days. In Experiment 1, Plasma adrenocorticotropin (ACTH) and corticosterone levels in response to AMPH were studied on days 1, 3, and 5, and locomotor response on days 2 and 4. In Experiment 2, ACTH and corticosterone responses were studied on days 2 and 4, and locomotor response on days 1, 3, and 5.

RESULTS

Across days, both locomotor and HPA responses to the drug were consistent, but independent measures, unrelated to the reactivity to novelty. As measured by the area under the curve, the HPA response to AMPH desensitized with the repeated injection, whereas the initial locomotor response to the drug increased.

CONCLUSIONS

Dissociation exists between HPA and locomotor activation induced by AMPH, which seemed to be both reliable individual traits. Locomotor reactivity to novelty was related neither to HPA nor to locomotor responses to AMPH.

A general enhancement of autonomic and cortisol responses during social evaluative threat

OBJECTIVE

To examine the Social Self Preservation Theory, which predicts that stressors involving social evaluative threat (SET) characteristically activate the hypothalamic-pituitary-adrenal (HPA) axis. The idea that distinct psychosocial factors may underlie specific patterns of neuroendocrine stress responses has been a topic of recurrent debate.

METHODS

Sixty-one healthy university students (n = 31 females) performed a challenging speech task in one of three conditions that aimed to impose increasing levels of SET: performing the task alone (no social evaluation), with one evaluating observer, or with four evaluating observers. Indices of sympathetic (preejection period) and parasympathetic (heart rate variability) cardiac drive were obtained by impedance- and electrocardiography. Salivary cortisol was used to index HPA activity. Questionnaires assessed affective responses.

RESULTS

Affective responses (shame/embarrassment, anxiety, negative affect, and self-esteem), cortisol, heart rate, sympathetic and parasympathetic activation all differentiated evaluative from nonevaluative task conditions (p < .001). The largest effect sizes were observed for cardiac autonomic responses. Physiological reactivity increased in parallel with increasing audience size (p < .001). An increase in cortisol was predicted by sympathetic activation during the task (p < .001), but not by affective responses.

CONCLUSION

It would seem that SET determines the magnitude, rather than the pattern, of physiological activation. This potential to perturb broadly multiple physiological systems may help explain why social stress has been associated with a range of health outcomes. We propose a threshold-activation model as a physiological explanation for why engaging stressors, such as those involving social evaluation or uncontrollability, may seem to induce selectively cortisol release.