Igor Brezina

Psychosocial stress based on public speech in humans: is there a real life/laboratory setting cross-adaptation?

Abstract Repeated or chronic exposure to stressors is associated with changes in neuroendocrine responses depending on the type, intensity, number and frequency of stress exposure as well as previous stress experience. The aim of the study was to test the hypothesis that salivary cortisol and cardiovascular responses to real-life psychosocial stressors related to public performance can cross-adapt with responses to psychosocial stress induced by public speech under laboratory setting. The sample consisted of 22 healthy male volunteers, which were either actors, more precisely students of dramatic arts or non-actors, students of other fields. The stress task consisted of 15 min anticipatory preparation phase and 15 min of public speech on an emotionally charged topic. The actors, who were accustomed to public speaking, responded with a rise in salivary cortisol as well as blood pressure to laboratory public speech. The values of salivary cortisol, systolic blood pressure and state anxiety were lower in actors compared to non-actors. Unlike non-actors, subjects with experience in public speaking did not show stress-induced rise in the heart rate. Evaluation of personality traits revealed that actors scored significantly higher in extraversion than the subjects in the non-actor group. In conclusion, neuroendocrine responses to real-life stressors in actors can partially cross-adapt with responses to psychosocial stress under laboratory setting. The most evident adaptation was at the level of heart rate responses. The public speech tasks may be of help in evaluation of the ability to cope with stress in real life in artists by simple laboratory testing.

Blunted cortisol response to psychosocial stress in atopic patients is associated with decrease in salivary alpha-amylase and aldosterone: Focus on sex and menstrual cycle phase

A decreased responsiveness of the hypothalamic-pituitary-adrenocortical axis to stress stimuli in patients with atopy is well documented. The aim of this study was to investigate personality traits, salivary alpha-amylase activity and the aldosterone response to psychosocial stress procedure based on public speech in atopic patients with respect to sex and the menstrual cycle (MC) phase. The study was performed in 106 subjects of both sexes, 53 atopic patients suffering from allergic rhinitis, allergic asthma or atopic dermatitis and 53 age-, sex-, the MC phase- and BMI- matched healthy controls. Substantially attenuated activity of alpha-amylase and reduced secretion of aldosterone during the psychosocial stress were observed in the whole sample of patients with atopy. Higher activity of alpha-amylase observed in the follicular compared to the luteal phase in healthy women was not present in atopic patients. In both males and females, atopy was associated with blunted cortisol response but no changes in the heart rate. Psychological characterization revealed a significantly higher trait anxiety and higher preference for avoidance-oriented coping strategy in female but not male atopic patients. These findings provide evidence that patients with atopy exhibit insufficient alpha-amylase and aldosterone responsiveness to psychosocial stress, thus suggesting decreased sympathetic activity. Potential disturbances in sex hormone status during the MC in female patients with atopy have to be considered in future research. Changes in personality traits were demonstrated in female atopic patients, but not in male patients.

Implementation of Microsensor Interface for Biomonitoring of Human Cognitive Processes

Miniaturization of biomedical sensors has increased the importance of microsystem technology in medical applications, particularly microelectronics and micromachining. This work presents a new approach to biomedical monitoring and analysis of selected human cognitive processes. The system is based on our preliminary described theory and experiments (Vavrinsky et al. 2010). We are primarily interested in biomonitoring of human cognitive processes and psychophysiological conditions of car drivers in order to enhance road safety. Actually often used method is evaluation of abnormal car driver actions (sudden changes of direction with no direction indicators or too hard cornering). Main disadvantage of such a system is that they offer no prediction. More effective are prediction systems, which offer enough reaction time before undesirable situations, and so they can minimize human error factors and improve road-traffic safety. Our present research is focused on sensing, processing and analysis of selected physiological signals for mental and medical condition recognition. They are known some studies describing interface between emotional condition and physiological responses, and we want also present some, since new ideas and research in psychological recognition and biomonitoring are very welcome. It is also proved that human decisions and reactions are affected by emotional and physical comfort. Emotional reconnoiter of a car driver conditions is influenced by many cognitive processes, such as mind organization, vigilance, planning or fatigue. Nervous and angry people can be very dangerous for traffic road safety. In our experiments, we have monitored: psycho-galvanic reflex (PGR) – skin conductivity changes, heart rate + electrocardiogram (ECG), body temperature, respiration frequency, emotions. To improve the reliability of our measurements, these parameters have been monitored often by duplicate methods, sometimes at macro level, sometimes by local microsystems technologies. In first step, we implemented our technology to the virtual reality driving simulator but preparations for real implementation have been already started, and the final car implementation will follow.

Increased Heart Rate Variability in Allergic and Highly Trait Anxious Individuals

Autonomic dysregulations were repeatedly observed in people with allergic reactions. Contradictory results of sympathetic over-activation on one hand and parasympathetic predominance on the other, were described for both atopic dermatitis and allergic rhinitis. Secondly, psychological traits of high anxiety and depression described in allergic patients are mostly associated with increased sympathetic and decreased vagal modulation. To address inconsistency in prior findings, we aim to study autonomic nervous system changes in allergic and highly anxious people via HR (heart rate) and HRV (heart rate variability) measures during stressful and relax days in day to day life. We further assess differences between allergic diagnoses and impact of acute symptom occurrence on HR and HRV. 61 subjects (26 allergic, 18 healthy high trait anxious and 17 healthy low trait anxious) took part in this study. They were repeatedly measured for HR by a portable electrocardiographic device, and assessed their subjectively experienced stress during everyday life. HRV was analyzed using time-domain, spectral and non-linear analyses. We observed increased HRV and decreased HR in allergic patients and also in healthy highly anxious subjects, when compared to controls. Both atopic dermatitis and allergic rhinitis patients exhibited parasympathetic predominance or sympathetic withdrawal, seen in increased HRV and lowered HR. Described effects of parasympathetic predominance were, however, not present during acute symptoms occurrence.

Psychological and physiological aspects of stress in atopic patients

mucosal humoral immunity has been identified in the small intestine, however little is known about the type of antibody response. We characterized the mucosal immunoglobulins (Ig) isotype and its association with IBS pathophysiology. Methods: Mucosal jejunal biopsies, stool and blood samples wereobtained fromhealthyvolunteers (H;n=18)andage-matched participantsmeeting diarrhoea-IBS Rome III criteria (IBS-D; n=20). Bowel movements, stool consistency and abdominal pain were monitored (10 days prior to biopsy). Psychological stress and depressionwere assessedwith validated questionnaires. The number and ultrastructure of mucosal plasma cells were determined by transmission electron microscopy, and mucosal IgG+ cells were quantifiedby immunofluorescence. Igswere quantified in stool and blood by ELISA technique. Results: The number of mucosal IgG+ cells and plasma cells was increased in IBS-D patients, the later in close proximity to nerve fibres, respect to H (P<0.05). Plasma cells displayed signs of activation but the presence of cell clusters was more abundant in the IBS-D group. IgG in faeces was higher in IBS-D than in H (P<0.05). Plasma cells-nerves proximity correlated with stress and depression, and IgG in faeces correlated with abdominal pain (P<0.05). Conclusion: IgG production rises as a distinctive marker of mucosal immuneactivity in associationwith clinical characteristics in IBS-D. Studies aimed at determining IgG subtype and antigens eliciting such responses warrant further investigation.

Monitoring of car driver physiological parameters

Miniaturization of biomedical sensors has increased the importance of microsystem technology in medical applications, particularly microelectronics and micromachining. This paper presents a new approach to biomedical monitoring of car driver physiological parameters. The system is based on our preliminary described theory and experiments [1].

Physiological Monitoring of Human Cognitive Processes

This paper presents a new approach of the noninvasive biomedical monitoring of selected psychosomatic processes. The proposed method measures human skin conductivities (psycho-galvanic reflex - PGR) using the interdigitated array (IDA) of microelectrodes as well as skin temperature, which will allow continuous monitoring and analysis of complicated physiological, pathophysiological, and therapeutic processes. The psychological test was focused on short-time stress situation with a large scale of tasks, which had the probands to do during the test. The tasks were chosen in the way to charge the same part of human brain in order to amplify the stress situation.

Electro-Optical Monitoring of Human Cognitive Processes

This paper presents a new approach of the non-invasive biomedical monitoring of selected psychosomatic processes. The proposed method measures human skin conductivities (psycho-galvanic reflex - PGR) using the interdigitated array (IDA) of microelectrodes as well as skin temperature and skin reflectance using optical spectrometer, which will allow continual monitoring and analysis of complicated physiological and therapeutic processes. The psychological test was focused on short-time stress situation with a large scale of tasks.