Skin Conductance Research Articles

Do managers “feel” the group? Managers’ autonomic responses during a creative task

This study aimed at assessing the psychophysiological correlates of managers, compared to a group of non-managers, during a creative problem-solving dynamic through the use of a psychophysiological method exploiting autonomic measures data collection. Individuals performed a realistic complex problem-solving task (RCPT), a modified version of the NASA Moon survival problem exercise, in two distinct conditions: individually or in groups of three participants. Two main patterns of findings were observed, specifically, for the managers’ group: first, electrodermal activity and cardiac variability indices increased during the group compared to individual condition; second, cardiovascular indices decreased in the above-mentioned condition. No statistically significant results were observed for the non-managers group. Results suggest that managers could be able to “feel”, even at a deeper and psycho-physiological level, which social condition (in this case, the group one) is more suitable for solving a complex problem in a creative way.

Effects of trace element dietary supplements on voice parameters and some physiological and psychological parameters related to stress

Trace elements, often used as dietary supplements, are widely accessible without prescription at pharmacies. Pronutri has pioneered Nutripuncture®, a methodology that utilizes orally consumed trace elements to elicit a physiological response akin to that of acupuncture. Pronutri has empirically observed that the user's voice becomes deeper following an exclusive ingestion procedure. Given that alterations in vocal characteristics are often linked to stress, the Pronutri researchers postulated that the pills have the capacity to promptly alleviate stress upon ingestion. Nevertheless, there is a lack of scientific substantiation about the impact of these supplements on voice (or stress) indicators. The aim of this research was to determine whether there is a consistent impact of trace element ingestion on vocal characteristics, namely the fundamental frequency of the voice, as well as other physiological and psychological stress measurements.In order to achieve this objective, we have devised a unique methodology to examine this hypothesis. This involves conducting a monocentric crossover, randomized, triple-blind, placebo-controlled trial with a sample size of 43 healthy individuals.This study demonstrates that compared to placebo tablets, consuming 10 metal traces containing tablets at once is enough to cause noticeable changes in the vocal spectrum in the direction of an improvement of the voice timbre “richness”, and a decrease in the occurrence of spontaneous electrodermal activity, suggesting a stress reduction. However, there were no significant changes observed in the other parameters that were tested. These parameters include vocal measures such as voice frequency F0, standard deviation from this frequency, jitter, and shimmer. Additionally, physiological measures such as respiratory rate, oxygenation and heart rate variability parameters, as well as psychological measures such as self-assessment analogic scales of anxiety, stress, muscle tension, and nervous tension, did not show any significant changes.Ultimately, our research revealed that the ingestion of 10 trace elements pills may promptly elicit a targeted impact on both vocal spectrum and electrodermal activity. Despite the limited impact, these findings warrant more research to explore the long-term effects of trace elements on voice and stress reduction.

359 Low-Intensity Focused Ultrasound to Human Dorsal Anterior Cingulate Cortex and Insula Attenuates Measures of Central Sensitization

INTRODUCTION: Central sensitization is the abnormal amplified response to pain and is associated with chronic pain. Increased insula and dorsal anterior cingulate cortex (dACC) activity is associated with central sensitization. Low-intensity focused ultrasound (LIFU) is a novel form of non-invasive neuromodulation that can precisely target the anterior insula (AI), posterior insula (PI) and dACC. METHODS: N = 18 healthy participants underwent conditioned pain modulation (CPM) and temporal summation of pain (TSP) tasks before and after 10 minutes of LIFU or sham stimulations. For CPM, the conditioning stimulus (CS) was a cold pressor test to the left hand and the test stimulus (TS) was a brief transient heat stimulus to the dorsum of the right hand. For TSP, 10 transient heat stimuli (>0.33 Hz) were administered to the dorsum of the right hand. The primary outcome measure for both tasks was perceived pain ratings (0-9). Electrodermal response and electrocardiogram was collected to evaluate the effect of LIFU on autonomic reactivity. RESULTS: LIFU to PI increased CPM 0.5 ± 0.181 compared to sham (p = 0.024). LIFU to PI also significantly reduced perceived pain during the TSP task compared to sham (p < 0.001). We also found a significant difference between dACC and sham conditions during TSP by -0.55 ± 0.05 (p < 0.001). LIFU to the AI increases frequency domain measures of heart-rate variability. CONCLUSIONS: LIFU to the insula and dACC affects pain processing in measures of central sensitization. This demonstrates the neuromodulation abilities of LIFU and is a promising tool to develop noninvasive clinical therapies for chronic pain conditions.

38 Impacts of Racial Discrimination on Cognitive and Affective Processes and Drug-Cue Reactivity

OBJECTIVES/GOALS: Our overarching aim is to examine, in an African American population, cognitive, affective, and neurophysiological processes, as well as risk-taking behavior, in response to racial stigma cues. While accounting for individual differences, we aim to see how these processes and drug-cue reactivity are impacted or altered by exposure to racial cues. METHODS/STUDY POPULATION: Participants will be African Americans between 18 and 25 years of age, equally distributed across genders. We will recruit 75 participants in order to have adequate power to conduct our intended analyses—particularly pertaining to individual differences in risk behavior outcomes. Participants will be asked to complete demographic and self-report questionnaires. Participants will also be asked to complete computerized tasks while their physiological responses (heart rate, skin conductance, and electroencephalographic (EEG) data) are recorded. The tasks are as follow: resting, gambling, go/no-go, picture viewing (positive, negative, and neutral images), and a drug cue image set. These tasks will be repeated after the participant views a racial stigma image set to evaluate the impact of discrimination. RESULTS/ANTICIPATED RESULTS: Data from 18 participants has been collected. Data will be periodically preprocessed and validated (e.g., 1 participant was removed due to data recording errors, so the current valid Nis 17). Generally, we anticipate that behaviors and neural activity will be modulated across all tasks after viewing the racial stigma image set. Specifically, (a) cognitive and affective processing of singular events of racial stigma may indicate a stress response, (b) modulation from chronic experiences of racial stigma render neural systems increasingly sensitive to stigma cues, and thereby less equipped to regulate stress response, (c) the impact of these processes on altering risk behavior (may increase such behaviors), and (d) the impact of these modulations on altering drug-cue reactivity (may amplify reactivity). DISCUSSION/SIGNIFICANCE: The study will identify factors that contribute to stress and risk behavior among African Americans. A substantial gap continues to exist regarding the nature of risk behavior among African Americans, despite the fact that African Americans represent a health disparity population with unique vulnerabilities to health-relevant risk behavior.

Validation of the Chinese version of the Fear of Birth Scale among pregnant women

Aim: Adapt Fear of Birth Scale (FOBS) for the Chinese context, evaluate psychometric properties and determine optimal cutoff point for pregnant women in 3rd trimester.Design: This is a descriptive cross-sectional study. Cultural guidelines informed the development of the Chinese version of FOBS (FOBS-C) incorporating validation on translation, equivalence index, content validity index, and cognitive debriefing. Thirty pregnant women took a test-retest survey and another 1019 took three cross-sectional surveys. Convergent validation of the FOBS-C involved comparison with Childbirth Attitudes Questionnaire (CAQ), Wijma Delivery Expectancy Questionnaire (WDEQ-A), Edinburgh Postnatal Depression Scale (EPDS), Generalized Anxiety Disorder Scale (GAD-7), and physiological indicators. Cutoff points for FOBS-C were identified using receiver operating characteristic analysis against medical indicators.Findings: FOBS-C demonstrated high translation equivalence (0.833–1), content validity (0.800–0.933), internal consistency (0.897), and test-retest reliability (0.860). Convergent validity was supported by statistically significant correlations between FOBS scores, heart rate, skin conductance changes, as well as scores from WDEQ-A, CAQ, EPDS, and GAD-7. Known-group validity was observed with different medical indicators. FOBS-C cutoff points indicating severe fear of childbirth were identified as 65, 68, 71, and 56, respectively, against WDEQ-A ≥ 85, CAQ ≥ 52, preference for C-section birth, and preference for analgesia, demonstrating known-group validity. A cutoff point of 65 showed the FOBS-C's strongest known-group validity.Conclusion: The FOBS-C exhibits robust psychometric properties, making it a valid screening tool for identifying severe fear of birth. Establishing a cutoff point at 65 facilitates effective screening.

What a relief! The pleasure of threat avoidance.

Relief, a pleasurable experience, is often triggered by successful threat avoidance. Although relief is regarded as the positive reinforcer for avoidance behavior, its rewarding nature remains to be demonstrated. In our study, 50 participants responded to cues associated with different magnitudes of monetary values or electrical stimuli. Successful responses to those cues resulted in monetary gains (i.e., rewards) or omissions of electrical stimulation (i.e., relief), followed by a pleasantness rating scale. We also measured physiological arousal via skin conductance. As expected, we found that for reward and relief similarly, higher magnitudes elicited more successful responses, higher pleasantness ratings, and higher skin conductance responses. Moreover, differential reward/relief response patterns predicted later choices between reward and relief cues. These findings indicate that relief induced by threat omissions is functionally equivalent to receiving a reward, confirming that relief is a positive reinforcer for threat avoidance behaviors, which provides a new theoretical perspective on the learning process of active threat avoidance. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Role of Central and Peripheral Physiological Markers in Understanding and Monitoring the Clinical Illness in Dementia

Patients with Alzheimer's dementia are known to have electrophysiological abnormalities such as increased slow wave power of resting electroencephalography (EEG), cortical excitability as detected using EEG epileptiform and epileptic activity, and deficits in cortical plasticity detected using brain stimulation combined with EEG. Understanding these neurophysiological abnormalities is important to improve our understanding of the mechanisms leading to brain dysfunction thus leading to the development of novel treatment interventions. Further, EEG is a non-invasive, low-cost, and portable technique that is widely available and can become an important tool in monitoring illness and response to treatment. To further improve objective measures to detect and monitor clinical symptoms of dementia, recently, there has been an increased interest in the development of peripheral physiological markers such as motor activity, skin conductance and temperature, and heart rate variability. These markers can be recorded using wearable devices and have shown usefulness in monitoring neuropsychiatric symptoms of dementia. Further development of these markers can improve clinical care by improving objective assessment of clinical profiles of persons with dementia living in the community or those admitted to hospitals and can help individualize care. In this session, we will first review novel findings from studies using EEG to assess central neurophysiological markers, and then discuss the role of peripheral physiological markers in the detection and monitoring of clinical symptoms of dementia in community and dementia care units.These talks will be followed by a discussion about the relevance of the central and peripheral physiological markers (biometrics) in dementia.

Wpływ bodźców przestrzennych na reakcje organizmu. Refleksje z wykorzystania bioczujników do badania warszawskiej przestrzeni publicznej

In the study of emotions associated with staying in a specific space, in addition to the subjective approach based on describing one’s feelings caused by the environment, an objective approach is also used, using ambulatory sensors to measure the body’s reaction to external stimuli. The aim of the article is, on the one hand, to formulate guidelines regarding the methodology of using electrodermal activity (EDA) sensors in public space research, and, on the other hand, to indicate the practical application of this type of research. The device was tested during a walk along the Krakowskie Przedmieście Street in Warsaw. The study confirmed that the effect of measurements using biosensors is not so much an objectively identified cause-and-effect relationship between a stimulus and a specific reaction of the body, but an in-depth reflection on the way we experience the space. Due to the multitude of stimuli coming from the environment and the individual emotional, as well as mental state of each person, biosensors are currently a better solution for static research in microspace. However, geographers should continue rigorous research on whether and how these devices should be used in field research, how to standardize the conditions under which recordings are made, and how to standardize measurement methodology and participant selection.

Threat directionality modulates defensive reactions in humans: cardiac and electrodermal responses

ABSTRACT Features of threatening cues and the associated context influence the perceived imminence of threat and the defensive responses evoked. To provide additional knowledge about how the directionality of a threat (i.e. directed-towards or away from the viewer) might impact defensive responses in humans, participants were shown pictures of a man carrying a gun (threat) or nonlethal object (neutral) directed-away from or towards the participant. Cardiac and electrodermal responses were collected. Compared to neutral images, threatening images depicting a gun directed-towards the participant induced sustained bradycardia and an increased electrodermal response, interpreted as immobility under attack. This defensive immobility reaction is evoked by high perceived threat and inescapable situations and indicates intense action preparation. Pictures of guns directed-away from the participant induced shorter bradycardia and no significant modulation of the electrodermal response compared to neutral pictures, which might be consistent with the perception of a less threatening situation. The results show that the directionality of threat stimuli is a key factor that prompts different patterns of defensive responses.

Exercise-induced central and peripheral sympathetic activity in a community-based group of epilepsy patients differ from healthy controls

Ictal and interictal activity within the autonomic nervous system is characterized by a sympathetic overshoot in people with epilepsy. This autonomic dysfunction is assumed to be driven by alterations in the central autonomic network. In this study, exercise-induced changes of the interrelation of central and peripheral autonomic activity in patients with epilepsy was assessed. 21 patients with epilepsy (16 seizure-free), and 21 healthy matched controls performed an exhaustive bicycle ergometer test. Immediately before and after the exercise test, resting state electroencephalography measurements (Brain Products GmbH, 128-channel actiCHamp) of 5 min were carried out to investigate functional connectivity assessed by phase locking value in source space for whole brain, central autonomic network and visual network. Additionally, 1-lead ECG (Brain products GmbH) was performed to analyze parasympathetic (root mean square of successive differences (RMSSD) of the heart rate variability) and sympathetic activity (electrodermal activity (meanEDA)). MeanEDA increased (p < 0.001) and RMSSD decreased (p < 0.001) from pre to post-exercise in both groups. Correlation coefficients of meanEDA and central autonomic network functional connectivity differed significantly between the groups (p = 0.004) after exercise. Both patients with epilepsy and normal control subjects revealed the expected physiological peripheral autonomic responses to acute exhaustive exercise, but alterations of the correlation between central autonomic and peripheral sympathetic activity may indicate a different sympathetic reactivity after exercise in patients with epilepsy. The clinical relevance of this finding and its modulators (seizures, anti-seizure medication, etc.) still needs to be elucidated.

Design of a Remote Multiparametric Tool to Assess Mental Well-Being and Distress in Young People (mHealth Methods in Mental Health Research Project): Protocol for an Observational Study.

Mental health conditions have become a substantial cause of disability worldwide, resulting in economic burden and strain on the public health system. Incorporating cognitive and physiological biomarkers using noninvasive sensors combined with self-reported questionnaires can provide a more accurate characterization of the individual's well-being. Biomarkers such as heart rate variability or those extracted from the electrodermal activity signal are commonly considered as indices of autonomic nervous system functioning, providing objective indicators of stress response. A model combining a set of these biomarkers can constitute a comprehensive tool to remotely assess mental well-being and distress. This study aims to design and validate a remote multiparametric tool, including physiological and cognitive variables, to objectively assess mental well-being and distress. This ongoing observational study pursues to enroll 60 young participants (aged 18-34 years) in 3 groups, including participants with high mental well-being, participants with mild to moderate psychological distress, and participants diagnosed with depression or anxiety disorder. The inclusion and exclusion criteria are being evaluated through a web-based questionnaire, and for those with a mental health condition, the criteria are identified by psychologists. The assessment consists of collecting mental health self-reported measures and physiological data during a baseline state, the Stroop Color and Word Test as a stress-inducing stage, and a final recovery period. Several variables related to heart rate variability, pulse arrival time, breathing, electrodermal activity, and peripheral temperature are collected using medical and wearable devices. A second assessment is carried out after 1 month. The assessment tool will be developed using self-reported questionnaires assessing well-being (short version of Warwick-Edinburgh Mental Well-being Scale), anxiety (Generalized Anxiety Disorder-7), and depression (Patient Health Questionnaire-9) as the reference. We will perform correlation and principal component analysis to reduce the number of variables, followed by the calculation of multiple regression models. Test-retest reliability, known-group validity, and predictive validity will be assessed. Participant recruitment is being carried out on a university campus and in mental health services. Recruitment commenced in October 2022 and is expected to be completed by June 2024. As of July 2023, we have recruited 41 participants. Most participants correspond to the group with mild to moderate psychological distress (n=20, 49%), followed by the high mental well-being group (n=13, 32%) and those diagnosed with a mental health condition (n=8, 20%). Data preprocessing is currently ongoing, and publication of the first results is expected by September 2024. This study will establish an initial framework for a comprehensive mental health assessment tool, taking measurements from sophisticated devices, with the goal of progressing toward a remotely accessible and objectively measured approach that maintains an acceptable level of accuracy in clinical practice and epidemiological studies. OSF Registries N3GCH; https://doi.org/10.17605/OSF.IO/N3GCH. DERR1-10.2196/51298.

The Importance of Evaluating Sudomotor Function in the Diagnosis of Cardiac Autonomic Neuropathy.

Cardiac autonomic neuropathy (CAN) is a disorder affecting the autonomic nerves that regulate the cardiovascular system, leading to irregular heart rate and blood pressure control. It is commonly associated with diabetes mellitus but can also result from other conditions such as autoimmune disorders, chronic kidney disease, alcohol abuse, and certain medications. Screening for CAN is essential, particularly in individuals with poor glycemic control, cardiovascular risk factors, or complications. Early identification of CAN is vital for timely intervention to prevent or manage cardiovascular complications effectively. Regular screening helps detect CAN before symptoms emerge, enabling early intervention to slow or halt its progression. This study examined the relationship between sudomotor function and cardiovascular reflex tests. This was a cross-sectional study conducted between June 2019 and June 2020. The study included 271 subjects aged 18 years and above who provided informed consent, were diagnosed with type 2 diabetes mellitus (T2DM), and were overweight or obese. Exclusion criteria encompassed patients with other types of diabetes, pregnant women, those with recent neoplasm diagnoses, stroke sequelae, history of myocardial infarction, or pelvic limb amputations. The assessment of cardiac autonomic neuropathy involved conducting an electrocardiogram and evaluating the QTc interval in the morning before taking medication. Additionally, cardiovascular reflex tests (CART) were conducted, including assessments of heart rate variability during deep breathing, the Valsalva maneuver, and changes in orthostatic position. Simultaneously, the diagnosis of CAN was assessed by performing a sweat test using a Sudoscan assessment (Impeto Medical, Moulineaux, France). Results: More than half of the participants (52%, n=143) were female. Significant differences in statistical measures were noted between females and males regarding age, systolic blood pressure, fasting blood glucose, A1c level, total cholesterol, triglycerides, gamma-glutamyl transferase, and bilirubin levels. Within the CAN-diagnosed group (CAN+), 40.92% were classified as mild cases (n=90), 47.27% as moderate cases (n=104), and 11.81% as severe cases (n=26). Among the CAN+ group, 54% (n=119) were women. Electrochemical skin conductance was lower in the CAN+ group than the CAN- group in hands (67.34±15.51 μS versus 72.38±12.12 μS, p=0.008) and feet (73.37±13.38 μS versus 82.84 ±10.29 μS, p<0.001). The Sudoscan-CAN score significantly correlated with Ewing scores (r= 0.522, p<0.001). In multiple linear regression analysis, the Sudoscan-CAN score remained significantly associated with age, high BMI, long-standing diabetes, and Ewing score. Sudoscan demonstrates potential in identifying patients with an increased risk of CAN. Its integration into clinical practice can improve patient outcomes through early detection, risk stratification, and personalized treatment approaches. Its non-invasive, portable, and user-friendly features render it suitable for utilization in outreach programs or resource-constrained settings as part of screening efforts designed to pinpoint high-risk individuals for additional assessment.

Emotion Fusion-Sense (Emo Fu-Sense) – A novel multimodal emotion classification technique

Human emotions play a vital role in overall well-being. With the advent of advance technologies growing interest has been observed in developing a multimodal emotion classification system that can accurately interpret human emotions. The article presents a comprehensive overview of a multimodal emotion classification system (Emo Fu-Sense) designed to capture the rich and nuanced nature of human emotions. Objective of Emo Fu-Sense is to integrates information from Electrocardiogram (ECG), Galvanic Skin Response (GSR), Electroencephalograph (EEG), respiration amplitude and body temperature to achieve holistic understanding of emotional states. To effectively extract information from multimodal data, designed system employs conventional methods with sophisticated machine learning algorithms including Long Short-Term Memory (LSTM), a variety of Recurrent Neural Network (RNN). Recommended solution extracts column wise features independently from different modalities based on the windowing operation. Finally, feature fusion and modality biasing were used to combine the information from different modalities. The proposed method has not only highlighted the limitations of unimodal system but has achieved a classification accuracy of 92.62 %, with an average F1-Score of 93 % and 9.2 % of Mean Absolute Error (MAE). Obtained results are better than existing state-of-the-art approaches. Evaluation of the multimodal emotion classification system was conducted on MAHNOB-HCI dataset, which encompasses a wide range of emotional expressions across various contexts and individuals. The integration of multiple modalities and advanced machine learning techniques enables a more comprehensive understanding of emotional states and highlights the significance of research and development in the field of affective computing.

ELINA: Emotion low-resources INference algorithm based on 1D ConvNets

In this study, a thorough analysis of the proposed approach in the context of emotion classification using both single-modal (A-13sbj) and multi-modal (B-12sbj) sets from the YAAD dataset was conducted. This dataset encompassed 25 subjects exposed to audiovisual stimuli designed to induce seven distinct emotional states. Electrocardiogram (ECG) and galvanic skin response (GSR) biosignals were collected and classified using two deep learning models, BEC-1D and ELINA, along with two different preprocessing techniques, a classical fourier-based filtering and an Empirical Mode Decomposition (EMD) approach. For the single-modal set, this proposal achieved an accuracy of 84.43±30.03, precision of 85.16±28.91, and F1-score of 84.06±29.97. Moreover, in the extended configuration the model maintained strong performance, yielding scores of 80.95±22.55, 82.44±24.34, and 79.91±24.55, respectively. Notably, for the multi-modal set (B-12sbj), the best results were obtained with EMD preprocessing and the ELINA model. This proposal achieved an improved accuracy, precision, and F1-score scores of 98.02±3.78, 98.31±3.31, and 97.98±3.83, respectively, demonstrating the effectiveness of this approach in discerning emotional states from biosignals.

Virtual Reality Adaptive Training for Personalized Stress Inoculation.

To evaluate a personalized adaptive training program designed for stress prevention using graduated stress exposure. Astronauts in the high-risk space mission environment are prone to performance-impairing stress responses, making preemptive stress inoculation essential for their training. This work developed an adaptive virtual reality-based system that adjusts environmental stressors based on real-time stress indicators to optimize training stress levels. Sixty-five healthy subjects underwent task training in one of three groups: skill-only (no stressors), fixed-graduated (prescheduled stressor changes), and adaptive. Psychological (subjective stress, task engagement, distress, worry, anxiety, and workload) and physiological (heart rate, heart rate variability, blood pressure, and electrodermal activity) responses were measured. The adaptive condition showed a significant decrease in heart rate and a decreasing trend in heart rate variability ratio, with no changes in the other training conditions. Distress showed a decreasing trend for the graduated and adaptive conditions. Task engagement showed a significant increase for adaptive and a significant decrease for the graduated condition. All training conditions showed a significant decrease in worry and anxiety and a significant increase in the other heart rate variability metrics. Although all training conditions mitigated some stress, the preponderance of trial effects for the adaptive condition supports that it is more successful at decreasing stress. The integration of real-time personalized stress exposure within a VR-based training program not only prepares individuals for high-stress situations by preemptively mitigating stress but also customizes stressor levels to the crew member's current state, potentially enhancing resilience to future stressors.

Neurophysiological and Autonomic Correlates of Metacognitive Control of and Resistance to Distractors in Ecological Setting: A Pilot Study.

In organisational contexts, professionals are required to decide dynamically and prioritise unexpected external inputs deriving from multiple sources. In the present study, we applied a multimethodological neuroscientific approach to investigate the ability to resist and control ecological distractors during decision-making and to explore whether a specific behavioural, neurophysiological (i.e., delta, theta, alpha and beta EEG band), or autonomic (i.e., heart rate-HR, and skin conductance response-SCR) pattern is correlated with specific personality profiles, collected with the 10-item Big Five Inventory. Twenty-four participants performed a novel Resistance to Ecological Distractors (RED) task aimed at exploring the ability to resist and control distractors and the level of coherence and awareness of behaviour (metacognition ability), while neurophysiological and autonomic measures were collected. The behavioural results highlighted that effectiveness in performance did not require self-control and metacognition behaviour and that being proficient in metacognition can have an impact on performance. Moreover, it was shown that the ability to resist ecological distractors is related to a specific autonomic profile (HR and SCR decrease) and that the neurophysiological and autonomic activations during task execution correlate with specific personality profiles. The agreeableness profile was negatively correlated with the EEG theta band and positively with the EEG beta band, the conscientiousness profile was negatively correlated with the EEG alpha band, and the extroversion profile was positively correlated with the EEG beta band. Taken together, these findings describe and disentangle the hidden relationship that lies beneath individuals' decision to inhibit or activate intentionally a specific behaviour, such as responding, or not, to an external stimulus, in ecological conditions.

Prediction of central nervous system oxygen toxicity symptoms using electrodermal activity and machine learning

ObjectiveBreathing elevated oxygen partial pressures (PO2) prior to SCUBA diving increases the risk of developing central nervous system oxygen toxicity (CNS-OT), which could impair performance or result in seizure and subsequent drowning. We aimed to study the dynamics of electrodermal activity (EDA) while breathing elevated PO2 in the hyperbaric environment (HBO2) as a possible means to predict impending CNS-OT. To this end, we used machine learning to automatically detect and predict the onset of symptoms associated with CNS-OT in humans by using features derived from EDA in both time and frequency domains. MethodsWe collected electrodermal activity (EDA) data from forty-nine exposures to HBO2 while subjects were undergoing cognitive load and exercise in a hyperbaric oxygen chamber. Four independent experts were present during the experiment to monitor and classify any symptoms associated with hyperbaric oxygen toxicity. We computed a highly sensitive time varying spectral EDA index, named TVSymp, and extracted informative features from skin conductance responses (SCRs). Machine learning algorithms were trained and validated for classifying features from SCRs and TVSymp as CNS-OT related or non-CNS-OT related. Machine learning models were validated using a subject-independent leave one subject out (LOSO) validation scheme. ResultsOur machine learning model was able to classify EDA dynamics related to CNS-OT with 100 % sensitivity and 84 % specificity via LOSO validation. Moreover, the median prediction time for CNS-OT symptoms was ∼ 250 s preceding the occurrence of actual symptoms. SignificanceThis study shows that EDA can potentially be used for early prediction of CNS-OT in divers with a high sensitivity and sufficient prediction time for countermeasures. While the study results are promising, independent validation datasets are warranted to confirm the findings. However, the current results are well corroborated in an animal study, which consistently showed seizure prediction time of 2 min prior to seizure.

Effects of psychological stress on the emission of volatile organic compounds from the skin

Thirty-five women were included in a clinical study to characterize the volatile organic compounds (VOCs) emitted by the skin during exposure to psychological stress. An original silicon-based polymeric phase was used for VOC sampling on the forehead before and after stress induction. Cognitive stress was induced using specialized software that included a chronometer for semantic and arithmetic tasks. Assessment of stress was monitored using a State-trait anxiety inventory questionnaire, analysis of participants’ verbal expressions and clinical measurements. Identification and relative quantification of VOCs were performed by gas chromatography-mass spectrometry. Stress induction was validated by a significant increase in state-anxiety as indicated by the questionnaire, modifications in electrodermal activity measurements and the expression of stress verbatims. In parallel, a sebum production increase and a skin pH decrease were observed. A total of 198 VOCs with different potential sources were identified. They were categorized in 5 groups: probable cosmetic composition, VOCs produced by the body or its microbiota, environmental origin, and dietary intake. In our qualitative statistical approach, three VOCs were found to be correlated with stress induction and 14 compounds showed significance in the paired Wilcoxon test. Fatty-acyls derived from lipids were predominantly identified as well as ethylbenzenes.

Features of neurovegetative and humoral regulation of cognitive activity in adolescents when using electronic devices

Background. Studying the functional state of the body of adolescents when they preform cognitive activity using electronic devices is of great importance due to the introduction of information and computer technologies into the educational process. Identifying the characteristics of the reactivity of students’ bodies when performing cognitive activities in a digital environment will contribute to both optimization of learning and health protection.The aim. To study the autonomic regulation of heart rate, electrodermal activity, cerebral circulation and the level of cortisol in saliva when adolescents performed a cognitive test on electronic devices (tablet, laptop) and on paper.Materials and methods. Using analysis of heart rate variability, electrodermal activity, rheoencephalography and enzyme-linked immunosorbent determination of cortisol in saliva, цe examined 48 adolescents while performing a cognitive activity on electronic devices.Results. When adolescents perform cognitive activity using electronic devices, we can register changes in heart rate variability, electrodermal activity and cerebral circulation. Cognitive activity in a digital environment causes an increase in sympathetic effect ontheheart rate with adecrease inparasympathetic activity, anincrease inthe integrative indicator ofgalvanic skin response, invascular tone and adecrease in the cerebral blood flow intensity. One in four adolescents experiences anticipatory stimulation of the endocrine system before taking a cognitive test. Correlation analysis revealed alarge number of correlations between the studied indicators both in the initial state and during cognitive activity.Conclusion. A large number of correlations, both in the initial state and during the cognitive test, between heart rate variability and cortisol concentration, cerebral circulation parameters indicate the preservation of a rigid system of neurovegetative and humoral regulation of heart rate when using electronic devices compared to paper-based media.

From lab to life: Evaluating the reliability and validity of psychophysiological data from wearable devices in laboratory and ambulatory settings.

Despite the increasing popularity of ambulatory assessment, the reliability and validity of psychophysiological signals from wearable devices is unproven in daily life settings. We evaluated the reliability and validity of physiological signals (electrocardiogram, ECG; photoplethysmography, PPG; electrodermal activity, EDA) collected from two wearable devices (Movisens EcgMove4 and Empatica E4) in the lab (N = 67) and daily life (N = 20) among adults aged 18-64 with Mindware as the laboratory gold standard. Results revealed that both wearable devices' valid data rates in daily life were lower than in the laboratory (Movisens ECG 82.94 vs. 93.10%, Empatica PPG 8.79 vs. 26.14%, and Empatica EDA 41.16 vs. 42.67%, respectively). The poor valid data rates of Empatica PPG signals in the laboratory could be partially attributed to participants' hand movements (r = - .27, p = .03). In laboratory settings, heart rate (HR) derived from both wearable devices exhibited higher concurrent validity than heart rate variability (HRV) metrics (ICCs 0.98-1.00 vs. 0.75-0.97). The number of skin conductance responses (SCRs) derived from Empatica showed higher concurrent validity than skin conductance level (SCL, ICCs 0.38 vs. 0.09). Movisens EcgMove4 provided more reliable and valid HRV measurements than Empatica E4 in both laboratory (split-half reliability: 0.95-0.99 vs. 0.85-0.98; concurrent validity: 0.95-1.00 vs. 0.75-0.98; valid data rate: 93.10 vs. 26.14%) and ambulatory settings (split-half reliability: 0.99-1.00 vs. 0.89-0.98; valid data rate: 82.94 vs. 8.79%). Although the reliability and validity of wearable devices are improving, findings suggest researchers should select devices that yield consistently robust and valid data for their measures of interest.