Electrodermal Activity: Simultaneous Recordings

Electrodermal activity (EDA) is a sensitive measure of the sympathetic nervous system activity. It is used to describe changes in the skin electrical properties. This chapter aimed to show advantages of simultaneous recordings of EDA parameters at the same skin site over other recordings. The literature databases, Web of Science and Google Scholar, were searched using terms like “electrodermal activity,” “sequential recording,” “simultaneous recording,” “skin conductance,” “skin potential,” and “skin susceptance.” Articles that include sequential and/or simultaneous recording of EDA parameters were analyzed. The chapter presents a description of the oldest and current methods used for recording EDA parameters and an explanation of the newest techniques used in EDA researches. Although sequential recordings are predominant and widely spreading, much effort has been made to simultaneously record skin conductance (SC) and skin potential (SP), and recently researchers realized the capability of simultaneously recording SC, SP, and skin susceptance (SS) at the same skin site. The advantage of simultaneous over the sequence measurements is that the latter must be manually time realigned when measured by different instruments, which means it is time-consuming. Although the simultaneous measurements are used exclusively for research purposes at this stage, this may open horizons in the modern trends of psychophysiology applications in the near future

Bioimpedance sensor and methodology for acute pain monitoring

The paper aims to revive the interest in bioimpedance analysis for pain studies in communicating and non-communicating (anesthetized) individuals for monitoring purpose. The plea for exploitation of full potential offered by the complex (bio)impedance measurement is emphasized through theoretical and experimental analysis. A non-invasive, low-cost reliable sensor to measure skin impedance is designed with off-the-shelf components. This is a second generation prototype for pain detection, quantification, and modeling, with the objective to be used in fully anesthetized patients undergoing surgery. The 2D and 3D time-frequency, multi-frequency evaluation of impedance data is based on broadly available signal processing tools. Furthermore, fractional-order impedance models are implied to provide an indication of change in tissue dynamics correlated with absence/presence of nociceptor stimulation. The unique features of the proposed sensor enhancements are described and illustrated here based on mechanical and thermal tests and further reinforced with previous studies from our first generation prototype

Financial Decision Making Under Stress

The aim of this paper is to examine the link between individuals\u27 financial decisions and stress. In a laboratory experiment, Holt and Laury lottery was used to elicit participants risk preferences. The Cold Pressor Test was used to induce a safe level of stress. In the treatment group, 62% of participants are risk averse; versus 76% in the control group. Additionally, inconsistent financial decision making was observed in both groups: 55% of participants in the treatment group versus 30% in the control

Live Biofeedback as a User Interface Design Element: A Review of the Literature

With the advances in sensor technology and real-time processing of neurophysiological data, a growing body of academic literature has begun to explore how live biofeedback can be integrated into information systems for everyday use. While researchers have traditionally studied live biofeedback in the clinical domain, the proliferation of affordable mobile sensor technology enables researchers and practitioners to consider live biofeedback as a user interface element in contexts such as decision support, education, and gaming. In order to establish the current state of research on live biofeedback, we conducted a literature review on studies that examine self and foreign live biofeedback based on neurophysiological data for healthy subjects in an information systems context. By integrating a body of highly fragmented work from computer science, engineering and technology, information systems, medical science, and psychology, this paper synthesizes results from existing research, identifies knowledge gaps, and suggests directions for future research. In this vein, this review can serve as a reference guide for researchers and practitioners on how to integrate self and foreign live biofeedback into information systems for everyday use

Utilizing virtual reality as a therapeutic tool psychiatry

Thesis (MEng)--Stellenbosch University, 2022.ENGLISH ABSTRACT: The mass production of modern cellphone technology has resulted in a dra matic cost reduction of producing Virtual Reality (VR) head-mounted dis plays. Although VR has been effective in the treatment of phobias, uptake is still far from mainstream. Fear of heights (i.e. acrophobia) is one of the more common forms of phobias in the general population. Up to 28% of people have distress and anxiety when exposed to heights (i.e. visual heights intoler ance (VHI)), with up to 6% of people meeting clinical criteria for the specific phobia. Virtual Reality Exposure Therapy (VRET) for acrophobia has been shown to be effective as early as the 1990s. There are, however, still relatively few randomized controlled studies that have looked at its effectiveness . Even fewer studies look at physiological responses associated with fear cessation. Biofeedback is the process of presenting participants with their physiological responses allowing them to gain a measure of control over them. Biofeedback shows promise as a treatment adjunct for specific phobias. We therefore aim to create a VR height exposure platform, that offers a graduated exposure, is optimized to avoid excessive motion sickness, is cost-effective for widespread use, and is validated by participant reports collected during the exposure. Here we developed and tested a cost effective VR acrophobia environment with biofeedback in a sample of 22 participants, 4 of whom had clinically measurable acrophobia. We constructed an Electrodermal Activity (EDA) biofeedback prototype using two Arduino boards, one being electrically isolated (Nano) to reduce noise and increase safety. The second Arduino (UNO R3) was con nected via USB to a VR workstation running the Unreal Engine 4.24.2. USB connectivity was established via the UE4duino plugin. All participants un derwent clinical screening, excluding for confounding psychopathology except acrophobia. Acrophobia symptoms were evaluated using the Visual Height Intolerance Severity Scale (vHISS) questionnaire. Participants were placed on a VR platform which ascended to 28 meters. Subjective stress responses were recorded during the task as well as VR related motion sickness. Data was en tered into a repeated measures ANOVA to check for within-subject differences in levels of stress, comparing when the platform was on the ground as well as in the air. Afterwards participants experiences were evaluated via a brief questionnaire. Biofeedback based on the mean of the signal consistently informed participants that they were stressed while the platform was elevated. Participants showed a significant increase in mean skin conductance signal while the platform was elevated. Continuous decomposition analysis as well as subjective responses confirmed the accuracy of the biofeedback provided. All participants reported a positive experience using the biofeedback, most perceiving it to be accurate. The present work indicates that biofeedback in VRET is a promising treatment adjunct, which should be explored in further clinical trials.AFRIKAANSE OPSOMMING: Met die koms van die massaproduksie van die moderne selfoontegnologie, het die koste van die vervaardiging van Virtual Reality (VR) kopgemonteerde skerms gedaal. Alhoewel VR baie belowend is met die behandeling van akrofobie, vrees vir vlieg en ander, is die opname nog ver van die hoofstroom. Hoogtevrees (d.w.s. akrofobie) is een van die meer algemene vorme van fobies in die algemene bevolking. Tot 28% van mense ervaar nood en angs wanneer hulle aan hoogtes blootgestel word (d.i. visuele hoogte-intoleransie (VHI)), met tot 6% van mense wat aan kliniese kriteria vir die spesifieke fobie voldoen. VRET vir akrofobie is reeds in die 1990’s doeltreffend getoon. Daar is egter nog relatief min gekontroleerde studies wat na die doeltreffendheid daar van gekyk het. Nog minder wat kyk na fisiologiese reaksies wat verband hou met vreesbeëindiging. Bioterugvoer is die proses om deelnemers hul fisiologiese reaksies voor te stel wat hulle in staat stel om ’n mate van beheer oor hul fisiologie te verkry. Bioterugvoer blyk belowend as ’n behandelingsaanvulling vir spesifieke fobies. Ons beoog dus om ’n VR-vrees vir hoogte-blootstellingsplatform te skep, wat geleidelike blootstelling bied, geoptimaliseer is om oormatige bewegingsiekte te vermy, koste-effektief is vir wydverspreide gebruik en bekragtig word deur kliëntverslae wat ingesamel word tydens die blootstelling. Hier het ons ’n koste-effektiewe VR-akrofobie-omgewing met bioterugvoer ontwikkel en getoets in ’n gesonde steekproef van 22 deelnemers, van wie 4 klinies meetbare akrofobie gehad het. Ons het ’n Electrodermal Activity (EDA) bioterugvoer toestel gebou deur van twee Arduino-borde gebruik te maak, waarvan een elektries geïsoleer is (Nano) om die sein te verbeter en veiligheid te verhoog. Die tweede Arduino (UNO R3) is via USB gekoppel aan ’n VRmet die Unreal Engine 4.24.2. USB-verbinding is tot stand gebring deur die UE4duino-plugin. Alle deelnemers het kliniese sifting ondergaan, en is uitgesluit vir psigopatologie behalwe akrofobie. Akrofobie simptome is geëvalueer deur gebruik te maak van die Visual Height Intolerance Severity (vHISS) vraelys. Deelnemers is op ’n VR-platform geplaas wat tot 28 meter gehys is. Subjektiewe stresreaksies is aangeteken tydens die taak sowel as VRverwante bewegingsiekte. Data is in ’n repeated measures ANOVA ingevoer om te kyk vir within-group verskille in stresvlakke, met vergelyking wanneer die platform op die grond sowel as in die lug was. Daarna is deelnemers se ervarings deur middel van ’n kort vraelys geëvalueer. Bioterugvoer gebaseer op die gemiddelde van die sein het deelnemers konsekwent ingelig dat hulle gestres is terwyl die platform in die lug was. Deelnemers het ’n beduidende toename in gemiddelde velgeleidingsein getoon terwyl die platform verhewe was. ’n Continuous decomposition analysis, sowel as subjektiewe response het die akkuraatheid van die bioterugvoer bevestig. Alle deelnemers het ’n positiewe ervaring met die gebruik van die bioterugvoer gerapporteer, en die meeste het dit as akkuraat beskou. Die huidige werk dui aan dat bioterugvoer in VRET ’n belowende behandelingshulpmiddel is, wat in verdere kliniese proewe ondersoek moet word.Master

Une forêt de réalité virtuelle pour la réduction du stress physiologique chez les personnes sans troubles neurodégénératifs

Ce travail de recherche pour la réduction du stress physiologique a été effectué initialement auprès de personnes n'ayant pas de troubles neurodégénératifs en vue de soutenir le projet visant à résorber l'anxiété des personnes atteintes de la maladie d'Alzheimer, qui se trouvent à un stade avancé, qui ont perdu leur motricité et qui ne peuvent donc plus se promener dans la nature, ou en forêt. L'exposition à la nature permet non seulement de se sentir mieux émotionnellement, mais elle contribue également au bien-être physique, en réduisant la tension artérielle, la fréquence cardiaque, la tension musculaire et la production d'hormones de stress. L'exposition à la nature à l'aide de technologies de réalité virtuelle pourrait donc apporter des avantages en termes de bien-être émotionnel aux personnes qui ne peuvent pas accéder à l'extérieur. L'article 1 présente une revue de la littérature, qui montre que bien qu'il existe un corpus comparant les effets entre la nature réelle et la nature virtuelle, il n'y a pas beaucoup d'études qui ont comparé l'effet relatif entre la nature reproduite avec différentes techniques de développement en réalité virtuelle. Plus précisément, si les différences en termes d'exploration active ou passive, la richesse de la scène ou son dynamisme, pourraient affecter le potentiel thérapeutique de ces environnements simulés, n'apparaît pas encore clairement. L'article 2 présente une étude auprès des adultes en bonne santé a été réalisée pour tester les effets de 10 min d'exposition à la nature virtuelle dans une forêt. L'objectif était d'évaluer si l'exploration d'une forêt virtuelle pouvait induire un état de connexion avec la nature, améliorer le confort des utilisateurs et réduire leur stress. Il a été émis l'hypothèse que l'exploration d'un environnement forestier virtuel à travers un visiocasque aurait un effet thérapeutique sur les manifestations de stress physiologique, dans un premier temps, chez l'adulte sans troubles neurodégénératifs.This research work for the reduction of physiological stress was initially carried out with people without neurodegenerative disorders in order to support the project aimed at reducing the anxiety of people with Alzheimer's disease, who are located at an advanced stage, who have lost their motor skills and who can no longer walk in nature, or in the forest. Exposure to nature not only makes you feel better emotionally, but it also contributes to physical well-being, by reducing blood pressure, heart rate, muscle tension and the production of stress hormones. Exposure to nature using virtual reality technologies could therefore bring emotional well-being benefits to people who cannot access the outdoors. Article 1 presents a review of the literature, which shows that although there is a body of work comparing the effects between real and virtual nature, there are not many studies that have compared the relative effect between nature reproduced with different development techniques in virtual reality. More precisely, whether the differences in terms of active or passive exploration, the richness of the scene or its dynamism, could affect the therapeutic potential of these simulated environments, is not yet clear. Article 2 presents a study in healthy adults was performed to test the effects of 10 min of exposure to virtual nature in a forest. The objective was to assess whether exploring a virtual forest could induce a state of connection with nature, improve user comfort and reduce stress. It was hypothesized that the exploration of a virtual forest environment through a head-mounted display would have a therapeutic effect on the manifestations of physiological stress, initially in adults without neurodegenerative disorders

The Effects of Primary and Secondary Task Workloads on Cybersickness in Immersive Virtual Active Exploration Experiences

Virtual reality (VR) technology promises to transform humanity. The technology enables users to explore and interact with computer-generated environments that can be simulated to approximate or deviate from reality. This creates an endless number of ways to propitiously apply the technology in our lives. It follows that large technological conglomerates are pushing for the widespread adoption of VR, financing the creation of the Metaverse - a hypothetical representation of the next iteration of the internet. Even with VR technology\u27s continuous growth, its widespread adoption remains long overdue. This can largely be attributed to an affliction called cybersickness, an analog to motion sickness, which often manifests in users as an undesirable side-effect of VR experiences, inhibiting its sustained usage. This makes it highly important to study factors related to the malady. The tasks performed in a simulated environment provide context, purpose, and meaning to the experience. Active exploration experiences afford users control over their motion, primarily allowing them to navigate through an environment. While navigating, users may also have to engage in secondary tasks that can be distracting. These navigation and distraction tasks differ in terms of the source and magnitude of attentional demands involved, potentially influencing how cyber-sickening a simulation can be. Given the sparse literature in this area, this dissertation sets out to investigate how the interplay between these factors impacts the onset and severity of sickness, thereby contributing to the knowledge base on how the attentional demands associated with the tasks performed during navigation affect cybersickness in virtual reality