01 / 2023 – 07 / 2023
In today’s fast-paced world, working under time pressure has become second nature to many people, which makes stress-related research a field of great interest. Yet, psychological stress has a direct impact on people’s health and well-being . When exposed to a stressful situation, this usually results in a series of psychological and physiological reactions to adapt to said situation . Focusing on the physiological responses, there are two different pathways that will be activated as stress response: the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis . The first stress response is the activation of the SNS which will trigger the release of the hormones epinephrine and norepinephrine, as well as activate processes such as the increase in heart rate and blood pressure . This will be followed up by the activation of the HPA axis, for which the most commonly used measure is cortisol . For stress research, the effects of the stress systems can be determined by measuring the released hormones and changes to vital parameters . As already mentioned, cortisol can be measured as marker for the HPA axis response, and to investigate the SNS activation it can be performed an electrocardiogram (ECG) to measure heart rate. Looking at both pathways is important to understand the complete system, as the SNS and HPA pathway are interacting with each other and are not independent from each other .
The said stress responses can vary greatly depending on what type of stressor a participant is exposed to, for example, it has been suggested that HPA axis responses are specifically activated by social evaluative threat and uncontrollable stressors [2, 4]. Therefore, attention should be paid to the kind of stressors that are used when designing a study. A flexible and adaptive study environment like virtual reality (VR) can help to address specific needs. The VR technology already found its ways into psychology in the last years . Besides a flexible study environment, VR also offers other advantages such as minimization of used resources and increased experimental control . Furthermore, VR allows researchers to use game features for placing various demands on participants . At the same time, it is still possible to ensure that participants are not overwhelmed or put in real danger, so that participants can also be exposed to stressors that would not be feasible in reality . Even if stress in general can be triggered with the help of VR, the problem remains that most of the stress experiments cannot reach the same intensity of stress responses via the HPA-axis . These weak answers lead to the assumption, that it is difficult to create a social-evaluative situation in a VR environment that is equal to the one in front of real people.
Some researchers already showed that it is possible to induce robust endocrine responses using virtual agents, for example Zimmer et al. with the implementation of a VR counterpart to the Trier Social Stress Test (TSST) . Parson et al. also implemented the Stroop task in a VR environment, but with their military simulation they did not explore the Stroop effect itself, but rather implemented a simulator for a specific audience . None of the already known VR implementations aimed explicitly for eliciting an endocrine stress response with the implementation of the Stroop task. This Master’s thesis will address this unexplored problem by adapting the already existing Virtual Reality Stroop Room (VRSR). As stressor the well-known Stroop Test was utilized in a VR setting, which is based on the interference that arises when participants are shown color words in inconsistent colors (e.g. “blue” written in green ink) and need to name either the word or the color of the word . The interference is caused through the difficulty of inhibiting the prepotent response of reading . In the VRSR the participants must choose one of six colored walls instead of naming the word or color. Summarizing, the aim of this Master’s thesis is to adjust the given VRSR room to create a feeling of more difficult and uncontrollable conditions in participants, as well as more social-evaluative stress to get a measurable release of cortisol as a consequence. This would indicate that it is also possible to trigger an endocrine stress response without using a virtual agent like Zimmer et al. . As measurement for the effects, saliva samples are taken at different time points throughout the study procedure, an electrocardiogram is recorded and the electrodermal activity is determined. Additionally, the participants are asked to complete questionnaires before and after the experiment in order to draw conclusions about the psychological effects.
 S. Cohen, D. Janicki-Deverts, und G. E. Miller, „Psychological Stress and Disease“, JAMA, Bd. 298, Nr. 14, S. 1685, Okt. 2007, doi: 10.1001/jama.298.14.1685.
 S. S. Dickerson und M. E. Kemeny, „Acute Stressors and Cortisol Responses: A Theoretical Integration and Synthesis of Laboratory Research.“, Psychol. Bull., Bd. 130, Nr. 3, Art. Nr. 3, 2004, doi: 10.1037/0033-2909.130.3.355.
 E. Grimm, S. Agrigoroaei, N. Rohleder, und L. Becker, „Executive functioning as a predictor of physiological and subjective acute stress responses in non-clinical adult populations: A systematic literature review and meta-analysis“, Neurosci. Biobehav. Rev., Bd. 131, S. 1096–1115, Dez. 2021, doi: 10.1016/j.neubiorev.2021.09.037.
 N. Skoluda u. a., „Intra-individual psychological and physiological responses to acute laboratory stressors of different intensity“, Psychoneuroendocrinology, Bd. 51, S. 227–236, Jan. 2015, doi: 10.1016/j.psyneuen.2014.10.002.
 N. Rohleder, „Stress and inflammation – The need to address the gap in the transition between acute and chronic stress effects“, Psychoneuroendocrinology, Bd. 105, S. 164–171, Juli 2019, doi: 10.1016/j.psyneuen.2019.02.021.
 P. Zimmer, B. Buttlar, G. Halbeisen, E. Walther, und G. Domes, „Virtually stressed? A refined virtual reality adaptation of the Trier Social Stress Test (TSST) induces robust endocrine responses“, Psychoneuroendocrinology, Bd. 101, S. 186–192, März 2019, doi: 10.1016/j.psyneuen.2018.11.010.
 T. Finseth, N. Barnett, E. A. Shirtcliff, M. C. Dorneich, und N. Keren, „Stress Inducing Demands in Virtual Environments“, Proc. Hum. Factors Ergon. Soc. Annu. Meet., Bd. 62, Nr. 1, S. 2066–2070, Sep. 2018, doi: 10.1177/1541931218621466.
 F. Scarpina und S. Tagini, „The Stroop Color and Word Test“, Front. Psychol., Bd. 8, 2017, doi: 10.3389/fpsyg.2017.00557.
 T. D. Parsons und C. G. Courtney, „Interactions Between Threat and Executive Control in a Virtual Reality Stroop Task“, IEEE Trans. Affect. Comput., Bd. 9, Nr. 1, S. 66–75, Jan. 2018, doi: 10.1109/TAFFC.2016.2569086.