@phdthesis{Cronje2024, author = {Cronj{\´e}, Johrine}, title = {Trust towards Virtual Humans in Immersive Virtual Reality and Influencing Factors}, doi = {10.25972/OPUS-34814}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-348143}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Virtual humans (VHs) hold immense potential for collaboration in social virtual reality (VR). As VR technology advances, it's vital to assess the psychological effects on VH trust and user privacy to build meaningful social interactions in VR. In social VR, users must be able to trust the VHs they interact with as they navigate through socio-cultural activities. The evaluation of trustworthiness in VHs profoundly impacts interaction quality and user willingness to engage. Conversely, untrustworthy VHs can harm user experiences, privacy, and VR engagement. To address this, we conducted immersive VR studies, exploring how psychological factors influence user's VH trust evaluation under various psychological conditions. This research is pivotal for developing strategies to enhance user privacy, establish secure VR environments, and create a foundation of trust that supports immersive socio-cultural experiences in VR. To date, there are no established interpersonal trust measurement tools specifically for VHs in VR. In study 1 (the familiarity study) of the current thesis the VR-adjusted version of the social conditioned place preference paradigm (SCPP) by Kiser et al., (2022) was identified as a potential trust measurement tool. We tested whether the familiarity of a VH influenced trust as measured with the SCPP paradigm and other self-defined outcome measures, in a Computer Augmented Virtual Environment (CAVE). The CAVE is a VR system that combines immersive VR with real-world elements. It consists of a room-sized space where the walls are used as projection screens to display virtual scenes and objects. In this within - subject design (n = 20), half of the participants were familiarized with one VH and tasked to explore and interact in a realistic looking virtual art museum environment. The participant's evaluation of the VH's trustworthiness was measured as well as their subsequent trust behaviours. Results revealed no significant differences in the evaluation of the VH's trustworthiness nor any behavioural differences between conditions. The findings of the impact of a VH's familiarity on trust is inconclusive due to the major limitations of the paradigm. We concluded that the SCPP paradigm needs further validation and the proposed proxies of trust need to be re-evaluated. The findings were considered in the following study. The virtual maze paradigm design of Hale, (2018) was identified as a potential trust measurement tool, however several limitations are associated with its use to measure trust in VR. In study 2 (a validation study), improvements were made to the virtual maze paradigm of Hale, (2018) and a variant of this paradigm was implemented. We conducted a validation study with 70 participants in a between-subject design with VH trustworthiness as the between-subject factor. Participants wore a head-mounted display (HMD), to deliver an immersive VR experience. In our version of the virtual maze, it was the task of the users (the trustors) to navigate through a maze in VR, where they could interact with a VH (the trustee). They could choose to ask for advice and follow the advice from the VH if they wanted to. The number of times participants asked and followed advice and the time it took to respond to the given advice served as behavioural proxies/measures of trust. The two conditions (trustworthy vs. untrustworthy) did not differ in the content of the advice but in the appearance, tone of voice and engagement of the trustees (allegedly an avatar controlled by other participants). Results indicated that the experimental manipulation was successful, as participants rated the VH as more trustworthy in the trustworthy condition compared with the VH in the untrustworthy condition. Importantly, this manipulation affected the trust behaviour of participants, who, in the trustworthy condition, asked for advice and followed advice more often, indicating that the paradigm is sensitive to differences in VH's trustworthiness. Thus, our paradigm can be used to measure differences in interpersonal trust towards VHs and may serve as a valuable research tool for researchers who study trust in VR. Therefore, study 2 fills the gap in the literature, for an interpersonal trust measurement tool specifically for VHs in VR. Two experimental studies, with a sample size of 50 participants each, utilized the virtual maze paradigm where participants entered 12 rooms under different conditions. We examined the influence of cognitive load (CL) on trust towards VH in VR in study 3 (Cognitive load study), and the influence of emotional affect (Emotional affect study) on trust towards VH in VR in study 4 (EA study). In both studies, we assessed participant's evaluation of a VH's trustworthiness, along with three behavioural indicators of trust in the maze task: 1) frequency of advice asked, 2) frequency of advice followed, and 3) the time taken by participants to execute the received advice. In study 3, the CL was manipulated with the auditory 1-back task in the high cognitive load condition (HCL). In study 4, the Autobiographical Emotional Memory Task (AEMT) was used to manipulate the EA of participants in the negative emotional affect (NEA) condition. As an additional manipulation, while participants were immersed in VR, they were exposed to 12 negative pictures and sounds that was presented simultaneously to strengthen the initial manipulation. The manipulation of the within-subject factors (CL and EA) was successful in both studies, as significant differences between conditions were observed in both studies (higher CL in the HCL condition and a more negative EA in the NEA condition). However, only CL influenced participant's evaluation of the VH's trustworthiness. The VH were evaluated as significantly more trustworthy after the HCL condition. Despite the difference in trust evaluation, there was no difference in advice asking or following. Participants in study 4 asked and followed advice due to their trust in the VH and asked and followed advice equally often in both conditions. Importantly, significant differences were observed in the participants response times in both studies. In study 3 during the HCL condition participants followed advice quicker. The order in which the conditions were presented influenced the experience of CL. Participants experienced higher levels of CL and responded to advice significantly faster when low cognitive load (LCL) was presented as the first condition compared with LCL as the second condition. In study 4 participants in the NEA condition followed advice slower similar to the findings of study 3. The order in which the conditions were presented had a significant effect on the EA. Participants asked and followed advice less when the NEA condition was presented first compared with when it is presented second. Possible explanations for the findings are discussed in the thesis. Overall, this thesis offers a novel tool for trust measurement (the virtual maze paradigm) and contributes to understanding the role of psychological factors in trust towards virtual humans in virtual reality.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @inproceedings{FoersterGrafe2023, author = {F{\"o}rster, Kristina and Grafe, Silke}, title = {Fostering Teacher Educators' Intercultural Media-Related Competencies Using a Social VR Environment}, series = {Proceedings of Society for Information Technology \& Teacher Education International Conference}, booktitle = {Proceedings of Society for Information Technology \& Teacher Education International Conference}, editor = {Langran, Elizabeth and Christensen, Peter and Sanson, Jarrod}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-322310}, pages = {2547-2557}, year = {2023}, abstract = {Recent studies suggest that teacher educators require intercultural media-related educational competencies to respond to contemporary and future educational needs. However, necessary professional development concepts, which are aimed at fostering these competencies, are underrepresented in current teacher education research. This study reports on the results of a case study within a Design-Based-Research project aimed at designing, implementing and evaluating a professional development concept to foster teacher educators' intercultural media-related competencies. A remote workshop using a Social VR environment was conducted with a convenience sample of 10 teacher educators. Data collected through a qualitative pre-post survey and a focus group was interpreted through qualitative content analysis. Findings showed intercultural aspects were addressed in several domains as well as an increased ability to evaluate potentials and risks related to interculturally focused teaching and learning with Social VR.}, subject = {Interkulturelles Lernen}, language = {en} } @inproceedings{OPUS4-31720, title = {Abstracts of the Wuertual Reality XR Meeting 2023}, editor = {Neumann, Isabel and Gado, Sabrina and K{\"a}thner, Ivo and Hildebrandt, Lea and Andreatta, Marta}, edition = {korrigierte Auflage}, doi = {10.25972/OPUS-31720}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-317203}, pages = {76}, year = {2023}, abstract = {The Wuertual Reality XR Meeting 2023 was initiated to bring together researchers from many fields who use VR/AR/XR. There was a focus on applied XR and social VR. In this conference band, you can find the abstracts of the two keynotes, the 34 posters and poster pitches, the 29 talks and the four workshops.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @inproceedings{OPUS4-31528, title = {Abstracts of the Wuertual Reality XR Meeting 2023}, editor = {Neumann, Isabel and Gado, Sabrina and K{\"a}thner, Ivo and Hildebrandt, Lea and Andreatta, Marta}, doi = {10.25972/OPUS-31528}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-315285}, pages = {76}, year = {2023}, abstract = {The Wuertual Reality XR Meeting 2023 was initiated to bring together researchers from many fields who use VR/AR/XR. There was a focus on applied XR and social VR. In this conference band, you can find the abstracts of the two keynotes, the 34 posters and poster pitches, the 29 talks and the four workshops.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @phdthesis{Ripka2023, author = {Ripka, Gabriela}, title = {Promoting Pre-Service Teachers' TPACK Development in Social Virtual Reality - Practice- and Theory-Oriented Development and Evaluation of a Pedagogical Concept for Initial Teacher Education}, doi = {10.25972/OPUS-31291}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-312913}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {The use of digital media by children and young people offers opportunities for communication, collaboration, and participation. However, to prepare them for the risks and challenges of media usage, promoting digital competencies of students and teachers is an indispensable goal for educational institutions. To meet this requirement, teacher education must be opened to innovative pedagogical concepts for initial teacher education that considers new technologies in a reflective, action-oriented way to promote competencies. Therefore, this work aims to promote the technological pedagogical content knowledge (TPACK) of prospective teachers that enables the purposeful integration of social virtual reality (social VR) into the classroom. Consequently, a pedagogical concept is developed and evaluated in an iterative research and development process following the design- based research approach (DBR) through four consecutive studies. The first study involved an analysis of the requirements of teachers and students for the effective use of social VR in the classroom. The second study examined how prospective teachers perceive teaching and learning activities within two theory-driven scenarios in social VR. The third study investigated the development of Technological Pedagogical Content Knowledge (TPACK) among students in social VR compared to video-based communication. Finally, the fourth study measured the development of TPACK in social VR using epistemic network analysis, finding that social VR can be an effective tool for teacher education, emphasizing the importance of authentic contexts and practical experiences for effective teaching in social VR. In the concluding chapter, appropriate implications for teacher education research and practice are derived from findings. For example, that a deeper understanding of TPACK as metacognitive awareness could enhance teacher education for media integration. It also highlights the need for digital literacy in seminars that address new technologies, emphasizing the importance of considering moral values and sustainability when using VR.}, subject = {Medienp{\"a}dagogik}, language = {en} } @phdthesis{Stauffert2022, author = {Stauffert, Jan-Philipp}, title = {Temporal Confounding Effects in Virtual and Extended Reality Systems}, doi = {10.25972/OPUS-29060}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-290609}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Latency is an inherent problem of computing systems. Each computation takes time until the result is available. Virtual reality systems use elaborated computer resources to create virtual experiences. The latency of those systems is often ignored or assumed as small enough to provide a good experience. This cumulative thesis is comprised of published peer reviewed research papers exploring the behaviour and effects of latency. Contrary to the common description of time invariant latency, latency is shown to fluctuate. Few other researchers have looked into this time variant behaviour. This thesis explores time variant latency with a focus on randomly occurring latency spikes. Latency spikes are observed both for small algorithms and as end to end latency in complete virtual reality systems. Most latency measurements gather close to the mean latency with potentially multiple smaller clusters of larger latency values and rare extreme outliers. The latency behaviour differs for different implementations of an algorithm. Operating system schedulers and programming language environments such as garbage collectors contribute to the overall latency behaviour. The thesis demonstrates these influences on the example of different implementations of message passing. The plethora of latency sources result in an unpredictable latency behaviour. Measuring and reporting it in scientific experiments is important. This thesis describes established approaches to measuring latency and proposes an enhanced setup to gather detailed information. The thesis proposes to dissect the measured data with a stacked z-outlier-test to separate the clusters of latency measurements for better reporting. Latency in virtual reality applications can degrade the experience in multiple ways. The thesis focuses on cybersickness as a major detrimental effect. An approach to simulate time variant latency is proposed to make latency available as an independent variable in experiments to understand latency's effects. An experiment with modified latency shows that latency spikes can contribute to cybersickness. A review of related research shows that different time invariant latency behaviour also contributes to cybersickness.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @phdthesis{Madeira2022, author = {Madeira, Octavia}, title = {The Human-Experimental Virtual Elevated Plus-Maze as an Anxiety Model}, doi = {10.25972/OPUS-28147}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-281478}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Anxiety research is one of the major psychological research domains and looks back on decades of research activity. Traditionally, novel theories and approaches are tested utilizing animal models. One way to study inherent anxiety in rodents is the elevated plus-maze (EPM). The EPM is a plus-shaped platform with two closed, i.e., walled, arms and two open unwalled arms. If given the opportunity to freely explore the apparatus, rodents instinctively avoid the open arms to protect themselves from predators. Hence, they spent less time on open and more time on closed arms, which is behaviorally associated with general anxiety. In the course of the pharmacological validation, it was found that this exploratory pattern can be reversed by anxiolytic substances, e.g., benzodiazepines, or potentiated by anxiogenics. One of the significant advantages of the EPM is that no prior training session is required in contrast to conditioning studies, thus allowing to observe natural behavior. Therefore, together with the economic and uncomplicated setup, the EPM has become a standard preclinical rodent anxiety test over the decades. In order to validate these rodent anxiety tests, there have recently been attempts to retranslate them to humans. A paramount of cross-species validation is not only the simple transferability of these animal tests but also the observation of anxiety behaviors that are evolutionarily conserved across species. Accordingly, it could be possible to conclude various factors associated with the etiology and maintenance of anxiety disorders in humans. So far, convincing translations of the EPM to humans are still lacking. For that reason, the primary aim of this dissertation is to retranslate the EPM throughout three studies and to evaluate cross-species validity critically. Secondly, the undertaken studies are set out to observe ambulatory activity equivalent to rodent EPM behavior, i.e., open arm avoidance. Thirdly, the undertaken studies aimed to assess the extent to which trait anxiety influences human exploratory activity on the platform to associate it with the assumption that rodent EPM-behavior is a reflection of general anxiety. Finally, virtual reality (VR) was the method of choice to maintain the economic advantage and adjust the EPM size to humans. Study 1 (N = 30) was set up to directly transfer the rodent EPM regarding test design and experimental procedure using a Computer Automatic Virtual Environment (CAVE). The results revealed that humans unlike rodents display a general open arms approach during free exploration. However, open arm avoidance was associated with high trait anxiety and acrophobia (fear of height), which was initially assessed as a control variable due to the virtual platform height. Regression analyses and subjective anxiety ratings hinted at a more significant influence of acrophobia on open arm avoidance. In addition, it was assumed that the open arms approach might have resulted from claustrophobic tendencies experienced in the closed arms due to the high walls. Study 2 (N = 61) sought to differentiate the influence of trait anxiety and acrophobia and adapt the virtual EPM to humans. Therefore, parts of the platform held a semi-transparent grid-floor texture, and the wall height on the closed arms was reduced to standard handrail level. Moreover, participants were priorly screened to exclude clinically significant levels of acrophobia, claustrophobia, and agoraphobia. The data on general exploratory activity showed no arm preference. Regression analyses confirmed that acrophobia is related to open arm avoidance, corroborating the finding of Study 1. Surprisingly, for trait anxiety, the result of Study 1 could not be replicated. Instead, for trait anxiety, no significant effect was found indicating that predominantly fear of heights shapes human EPM behavior even on a subclinical stage. In Study 3 (N = 57), the EPM was embedded into a city setting to 1) create a more natural human environment and 2) eliminate height. Furthermore, a head-mounted display was utilized for VR presentation, and arousal ratings were introduced. Participants were screened for high and low levels of trait anxiety and agoraphobia, and claustrophobia. Replicating the findings of Study 2, no difference in open and closed arm activity was observed, and no effect was found in relationship with trait anxiety. The data on anxiety ratings and claustrophobia suggest a positive correlation indicating that in this city EPM, claustrophobic tendencies might play a role in closed arm avoidance. In summary, this thesis added valuable insights into the retranslation of a well-established standard anxiety test used in rodents. However, it also majorly challenges current findings on the cross-species validity of the EPM. Various explanatory models for the results are critically discussed and associated with clinical implications concerning future research.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @phdthesis{Grossekathoefer2022, author = {Großekath{\"o}fer, Jonas David}, title = {Virtually Valid? On the Importance of Ecological Validity and Virtual Reality for Social Attention Research}, doi = {10.25972/OPUS-26041}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260417}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Gazes are of central relevance for people. They are crucial for navigating the world and communicating with others. Nevertheless, research in recent years shows that many findings from experimental research on gaze behavior cannot be transferred from the laboratory to everyday behavior. For example, the frequency with which conspecifics are looked at is considerably higher in experimental contexts than what can be observed in daily behavior. In short: findings from laboratories cannot be generalized into general statements. This thesis is dedicated to this matter. The dissertation describes and documents the current state of research on social attention through a literature review, including a meta-analysis on the /gaze cueing/ paradigm and an empirical study on the robustness of gaze following behavior. In addition, virtual reality was used in one of the first studies in this research field. Virtual reality has the potential to significantly improve the transferability of experimental laboratory studies to everyday behavior. This is because the technology enables a high degree of experimental control in naturalistic research designs. As such, it has the potential to transform empirical research in the same way that the introduction of computers to psychological research did some 50 years ago. The general literature review on social attention is extended to the classic /gaze cueing/ paradigm through a systematic review of publications and a meta-analytic evaluation (Study 1). The cumulative evidence supported the findings of primary studies: Covert spatial attention is directed by faces. However, the experimental factors included do not explain the surprisingly large variance in the published results. Thus, there seem to be further, not well-understood variables influencing these social processes. Moreover, classic /gaze cueing/ studies have limited ecological validity. This is discussed as a central reason for the lack of generalisability. Ecological validity describes the correspondence between experimental factors and realistic situations. A stimulus or an experimental design can have high and low ecological validity on different dimensions and have different influences on behavior. Empirical research on gaze following behavior showed that the /gaze cueing/ effect also occurs with contextually embedded stimuli (Study 2). The contextual integration of the directional cue contrasted classical /gaze cueing/ studies, which usually show heads in isolation. The research results can thus be transferred /within/ laboratory studies to higher ecologically valid research paradigms. However, research shows that the lack of ecological validity in experimental designs significantly limits the transferability of experimental findings to complex situations /outside/ the laboratory. This seems to be particularly the case when social interactions and norms are investigated. However, ecological validity is also often limited in these studies for other factors, such as contextual embedding /of participants/, free exploration behavior (and, thus, attentional control), or multimodality. In a first study, such high ecological validity was achieved for these factors with virtual reality, which could not be achieved in the laboratory so far (Study 3). Notably, the observed fixation patterns showed differences even under /most similar/ conditions in the laboratory and natural environments. Interestingly, these were similar to findings also derived from comparisons of eye movement in the laboratory and field investigations. These findings, which previously came from hardly comparable groups, were thus confirmed by the present Study 3 (which did not have this limitation). Overall, /virtual reality/ is a new technical approach to contemporary social attention research that pushes the boundaries of previous experimental research. The traditional trade-off between ecological validity and experimental control thus becomes obsolete, and laboratory studies can closely inherit an excellent approximation of reality. Finally, the present work describes and discusses the possibilities of this technology and its practical implementation. Within this context, the extent to which this development can still guarantee a constructive classification of different laboratory tests in the future is examined.}, subject = {Aufmerksamkeit}, language = {en} } @inproceedings{FoersterHeinGrafeetal.2021, author = {F{\"o}rster, Kristina and Hein, Rebecca and Grafe, Silke and Latoschik, Marc Erich and Wienrich, Carolin}, title = {Fostering Intercultural Competencies in Initial Teacher Education: Implementation of Educational Design Prototypes Using a Social Virtual Reality Environment}, series = {Proceedings of Innovate Learning Summit}, booktitle = {Proceedings of Innovate Learning Summit}, editor = {Basteans, Theo}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260586}, pages = {95-108}, year = {2021}, abstract = {The combination of globalization and digitalization emphasizes the importance of media-related and intercultural competencies of teacher educators and preservice teachers. This article reports on the initial prototypical implementation of a pedagogical concept to foster such competencies of preservice teachers. The proposed pedagogical concept utilizes a social virtual reality (VR) framework since related work on the characteristics of VR has indicated that this medium is particularly well suited for intercultural professional development processes. The development is integrated into a larger design-based research approach that develops a theory-guided and empirically grounded professional development concept for teacher educators with a special focus on teacher educator technology competencies (TETC8). TETCs provide a suitable competence framework capable of aligning requirements for both media-related and intercultural competencies. In an exploratory study with student teachers, we designed, implemented, and evaluated a pedagogical concept. Reflection reports were qualitatively analyzed to gain insights into factors that facilitate or hinder the implementation of the immersive learning scenario as well as into the participants' evaluation of their learning experience. The results show that our proposed pedagogical concept is particularly suitable for promoting the experience of social presence, agency, and empathy in the group.}, subject = {Interkulturelles Lernen}, language = {en} } @phdthesis{Gromer2021, author = {Gromer, Daniel}, title = {Mechanisms Underlying Virtual Reality Exposure Therapy for Specific Phobias}, doi = {10.25972/OPUS-20733}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207334}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Virtual reality exposure therapy (VRET) is an effective cognitive-behavioral treatment for anxiety disorders that comprises systematic confrontations to virtual representations of feared stimuli and situations. However, not all patients respond to VRET, and some patients relapse after successful treatment. One explanation for this limitation of VRET is that its underlying mechanisms are not yet fully understood, leaving room for further improvement. On these grounds, the present thesis aimed to investigate two major research questions: first, it explored how virtual stimuli induce fear responses in height-fearful participants, and second, it tested if VRET outcome could be improved by incorporating techniques derived from two different theories of exposure therapy. To this end, five studies in virtual reality (VR) were conducted. Study 1 (N = 99) established a virtual environment for height exposure using a Computer Automatic Virtual Environment (CAVE) and investigated the effects of tactile wind simulation in VR. Height-fearful and non-fearful participants climbed a virtual outlook, and half of the participants received wind simulation. Results revealed that height-fearful participants showed stronger fear responses, on both a subjective and behavioral level, and that wind simulation increased subjective fear. However, adding tactile wind simulation in VR did not affect presence, the user's sense of 'being there' in the virtual environment. Replicating previous studies, fear and presence in VR were correlated, and the correlation was higher in height-fearful compared to non-fearful participants. Study 2 (N = 43) sought to corroborate the findings of the first study, using a different VR system for exposure (a head-mounted display) and measuring physiological fear responses. In addition, the effects of a visual cognitive distractor on fear in VR were investigated. Participants' fear responses were evident on both a subjective and physiological level---although much more pronounced on skin conductance than on heart rate---but the virtual distractor did not affect the strength of fear responses. In Study 3 (N = 50), the effects of trait height-fearfulness and height level on fear responses were investigated in more detail. Self-rated level of acrophobia and five different height levels in VR (1 m--20 m) were used as linear predictors of subjective and physiological indices of fear. Results showed that subjective fear and skin conductance responses were a function of both trait height-fearfulness and height level, whereas no clear effects were visible for heart rate. Study 4 (N = 64 + N = 49) aimed to advance the understanding of the relationship between presence and fear in VR. Previous research indicates a positive correlation between both measures, but possible causal mechanisms have not yet been identified. The study was the first to experimentally manipulate both presence (via the visual and auditive realism of the virtual environment) and fear (by presenting both height and control situations). Results indicated a causal effect of fear on presence, i.e., experiencing fear in a virtual environment led to a stronger sense of `being there' in the virtual environment. However, conversely, presence increased by higher scene realism did not affect fear responses. Nonetheless, presence seemed to have some effects on fear responding via another pathway, as participants whose presence levels were highest in the first safe context were also those who had the strongest fear responses in a later height situation. This finding indicated the importance of immersive user characteristics in the emergence of presence and fear in VR. The findings of the first four studies were integrated into a model of fear in VR, extending previous models and highlighting factors that lead to the emergence of both fear and presence in VR. Results of the studies showed that fear responses towards virtual heights were affected by trait height-fearfulness, phobic elements in the virtual environment, and, at least to some degree, on presence. Presence, on the other hand, was affected by experiencing fear in VR, immersion---the characteristics of the VR system---and immersive user characteristics. Of note, the manipulations of immersion used in the present thesis, visual and auditory realism of the virtual environment and tactile wind simulation, were not particularly effective in manipulating presence. Finally, Study 5 (N = 34) compared two different implementations of VRET for acrophobia to investigate mechanisms underlying its efficacy. The first implementation followed the Emotional Processing Theory, assuming that fear reduction during exposure is crucial for positive treatment outcome. In this condition, patients were asked to focus on their fear responses and on the decline of fear (habituation) during exposures. The second implementation was based on the inhibitory learning model, assuming that expectancy violation is the primary mechanism underlying exposure therapy efficacy. In this condition, patients were asked to focus on the non-occurrence of feared outcomes (e.g., 'I could fall off') during exposure. Based on predictions of the inhibitory learning model, the hypothesis for the study was that expectancy-violation-based exposure would outperform habituation-based exposure. After two treatment sessions in VR, both treatment conditions effectively reduced the patients' fear of heights, but the two conditions did not differ in their efficacy. The study replicated previous studies by showing that VRET is an effective treatment for acrophobia; however, contrary to the assumption, explicitly targeting the violation of threat expectancies did not improve outcome. This finding adds to other studies failing to provide clear evidence for expectancy violation as the primary mechanism underlying exposure therapy. Possible explanations for this finding and clinical implications are discussed, along with suggestions for further research.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @masterthesis{Schmittinger2021, type = {Bachelor Thesis}, author = {Schmittinger, Sarah}, title = {Observing the Digital Self}, issn = {2511-9486}, doi = {10.25972/OPUS-22505}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225058}, school = {Universit{\"a}t W{\"u}rzburg}, pages = {60}, year = {2021}, abstract = {Facebook, Instagram, Twitter \& Co. Social media have become an essential part of everyday life for many people in recent years, and as such, it is impossible to imagine a life without them. It seems self-evident to operate as an active prosumer in the net via various end devices. We create personal profiles in various social networks, exchange ideas, and connect with others. We take part in virtual events, and above all: we actively shape the web. The photo and video platform Instagram is one of the most popular social networking sites. Since 2010, the online service has offered its users the opportunity for personal development and space for creativity. Therefore, the personal profiles serve not only participatory reasons but also facilitate acts of self-representation. In addition to apparently visible aspects, questions about self-perception arise: How do users experience and evaluate their activities in virtual space? How do they perceive their actions between the offline and online world, and how intertwined are these spheres? Through an ethnographical approach, this work represents the attempt to look beyond the self-evident aspects of the digital self. For this purpose, two Instagram users were accompanied for more than a year.}, subject = {Kulturanthropologie}, language = {en} } @phdthesis{Oberdoerfer2021, author = {Oberd{\"o}rfer, Sebastian}, title = {Better Learning with Gaming: Knowledge Encoding and Knowledge Learning Using Gamification}, doi = {10.25972/OPUS-21970}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219707}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Computer games are highly immersive, engaging, and motivating learning environments. By providing a tutorial at the start of a new game, players learn the basics of the game's underlying principles as well as practice how to successfully play the game. During the actual gameplay, players repetitively apply this knowledge, thus improving it due to repetition. Computer games also challenge players with a constant stream of new challenges which increase in difficulty over time. As a result, computer games even require players to transfer their knowledge to master these new challenges. A computer game consists of several game mechanics. Game mechanics are the rules of a computer game and encode the game's underlying principles. They create the virtual environments, generate a game's challenges and allow players to interact with the game. Game mechanics also can encode real world knowledge. This knowledge may be acquired by players via gameplay. However, the actual process of knowledge encoding and knowledge learning using game mechanics has not been thoroughly defined, yet. This thesis therefore proposes a theoretical model to define the knowledge learning using game mechanics: the Gamified Knowledge Encoding. The model is applied to design a serious game for affine transformations, i.e., GEtiT, and to predict the learning outcome of playing a computer game that encodes orbital mechanics in its game mechanics, i.e., Kerbal Space Program. To assess the effects of different visualization technologies on the overall learning outcome, GEtiT visualizes the gameplay in desktop-3D and immersive virtual reality. The model's applicability for effective game design as well as GEtiT's overall design are evaluated in a usability study. The learning outcome of playing GEtiT and Kerbal Space Program is assessed in four additional user studies. The studies' results validate the use of the Gamified Knowledge Encoding for the purpose of developing effective serious games and to predict the learning outcome of existing serious games. GEtiT and Kerbal Space Program yield a similar training effect but a higher motivation to tackle the assignments in comparison to a traditional learning method. In conclusion, this thesis expands the understanding of using game mechanics for an effective learning of knowledge. The presented results are of high importance for researches, educators, and developers as they also provide guidelines for the development of effective serious games.}, subject = {Serious game}, language = {en} } @phdthesis{LangeneSoehnchen2020, author = {Lange [n{\´e} S{\"o}hnchen], Bastian}, title = {Influence of social anxiety on social attention and corresponding changes in action patterns}, doi = {10.25972/OPUS-18900}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-189001}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {People who suffer Social Anxiety Disorder (SAD) are under substantial personal distress and endure impaired normal functioning in at least some parts of everyday life. Next, to the personal suffering, there are also the immense public health costs to consider, as SAD is the most common anxiety disorder and thereby one of the major psychiatric disorders in general. Over the last years, fundamental research found cognitive factors as essential components in the development and maintenance of social fears. Following leading cognitive models, avoidance behaviors are thought to be an important factor in maintaining the developed social anxieties. Therefore, this thesis aims to deepen the knowledge of avoidance behaviors exhibited in social anxiety, which allows to get a better understanding of how SAD is maintained. To reach this goal three studies were conducted, each using a different research approach. In the first study cutting-edge Virtual Reality (VR) equipment was used to immerse participants in a virtual environment. In this virtual setting, High Socially Anxious (HSA) individuals and matched controls had to execute a social Approach-Avoidance Task (AAT). In the task, participants had to pass a virtual person displaying neutral or angry facial expressions. By using a highly immersive VR apparatus, the first described study took the initial step in establishing a new VR task for the implicit research on social approach-avoidance behaviors. By moving freely through a VR environment, participants experienced near real-life social situations. By tracking body and head movements, physical and attentional approach-avoidance processes were studied. The second study looked at differences in attention shifts initiated by gaze-cues of neutral or emotional faces. Comparing HSA and controls, enabled a closer look at attention re-allocation with special focus on social stimuli. Further, context conditioning was used to compare task performance in a safe and in a threatening environment. Next to behavioral performance, the study also investigated neural activity using Electroencephalography (EEG) primarily looking at the N2pc component. In the third study, eye movements of HSA and Low Socially Anxious (LSA) were analyzed using an eye-tracking apparatus while participants executed a computer task. The participants' tasks consisted of the detection of either social or non-social stimuli in complex visual settings. The study intended to compare attention shifts towards social components between these two tasks and how high levels of social anxiety influence them. In other words, the measurements of eye movements enabled the investigation to what extent social attention is task-dependent and how it is influenced by social anxiety. With the three described studies, three different approaches were used to get an in-depth understanding of what avoidance behaviors in SAD are and to which extent they are exhibited. Overall, the results showed that HSA individuals exhibited exaggerated physical and attentional avoidance behavior. Furthermore, the results highlighted that the task profoundly influences attention allocation. Finally, all evidence indicates that avoidance behaviors in SAD are exceedingly complex. They are not merely based on the fear of a particular stimulus, but rather involve highly compound cognitive processes, which surpass the simple avoidance of threatening stimuli. To conclude, it is essential that further research is conducted with special focus on SAD, its maintaining factors, and the influence of the chosen research task and method.}, subject = {Sozialangst}, language = {en} } @phdthesis{Roth2020, author = {Roth, Daniel}, title = {Intrapersonal, Interpersonal, and Hybrid Interactions in Virtual Reality}, doi = {10.25972/OPUS-18862}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188627}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Virtual reality and related media and communication technologies have a growing impact on professional application fields and our daily life. Virtual environments have the potential to change the way we perceive ourselves and how we interact with others. In comparison to other technologies, virtual reality allows for the convincing display of a virtual self-representation, an avatar, to oneself and also to others. This is referred to as user embodiment. Avatars can be of varying realism and abstraction in their appearance and in the behaviors they convey. Such userembodying interfaces, in turn, can impact the perception of the self as well as the perception of interactions. For researchers, designers, and developers it is of particular interest to understand these perceptual impacts, to apply them to therapy, assistive applications, social platforms, or games, for example. The present thesis investigates and relates these impacts with regard to three areas: intrapersonal effects, interpersonal effects, and effects of social augmentations provided by the simulation. With regard to intrapersonal effects, we specifically explore which simulation properties impact the illusion of owning and controlling a virtual body, as well as a perceived change in body schema. Our studies lead to the construction of an instrument to measure these dimensions and our results indicate that these dimensions are especially affected by the level of immersion, the simulation latency, as well as the level of personalization of the avatar. With regard to interpersonal effects we compare physical and user-embodied social interactions, as well as different degrees of freedom in the replication of nonverbal behavior. Our results suggest that functional levels of interaction are maintained, whereas aspects of presence can be affected by avatar-mediated interactions, and collaborative motor coordination can be disturbed by immersive simulations. Social interaction is composed of many unknown symbols and harmonic patterns that define our understanding and interpersonal rapport. For successful virtual social interactions, a mere replication of physical world behaviors to virtual environments may seem feasible. However, the potential of mediated social interactions goes beyond this mere replication. In a third vein of research, we propose and evaluate alternative concepts on how computers can be used to actively engage in mediating social interactions, namely hybrid avatar-agent technologies. Specifically, we investigated the possibilities to augment social behaviors by modifying and transforming user input according to social phenomena and behavior, such as nonverbal mimicry, directed gaze, joint attention, and grouping. Based on our results we argue that such technologies could be beneficial for computer-mediated social interactions such as to compensate for lacking sensory input and disturbances in data transmission or to increase aspects of social presence by visual substitution or amplification of social behaviors. Based on related work and presented findings, the present thesis proposes the perspective of considering computers as social mediators. Concluding from prototypes and empirical studies, the potential of technology to be an active mediator of social perception with regard to the perception of the self, as well as the perception of social interactions may benefit our society by enabling further methods for diagnosis, treatment, and training, as well as the inclusion of individuals with social disorders. To this regard, we discuss implications for our society and ethical aspects. This thesis extends previous empirical work and further presents novel instruments, concepts, and implications to open up new perspectives for the development of virtual reality, mixed reality, and augmented reality applications.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @phdthesis{Rubo2019, author = {Rubo, Marius}, title = {Social Attention in the Laboratory, in Real Life and in Virtual Reality}, doi = {10.25972/OPUS-18845}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-188452}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Social attention is a ubiquitous, but also enigmatic and sometimes elusive phenomenon. We direct our gaze at other human beings to see what they are doing and to guess their intentions, but we may also absorb social events en passant as they unfold in the corner of the eye. We use our gaze as a discrete communication channel, sometimes conveying pieces of information which would be difficult to explicate, but we may also find ourselves avoiding eye-contact with others in moments when self-disclosure is fear-laden. We experience our gaze as the most genuine expression of our will, but research also suggests considerable levels of predictability and automaticity in our gaze behavior. The phenomenon's complexity has hindered researchers from developing a unified framework which can conclusively accommodate all of its aspects, or from even agreeing on the most promising research methodologies. The present work follows a multi-methods approach, taking on several aspects of the phenomenon from various directions. Participants in study 1 viewed dynamic social scenes on a computer screen. Here, low-level physical saliency (i.e. color, contrast, or motion) and human heads both attracted gaze to a similar extent, providing a comparison of two vastly different classes of gaze predictors in direct juxtaposition. In study 2, participants with varying degrees of social anxiety walked in a public train station while their eye movements were tracked. With increasing levels of social anxiety, participants showed a relative avoidance of gaze at near compared to distant people. When replicating the experiment in a laboratory situation with a matched participant group, social anxiety did not modulate gaze behavior, fueling the debate around appropriate experimental designs in the field. Study 3 employed virtual reality (VR) to investigate social gaze in a complex and immersive, but still highly controlled situation. In this situation, participants exhibited a gaze behavior which may be more typical for real-life compared to laboratory situations as they avoided gaze contact with a virtual conspecific unless she gazed at them. This study provided important insights into gaze behavior in virtual social situations, helping to better estimate the possible benefits of this new research approach. Throughout all three experiments, participants showed consistent inter-individual differences in their gaze behavior. However, the present work could not resolve if these differences are linked to psychologically meaningful traits or if they instead have an epiphenomenal character.}, subject = {Aufmerksamkeit}, language = {en} } @phdthesis{Fischbach2017, author = {Fischbach, Martin Walter}, title = {Enhancing Software Quality of Multimodal Interactive Systems}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-152723}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2017}, abstract = {Multimodal interfaces (MMIs) are a promising human-computer interaction paradigm. They are feasible for a wide rang of environments, yet they are especially suited if interactions are spatially and temporally grounded with an environment in which the user is (physically) situated. Real-time interactive systems (RISs) are technical realizations for situated interaction environments, originating from application areas like virtual reality, mixed reality, human-robot interaction, and computer games. RISs include various dedicated processing-, simulation-, and rendering subsystems which collectively maintain a real-time simulation of a coherent application state. They thus fulfil the complex functional requirements of their application areas. Two contradicting principles determine the architecture of RISs: coupling and cohesion. On the one hand, RIS subsystems commonly use specific data structures for multiple purposes to guarantee performance and rely on close semantic and temporal coupling between each other to maintain consistency. This coupling is exacerbated if the integration of artificial intelligence (AI) methods is necessary, such as for realizing MMIs. On the other hand, software qualities like reusability and modifiability call for a decoupling of subsystems and architectural elements with single well-defined purposes, i.e., high cohesion. Systems predominantly favour performance and consistency over reusability and modifiability to handle this contradiction. They thus accept low maintainability in general and hindered scientific progress in the long-term. This thesis presents six semantics-based techniques that extend the established entity-component system (ECS) pattern and pose a solution to this contradiction without sacrificing maintainability: semantic grounding, a semantic entity-component state, grounded actions, semantic queries, code from semantics, and decoupling by semantics. The extension solves the ECS pattern's runtime type deficit, improves component granularity, facilitates access to entity properties outside a subsystem's component association, incorporates a concept to semantically describe behavior as complement to the state representation, and enables compatibility even between RISs. The presented reference implementation Simulator X validates the feasibility of the six techniques and may be (re)used by other researchers due to its availability under an open-source licence. It includes a repertoire of common multimodal input processing steps that showcase the particular adequacy of the six techniques for such processing. The repertoire adds up to the integrated multimodal processing framework miPro, making Simulator X a RIS platform with explicit MMI support. The six semantics-based techniques as well as the reference implementation are validated by four expert reviews, multiple proof of concept prototypes, and two explorative studies. Informal insights gathered throughout the design and development supplement this assessment in the form of lessons learned meant to aid future development in the area.}, subject = {Echtzeitsystem}, language = {en} } @phdthesis{Wiebusch2016, author = {Wiebusch, Dennis}, title = {Reusability for Intelligent Realtime Interactive Systems}, publisher = {W{\"u}rzburg University Press}, address = {W{\"u}rzburg}, isbn = {978-3-95826-040-5 (print)}, doi = {10.25972/WUP-978-3-95826-041-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121869}, school = {W{\"u}rzburg University Press}, pages = {260}, year = {2016}, abstract = {Software frameworks for Realtime Interactive Systems (RIS), e.g., in the areas of Virtual, Augmented, and Mixed Reality (VR, AR, and MR) or computer games, facilitate a multitude of functionalities by coupling diverse software modules. In this context, no uniform methodology for coupling these modules does exist; instead various purpose-built solutions have been proposed. As a consequence, important software qualities, such as maintainability, reusability, and adaptability, are impeded. Many modern systems provide additional support for the integration of Artificial Intelligence (AI) methods to create so called intelligent virtual environments. These methods exacerbate the above-mentioned problem of coupling software modules in the thus created Intelligent Realtime Interactive Systems (IRIS) even more. This, on the one hand, is due to the commonly applied specialized data structures and asynchronous execution schemes, and the requirement for high consistency regarding content-wise coupled but functionally decoupled forms of data representation on the other. This work proposes an approach to decoupling software modules in IRIS, which is based on the abstraction of architecture elements using a semantic Knowledge Representation Layer (KRL). The layer facilitates decoupling the required modules, provides a means for ensuring interface compatibility and consistency, and in the end constitutes an interface for symbolic AI methods.}, subject = {Virtuelle Realit{\"a}t}, language = {en} } @phdthesis{GlotzbachSchoon2013, author = {Glotzbach-Schoon, Evelyn}, title = {Contextual fear conditioning in humans: The return of contextual anxiety and the influence of genetic polymorphisms}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87955}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Als Angst bezeichnet man einen nicht auf spezifische Objekte gerichteten l{\"a}nger anhaltenden zukunfts-orientierten Zustand der Besorgnis. Diese ist kennzeichnend f{\"u}r Angstst{\"o}rungen wie Panikst{\"o}rung, generalisierte Angstst{\"o}rung und Posttraumatische Belastungsst{\"o}rung (PTBS). Experimentell kann Angst durch kontextuelle Furchtkonditionierung ausgel{\"o}st werden. Bei dieser Art der Konditionierung werden aversive Ereignisse als unvorhersehbar erlebt, wodurch der gesamte Kontext mit der Gefahr assoziiert wird. Diese Arbeit hat zum Ziel, Mechanismen der Entstehung und Aufrechterhaltung von Kontextangst zu untersuchen. Dies sind zum einem erleichterte Akquisition von Kontextkonditionierungen und deren fehlerhafte Extinktion. Hier ist vor allem die Fragestellung relevant, wie dies durch genetische Varianten moduliert wird (Studie 1). Zum anderen soll die Wiederkehr der Angst nach der Extinktion mit einem neuen Reinstatement-Paradigma untersucht werden (Studie 2). Zur Untersuchung dieser Forschungsfragen wurden zwei kontextuelle Furchtkonditionierungsstudien in virtueller Realit{\"a}t (VR) durchgef{\"u}hrt. W{\"a}hrend der Akquisition wurden leicht schmerzhafte elektrische Reize (unkonditionierter Stimulus, US) unvorhersehbar pr{\"a}sentiert, w{\"a}hrend die Probanden in einem virtuellen B{\"u}roraum waren. Dadurch wurde dieser Raum zum Angstkontext (CXT+). Ein zweiter B{\"u}roraum wurde nie mit dem US gepaart, deshalb wurde dieser Raum zum Sicherheitskontext (CXT-). Die Extinktion, in der die Kontexte ohne US pr{\"a}sentiert wurden, fand 24 h sp{\"a}ter statt, und ein Test zum Abruf der Extinktion bzw. zur Wiederkehr der Angst nochmals 24 h sp{\"a}ter. In beiden Studien wurde die Angst auf drei verschiedenen Ebenen gemessen: Verhalten (angstpotenzierter Schreckreflex), Physiologie (tonische Hautleitf{\"a}higkeit), und verbale Ebene (explizite Ratings). Die Probanden f{\"u}r Studie 1 wurden anhand der 5-HTTLPR (S+ Risikoallel vs. LL nicht-Risikoallel) und NPSR1 rs324981 (T+ Risikoallel vs. AA nicht-Risikoallel) Polymorphismen stratifiziert, sodass vier kombinierte Genotyp Gruppen (S+/T+, S+/LL, LL/T+ und LL/AA) mit je 20 Probanden vorlagen. Es zeigte sich, dass der angstpotenzierte Schreckreflex durch die Interaktion zwischen beiden genetischen Polymorphismen moduliert wurde. Nur Tr{\"a}ger beider Risikoallele (S+ Tr{\"a}ger des 5-HTTLPR und T+ Tr{\"a}ger des NPSR1 Polymorphismus) zeigten einen h{\"o}heren Schreckreflex im CXT+ als im CXT- w{\"a}hrend der Akquisition. Der Abruf der Extinktion an Tag 3, gemessen anhand des Schreckreflexes, wurde allerdings nicht durch die Genotypen moduliert. Interessanterweise zeigte sich auf dem expliziten Angstlevel (Valenz- und Angstratings) nur ein Einfluss des NPSR1 Polymorphismus, und zwar bewerteten die nicht-Risikoallel Tr{\"a}ger (AA) den CXT+ mit negativerer Valenz und h{\"o}herer Angst im Vergleich zum CXT-; die Risikoallel Tr{\"a}ger (T+) taten dies nicht. In der zweiten Studie wurde fast das gleiche Paradigma benutzt wie in der ersten Studie mit der Ausnahme, dass eine Versuchsgruppe (Reinstatementgruppe) den US noch einmal am Anfang des dritten Untersuchungstages vor der Pr{\"a}sentation von CXT+ und CXT- appliziert bekam. Die zweite Versuchsgruppe (Kontrollgruppe) erhielt keinen US, sondern wurde direkt durch CXT+ und CXT- gef{\"u}hrt. Es zeigte sich, dass nur in der Reinstatementgruppe die Angst auf impliziter und expliziter Ebene wiederkehrte, d.h. die Probanden zeigten einen h{\"o}heren Schreckreflex und h{\"o}here Angstratings auf den CXT+ im Vergleich zum CXT-. Wichtig war vor allem, dass die Wiederkehr der Angst in der Reinstatementgruppe mit der Ver{\"a}nderung der Zustandsangst und der Stimmung (von der Extinktion zum Test) korrelierte. D.h. je gr{\"o}ßer die Angst und je negativer die Stimmung wurden, desto h{\"o}her war die Wiederkehr der Angst. Zusammengefasst belegt Studie 1, dass erleichterte kontextuelle Furchtkonditionierung auf impliziter Ebene (Schreckreflex) ein Endoph{\"a}notyp f{\"u}r Angstst{\"o}rungen sein k{\"o}nnte, was zu unserem Verst{\"a}ndnis der {\"A}tiologie von Angstst{\"o}rungen beitragen k{\"o}nnte. Die Ergebnisse der zweiten Studie legen nahe, dass eine {\"a}ngstliche und negative Stimmung nach der Extinktion die R{\"u}ckkehr von Angst beg{\"u}nstigen k{\"o}nnte. Dar{\"u}ber hinaus scheint das VR-basierte kontextuelle Furchtkonditionierungsparadigma ein geeignetes Mittel zu sein, um Mechanismen der Angstentstehung und Angstwiederkehr experimentell zu erforschen. Weiterf{\"u}hrende Studien k{\"o}nnten nun auch Angstpatienten untersuchen und das Paradigma auf evolution{\"a}r-relevante Kontexte (z.B. H{\"o}he, Dunkelheit, weite Pl{\"a}tze) ausweiten.}, subject = {Angst}, language = {en} } @phdthesis{Ewald2014, author = {Ewald, Heike}, title = {Influence of context and contingency awareness on fear conditioning - an investigation in virtual reality}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111226}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2014}, abstract = {Fear conditioning is an efficient model of associative learning, which has greatly improved our knowledge of processes underlying the development and maintenance of pathological fear and anxiety. In a differential fear conditioning paradigm, one initially neutral stimulus (NS) is paired with an aversive event (unconditioned stimulus, US), whereas another stimulus does not have any consequences. After a few pairings the NS is associated with the US and consequently becomes a conditioned stimulus (CS+), which elicits a conditioned response (CR). The formation of explicit knowledge of the CS/US association during conditioning is referred to as contingency awareness. Findings about its role in fear conditioning are ambiguous. The development of a CR without contingency awareness has been shown in delay fear conditioning studies. One speaks of delay conditioning, when the US coterminates with or follows directly on the CS+. In trace conditioning, a temporal gap or "trace interval" lies between CS+ and US. According to existing evidence, trace conditioning is not possible on an implicit level and requires more cognitive resources than delay conditioning. The associations formed during fear conditioning are not exclusively associations between specific cues and aversive events. Contextual cues form the background milieu of the learning process and play an important role in both acquisition and the extinction of conditioned fear and anxiety. A common limitation in human fear conditioning studies is the lack of ecological validity, especially regarding contextual information. The use of Virtual Reality (VR) is a promising approach for creating a more complex environment which is close to a real life situation. I conducted three studies to examine cue and contextual fear conditioning with regard to the role of contingency awareness. For this purpose a VR paradigm was created, which allowed for exact manipulation of cues and contexts as well as timing of events. In all three experiments, participants were guided through one or more virtual rooms serving as contexts, in which two different lights served as CS and an electric stimulus as US. Fear potentiated startle (FPS) responses were measured as an indicator of implicit fear conditioning. To test whether participants had developed explicit awareness of the CS-US contingencies, subjective ratings were collected. The first study was designed as a pilot study to test the VR paradigm as well as the conditioning protocol. Additionally, I was interested in the effect of contingency awareness. Results provided evidence, that eye blink conditioning is possible in the virtual environment and that it does not depend on contingency awareness. Evaluative conditioning, as measured by subjective ratings, was only present in the group of participants who explicitly learned the association between CS and US. To examine acquisition and extinction of both fear associated cues and contexts, a novel cue-context generalization paradigm was applied in the second study. Besides the interplay of cues and contexts I was again interested in the effect of contingency awareness. Two different virtual offices served as fear and safety context, respectively. During acquisition, the CS+ was always followed by the US in the fear context. In the safety context, none of the lights had any consequences. During extinction, a additional (novel) context was introduced, no US was delivered in any of the contexts. Participants showed enhanced startle responses to the CS+ compared to the CS- in the fear context. Thus, discriminative learning took place regarding both cues and contexts during acquisition. This was confirmed by subjective ratings, although only for participants with explicit contingency awareness. Generalization of fear to the novel context after conditioning did not depend on awareness and was observable only on trend level. In a third experiment I looked at neuronal correlates involved in extinction of fear memory by means of functional magnetic resonance imaging (fMRI). Of particular interest were differences between extinction of delay and trace fear conditioning. I applied the paradigm tested in the pilot study and additionally manipulated timing of the stimuli: In the delay conditioning group (DCG) the US was administered with offset of one light (CS+), in the trace conditioning group (TCG) the US was presented 4s after CS+ offset. Most importantly, prefrontal activation differed between the two groups. In line with existing evidence, the ventromedial prefrontal cortex (vmPFC) was activated in the DCG. In the TCG I found activation of the dorsolateral prefrontal cortex (dlPFC), which might be associated with modulation of working memory processes necessary for bridging the trace interval and holding information in short term memory. Taken together, virtual reality proved to be an elegant tool for examining human fear conditioning in complex environments, and especially for manipulating contextual information. Results indicate that explicit knowledge of contingencies is necessary for attitude formation in fear conditioning, but not for a CR on an implicit level as measured by FPS responses. They provide evidence for a two level account of fear conditioning. Discriminative learning was successful regarding both cues and contexts. Imaging results speak for different extinction processes in delay and trace conditioning, hinting that higher working memory contribution is required for trace than for delay conditioning.}, subject = {Klassische Konditionierung}, language = {en} } @phdthesis{Shiban2013, author = {Shiban, Youssef}, title = {Attenuating Renewal following Exposure Therapy : Mechanisms of Exposure in Multiple Contexts and its Influence on the Renewal of Fear: Studies in Virtual Reality}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76673}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {„Renewal" bezeichnet das Wiederauftreten von Angst nach erfolgreicher Expositionstherapie in Folge einer erneuten Konfrontation mit dem phobischen Stimulus in einem neuen, sich vom Expositionskontext unterscheidenden Kontext. Bouton (1994) zufolge deutet diese Angstr{\"u}ckkehr durch einen Kontextwechsel darauf hin, dass die Angst nicht gel{\"o}scht wurde. Stattdessen wurde w{\"a}hrend der Expositionssitzung eine neue Assoziation gelernt, die das gef{\"u}rchtete Objekt mit „keiner Angst", also den konditionierten Reiz (conditioned stimulus, CS) mit „keinem unkonditionierten Reiz" (no unconditioned stimulus, no US), verbindet. Bouton argumentiert weiter, dass diese Assoziation kontextabh{\"a}ngig ist, wodurch Effekte wie Angst-Renewal erkl{\"a}rt werden k{\"o}nnen. Da in einem neuen Kontext die CS-no US-Assoziation nicht aktiviert wird, wird die Angst auch nicht gehemmt. Die Kontextabh{\"a}ngigkeit der CS-no US-Assoziation wurde in mehreren Studien belegt (Balooch \& Neumann, 2011; Siavash Bandarian Balooch, Neumann, \& Boschen, 2012; Culver, Stoyanova, \& Craske, 2011; Kim \& Richardson, 2009; Neumann \& Kitlertsirivatana, 2010). Aktuell konzentriert sich die Forschung zur Therapie von Angstst{\"o}rungen auf die Frage, wie Angst reduziert und gleichzeitig ein R{\"u}ckfall verhindert werden kann. Hierzu werden verschiedene Expositionsprotokolle untersucht, wie zum Beispiel (1) Exposition in mehreren Kontexten (multiple contexts exposure, MCE), um Renewal zu reduzieren (z.B. Balooch \& Neumann, 2011); (2) verl{\"a}ngerte Exposition (prolonged exposure, PE), um die hemmende Assoziation w{\"a}hrend des Extinktionslernes zu st{\"a}rken (z.B. Thomas, Vurbic, \& Novak, 2009) und (3) Rekonsolidierungs-Updates (reconsolidation update, RU), die den Rekonsolidierungsprozess durch eine kurze Exposition des CS+ vor der eigentlichen Exposition aktualisieren sollen (Schiller et al., 2010). Bisher liegen jedoch nur sehr wenige Studien vor, die diese neuen Expositionsprotokolle an klinischen Stichproben untersucht haben, und - soweit bekannt - keine Studie, welche die Wirkmechanismen dieser Protokolle an einer klinischen Stichprobe erforscht. Die vorliegende Dissertation hat drei Ziele. Das erste Ziel besteht darin zu pr{\"u}fen, ob Expositionstherapie in multiplen Kontexten die Wahrscheinlichkeit von Renewal reduziert. Das zweite Ziel ist die Untersuchung der Mechanismen, die dem Effekt der Exposition in multiplen Kontexten zugrunde liegen und das dritte ist den Kontext im Zusammenhang mit Konditionierung und Extinktion zu konzeptualisieren. Insgesamt wurden drei Studien durchgef{\"u}hrt. Die erste Studie untersuchte den Effekt von Exposition in multiplen Kontexten auf Renewal, die zweite und dritte Studie die Wirkmechanismen von MCE. In der ersten Studie wurden spinnenphobische Probanden (N = 30) viermal mit einer virtuellen Spinne konfrontiert. Die Expositionstrials wurden entweder in einem gleichbleibenden Kontext oder in vier verschiedenen Kontexten durchgef{\"u}hrt. Am Ende der Sitzung absolvierten alle Teilnehmer einen virtuellen Renewaltest, bei dem die virtuelle Spinne in einem neuen Kontext gezeigt wurde, und einen in vivo Verhaltensvermeidungstest (behavioral avoidance test, BAT) mit einer echten Spinne. Die Ergebnisse zeigten, dass Probanden, welche die vier Expositionstrials in unterschiedlichen Kontexten erfuhren, weniger Angst, sowohl im virtuellen Renewaltest als auch im BAT, erlebten. In dieser Studie konnte die Wirksamkeit von MCE f{\"u}r die Reduktion von Renewal erfolgreich nachgewiesen werden. Studie 2 (N = 35) untersuchte die Wirkmechanismen von MCE in einem differentiellen Konditionierungsparadigma. Die Extinktion wurde in multiplen Kontexten durchgef{\"u}hrt. Hierbei war das Ziel, eine {\"a}hnliche Verminderung von Renewal wie in Studie 1 nachzuweisen. Der Extinktion folgten zwei Tests, mit dem Ziel m{\"o}gliche hemmende Effekte des Kontexts, die w{\"a}hrend der Extinktionsphase erworben wurden, aufzudecken. Bez{\"u}glich des Effektes von MCE wurden drei Hypothesen aufgestellt: (1) Der Extinktionskontext wird mit der Exposition assoziiert, fungiert folglich w{\"a}hrend der Extinktion als Sicherheitssignal und konkurriert daher mit dem Sicherheitslernen des CS. Dies f{\"u}hrt zu einem verminderten Extinktionseffekt auf den CS, wenn die Extinktion nur in einem Kontext durchgef{\"u}hrt wird. (2) Die Elemente im Extinktionskontext (z.B. Raumfarbe, M{\"o}bel) stehen im Zusammenhang mit der CS-no US-Assoziation und erinnern daher an die Extinktion, was zu einer gr{\"o}ßeren Angsthemmung f{\"u}hrt, wenn sie w{\"a}hrend eines Tests gezeigt werden. (3) Nach der emotionalen Prozesstheorie (emotional process theory; Bouton, 1994; Foa et al., 1996) bestimmen die Therapieprozessfaktoren die St{\"a}rke des Renewals. Beispielsweise korrelieren initiale Angstaktivierung, Aktivierung in und zwischen den Sitzungen mit der St{\"a}rke des Renewals. Jedoch waren in dieser Studie keine Unterschiede zwischen den Gruppen im Renewaltest zu beobachten, weswegen die Ergebnisse der zwei Nachtests nicht zu interpretieren sind. Das Ziel von Studie 3 (N = 61) war es, das Konzept des Kontexts im Rahmen von Konditionierung und Exposition zu definieren. In Studie 3 wurde das Auftreten der Generalisierungsabnahme (generalization decrement) genutzt, bei der eine konditionierte Reaktion infolge eines Kontextwechsels nur reduziert auftritt. Auf diesem Weg kann Kontext{\"a}hnlichkeit quantifiziert werden. Nach einer Akquisitonsphase in einem Kontext wurden die Teilnehmer in einem von drei verschiedenen Kontexten getestet. Zwei dieser Kontexte unterschieden sich nur in einer Dimension (Anordnung der Objekte vs. Objekteigenschaften). Die dritte Gruppe wurde im Akquisitonskontext getestet und diente als Kontrollgruppe. Es fanden sich jedoch keine Unteschiede zwischen den Gruppen in den Testphasen. Eine m{\"o}gliche Erkl{\"a}rung ist die Neuartigkeit des Testkontextes. Teilnehmer, die nach der Extinktion einem neuen Kontext ausgesetzt waren, erwarteten in einem anderen Kontext eine zweite Extinktionsphase und zeigten daher mehr statt weniger Angst als erwartet.}, subject = {Angst}, language = {en} }