@phdthesis{Wannagat2018,
  author    = {Wannagat, Wienke Charlotte},
  title     = {Cognitive Processes of Discourse Comprehension in Children and Adults - Comparisons between Written, Auditory, and Audiovisual Modes of Presentation -},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-162515},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {In drei Studien wurde untersucht, wie sich unterschiedliche Darbietungsformate (schriftlich, auditiv, audiovisuell (auditiv + Bilder) auf das Verst{\"a}ndnis semantisch identischer Inhalte auswirken. Dabei interessierte insbesondere der Entwicklungsverlauf von der ersten Klasse bis zum Erwachsenenalter. Dass sich Bilder f{\"o}rderlich auf die Verst{\"a}ndnisleistung auswirken k{\"o}nnen, gilt als gut untersucht (z.B. Carney \& Levin, 2002). Anders als viele bisherige Studien erfassen wir Textverstehen mit impliziten Maßen, die differenziertere R{\"u}ckschl{\"u}sse auf die, g{\"a}ngigen Theorien zufolge, zugrundeliegenden Prozesse zulassen: Textverstehen geht mit der Konstruktion von drei Ebenen mentaler Repr{\"a}sentationen einher (vgl. Kintsch, 1998). Weiterhin bedeutet erfolgreiches Textverstehen, eine auf lokaler und globaler Ebene koh{\"a}rente mentale Repr{\"a}sentation zu konstruieren (z.B. Schnotz \& Dutke, 2004). Mit einem Satz-Rekognitionstest (vgl. Schmalhofer \& Glavanov, 1986) untersuchten wir, ob sich das Ged{\"a}chtnis f{\"u}r die Textoberfl{\"a}che, die Textbasis und das Situationsmodell bei 103 8- und 10-J{\"a}hrigen zwischen schriftlicher, auditiver und audiovisueller (Studie 1) und bei 106 7-, 9- und 11-J{\"a}hrigen zwischen auditiver und audiovisueller Darbietung narrativer Texte (Studie 2) unterscheidet. Weiterhin (Studie 3) untersuchten wir mit 155 9- und 11-J{\"a}hrigen, inwieweit sich die F{\"a}higkeit der Inferenzbildung zur Herstellung lokaler und globaler Koh{\"a}renz zwischen schriftlicher, auditiver und audiovisueller Darbietung unterscheidet. Als Indikator dienten die Reaktionszeiten auf W{\"o}rter, die mit einem {\"u}ber (global)- oder untergeordneten (lokal) Protagonistenziel assoziiert sind. Insgesamt zeigte sich, dass Sch{\"u}ler bis zu einem Alter von 11 Jahren nicht nur die Textoberfl{\"a}che besser erinnern, sondern auch besser in der Lage sind ein Situationsmodell zu konstruieren, wenn einem Text Bilder beigef{\"u}gt sind. Dies zeigte sich sowohl im Vergleich mit auditiver als auch mit schriftlicher Darbietung. Bei Erwachsenen zeigte sich kein Effekt der Darbietungsform. Sowohl 9- als auch 11-J{\"a}hrigen gelingt außerdem die Herstellung globaler Koh{\"a}renz bei audiovisueller Darbietung besser als bei auditiver. Die schriftliche Darbietung zeigte sich im Vergleich zur auditiven sowohl im Hinblick auf lokale als auch auf globale Koh{\"a}renz {\"u}berlegen.},
  subject      = {Textverstehen},
  language  = {en}
}
@phdthesis{Huestegge2019,
  author    = {Huestegge, Sujata Maya},
  title     = {Cognitive mechanisms of voice processing},
  doi       = {10.25972/OPUS-18608},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-186086},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {The present thesis addresses cognitive processing of voice information. Based on general theoretical concepts regarding mental processes it will differentiate between modular, abstract information processing approaches to cognition and interactive, embodied ideas of mental processing. These general concepts will then be transferred to the context of processing voice-related information in the context of parallel face-related processing streams. One central issue here is whether and to what extent cognitive voice processing can occur independently, that is, encapsulated from the simultaneous processing of visual person-related information (and vice versa). In Study 1 (Huestegge \& Raettig, in press), participants are presented with audio-visual stimuli displaying faces uttering digits. Audiovisual gender congruency was manipulated: There were male and female faces, each uttering digits with either a male or female voice (all stimuli were AV- synchronized). Participants were asked to categorize the gender of either the face or the voice by pressing one of two keys in each trial. A central result was that audio-visual gender congruency affected performance: Incongruent stimuli were categorized slower and more error-prone, suggesting a strong cross-modal interaction of the underlying visual and auditory processing routes. Additionally, the effect of incongruent visual information on auditory classification was stronger than the effect of incongruent auditory information on visual categorization, suggesting visual dominance over auditory processing in the context of gender classification. A gender congruency effect was also present under high cognitive load. Study 2 (Huestegge, Raettig, \& Huestegge, in press) utilized the same (gender-congruent and -incongruent) stimuli, but different tasks for the participants, namely categorizing the spoken digits (into odd/even or smaller/larger than 5). This should effectively direct attention away from gender information, which was no longer task-relevant. Nevertheless, congruency effects were still observed in this study. This suggests a relatively automatic processing of cross-modal gender information, which eventually affects basic speech-based information processing. Study 3 (Huestegge, subm.) focused on the ability of participants to match unfamiliar voices to (either static or dynamic) faces. One result was that participants were indeed able to match voices to faces. Moreover, there was no evidence for any performance increase when dynamic (vs. mere static) faces had to be matched to concurrent voices. The results support the idea that common person-related source information affects both vocal and facial features, and implicit corresponding knowledge appears to be used by participants to successfully complete face-voice matching. Taken together, the three studies (Huestegge, subm.; Huestegge \& Raettig, in press; Huestegge et al., in press) provided information to further develop current theories of voice processing (in the context of face processing). On a general level, the results of all three studies are not in line with an abstract, modular view of cognition, but rather lend further support to interactive, embodied accounts of mental processing.},
  subject      = {Stimme},
  language  = {en}
}
@phdthesis{Reicherts2013,
  author    = {Reicherts, Philipp},
  title     = {Cognitive and Emotional Influences on Placebo Analgesia and Nocebo Hyperalgesia},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-106455},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {The perception of pain can be modulated by a variety of factors such as biological/pharmacological treatments as well as potent cognitive and emotional manipulations. Placebo and nocebo effects are among the most prominent examples for such manipulations. Placebo and nocebo manipulations cause reliable psychological and physiological changes, although the administered agent or treatment is inert. The present dissertation aimed at investigating the role of cognitive and emotional influences in the generation of placebo and nocebo effects on pain perception. In addition, the feasibility of solely psychological placebo manipulations to alter the perception of pain was tested. Two commonly discussed preconditions for the generation of placebo and nocebo effects are prior experiences (i.e., past encounter of drug effects) and expectations (i.e., positive or negative attitudes towards an intervention). So far, research on placebo and nocebo effects relied on the administration of sham interventions, which resembled medical treatments like inert pills, creams or injections. However, such experimental procedures deal with confounds due to earlier experiences and expectations resulting from the individual's history with medical interventions. Accordingly, the implementation of a placebo manipulation that is completely new to an individual, seems necessary to disentangle the contribution of experience and expectation for the induction of placebo and nocebo effects. To this end, in Experiment 1 the level of experience and expectation regarding a placebo-nocebo treatment was stepwise manipulated across three different experimental groups. To avoid any resemblances to earlier experiences and individual expectations, a mere psychological placebo-nocebo treatment was chosen that was new to all participants. They were instructed that visual black and white stripe patterns had been found to reliably alter the perception of pain. One group of participants received only the placebo-nocebo instruction (expectation), a second group experienced a placebo-nocebo treatment within a conditioning phase (experience) but no instruction, and a third group received the combination of both that is a placebo-nocebo instruction and a placebo-nocebo conditioning (experience + expectation). It was shown that only the experience + expectation group revealed significantly higher pain ratings and physiological responses during nocebo, compared to placebo trials of the succeeding test phase. These findings demonstrate that the induction of a mere psychological placebo-nocebo effect on pain is in principle possible. Most important, results indicate that such effects most likely rely on both, a positive treatment experience, due to the encounter of an effective intervention (placebo conditioning), and a positive expectation about the intervention (placebo instruction).Besides experience and expectation, the current mood state has been shown to modulate pain and to impact the induction of placebo and nocebo effects. In this vein it has been demonstrated that placebo effects come along with positive affect, while nocebo effects often occur together with elevated feelings of anxiety. To clarify the interaction of emotions and placebo-nocebo manipulations on pain perception, in Experiment 2 the paradigm of Experiment 1 was modified. Instead of black and white stripe patterns, positive and negative emotional pictures were presented, which either cued pain increase (nocebo) or pain decrease (placebo). Two experimental groups were compared, which differed with regard to the instructed contingency of positive pictures serving as placebo and negative pictures serving as nocebo cues or vice versa (congruent vs. incongruent). Results indicate that the differentiation of placebo and nocebo trials (behaviorally and physiologically) was more pronounced for the congruent compared to the incongruent group. However, in the incongruent group, affective pain ratings were also significantly higher for nocebo (positive pictures) than placebo (negative pictures) trials, similar to the congruent group. These findings demonstrate that a placebo-nocebo manipulation is capable to dampen and even reverse the originally pain augmenting effect of negative emotions. The results of Experiment 2 were further corroborated in Experiment 3, when the design was adapted to the fMRI scanner, and again a congruent and an incongruent experimental group were compared. Behavioral, physiological and neurophysiological markers of pain processing revealed a differentiation between nocebo and placebo conditions that was present irrespective of the experimental group. In addition, the fMRI analysis revealed an increased engagement of prefrontal areas for the incongruent group only, supposedly reflecting the reinterpretation or appraisal process when positive pictures were cueing negative outcomes. Taken together, the results of the present studies showed (a) that it is possible to induce a placebo-nocebo effect on pain solely by a psychological manipulation, (b) that both, prior experiences and positive expectation, are necessary preconditions for this placebo-nocebo effect, (c) that the impact of negative emotion on pain can be dampened and even reversed by placebo-nocebo manipulations, and (d) that most likely a cognitive top-down process is crucial for the induction of (psychological) placebo-nocebo effects. These results significantly enhance our understanding of psychological mechanisms involved in the induction of placebo-nocebo effects. Further, a fruitful foundation for future studies is provided, which will need to determine the contributions of primarily nocebo or placebo responses mediating the effects as demonstrated in the present studies. In a long-term perspective, the present findings may also help to exploit placebo effects and prevent from nocebo effect in clinical contexts by further elucidating crucial psychological factors that contribute to the placebo and nocebo response.},
  subject      = {Placebo},
  language  = {en}
}
@phdthesis{Seger2021,
  author    = {Seger, Benedikt Thomas},
  title     = {Children's Comprehension of Illustrated Narrative Text: The Role of Tripartite Representations and Perceptual Simulation},
  doi       = {10.25972/OPUS-24228},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242280},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {This doctoral thesis is part of a research project on the development of the cognitive compre-hension of film at W{\"u}rzburg University that was funded by the German Research Foundation (Deutsche Forschungsgemeinschaft) between 2013 and 2019 and awarded to Gerhild Nied-ing. That project examined children's comprehension of narrative text and its development in illustrated versus non-illustrated formats. For this purpose, van Dijk and Kintsch's (1983) tri-partite model was used, according to which text recipients form text surface and textbase rep-resentations and construct a situation model. In particular, predictions referring to the influ-ence of illustrations on these three levels of text representation were derived from the inte-grated model of text and picture comprehension (ITPC; Schnotz, 2014), which holds that text-picture units are processed on both text-based (descriptive) and picture-based (depictive) paths. Accordingly, illustrations support the construction of a situation model. Moreover, in line with the embodied cognition account (e.g., Barsalou, 1999), it was assumed that the situa-tion model is grounded in perception and action; text recipients mentally simulate the situation addressed in the text through their neural systems related to perception (perceptual simulation) and action (motor resonance). Therefore, the thesis also examines whether perceptual simula-tion takes place during story reception, whether it improves the comprehension of illustrated stories, and whether motor resonance is related to the comprehension of text accompanied by dynamic illustrations. Finally, predictions concerning the development of comprehending illus-trated text were made in line with Springer's (2001) hypotheses according to which younger children, compared with older children and adults, focus more on illustrations during text comprehension (perceptual boundedness) and use illustrations for the development of cogni-tive skills (perceptual support). The first research question sought to validate the tripartite model in the context of children's comprehension of narrative text, so Hypothesis 1 predicted that children yield representations of the text surface, the textbase, and the situation model during text reception. The second research question comprised the assumptions regarding the impact of illustrations on text comprehension. Accordingly, it was expected that illustrations improve the situation model (Hypothesis 2a), especially when they are processed before their corresponding text passages (Hypothesis 2b). Both hypotheses were derived from the ITPC and the assumption that per-ceptual simulation supports the situation model. It was further predicted that dynamic illustra-tions evoke more accurate situation models than static ones (Hypothesis 2c); this followed from the assumption that motor resonance supports the situation model. In line with the ITPC, it was assumed that illustrations impair the textbase (Hypothesis 2d), especially when they are presented after their corresponding text passages (Hypothesis 2e). In accordance with earlier results, it was posited that illustrations have a beneficial effect for the text surface (Hypothesis 2f). The third research question addressed the embodied approach to the situation model. Here, it was assumed that perceptual simulation takes place during text reception (Hypothesis 3a) and that it is more pronounced in illustrated than in non-illustrated text (Hypothesis 3b); the latter hypothesis was related to a necessary premise of the assumption that perceptual sim-ulation improves the comprehension of illustrated text. The fourth research question was relat-ed to perceptual boundedness and perceptual support and predicted age-related differences; younger children were expected to benefit more from illustrations regarding the situation model (Hypothesis 4a) and to simulate vertical object movements in a more pronounced fash-ion (Hypothesis 4b) than older children. In addition, Hypothesis 4c held that perceptual simu-lation is more pronounced in younger children particularly when illustrations are present. Three experiments were conducted to investigate these hypotheses. Experiment 1 (Seger, Wannagat, \& Nieding, submitted).compared the tripartite representations of written text without illustrations, with illustrations presented first, and with illustrations presented after their corresponding sentences. Students between 7 and 13 years old (N = 146) took part. Ex-periment 2 (Seger, Wannagat, \& Nieding, 2019) investigated the tripartite representations of auditory text, audiovisual text with static illustrations, and audiovisual text with dynamic il-lustrations among children in the same age range (N = 108). In both experiments, a sentence recognition method similar to that introduced by Schmalhofer and Glavanov (1986) was em-ployed. This method enables the simultaneous measurement of all three text representations. Experiment 3 (Seger, Hauf, \& Nieding, 2020) determined the perceptual simulation of vertical object movements during the reception of auditory and audiovisual narrative text among chil-dren between 5 and 11 years old and among adults (N = 190). For this experiment, a picture verification task based on Stanfield and Zwaan's (2001) paradigm and adapted from Hauf (2016) was used. The first two experiments confirmed Hypothesis 1, indicating that the tripartite model is appli-cable to the comprehension of auditory and written narrative text among children. A benefi-cial effect of illustrations to the situation model was observed when they were presented syn-chronously with auditory text (Hypotheses 2a), but not when presented asynchronously with written text (Hypothesis 2b), so the ITPC is partly supported on this point. Hypothesis 2c was rejected, indicating that motor resonance does not make an additional contribution to the comprehension of narrative text with dynamic illustrations. Regarding the textbase, a general negative effect of illustrations was not observed (Hypothesis 2d), but a specific negative effect of illustrations that follow their corresponding text passages was seen (Hypothesis 2e); the latter result is also in line with the ITPC. The text surface (Hypothesis 2f) appears to benefit from illustrations in auditory but not written text. The results obtained in Experiment 3 sug-gest that children and adults perceptually simulate vertical object movements (Hypothesis 3a), but there appears to be no difference between auditory and audiovisual text (Hypothesis 3b), so there is no support for a functional relationship between perceptual simulation and the situ-ation model in illustrated text. Hypotheses 4a-4c were investigated in all three experiments and did not receive support in any of them, which indicates that representations of illustrated and non-illustrated narrative text remain stable within the age range examined here.},
  subject      = {Textverstehen},
  language  = {en}
}
@phdthesis{Beinicke2017,
  author    = {Beinicke, Andrea},
  title     = {Career Construction Across the Life Span: Career Choice and Career Development},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-117447},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2017},
  abstract  = {This dissertation contributes to deepen our understanding of constructs that play a key role in individuals' vocational career construction. In this regard, many previous studies have focused exclusively on a specific phase of an individual's career. Yet, modern societies require continuous investments in one's career to adapt to changing Environments throughout the life span. Consequently, this dissertation takes a broad approach to capture a wide spectrum of career construction processes. According to Super's (1990) developmental stage framework, individuals have to manage vocational developmental tasks corresponding to each of the developmental life stages in order to be career mature across the life span. As the two stages exploration and maintenance set the stage for individuals' future career pathways, they are especially important in individuals' vocational career construction. Therefore, both of them are addressed in this dissertation. By answering open research questions relevant to career choice in early career stages and to career development in later career stages, this dissertation contributes to the overarching goal of shedding more light on constructs relevant to individuals' vocational career construction processes across the life span. Beyond the results presented within each study's horizon, this dissertation aimed at offering practical guidance to career counselors, trainees, and training and development (T\&D) professionals. Career counselors and T\&D professionals are involved in guiding vocational career construction processes of individuals across the life span. Thus, on the one hand, this dissertation supports career counselors' work so that they can help deliberating individuals make optimal and effective career choices. On the other hand, this dissertation facilitates T\&D professionals' work so that they can effectively design and evaluate e-learning and classroom trainings in corporate educational settings. Identifying individuals' vocational interests combined with cognitive abilities through adequate test measures and maximizing success of learning and success of transfer through fostering evidence-based transfer support actions will help individuals adapt quickly to the changing nature of work environments in the 21st century and to continue to successfully construct careers across the life span.},
  subject      = {Karriere},
  language  = {en}
}
@phdthesis{Zetzl2021,
  author    = {Zetzl, Teresa Margarete},
  title     = {Cancer-related fatigue intervention},
  doi       = {10.25972/OPUS-25166},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-251662},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2021},
  abstract  = {The incidence of cancer cases is rising steadily, while improved early detection and new cancer-specific therapies are reducing the mortality rate. In addition to curing cancer or prolonging life, increasing the quality of life is thus an important goal of oncology, which is why the burdens of cancer and treatment are becoming more important. A common side effect of cancer and its therapy is cancer-related fatigue, a tiredness that manifests itself on physical, emotional and cognitive levels and is not in proportion to previous physical efforts. Since the etiology of fatigue has not yet been fully clarified, symptom-oriented therapy is preferable to cause-specific therapy. In addition to activity management, sleep hygiene, and cognitive behavioral therapy, mind-body interventions such as yoga are recommended for reducing fatigue. Previous studies with small sample sizes were able to examine the efficacy of yoga regarding fatigue predominantly in patients with breast cancer. Long-term effects of yoga have rarely been studied and there have been no attempts to increase long-term effects through interventions such as reminder e-mails. This dissertation takes a closer look at these mentioned aspects of the study sample and long-term effects. An 8-week randomized controlled yoga intervention was conducted, including patients with different cancer types reporting mild to severe fatigue. Following the 8-week yoga therapy, a randomized group of participants received weekly reminder e-mails for 6 months for regular yoga practice, whereas the control group did not receive reminder e-mails. The first paper is a protocol article, which addresses the design and planned implementation of the research project this dissertation is based upon. This serves to ensure better replicability and comparability with other yoga studies. Due to a very low consent rate of patients in the pilot phase, it was necessary to deviate from the protocol article in the actual implementation and the planned inclusion criterion of fatigue >5 was reduced to fatigue >1. The second paper examines the efficacy of the eight-week yoga intervention. Patients in the intervention group who participated in the yoga classes seven times or more showed a significantly greater reduction in general and physical fatigue than those who participated less often. The efficacy of yoga was related to the number of attended yoga sessions. Women with breast cancer who participated in yoga reported greater reductions in fatigue than women with other cancer types. There was also an improvement for depression and quality of life after eight weeks of yoga therapy compared to no yoga therapy. These results imply that yoga is helpful in reducing depression and cancer-related fatigue, especially in terms of physical aspects and improving quality of life. The third paper focuses on the efficacy of reminder e-mails in terms of fatigue and practice frequency. Patients who received reminder e-mails reported greater reductions in general and emotional fatigue, as well as significant increases in practice frequency, compared to patients who did not receive reminder e-mails. Compared to fatigue scores before yoga, significantly lower fatigue and depression scores and higher quality of life were reported after yoga therapy and at follow-up six months later. Weekly e-mail reminders after yoga therapy may have positive effects on general and emotional fatigue and help cancer patients with fatigue establish a regular yoga practice at home. However, higher practice frequency did not lead to higher improvement in physical fatigue as found in Paper 2. This may indicate other factors that influence the efficacy of yoga practice on physical fatigue, such as mindfulness or side effects of therapy. This research project provides insight into the efficacy of yoga therapy for oncology patients with fatigue. It is important that such interventions be offered early, while fatigue symptoms are not too severe. Regular guided yoga practice can reduce physical fatigue, but subsequent yoga practice at home does not further reduce physical fatigue. Reminder emails after completed yoga therapy could only reduce patients' emotional fatigue. It may be that physical fatigue was reduced as much as possible by the previous yoga therapy and that there was a floor effect, or it may be that reminder emails are not suitable as an intervention to reduce physical fatigue at all. Further research is needed to examine the mechanisms of the different interventions in more detail and to find appropriate interventions that reduce all levels of fatigue equally.},
  subject      = {Erm{\"u}dungssyndrom},
  language  = {en}
}
@phdthesis{Kaufmann2013,
  author    = {Kaufmann, Tobias},
  title     = {Brain-computer interfaces based on event-related potentials: toward fast, reliable and easy-to-use communication systems for people with neurodegenerative disease},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-83441},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Objective: Brain Computer Interfaces (BCI) provide a muscle independent interaction channel making them particularly valuable for individuals with severe motor impairment. Thus, different BCI systems and applications have been proposed as assistive technology (AT) solutions for such patients. The most prominent system for communication utilizes event-related potentials (ERP) obtained from the electroencephalogram (EEG) to allow for communication on a character-by-character basis. Yet in their current state of technology, daily life use cases of such systems are rare. In addition to the high EEG preparation effort, one of the main reasons is the low information throughput compared to other existing AT solutions. Furthermore, when testing BCI systems in patients, a performance drop is usually observed compared to healthy users. Patients often display a low signal-to-noise ratio of the recorded EEG and detection of brain responses may be aggravated due to internally (e.g. spasm) or externally induced artifacts (e.g. from ventilation devices). Consequently, practical BCI systems need to cope with mani-fold inter-individual differences. Whilst these high demands lead to increasing complexity of the technology, daily life use of BCI systems requires straightforward setup including an easy-to-use graphical user interface that nonprofessionals can handle without expert support. Research questions of this thesis: This dissertation project aimed at bringing forward BCI technology toward a possible integration into end-users' daily life. Four basic research questions were addressed: (1) Can we identify performance predictors so that we can provide users with individual BCI solutions without the need of multiple, demanding testing sessions? (2) Can we provide complex BCI technology in an automated, user-friendly and easy-to-use manner, so that BCIs can be used without expert support at end-users' homes? (3) How can we account for and improve the low information transfer rates as compared to other existing assistive technology solutions? (4) How can we prevent the performance drop often seen when bringing BCI technology that was tested in healthy users to those with severe motor impairment? Results and discussion: (1) Heart rate variability (HRV) as an index of inhibitory control (i.e. the ability to allocate attention resources and inhibit distracting stimuli) was significantly related to ERP-BCI performance and accounted for almost 26\% of variance. HRV is easy to assess from short heartbeat recordings and may thus serve as a performance predictor for ERP-BCIs. Due to missing software solutions for appropriate processing of artifacts in heartbeat data (electrocardiogram and inter-beat interval data), our own tool was developed that is available free of charge. To date, more than 100 researchers worldwide have requested the tool. Recently, a new version was developed and released together with a website (www.artiifact.de). (2) Furthermore, a study of this thesis demonstrated that BCI technology can be incorporated into easy-to-use software, including auto-calibration and predictive text entry. Na{\"i}ve, healthy nonprofessionals were able to control the software without expert support and successfully spelled words using the auto-calibrated BCI. They reported that software handling was straightforward and that they would be able to explain the system to others. However, future research is required to study transfer of the results to patient samples. (3) The commonly used ERP-BCI paradigm was significantly improved. Instead of simply highlighting visually displayed characters as is usually done, pictures of famous faces were used as stimulus material. As a result, specific brain potentials involved in face recognition and face processing were elicited. The event-related EEG thus displayed an increased signal-to-noise ratio, which facilitated the detection of ERPs extremely well. Consequently, BCI performance was significantly increased. (4) The good results of this new face-flashing paradigm achieved with healthy participants transferred well to users with neurodegenerative disease. Using a face paradigm boosted information throughput. Importantly, two users who were highly inefficient with the commonly used paradigm displayed high accuracy when exposed to the face paradigm. The increased signal-to-noise ratio of the recorded EEG thus helped them to overcome their BCI inefficiency. Significance: The presented work at hand (1) successfully identified a physiological predictor of ERP-BCI performance, (2) proved the technology ready to be operated by na{\"i}ve nonprofessionals without expert support, (3) significantly improved the commonly used spelling paradigm and (4) thereby displayed a way to effectively prevent BCI inefficiency in patients with neurodegenerative disease. Additionally, missing software solutions for appropriate handling of artifacts in heartbeat data encouraged development of our own software tool that is available to the research community free of charge. In sum, this thesis significantly improved current BCI technology and enhanced our understanding of physiological correlates of BCI performance.},
  subject      = {Gehirn-Computer-Schnittstelle},
  language  = {en}
}
@phdthesis{Botrel2018,
  author    = {Botrel, Loic},
  title     = {Brain-computer interfaces (BCIs) based on sensorimotor rhythms - Evaluating practical interventions to improve their performance and reduce BCI inefficiency},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-168110},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {Brain computer interfaces based on sensorimotor rhythms modulation (SMR-BCIs) allow people to emit commands to an interface by imagining right hand, left hand or feet movements. The neurophysiological activation associated with those specific mental imageries can be measured by electroencephalography and detected by machine learning algorithms. Improvements for SMR-BCI accuracy in the last 30 years seem to have reached a limit. The currrent main issue with SMR-BCIs is that between 15\% to 30\% cannot use the BCI, called the "BCI inefficiency" issue. Alternatively to hardware and software improvements, investigating the individual characteristics of the BCI users has became an interesting approach to overcome BCI inefficiency. In this dissertation, I reviewed existing literature concerning the individual sources of variation in SMR-BCI accuracy and identified generic individual characteristics. In the empirical investigation, attention and motor dexterity predictors for SMR-BCI performance were implemented into a trainings that would manipulate those predictors and lead to higher SMR-BCI accuracy. Those predictors were identified by Hammer et al. (2012) as the ability to concentrate (associated with relaxation levels) and "mean error duration" in a two-hand visuo-motor coordination task (VMC). Prior to a SMR-BCI session, a total of n=154 participants in two locations took part of 23 min sessions of either Jacobson's Progressive Muscle Relaxation session (PMR), a VMC session, or a control group (CG). No effect of PMR or VMC manipulation was found, but the manipulation checks did not consistently confirm whether PMR had an effect of relaxation levels and VMC on "mean error duration". In this first study, correlations between relaxation levels or "mean error duration" and accuracy were found but not in both locations. A second study, involving n=39 participants intensified the training in four sessions on four consecutive days or either PMR, VMC or CG. The effect or manipulation was assessed for in terms of a causal relationship by using a PRE-POST study design. The manipulation checks of this second study validated the positive effect of training on both relaxation and "mean error duration". But the manipulation did not yield a specific effect on BCI accuracy. The predictors were not found again, displaying the instability of relaxation levels and "mean error duration" in being associated with BCI performance. An effect of time on BCI accuracy was found, and a correlation between State Mindfulness Scale and accuracy were reported. Results indicated that a short training of PMR or VMC were insufficient in increasing SMR-BCI accuracy. This study contrasted with studies succeeding in increasing SMR-BCI accuracy Tan et al. (2009, 2014), by the shortness of its training and the relaxation training that did not include mindfulness. It also contrasted by its manipulation checks and its comprehensive experimental approach that attempted to replicate existing predictors or correlates for SMR-BCI accuracy. The prediction of BCI accuracy by individual characteristics is receiving increased attention, but requires replication studies and a comprehensive approach, to contribute to the growing base of evidence of predictors for SMR-BCI accuracy. While short PMR and VMC trainings could not yield an effect on BCI performance, mindfulness meditation training might be beneficial for SMR-BCI accuracy. Moreover, it could be implemented for people in the locked-in-syndrome, allowing to reach the end-users that are the most in need for improvements in BCI performance.},
  subject      = {Gehirn-Computer-Schnittstelle},
  language  = {en}
}
@phdthesis{Hoefling2008,
  author    = {H{\"o}fling, Atilla},
  title     = {Beggars cannot be choosers - The influence of food deprivation on food related disgust},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34609},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2008},
  abstract  = {The main goals of the present thesis were to investigate how food deprivation influences food related disgust and to identify mental mechanisms that might underlie alterations in food related disgust. For this purpose, 9 studies were conducted that employed direct and indirect measures of attitudes, biological measures of affect as well as measures of real eating behavior and food choice, and compared responses of deprived and non deprived subjects on each of these measures. Spontaneous facial reactions were assessed via EMG and revealed that food deprived subjects showed weaker disgust reactions than satiated participants when being confronted with photographs of disgusting foods. Interestingly, deprived and non deprived subjects evaluated disgusting foods equally negative on a conscious level of information processing, indicating that food deprivation has the potential to attenuate food related disgust irrespective of conscious evaluations. Furthermore, it was found that food deprived participants readily consumed disgust related foods ("genetically modified foods"), while satiated participants rejected those foods. Again, no difference emerged between deprived and non deprived subjects in respect to their conscious evaluations of genetically modified foods (that were negative in both experimental groups). The dissociation between conscious evaluations and actual eating behavior that was observed amongst food deprived participants resembles the dissociation between conscious evaluations and facial reactions, thereby corroborating the assumption that alterations in food related disgust might directly influence eating behavior without changing conscious evaluations of foods. The assumption that a shift in automatic attitudes towards disgusting foods might be responsible for these effects received only partial support. That is, there was only a non significant tendency for food deprived subjects to evaluate disgusting foods more positive than satiated subjects on an automatic level of information processing. Instead, the results of the present thesis suggest that food deprived subjects exhibit a stronger motivation than satiated subjects to approach disgusting foods immediately. More precisely, food deprived participants exhibited strong approach motivational tendencies towards both, palatable and disgusting foods in an "Approach- Avoidance Task" whereas satiated participants only approached palatable (but not disgusting) foods on an automatic level of information processing. Moreover, food deprivation seems to change the subjective weighting of hedonic and functional food attributes in the context of more elaborated decisions about which foods to pick for consumption and which foods to reject. It was found that individual taste preferences were of minor importance for food deprived subjects but very important for satiated subjects when actually choosing between several food alternatives. In contrast, functional food attributes (e.g., immediate availability of a given food, large portion size) were more important selection criteria for food deprived subjects than for satiated subjects. Thus, food deprived participants were less picky than satiated participants, but showed a clear preference for those food alternatives that were functional in ending a state of food deprivation quickly - even if this meant choosing a food that was not considered tasty. Taken together, the present thesis shows that physiological need states (e.g., food deprivation) are tightly linked to the affective and motivational processing of need relevant cues. This link is so strong that food deprivation even modulates affective and motivational reactions as well as eating behavior and choice behavior towards disgusting (but need relevant) foods.},
  subject      = {Ekel},
  language  = {en}
}
@phdthesis{Kaethner2015,
  author    = {K{\"a}thner, Ivo R. J.},
  title     = {Auditory and visual brain-computer interfaces as communication aids for persons with severe paralysis},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135477},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Brain-computer interfaces (BCIs) could provide a muscle-independent communication channel to persons with severe paralysis by translating brain activity into device commands. As a means of communication, in particular BCIs based on event-related potentials (ERPs) as control signal have been researched. Most of these BCIs rely on visual stimulation and have been investigated with healthy participants in controlled laboratory environments. In proof-of-principle studies targeted end users gained control over BCI systems; however, these systems are not yet established as an assistive technology for persons who would most benefit from them. The main aim of this thesis is to advance the usability of ERP-BCIs for target users. To this end, five studies with BCIs have been conducted that enabled users to communicate by focusing their attention on external stimuli. Two studies were conducted in order to demonstrate the advantages and to further improve the practical application of visual BCIs. In the first study, mental workload was experimentally manipulated during prolonged BCI operation. The study showed the robustness of the visual ERP-BCI since users maintained a satisfactory level of control despite constant distraction in the form of background noise. Moreover, neurophysiological markers that could potentially serve as indicators of high mental workload or fatigue were revealed. This is a first step towards future applications in which the BCI could adapt to the mental state of the user (e.g. pauses if high mental workload is detected to prevent false selections). In the second study, a head-mounted display (HMD), which assures that stimuli are presented in the field of view of the user, was evaluated. High accuracies and information transfer rates, similar to a conventional display, were achieved by healthy participants during a spelling task. Furthermore, a person in the locked-in state (LIS) gained control over the BCI using the HMD. The HMD might be particularly suited for initial communication attempts with persons in the LIS in situations, where mounting a conventional monitor is difficult or not feasible. Visual ERP-BCIs could prove valuable for persons with residual control over eye muscles and sufficient vision. However, since a substantial number of target users have limited control over eye movements and/or visual impairments, BCIs based on non-visual modalities are required. Therefore, a main aspect of this thesis was to improve an auditory paradigm that should enable motor impaired users to spell by focusing attention on different tones. The two conducted studies revealed that healthy participants were able to achieve high spelling performance with the BCI already in the first session and stress the importance of the choice of the stimulus material. The employed natural tones resulted in an increase in performance compared to a previous study that used artificial tones as stimuli. Furthermore, three out of five users with a varying degree of motor impairments could gain control over the system within the five conducted sessions. Their performance increased significantly from the first to the fifth session - an effect not previously observed for visual ERP-BCIs. Hence, training is particularly important when testing auditory multiclass BCIs with potential users. A prerequisite for user satisfaction is that the BCI technology matches user requirements. In this context, it is important to compare BCIs with already established assistive technology. Thus, the fifth study of this dissertation evaluated gaze dependent methods (EOG, eye tracking) as possible control signals for assistive technology and a binary auditory BCI with a person in the locked-in state. The study participant gained control over all tested systems and rated the ease of use of the BCI as the highest among the tested alternatives, but also rated it as the most tiring due to the high amount of attention that was needed for a simple selection. Further efforts are necessary to simplify operation of the BCI. The involvement of end users in all steps of the design and development process of BCIs will increase the likelihood that they can eventually be used as assistive technology in daily life. The work presented in this thesis is a substantial contribution towards the goal of re-enabling communication to users who cannot rely on motor activity to convey their thoughts.},
  subject      = {Gehirn-Computer Schnittstelle},
  language  = {en}
}