@article{HalderRufFurdeaetal.2013,
  author    = {Halder, Sebastian and Ruf, Carolin Anne and Furdea, Adrian and Pasqualotto, Emanuele and De Massari, Daniele and van der Heiden, Linda and Bogdan, Martin and Rosenstiel, Wolfgang and Birbaumer, Niels and K{\"u}bler, Andrea and Matuz, Tamara},
  title     = {Prediction of P300 BCI Aptitude in Severe Motor Impairment},
  series = {PLoS ONE},
  journal   = {PLoS ONE},
  doi       = {10.1371/journal.pone.0076148},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97268},
  year      = {2013},
  abstract  = {Brain-computer interfaces (BCIs) provide a non-muscular communication channel for persons with severe motor impairments. Previous studies have shown that the aptitude with which a BCI can be controlled varies from person to person. A reliable predictor of performance could facilitate selection of a suitable BCI paradigm. Eleven severely motor impaired participants performed three sessions of a P300 BCI web browsing task. Before each session auditory oddball data were collected to predict the BCI aptitude of the participants exhibited in the current session. We found a strong relationship of early positive and negative potentials around 200 ms (elicited with the auditory oddball task) with performance. The amplitude of the P2 (r = -0.77) and of the N2 (r = -0.86) had the strongest correlations. Aptitude prediction using an auditory oddball was successful. The finding that the N2 amplitude is a stronger predictor of performance than P3 amplitude was reproduced after initially showing this effect with a healthy sample of BCI users. This will reduce strain on the end-users by minimizing the time needed to find suitable paradigms and inspire new approaches to improve performance.},
  language  = {en}
}
@article{BiehlEhlisMuelleretal.2013,
  author    = {Biehl, Stefanie C. and Ehlis, Ann-Christine and M{\"u}ller, Laura D. and Niklaus, Andrea and Pauli, Paul and Herrmann, Martin J.},
  title     = {The impact of task relevance and degree of distraction on stimulus processing},
  series = {BMC Neuroscience},
  journal   = {BMC Neuroscience},
  doi       = {10.1186/1471-2202-14-107},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97271},
  year      = {2013},
  abstract  = {Background The impact of task relevance on event-related potential amplitudes of early visual processing was previously demonstrated. Study designs, however, differ greatly, not allowing simultaneous investigation of how both degree of distraction and task relevance influence processing variations. In our study, we combined different features of previous tasks. We used a modified 1-back task in which task relevant and task irrelevant stimuli were alternately presented. The task irrelevant stimuli could be from the same or from a different category as the task relevant stimuli, thereby producing high and low distracting task irrelevant stimuli. In addition, the paradigm comprised a passive viewing condition. Thus, our paradigm enabled us to compare the processing of task relevant stimuli, task irrelevant stimuli with differing degrees of distraction, and passively viewed stimuli. EEG data from twenty participants was collected and mean P100 and N170 amplitudes were analyzed. Furthermore, a potential connection of stimulus processing and symptoms of attention deficit hyperactivity disorder (ADHD) was investigated. Results Our results show a modulation of peak N170 amplitudes by task relevance. N170 amplitudes to task relevant stimuli were significantly higher than to high distracting task irrelevant or passively viewed stimuli. In addition, amplitudes to low distracting task irrelevant stimuli were significantly higher than to high distracting stimuli. N170 amplitudes to passively viewed stimuli were not significantly different from either kind of task irrelevant stimuli. Participants with more symptoms of hyperactivity and impulsivity showed decreased N170 amplitudes across all task conditions. On a behavioral level, lower N170 enhancement efficiency was significantly correlated with false alarm responses. Conclusions Our results point to a processing enhancement of task relevant stimuli. Unlike P100 amplitudes, N170 amplitudes were strongly influenced by enhancement and enhancement efficiency seemed to have direct behavioral consequences. These findings have potential implications for models of clinical disorders affecting selective attention, especially ADHD.},
  language  = {en}
}
@article{HalderVarkutiBogdanetal.2013,
  author    = {Halder, Sebastian and Varkuti, Balint and Bogdan, Martin and K{\"u}bler, Andrea and Rosenstiel, Wolfgang and Sitaram, Ranganatha and Birbaumer, Niels},
  title     = {Prediction of brain-computer interface aptitude from individual brain structure},
  series = {Frontiers in Human Neuroscience},
  journal   = {Frontiers in Human Neuroscience},
  doi       = {10.3389/fnhum.2013.00105},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96558},
  year      = {2013},
  abstract  = {Objective: Brain-computer interface (BCI) provide a non-muscular communication channel for patients with impairments of the motor system. A significant number of BCI users is unable to obtain voluntary control of a BCI-system in proper time. This makes methods that can be used to determine the aptitude of a user necessary. Methods: We hypothesized that integrity and connectivity of involved white matter connections may serve as a predictor of individual BCI-performance. Therefore, we analyzed structural data from anatomical scans and DTI of motor imagery BCI-users differentiated into high and low BCI-aptitude groups based on their overall performance. Results: Using a machine learning classification method we identified discriminating structural brain trait features and correlated the best features with a continuous measure of individual BCI-performance. Prediction of the aptitude group of each participant was possible with near perfect accuracy (one error). Conclusions: Tissue volumetric analysis yielded only poor classification results. In contrast, the structural integrity and myelination quality of deep white matter structures such as the Corpus Callosum, Cingulum, and Superior Fronto-Occipital Fascicle were positively correlated with individual BCI-performance. Significance: This confirms that structural brain traits contribute to individual performance in BCI use.},
  language  = {en}
}
@article{HalderHammerKleihetal.2013,
  author    = {Halder, Sebastian and Hammer, Eva Maria and Kleih, Sonja Claudia and Bogdan, Martin and Rosenstiel, Wolfgang and Birbaumer, Nils and K{\"u}bler, Andrea},
  title     = {Prediction of Auditory and Visual P300 Brain-Computer Interface Aptitude},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-77992},
  year      = {2013},
  abstract  = {Objective: Brain-computer interfaces (BCIs) provide a non-muscular communication channel for patients with late-stage motoneuron disease (e.g., amyotrophic lateral sclerosis (ALS)) or otherwise motor impaired people and are also used for motor rehabilitation in chronic stroke. Differences in the ability to use a BCI vary from person to person and from session to session. A reliable predictor of aptitude would allow for the selection of suitable BCI paradigms. For this reason, we investigated whether P300 BCI aptitude could be predicted from a short experiment with a standard auditory oddball. Methods: Forty healthy participants performed an electroencephalography (EEG) based visual and auditory P300-BCI spelling task in a single session. In addition, prior to each session an auditory oddball was presented. Features extracted from the auditory oddball were analyzed with respect to predictive power for BCI aptitude. Results: Correlation between auditory oddball response and P300 BCI accuracy revealed a strong relationship between accuracy and N2 amplitude and the amplitude of a late ERP component between 400 and 600 ms. Interestingly, the P3 amplitude of the auditory oddball response was not correlated with accuracy. Conclusions: Event-related potentials recorded during a standard auditory oddball session moderately predict aptitude in an audiory and highly in a visual P300 BCI. The predictor will allow for faster paradigm selection. Significance: Our method will reduce strain on patients because unsuccessful training may be avoided, provided the results can be generalized to the patient population.},
  subject      = {Psychologie},
  language  = {en}
}
@article{HerbertKueblerVoegele2013,
  author    = {Herbert, Cornelia and K{\"u}bler, Andrea and V{\"o}gele, Klaus},
  title     = {Risk for Eating Disorders Modulates Startle-Responses to Body Words},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78140},
  year      = {2013},
  abstract  = {Body image disturbances are core symptoms of eating disorders (EDs). Recent evidence suggests that changes in body image may occur prior to ED onset and are not restricted to in-vivo exposure (e.g. mirror image), but also evident during presentation of abstract cues such as body shape and weight-related words. In the present study startle modulation, heart rate and subjective evaluations were examined during reading of body words and neutral words in 41 student female volunteers screened for risk of EDs. The aim was to determine if responses to body words are attributable to a general negativity bias regardless of ED risk or if activated, ED relevant negative body schemas facilitate priming of defensive responses. Heart rate and word ratings differed between body words and neutral words in the whole female sample, supporting a general processing bias for body weight and shape-related concepts in young women regardless of ED risk. Startle modulation was specifically related to eating disorder symptoms, as was indicated by significant positive correlations with self-reported body dissatisfaction. These results emphasize the relevance of examining body schema representations as a function of ED risk across different levels of responding. Peripheral-physiological measures such as the startle reflex could possibly be used as predictors of females' risk for developing EDs in the future.},
  subject      = {Psychologie},
  language  = {en}
}
@phdthesis{Wu2013,
  author    = {Wu, Lingdan},
  title     = {Emotion Regulation in Addicted Smokers},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85471},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Background: Nicotine addiction is the most prevalent type of drug addiction that has been described as a cycle of spiraling dysregulation of the brain reward systems. Imaging studies have shown that nicotine addiction is associated with abnormal function in prefrontal brain regions that are important for cognitive emotion regulation. It was assumed that addicts may perform less well than healthy nonsmokers in cognitive emotion regulation tasks. The primary aims of this thesis were to investigate emotional responses to natural rewards among smokers and nonsmokers and to determine whether smokers differ from nonsmokers in cognitive regulation of positive and negative emotions. To address these aims, two forms of appraisal paradigms (i.e., appraisal frame and reappraisal) were applied to compare changes in emotional responses of smokers with that of nonsmokers as a function of appraisal strategies. Experiment 1: The aim of the first experiment was to evaluate whether and how appraisal frames preceding positive and negative picture stimuli affect emotional experience and facial expression of individuals. Twenty participants were exposed to 125 pairs of auditory appraisal frames (either neutral or emotional) followed by picture stimuli reflecting five conditions: unpleasant-negative, unpleasant-neutral, pleasant-positive, pleasant-neutral and neutral-neutral. Ratings of valence and arousal as well as facial EMG activity over the corrugator supercilii and the zygomaticus major were measured simultaneously. The results indicated that appraisal frames could alter both subjective emotional experience and facial expressions, irrespective of the valence of the pictorial stimuli. These results suggest and support that appraisal frame is an efficient paradigm in regulation of multi-level emotional responses. 8 Experiment 2: The second experiment applied the appraisal frame paradigm to investigate how smokers differ from nonsmokers on cognitive emotion regulation. Sixty participants (22 nonsmokers, 19 nondeprived smokers and 19 12-h deprived smokers) completed emotion regulation tasks as described in Experiment 1 while emotional responses were concurrently recorded as reflected by self-ratings and psychophysiological measures (i.e., facial EMG and EEG). The results indicated that there was no group difference on emotional responses to natural rewards. Moreover, nondeprived smokers and deprived smokers performed as well as nonsmokers on the emotion regulation task. The lack of group differences in multiple emotional responses (i.e., self-reports, facial EMG activity and brain EEG activity) suggests that nicotine addicts have no deficit in cognitive emotion regulation of natural rewards via appraisal frames. Experiment 3: The third experiment aimed to further evaluate smokers' emotion regulation ability by comparing performances of smokers and nonsmokers in a more challenging cognitive task (i.e., reappraisal task). Sixty-five participants (23 nonsmokers, 22 nondeprived smokers and 20 12-h deprived smokers) were instructed to regulate emotions by imagining that the depicted negative or positive scenario would become less negative or less positive over time, respectively. The results showed that nondeprived smokers and deprived smokers responded similarly to emotional pictures and performed as well as nonsmokers in down-regulating positive and negative emotions via the reappraisal strategy. These results indicated that nicotine addicts do not have deficit in emotion regulation using cognitive appraisal strategies. In sum, the three studies consistently revealed that addicted smokers were capable to regulate emotions via appraisal strategies. This thesis establishes the groundwork for therapeutic use of appraisal instructions to cope with potential self-regulation failures in nicotine addicts.},
  subject      = {Gef{\"u}hl},
  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{Walz2013,
  author    = {Walz, Nora},
  title     = {Der Mensch im Open-Field-Test: Agoraphobie als pathologische Form extraterritorialer Angst},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-81402},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {Angstverhalten bei der Panikst{\"o}rung mit Agoraphobie wird haupts{\"a}chlich unter dem Aspekt des „safety seekings" betrachtet. Kontrovers diskutiert wird, ob diese Verhaltensweisen f{\"u}r eine erfolgreiche Behandlung abgebaut werden sollen. Es wurde bisher kaum nach der ethologischen Bedeutung bestimmter Verhaltensweisen unter Angst gefragt. Dies ist erstaunlich, weil die Panikst{\"o}rung mit Agoraphobie h{\"a}ufig als gesteigerte Form extraterritorialer Angst gesehen wird. Extraterritoriale Angst tritt typischerweise bei Tieren auf, wenn sie ihr vertrautes Gebiet verlassen. Im Tiermodell liegen zahlreiche ethoexperimentelle Paradigmen vor, mit denen man das nat{\"u}rliche Angstverhalten von Tieren untersucht. Letztlich kl{\"a}rt man am Tiermodell aber Fragestellungen, die am Menschen nicht umsetzbar sind. Die experimentelle Untersuchung menschlichen Angstverhaltens unter ethologischer Perspektive erfordert eine Situation, die solches Verhalten ethisch unbedenklich ausl{\"o}st und geeignete messbare Parameter liefert. Der Open-Field Test als bekanntes Paradigma aus der Tierforschung erf{\"u}llt diese Voraussetzungen. Es war Ziel des Promotionsvorhabens, in einem realen Open-Field Test bei Agoraphobiepatien-ten und hoch{\"a}ngstlichen Probanden Thigmotaxis als ethologisches Angstverhalten nachzuweisen und mit dem Verhalten einer Kontrollgruppe bzw. niedrig{\"a}ngstlichen Personen zu vergleichen (Studie I). Thigmotaxis ist eine Bewegungstendenz entlang des Randes und wird im Tiermodell als Index f{\"u}r Angst benutzt. Es sollte die Frage gekl{\"a}rt werden, ob agoraphobes Verhalten evolution{\"a}r verankert werden kann. Ziel von Studie II war die Untersuchung der Wege in einer typischen Alltagstopographie. Dazu wurden Unterschiede im Raum-Zeit-Verhalten von Agora-phobiepatienten vs. Kontrollgruppe, sowie hoch- vs. niedrig{\"a}ngstlichen Probanden beim Gehen durch die Stadt verglichen. Die Aufzeichnung des Raum-Zeit-Verhaltens erfolgte in beiden Studien per GPS-Tracking. Studie I zeigte an insgesamt 69 Studienteilnehmern, dass Angstverhalten mit ethologischer Bedeutung bei Menschen im Open-Field Test eindeutig messbar ist. Agoraphobiepatienten zeigten w{\"a}hrend der Exploration eines ungef{\"a}hrlichen freien Fußballfeldes deutlich mehr Thigmotaxis und Vermeidung der Mitte als die Kontrollgruppe. Hoch{\"a}ngstliche im Vergleich zu niedrig{\"a}ngstlichen gesunden Probanden zeigten dies ebenfalls. So konnte die Vermutung unterst{\"u}tzt werden, dass die Agoraphobie m{\"o}glicherweise eine evolution{\"a}re Entsprechung in der tierischen Extraterritorialangst hat. Die Befunde sprechen auch f{\"u}r eine gemeinsame Pr{\"a}disposition zu Sicherheitsverhalten bei pathologischer Angst und hoher {\"A}ngstlichkeit. Die Bedeutung gemeinsamer Verhaltensdispositionen bei klinischen und nicht-klinischen Gruppen kann im Hinblick auf gemeinsame Endoph{\"a}notypen f{\"u}r die neuronale Angstverarbeitung diskutiert werden. Zuletzt konnte mit dem Open-Field Test ein aus der Tierforschung bekanntes ethoexperimentelles Paradigma auf den Menschen {\"u}bertragen werden, was die G{\"u}ltigkeit des Tiermodells unterst{\"u}tzt. Studie II lieferte Unterschiede in den Wegen der Agoraphobiepatienten vs. Kontrollpersonen bei der Passage des Marktplatzes. Die Patienten {\"u}berquerten den Marktplatz seltener als die Kon-trollgruppe, und tangierten ihn h{\"a}ufiger am Rand. Die Daten konnten in korrelativen Zusammenhang mit der Vermeidung der Mitte im Open-Field Test gebracht werden. Dies deutet auf eine starke Auswirkung der agoraphoben Symptomatik auf das Raum-Zeit-Verhalten in unterschiedlichen Situationen hin. Im Weiteren zeigte Studie II, dass sich GPS Tracking als Assessment-Methode in der klinischen Psychologie eignet. Bei den hoch-und niedrig{\"a}ngstlichen Probanden fand sich bei der Passage des Marktplatzes kein Unterschied, aber der weitere Streckenverlauf lieferte Hinweise darauf, dass bei hoher {\"A}ngstlichkeit die Navigation entlang h{\"a}ufig zur{\"u}ckgelegter Strecken bevorzugt werden k{\"o}nnte. Schlussfolgerung des explorativen Vorgehens bei Studie II ist, dass es sich lohnt, den Zusammenhang zwischen Emotion und Navigation in komplexer Umgebung weiter zu untersuchen},
  subject      = {Agoraphobie},
  language  = {de}
}
@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{Bruetting2013,
  author    = {Br{\"u}tting, Johanna},
  title     = {Psychotherapie spezifischer Phobien: Die Bedeutung der Angstaktivierung f{\"u}r Therapieprozess und Therapieerfolg},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-80578},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2013},
  abstract  = {In der vorliegenden Arbeit wurde untersucht, inwiefern die Angstaktivierung Einfluss auf den Therapieprozess und den Therapieerfolg bei der Behandlung spezifischer Phobien hat. Obwohl expositionsbasierte Therapieverfahren nachweislich effektiv sind und vor allem bei der Behandlung spezifischer Phobien als die Methode der Wahl gelten, sind deren genauen Wirkmechanismen doch noch nicht v{\"o}llig gekl{\"a}rt. In zwei empirischen Studien wurde hier die von Foa und Kozak (1986, 1991) in der „Emotional Processing Theory" als notwendig postulierte Rolle der Angstaktivierung w{\"a}hrend der Exposition untersucht. In der ersten Studie wurde auf Grundlage tier- und humanexperimenteller Befunde untersucht, ob durch eine Reaktivierung der Angst und darauffolgende Exposition innerhalb eines bestimmten Zeitfensters (= Rekonsolidierungsfenster) die R{\"u}ckkehr der Angst verhindert werden kann. Ziel dieser Untersuchung war die {\"U}bertragung bisheriger Ergebnisse aus Konditionierungsstudien auf eine klinische Stichprobe. Die spinnenphobischen Untersuchungsteilnehmer (N = 36) wurden randomisiert entweder der Reaktivierungsgruppe (RG) oder einer Standardexpositionsgruppe (SEG) zugewiesen. Die RG bekam vor der Exposition in virtueller Realit{\"a}t (VRET) f{\"u}nf Sekunden lang einen Reaktivierungsstimulus - eine virtuelle Spinne - dargeboten, woraufhin zehn Minuten standardisierte Wartezeit folgte. In der SEG wurde die Angst vor der Exposition nicht reaktiviert. 24 Stunden nach der VRET wurde in einem Test die spontane R{\"u}ckkehr der Angst erfasst. Entgegen der Annahmen f{\"u}hrte die Reaktivierung vor der VRET nicht zu einer geringeren R{\"u}ckkehr der Angst in der Testsitzung 24 Stunden sp{\"a}ter. Die Angst kehrte in keiner der beiden Versuchsgruppen zur{\"u}ck, was sich bez{\"u}glich subjektiver Angstratings, f{\"u}r Verhaltensdaten und auch f{\"u}r physiologische Maße zeigte. Auch zeigte sich ein grunds{\"a}tzlich positiver Effekt der Behandlung, bei der im Anschluss noch eine Exposition in vivo stattfand. Ein Follow-Up nach sechs Monaten ergab eine weitere Reduktion der Spinnenangst. Die Ergebnisse legen nahe, dass sich die experimentellen Befunde zu Rekonsolidierungsprozessen aus Konditionierungsstudien nicht einfach auf ein Therapiesetting und die Behandlung spezifischer Phobien {\"u}bertragen lassen. Die zweite Studie befasste sich mit der Frage, ob Koffein die initiale Angstaktivierung erh{\"o}hen kann und ob sich dies positiv auf den Therapieerfolg auswirkt. Die spinnenphobischen Studienteilnehmer (N = 35) wurden in einem doppelblinden Versuchsdesign entweder der Koffeingruppe (KOFG) oder der Placebogruppe (PG) zugeordnet. Die KOFG erhielt eine Stunde vor Beginn der VRET eine Koffeintablette mit 200 mg Koffein, die PG erhielt als {\"A}quivalent zur gleichen Zeit eine Placebotablette. Eine Analyse der Speichelproben der Probanden ergab, dass sich die Koffeinkonzentration durch die Koffeintablette signifikant erh{\"o}hte. Dies f{\"u}hrte jedoch nicht, wie erwartet, zu einer h{\"o}heren Angstaktivierung w{\"a}hrend der VRET, weshalb unter anderem diskutiert wird, ob evtl. die Koffeinkonzentration zu niedrig war, um anxiogen zu wirken. Dennoch profitierten die Teilnehmer beider Versuchsgruppen von unserem Behandlungsangebot. Die Spinnenangst reduzierte sich signifikant {\"u}ber vier Sitzungen hinweg. Diese Reduktion blieb stabil bis zum Follow-Up drei Monate nach Studienende. Zusammengefasst l{\"a}sst sich zur optimalen H{\"o}he der Angstaktivierung aufgrund der hier durchgef{\"u}hrten beiden Studien keine exakte Aussage machen, da sich die Versuchsgruppen in beiden Studien hinsichtlich der H{\"o}he der Angstaktivierung zu Beginn (und auch w{\"a}hrend) der Exposition nicht unterschieden. Es l{\"a}sst sich aber festhalten, dass die VRET und auch die in vivo Exposition in beiden Studien effektiv Angst ausl{\"o}sten und dass sich die Angst in beiden Gruppen signifikant bis zu den Follow-Ups (sechs bzw. drei Monate nach Studienende) signifikant reduzierte. Die Behandlung kann also als erfolgreich angesehen werden. M{\"o}gliche andere Wirkfaktoren der Expositionstherapie, wie z.B. die Rolle der wahrgenommenen Kontrolle werden neben der H{\"o}he der Angstaktivierung diskutiert.},
  subject      = {Psychotherapie},
  language  = {de}
}