@article{KaufmannHolzKuebler2013, author = {Kaufmann, Tobias and Holz, Elisa M. and K{\"u}bler, Andrea}, title = {Comparison of tactile, auditory, and visual modality for brain-computer interface use: a case study with a patient in the locked-in state}, series = {Frontiers in Human Neuroscience}, journal = {Frontiers in Human Neuroscience}, doi = {10.3389/fnins.2013.00129}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97079}, year = {2013}, abstract = {This paper describes a case study with a patient in the classic locked-in state, who currently has no means of independent communication. Following a user-centered approach, we investigated event-related potentials (ERP) elicited in different modalities for use in brain-computer interface (BCI) systems. Such systems could provide her with an alternative communication channel. To investigate the most viable modality for achieving BCI based communication, classic oddball paradigms (1 rare and 1 frequent stimulus, ratio 1:5) in the visual, auditory and tactile modality were conducted (2 runs per modality). Classifiers were built on one run and tested offline on another run (and vice versa). In these paradigms, the tactile modality was clearly superior to other modalities, displaying high offline accuracy even when classification was performed on single trials only. Consequently, we tested the tactile paradigm online and the patient successfully selected targets without any error. Furthermore, we investigated use of the visual or tactile modality for different BCI systems with more than two selection options. In the visual modality, several BCI paradigms were tested offline. Neither matrix-based nor so-called gaze-independent paradigms constituted a means of control. These results may thus question the gaze-independence of current gaze-independent approaches to BCI. A tactile four-choice BCI resulted in high offline classification accuracies. Yet, online use raised various issues. Although performance was clearly above chance, practical daily life use appeared unlikely when compared to other communication approaches (e.g., partner scanning). Our results emphasize the need for user-centered design in BCI development including identification of the best stimulus modality for a particular user. Finally, the paper discusses feasibility of EEG-based BCI systems for patients in classic locked-in state and compares BCI to other AT solutions that we also tested during the study.}, language = {en} } @article{HerbertSfaerleaBlumenthal2013, author = {Herbert, Cornelia and Sf{\"a}rlea, Anca and Blumenthal, Terry}, title = {Your emotion or mine: labeling feelings alters emotional face perception—an ERP study on automatic and intentional affect labeling}, series = {Frontiers in Human Neuroscience}, journal = {Frontiers in Human Neuroscience}, doi = {10.3389/fnhum.2013.00378}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97065}, year = {2013}, abstract = {Empirical evidence suggests that words are powerful regulators of emotion processing. Although a number of studies have used words as contextual cues for emotion processing, the role of what is being labeled by the words (i.e., one's own emotion as compared to the emotion expressed by the sender) is poorly understood. The present study reports results from two experiments which used ERP methodology to evaluate the impact of emotional faces and self- vs. sender-related emotional pronoun-noun pairs (e.g., my fear vs. his fear) as cues for emotional face processing. The influence of self- and sender-related cues on the processing of fearful, angry and happy faces was investigated in two contexts: an automatic (experiment 1) and intentional affect labeling task (experiment 2), along with control conditions of passive face processing. ERP patterns varied as a function of the label's reference (self vs. sender) and the intentionality of the labeling task (experiment 1 vs. experiment 2). In experiment 1, self-related labels increased the motivational relevance of the emotional faces in the time-window of the EPN component. Processing of sender-related labels improved emotion recognition specifically for fearful faces in the N170 time-window. Spontaneous processing of affective labels modulated later stages of face processing as well. Amplitudes of the late positive potential (LPP) were reduced for fearful, happy, and angry faces relative to the control condition of passive viewing. During intentional regulation (experiment 2) amplitudes of the LPP were enhanced for emotional faces when subjects used the self-related emotion labels to label their own emotion during face processing, and they rated the faces as higher in arousal than the emotional faces that had been presented in the "label sender's emotion" condition or the passive viewing condition. The present results argue in favor of a differentiated view of language-as-context for emotion processing.}, language = {en} } @article{KopfDreslerReichertsetal.2013, author = {Kopf, Juliane and Dresler, Thomas and Reicherts, Philipp and Herrmann, Martin J. and Reif, Andreas}, title = {The Effect of Emotional Content on Brain Activation and the Late Positive Potential in a Word n-back Task}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075598}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96687}, year = {2013}, abstract = {Introduction There is mounting evidence for the influence of emotional content on working memory performance. This is particularly important in light of the emotion processing that needs to take place when emotional content interferes with executive functions. In this study, we used emotional words of different valence but with similar arousal levels in an n-back task. Methods We examined the effects on activation in the prefrontal cortex by means of functional near-infrared spectroscopy (fNIRS) and on the late positive potential (LPP). FNIRS and LPP data were examined in 30 healthy subjects. Results Behavioral results show an influence of valence on the error rate depending on the difficulty of the task: more errors were made when the valence was negative and the task difficult. Brain activation was dependent both on the difficulty of the task and on the valence: negative valence of a word diminished the increase in activation, whereas positive valence did not influence the increase in activation, while difficulty levels increased. The LPP also differentiated between the different valences, and in addition was influenced by the task difficulty, the more difficult the task, the less differentiation could be observed. Conclusions Summarized, this study shows the influence of valence on a verbal working memory task. When a word contained a negative valence, the emotional content seemed to take precedence in contrast to words containing a positive valence. Working memory and emotion processing sites seemed to overlap and compete for resources even when words are carriers of the emotional content.}, 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{PauliGlotzbachSchoonAndreattaetal.2013, author = {Pauli, Paul and Glotzbach-Schoon, Evelyn and Andreatta, Marta and Reif, Andreas and Ewald, Heike and Tr{\"o}ger, Christian and Baumann, Christian and Deckert, J{\"u}rgen and M{\"u}hlberger, Andreas}, title = {Contextual fear conditioning in virtual reality is affected by 5HTTLPR and NPSR1 polymorphisms: effects on fear-potentiated startle}, series = {Frontiers in Behavioral Neuroscience}, journal = {Frontiers in Behavioral Neuroscience}, doi = {10.3389/fnbeh.2013.00031}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96516}, year = {2013}, abstract = {The serotonin (5-HT) and neuropeptide S (NPS) systems are discussed as important genetic modulators of fear and sustained anxiety contributing to the etiology of anxiety disorders. Sustained anxiety is a crucial characteristic of most anxiety disorders which likely develops through contextual fear conditioning. This study investigated if and how genetic alterations of the 5-HT and the NPS systems as well as their interaction modulate contextual fear conditioning; specifically, function polymorphic variants in the genes coding for the 5-HT transporter (5HTT) and the NPS receptor (NPSR1) were studied. A large group of healthy volunteers was therefore stratified for 5HTTLPR (S+ vs. LL carriers) and NPSR1 rs324981 (T+ vs. AA carriers) polymorphisms resulting in four genotype groups (S+/T+, S+/AA, LL/T+, LL/AA) of 20 participants each. All participants underwent contextual fear conditioning and extinction using a virtual reality (VR) paradigm. During acquisition, one virtual office room (anxiety context, CXT+) was paired with an unpredictable electric stimulus (unconditioned stimulus, US), whereas another virtual office room was not paired with any US (safety context, CXT-). During extinction no US was administered. Anxiety responses were quantified by fear-potentiated startle and ratings. Most importantly, we found a gene × gene interaction on fear-potentiated startle. Only carriers of both risk alleles (S+/T+) exhibited higher startle responses in CXT+ compared to CXT-. In contrast, anxiety ratings were only influenced by the NPSR1 polymorphism with AA carriers showing higher anxiety ratings in CXT+ as compared to CXT-. Our results speak in favor of a two level account of fear conditioning with diverging effects on implicit vs. explicit fear responses. Enhanced contextual fear conditioning as reflected in potentiated startle responses may be an endophenotype for anxiety disorders.}, language = {en} } @article{PlatteHerbertPaulietal.2013, author = {Platte, Petra and Herbert, Cornelia and Pauli, Paul and Breslin, Paul A. S.}, title = {Oral Perceptions of Fat and Taste Stimuli Are Modulated by Affect and Mood Induction}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0065006}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96421}, year = {2013}, abstract = {This study examined the impact of three clinical psychological variables (non-pathological levels of depression and anxiety, as well as experimentally manipulated mood) on fat and taste perception in healthy subjects. After a baseline orosensory evaluation, 'sad', 'happy' and 'neutral' video clips were presented to induce corresponding moods in eighty participants. Following mood manipulation, subjects rated five different oral stimuli, appearing sweet, umami, sour, bitter, fatty, which were delivered at five different concentrations each. Depression levels were assessed with Beck's Depression Inventory (BDI) and anxiety levels were assessed via the Spielberger's STAI-trait and state questionnaire. Overall, subjects were able to track the concentrations of the stimuli correctly, yet depression level affected taste ratings. First, depression scores were positively correlated with sucrose ratings. Second, subjects with depression scores above the sample median rated sucrose and quinine as more intense after mood induction (positive, negative and neutral). Third and most important, the group with enhanced depression scores did not rate low and high fat stimuli differently after positive or negative mood induction, whereas, during baseline or during the non-emotional neutral condition they rated the fat intensity as increasing with concentration. Consistent with others' prior observations we also found that sweet and bitter stimuli at baseline were rated as more intense by participants with higher anxiety scores and that after positive and negative mood induction, citric acid was rated as stronger tasting compared to baseline. The observation that subjects with mild subclinical depression rated low and high fat stimuli similarly when in positive or negative mood is novel and likely has potential implications for unhealthy eating patterns. This deficit may foster unconscious eating of fatty foods in sub-clinical mildly depressed populations.}, language = {en} } @phdthesis{Braun2013, author = {Braun, Barbara}, title = {Versorgung pathologischer Gl{\"u}cksspieler: Differentielle Aspekte der Inanspruchnahme von Hilfsangeboten}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-95703}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Ziele. Die Zielsetzung der vorliegenden Arbeit war eine Bewertung der Versorgungslage von Personen mit gl{\"u}cksspielbezogenen Problemen in Deutschland. Dabei wurden 1) der Zugang zum Versorgungssystem, n{\"a}mlich 1.1) Problembewusstsein bzgl. gl{\"u}cksspielbezogener Probleme und Erreichbarkeit von Gl{\"u}cksspielern {\"u}ber das Internet und 1.2) Faktoren der Inanspruchnahme von Hilfsangeboten untersucht sowie 1.3) eine Charakterisierung der Klientel in ambulanten Suchthilfeeinrichtungen und deren Zugang zum Hilfesystem vorgenommen. Zudem wurden in ambulanten Suchthilfeeinrichtungen 2) die erbrachten Leistungen f{\"u}r Personen mit gl{\"u}cksspielbezogenen Problemen und Einflussfaktoren auf die Versorgungsnutzung bzw. den Behandlungsverlauf sowie 3) das Behandlungsergebnis einer Analyse unterzogen. Methodik. Die Arbeit basiert auf drei Studien: einer Onlinestudie (OS), einer Versorgungsstudie (VS) und einer Bev{\"o}lkerungsstudie (BS). In der OS wurde eine Gelegenheitsstichprobe von Personen, die einen im Internet bereitgestellten Selbsttest zu pathologischem Gl{\"u}cksspielen (PG) vollst{\"a}ndig ausf{\"u}llten (n=277) und bei Erf{\"u}llen der Einschlusskriterien anschließend an einer vertiefenden Studie teilnahmen (n=52), hinsichtlich soziodemographischer Charakteristika, Spielverhalten und spielbezogener Motive, PG inklusive Folgen, Beratungserfahrungen sowie psychopathologischen Variablen untersucht. In den anderen Studien wurden weitestgehend dieselben Instrumente verwendet. Die VS war eine Verlaufsstudie (Messzeitpunkte: Behandlungsbeginn und -ende), bei der konsekutiv Klienten aus n=36 ambulanten Suchthilfeeinrichtungen in Bayern aufgenommen wurden, die sich zwischen April 2009 und August 2010 vorstellten (n=461). F{\"u}r die BS wurden Daten aus dem Epidemiologi-schen Suchtsurvey 2006 und 2009 herangezogen, einer Deutschland weiten repr{\"a}sentativen Querschnittbefragung 18- bis 64-J{\"a}hriger Erwachsener (2006: n=7.810; 2009: n=8.002). Ergebnisse. Zum Zugang zur Versorgung sind 1.1) {\"u}ber das Internet erreichbare Gl{\"u}cksspieler haupts{\"a}chlich junge, ledige M{\"a}nner, von denen ungef{\"a}hr die H{\"a}lfte die Diagnose PG erf{\"u}llen. Anhand der Spielmotive lassen sich drei Spielerklassen abbilden, die sich hinsichtlich ihres Schweregrads von PG unterschieden. Die Bereitschaft zur Teilnahme an einem Online-Pr{\"a}ventionsprogramm h{\"a}ngt haupts{\"a}chlich mit der Anzahl erf{\"u}llter DSM-IV-Kriterien f{\"u}r PG zusammen. Im Gegensatz zur VS sind die online erreichten Gl{\"u}cksspieler j{\"u}nger und zu einem h{\"o}heren Anteil subklinisch pathologische Gl{\"u}cksspieler (SPG, ein bis vier erf{\"u}llte DSM-IV-Kriterien f{\"u}r PG). 1.2) Hinsichtlich der Faktoren der Inanspruchnahme best{\"a}tigen sich systematische Unterschiede zwischen Gl{\"u}cksspielern in Behandlung und nicht in Behandlung. Ebenso zeigen sich Unterschiede zwischen SPGr und pathologischen Gl{\"u}cksspielern (PGr). Dabei ist die Anzahl erf{\"u}llter DSM-IV-Kriterien f{\"u}r PG der wichtigste Pr{\"a}diktor f{\"u}r einen positiven Behandlungsstatus. Auch soziodemographische Merkmale, insbesondere Alter und Staatsangeh{\"o}rigkeit, spielen eine Rolle. 1.3) Die Mehrheit der Klienten in ambulanten Suchthilfeeinrichtungen ist m{\"a}nnlich, durchschnittlich 37 Jahre alt, ledig und kinderlos und hat h{\"a}ufig eine ausl{\"a}ndische Staatsb{\"u}rgerschaft. Die am h{\"a}ufigsten gespielte und bevorzugte Spielform ist das Spielen an Geldspielautomaten. Viele der Klienten haben bereits im Vorfeld Hilfe in Anspruch genommen und Gr{\"u}nde f{\"u}r die Vorstellung in der Beratungsstelle waren in ungef{\"a}hr drei Viertel der F{\"a}llen finanzielle Probleme und bei ungef{\"a}hr der H{\"a}lfte Probleme in der Partnerschaft. In der ambulanten Suchthilfe sind 2) Pr{\"a}diktoren f{\"u}r eine l{\"a}ngere Kontaktdauer u.a. der Einbezug der Familie und Gruppengespr{\"a}che. Behandlungsabbr{\"u}che werden u.a. durch eine nicht-deutsche Staatsb{\"u}rgerschaft und h{\"o}here Spielfrequenz vorhergesagt. 3) Regul{\"a}re Beendigung und h{\"o}here Kontaktzahl sind u.a. Pr{\"a}diktoren f{\"u}r eine Verbesserung der Gl{\"u}cksspielsymptomatik. Schlussfolgerungen. Vor dem Hintergrund der Ergebnisse werden Implikationen f{\"u}r die Weiterentwicklung des Versorgungssystems zum einen im Sinne einer Erweiterung und Anpassung der Versorgungsstrukturen abgeleitet, wobei auf Information und Aufkl{\"a}rung, Fr{\"u}herkennung und Fr{\"u}hintervention mit einem Fokus auf Online-Angeboten sowie zielgruppen-spezifische Angebote unter anderem f{\"u}r Angeh{\"o}rige eingegangen wird. Auch die Wichtigkeit der Vernetzung verschiedener an der Beratung/Behandlung von PGr beteiligten Einrichtungen wird herausgestellt. Zum anderen beziehen sich die diskutierten m{\"o}glichen Weiterentwicklungen auf das Versorgungsangebot und Behandlungsmerkmale, was Therapieumfeld/-voraussetzungen, Therapieplanung sowie therapeutische Maßnahmen beinhaltet.}, subject = {Gl{\"u}cksspieler}, language = {de} } @article{MeuleFathRealetal.2013, author = {Meule, Adrian and Fath, Katharina and Real, Ruben G. L. and S{\"u}tterlin, Stefan and V{\"o}gele, Claus and K{\"u}bler, Andrea}, title = {Quality of life, emotion regulation, and heart rate variability in individuals with intellectual disabilities and concomitant impaired vision}, series = {Psychology of Well-Being: Theory, Research and Practice}, journal = {Psychology of Well-Being: Theory, Research and Practice}, doi = {10.1186/2211-1522-3-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96247}, year = {2013}, abstract = {Background Positive associations have been found between quality of life, emotion regulation strategies, and heart rate variability (HRV) in people without intellectual disabilities. However, emotion regulation and HRV have rarely been investigated in people with intellectual disabilities. Assessment of subjectively reported quality of life and emotion regulation strategies in this population is even more difficult when participants are also visually impaired. Methods Subjective and objective quality of life, emotion regulation strategies, and HRV at rest were measured in a sample of people with intellectual disabilities and concomitant impaired vision (N = 35). Heart rate was recorded during a 10 min resting period. For the assessment of quality of life and emotion regulation, custom made tactile versions of questionnaire-based instruments were used that enabled participants to grasp response categories. Results The combined use of reappraisal and suppression as emotion regulation strategies was associated with higher HRV and quality of life. HRV was associated with objective quality of life only. Emotion regulation strategies partially mediated the relationship between HRV and quality of life. Conclusions Results replicate findings about associations between quality of life, emotion regulation, and HRV and extend them to individuals with intellectual disabilities. Furthermore, this study demonstrated that quality of life and emotion regulation could be assessed in such populations even with concomitant impaired vision with modified tactile versions of established questionnaires. HRV may be used as a physiological index to evaluate physical and affective conditions in this population.}, language = {en} } @phdthesis{Muehlbacher2013, author = {M{\"u}hlbacher, Dominik}, title = {Die Pulksimulation als Methode zur Untersuchung verkehrspsychologischer Fragestellungen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-90051}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Fahr- und Verkehrssimulation sind neben Studien mit realen Fahrzeugen die g{\"a}ngigen Methoden der empirischen Verkehrswissenschaft. W{\"a}hrend sich die Fahrsimulation mit dem Erleben und Verhalten von Fahrern besch{\"a}ftigt, untersucht die Verkehrssimulation das gesamte Verkehrssystem. Der Bereich zwischen diesen Polen „Fahrer" und „Verkehr", in dem Fahrer aufeinander treffen und miteinander interagieren, ist angesichts der Bedeutung sozialer Prozesse f{\"u}r das Erleben und Verhalten ein wichtiger Aspekt. Allerdings wurde dieser Bereich in der Verkehrswissenschaft bisher nur unzureichend abgebildet. Auch in der Fahr- und Verkehrssimulation wurde dieser Aspekt bislang weitgehend vernachl{\"a}ssigt. Um diese L{\"u}cke zu schließen, wurde mit der Pulksimulation eine neue Versuchsumgebung entwickelt. Sie besteht aus miteinander vernetzten Fahrsimulatoren und erm{\"o}glicht es, Interaktionsfragestellungen zu untersuchen. Jedoch bringt die Anwendung der Pulksimulation neue Anforderungen an den Untersucher mit sich, die bei der Fahr- bzw. Verkehrssimulation nicht notwendig sind und f{\"u}r die Pulksimulation neu entwickelt werden m{\"u}ssen. Das Ziel der vorliegenden Arbeit ist, diese Methode zur Untersuchung verkehrspsychologischer Fragestellungen weiterzuentwickeln, zu pr{\"u}fen und zu etablieren. In ersten Untersuchungsans{\"a}tzen werden in acht Teilstudien die grundlegenden methodischen Besonderheiten der Pulksimulation am Beispiel des Folgefahrens und des Kreuzens betrachtet. Hierbei wird auch stets der Vergleich zu den bisher genutzten Versuchsumgebungen Einzelfahrsimulation und Verkehrssimulation gezogen. Folgende Fragstellungen wurden im Rahmen dessen beantwortet: (1) Wie unterscheidet sich eine Pulkfahrt von einer Einzelfahrt? (2) Welchen Einfluss haben nachfolgende Fahrzeuge im Pulk? (3) Welche Effekte haben Positionierungen im Pulk? (4) Wie unterscheiden sich reale Fahrer und Modelle im Pulk? (5) Wie wirkt sich die Einf{\"u}hrung einer Nebenaufgabe auf den Pulk aus? (6) Wie wirken sich verschiedene Abstandsinstruktionen aus? (7) Mit welchen Parametern kann der Pulk beschrieben werden? (8) Wie kann das Verhalten des Pulks an Kreuzungen untersucht werden? Schließlich werden zwei Anwendungsbeispiele der Pulksimulation zu aktuell relevanten Themen aufgezeigt. In der ersten Untersuchung wird ein Gefahrenwarner evaluiert, der vor Bremsungen vorausfahrender Fahrzeuge warnt. W{\"a}hrend Fahrer direkt hinter dem bremsenden Fahrzeug vom System nicht profitieren, steigt der Nutzen des Systems mit zunehmender Positionierung im Pulk an. In einer zweiten Studie wird ein Ampelphasenassistent untersucht. Dieser informiert den Fahrer w{\"a}hrend der Ann{\"a}herung an eine Ampel {\"u}ber die optimale Geschwindigkeit, mit der diese Ampel ohne Halt bei Gr{\"u}n durchfahren werden kann. Um die Auswirkungen des Systems auf den nicht-assistierten Umgebungsverkehr bestimmen zu k{\"o}nnen, werden verschiedene Ausstattungsraten innerhalb des Pulks eingef{\"u}hrt. Mit diesem Untersuchungsansatz k{\"o}nnen gleichzeitig Effekte des Systems auf die assistierten Fahrer (z. B. Befolgungsverhalten), die nicht-assistierten Fahrer (z. B. {\"A}rger) sowie das Verkehrssystem (z. B. Verkehrsfluss) bestimmt werden. Der Ampelphasenassistent resultiert in einem {\"o}konomischeren Fahrverhalten der assistierten Fahrer, erh{\"o}ht aber gleichzeitig in gemischten Ausstattungsraten den {\"A}rger der nicht-assistierten Fahrer im Verkehrssystem. Erst bei Vollausstattung entwickelt sich dieser negative Effekt zur{\"u}ck. Die in den Anwendungsbeispielen berichteten Ph{\"a}nomene sind durch Untersuchungen in einer Einzelfahrsimulation oder Verkehrssimulation nicht beobachtbar. Insbesondere f{\"u}r die Untersuchung von Fragen, in denen soziale Interaktionen mit anderen Fahrern eine Rolle spielen, zeichnet sich die Pulksimulation in besonderer Weise aus. Hierf{\"u}r liefert die Anwendung in der Pulksimulation zus{\"a}tzliche Informationen und zeigt somit, dass die Pulksimulation das Methodeninventar in der Verkehrswissenschaft effektiv erg{\"a}nzt. Sie stellt zum einen eine Erweiterung der Fahrsimulation um den Faktor „Verkehr" und zum anderen eine Erweiterung der Verkehrssimulation um den Faktor „Mensch" dar und wird so zu einem zentralen Bindeglied beider Versuchsumgebungen. Dar{\"u}ber hinaus erlaubt die Pulksimulation die Modellierung von Interaktionsverhalten im Straßenverkehr, was bisher nicht bzw. nur unter gr{\"o}ßtem Aufwand realisierbar war. Hierdurch k{\"o}nnen die Modelle der Fahr- und Verkehrssimulation weiterentwickelt werden. Mit den in dieser Arbeit neu entworfenen Parametern werden Kenngr{\"o}ßen zur Verf{\"u}gung gestellt, die Variationen bez{\"u}glich Quer- und L{\"a}ngsf{\"u}hrung auch auf Ebene des Pulks abbilden k{\"o}nnen. Weitere neu entwickelte Parameter sind in der Lage, Interaktionen {\"u}ber den Zeitverlauf zu beschreiben. Diese Parameter sind notwendig f{\"u}r den Einsatz der Pulksimulation in zuk{\"u}nftigen Untersuchungen. Zusammenfassend wurde in der vorliegenden Arbeit die Methodik der Pulksimulation f{\"u}r den gesamten Anwendungsprozess von der Fragestellung bis hin zur Interpretation der Ergebnisse weiterentwickelt. Der Mehrwert dieser Methode wurde an aktuellen und bisher nicht untersuchbaren Fragestellungen belegt und somit die Validit{\"a}t der Pulksimulation gest{\"a}rkt. Die vorgestellten Untersuchungen zeigen das große Potenzial der Pulksimulation zur Bearbeitung von Fragen, die auf der Interaktion verschiedener Verkehrsteilnehmer basieren. Hierdurch wird erstmals die M{\"o}glichkeit geschaffen, soziale Interaktionen {\"u}ber den Zeitverlauf in die Fahrermodelle der Verkehrssimulation zu integrieren. Damit ist der Br{\"u}ckenschlag von der Fahr- zur Verkehrssimulation gelungen.}, subject = {Verkehrspsychologie}, 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} }