TY - JOUR A1 - Kleih, Sonja C. A1 - Kübler, Andrea T1 - Empathy, motivation, and P300-BCI performance JF - Frontiers in Human Neuroscience N2 - Motivation moderately influences brain–computer interface (BCI) performance in healthy subjects when monetary reward is used to manipulate extrinsic motivation. However, the motivation of severely paralyzed patients, who are potentially in need for BCI, could mainly be internal and thus, an intrinsic motivator may be more powerful. Also healthy subjects who participate in BCI studies could be internally motivated as they may wish to contribute to research and thus extrinsic motivation by monetary reward would be less important than the content of the study. In this respect, motivation could be defined as “motivation-to-help.” The aim of this study was to investigate, whether subjects with high motivation for helping and who are highly empathic would perform better with a BCI controlled by event-related potentials (P300-BCI). We included N = 20 healthy young participants naïve to BCI and grouped them according to their motivation for participating in a BCI study in a low and highly motivated group. Motivation was further manipulated with interesting or boring presentations about BCI and the possibility to help patients. Motivation for helping did neither influence BCI performance nor the P300 amplitude. Post hoc, subjects were re-grouped according to their ability for perspective taking. We found significantly higher P300 amplitudes on parietal electrodes in participants with a low ability for perspective taking and therefore, lower empathy, as compared to participants with higher empathy. The lack of an effect of motivation on BCI performance contradicts previous findings and thus, requires further investigation. We speculate that subjects with higher empathy who are good perspective takers with regards to patients in potential need of BCI, may be more emotionally involved and therefore, less able to allocate attention on the BCI task at hand. KW - psychological variables KW - empathy KW - motivation KW - brain–computer interface KW - ERP KW - P300 Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130559 VL - 7 IS - 642 ER - TY - JOUR A1 - Andreatta, Marta A1 - Mühlberger, Andreas A1 - Glotzbach-Schoon, Evelyn A1 - Pauli, Paul T1 - Pain predictability reverses valence ratings of a relief-associated stimulus JF - Front in Systems Neuroscience N2 - Relief from pain is positively valenced and entails reward-like properties. Notably, stimuli that became associated with pain relief elicit reward-like implicit responses too, but are explicitly evaluated by humans as aversive. Since the unpredictability of pain makes pain more aversive, this study examined the hypotheses that the predictability of pain also modulates the valence of relief-associated stimuli. In two studies, we presented one conditioned stimulus \((_{FORWARD}CS+)\) before a painful unconditioned stimulus (US), another stimulus \((_{BACKWARD}CS+)\) after the painful US, and a third stimulus (CS−) was never associated with the US. In Study 1, \(_{FORWARD}CS+\) predicted half of the USs while the other half was delivered unwarned and followed by \(_{BACKWARD}CS+\). In Study 2, all USs were predicted by \(_{FORWARD}CS+\) and followed by \(_{BACKWARD}CS+\). In Study 1 both \(_{FORWARD}CS+\) and \(_{BACKWARD}CS+\) were rated as negatively valenced and high arousing after conditioning, while \(_{BACKWARD}CS+\) in Study 2 acquired positive valence and low arousal. Startle amplitude was significantly attenuated to \(_{BACKWARD}CS+\) compared to \(_{FORWARD}CS+\) in Study 2, but did not differ among CSs in Study 1. In summary, predictability of aversive events reverses the explicit valence of a relief-associated stimulus. KW - threat unpredictability KW - implicit and explicit responses KW - forward conditioning KW - backward conditioning KW - pain relief Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129275 VL - 7 IS - 53 ER - TY - JOUR A1 - Schwarz, Katharina A. A1 - Wieser, Matthias J. A1 - Gerdes, Antje B. M. A1 - Mühlberger, Andreas A1 - Pauli, Paul T1 - Why are you looking like that? How the context influences evaluation and processing of human faces JF - Social Cognitive and Affective Neuroscience N2 - Perception and evaluation of facial expressions are known to be heavily modulated by emotional features of contextual information. Such contextual effects, however, might also be driven by non-emotional aspects of contextual information, an interaction of emotional and non-emotional factors, and by the observers’ inherent traits. Therefore, we sought to assess whether contextual information about self-reference in addition to information about valence influences the evaluation and neural processing of neutral faces. Furthermore, we investigated whether social anxiety moderates these effects. In the present functional magnetic resonance imaging (fMRI) study, participants viewed neutral facial expressions preceded by a contextual sentence conveying either positive or negative evaluations about the participant or about somebody else. Contextual influences were reflected in rating and fMRI measures, with strong effects of self-reference on brain activity in the medial prefrontal cortex and right fusiform gyrus. Additionally, social anxiety strongly affected the response to faces conveying negative, self-related evaluations as revealed by the participants’ rating patterns and brain activity in cortical midline structures and regions of interest in the left and right middle frontal gyrus. These results suggest that face perception and processing are highly individual processes influenced by emotional and non-emotional aspects of contextual information and further modulated by individual personality traits. KW - social anxiety KW - facial expression KW - context KW - self-reference Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-132126 VL - 8 IS - 4 ER - TY - THES A1 - Sollfrank, Teresa T1 - Feedback efficiency and training effects during alpha band modulation over the sensorimotor cortex T1 - Die Wirksamkeit von Feedback und Trainingseffekten während der Alphaband Modulation über dem menschlichen sensomotorischen Cortex N2 - Neural oscillations can be measured by electroencephalography (EEG) and these oscillations can be characterized by their frequency, amplitude and phase. The mechanistic properties of neural oscillations and their synchronization are able to explain various aspects of many cognitive functions such as motor control, memory, attention, information transfer across brain regions, segmentation of the sensory input and perception (Arnal and Giraud, 2012). The alpha band frequency is the dominant oscillation in the human brain. This oscillatory activity is found in the scalp EEG at frequencies around 8-13 Hz in all healthy adults (Makeig et al., 2002) and considerable interest has been generated in exploring EEG alpha oscillations with regard to their role in cognitive (Klimesch et al., 1993; Hanselmayr et al., 2005), sensorimotor (Birbaumer, 2006; Sauseng et al., 2009) and physiological (Lehmann, 1971; Niedermeyer, 1997; Kiyatkin, 2010) aspects of human life. The ability to voluntarily regulate the alpha amplitude can be learned with neurofeedback training and offers the possibility to control a brain-computer interface (BCI), a muscle independent interaction channel. BCI research is predominantly focused on the signal processing, the classification and the algorithms necessary to translate brain signals into control commands than on the person interacting with the technical system. The end-user must be properly trained to be able to successfully use the BCI and factors such as task instructions, training, and especially feedback can therefore play an important role in learning to control a BCI (Neumann and Kübler, 2003; Pfurtscheller et al., 2006, 2007; Allison and Neuper, 2010; Friedrich et al., 2012; Kaufmann et al., 2013; Lotte et al., 2013). The main purpose of this thesis was to investigate how end-users can efficiently be trained to perform alpha band modulation recorded over their sensorimotor cortex. The herein presented work comprises three studies with healthy participants and participants with schizophrenia focusing on the effects of feedback and training time on cortical activation patterns and performance. In the first study, the application of a realistic visual feedback to support end-users in developing a concrete feeling of kinesthetic motor imagery was tested in 2D and 3D visualization modality during a single training session. Participants were able to elicit the typical event-related desynchronisation responses over sensorimotor cortex in both conditions but the most significant decrease in the alpha band power was obtained following the three-dimensional realistic visualization. The second study strengthen the hypothesis that an enriched visual feedback with information about the quality of the input signal supports an easier approach for motor imagery based BCI control and can help to enhance performance. Significantly better performance levels were measurable during five online training sessions in the groups with enriched feedback as compared to a conventional simple visual feedback group, without significant differences in performance between the unimodal (visual) and multimodal (auditory–visual) feedback modality. Furthermore, the last study, in which people with schizophrenia participated in multiple sessions with simple feedback, demonstrated that these patients can learn to voluntarily regulate their alpha band. Compared to the healthy group they required longer training times and could not achieve performance levels as high as the control group. Nonetheless, alpha neurofeedback training lead to a constant increase of the alpha resting power across all 20 training session. To date only little is known about the effects of feedback and training time on BCI performance and cortical activation patterns. The presented work contributes to the evidence that healthy individuals can benefit from enriched feedback: A realistic presentation can support participants in getting a concrete feeling of motor imagery and enriched feedback, which instructs participants about the quality of their input signal can give support while learning to control the BCI. This thesis demonstrates that people with schizophrenia can learn to gain control of their alpha oscillations recorded over the sensorimotor cortex when participating in sufficient training sessions. In conclusion, this thesis improved current motor imagery BCI feedback protocols and enhanced our understanding of the interplay between feedback and BCI performance. N2 - Die Wirksamkeit von Feedback und Trainingseffekten während der Alphaband Modulation über dem menschlichen sensomotorischen Cortex KW - Neurofeedback KW - Gehirn-Computer-Schnittstelle KW - Brain-computer interface KW - Übung KW - Alpha Neurofeedback KW - EEG Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131769 ER - TY - JOUR A1 - Fischer, Rico A1 - Plessow, Franziska A1 - Kiesel, Andrea T1 - The effects of alerting signals in masked priming JF - Frontiers in Psychology N2 - Alerting signals often serve to reduce temporal uncertainty by predicting the time of stimulus onset. The resulting response time benefits have often been explained by facilitated translation of stimulus codes into response codes on the basis of established stimulus-response (S-R) links. In paradigms of masked S-R priming alerting signals also modulate response activation processes triggered by subliminally presented prime stimuli. In the present study we tested whether facilitation of visuo-motor translation processes due to alerting signals critically depends on established S-R links. Alerting signals resulted in significantly enhanced masked priming effects for masked prime stimuli that included and that did not include established S-R links fi.e., target vs. novel primes). Yet, the alerting-priming interaction was more pronounced for target than for novel primes. These results suggest that effects of alerting signals on masked priming are especially evident when S-R links between prime and target exist. At the same time, an alerting-priming interaction also for novel primes suggests that alerting signals also facilitate stimulus-response translation processes when masked prime stimuli provide action-trigger conditions in terms of programmed S-R links. KW - response selection KW - visual cortex KW - temporal predictability KW - stimuli KW - primes KW - target primes KW - simon task KW - automaticity KW - performance KW - perception KW - mechanism KW - novel primes KW - action-trigger KW - masked priming KW - accessory KW - alerting signal Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122581 SN - 1664-1078 VL - 4 IS - 448 ER - TY - JOUR A1 - Meule, Adrian A1 - Kübler, Andrea A1 - Blechert, Jens T1 - Time course of electrocortical food-cue responses during cognitive regulation of craving JF - Frontiers in Psychology N2 - In our current obesogenic environment, exposure to visual food-cues can easily lead to craving and overeating because short-term, pleasurable effects of food intake dominate over the anticipated long-term adverse effects such as weight gain and associated health problems. Here we contrasted these two conditions during food-cue presentation while acquiring event-related potentials (ERPs) and subjective craving ratings. Female participants (n = 25) were presented with either high-calorie (HC) or low-calorie (LC) food images under instructions to imagine either immediate (NOW) or long-term effects (LATER) of consumption. On subjective ratings for HC foods, the LATER perspective reduced cravings as compared to the NOW perspective. For LC foods, by contrast, craving increased under the LATER perspective. Early ERPs (occipital N1, 150-200 ms) were sensitive to food type but not to perspective. Late ERPs (late positive potential, LPP, 350-550 ms) were larger in the HC-LATER condition than in all other conditions, possibly indicating that a cognitive focus on negative long-term consequences induced negative arousal. This enhancement for HC-LATER attenuated to the level of the LC conditions during the later slow wave (550-3000 ms), but amplitude in the HC-NOW condition was larger than in all other conditions, possibly due to a delayed appetitive response. Across all conditions, LPP amplitudes were positively correlated with self-reported emotional eating. In sum, results reveal that regulation effects are secondary to an early attentional analysis of food type and dynamically evolve over time. Adopting a long-term perspective on eating might promote a healthier food choice across a range of food types. KW - EEG KW - disorder examination questionnaire KW - eating disorder KW - emotion regulation KW - future directions KW - attention KW - brain KW - high-calorie KW - german version KW - bulimia nervosa KW - chocolate images KW - event-related potentials KW - eating KW - calorie content KW - food-cues KW - food craving KW - LPP KW - slow wave Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122566 SN - 1664-1078 VL - 4 IS - 669 ER - TY - JOUR A1 - Ehrenfeld, Stephan A1 - Herbort, Oliver A1 - Butz, Martin V. T1 - Modular neuron-based body estimation: maintaining consistency over different limbs, modalities, and frames of reference JF - Frontiers in Computational Neuroscience N2 - This paper addresses the question of how the brain maintains a probabilistic body state estimate over time from a modeling perspective. The neural Modular Modality Frame (nMMF) model simulates such a body state estimation process by continuously integrating redundant, multimodal body state information sources. The body state estimate itself is distributed over separate, but bidirectionally interacting modules. nMMF compares the incoming sensory and present body state information across the interacting modules and fuses the information sources accordingly. At the same time, nMMF enforces body state estimation consistency across the modules. nMMF is able to detect conflicting sensory information and to consequently decrease the influence of implausible sensor sources on the fly. In contrast to the previously published Modular Modality Frame (MMF) model, nMMF offers a biologically plausible neural implementation based on distributed, probabilistic population codes. Besides its neural plausibility, the neural encoding has the advantage of enabling (a) additional probabilistic information flow across the separate body state estimation modules and (b) the representation of arbitrary probability distributions of a body state. The results show that the neural estimates can detect and decrease the impact of false sensory information, can propagate conflicting information across modules, and can improve overall estimation accuracy due to additional module interactions. Even bodily illusions, such as the rubber hand illusion, can be simulated with nMMF. We conclude with an outlook on the potential of modeling human data and of invoking goal-directed behavioral control. KW - information KW - posterior parietal cortex KW - hand KW - population code KW - conflicting information KW - multimodal interaction KW - probabilistic inference KW - modular body schema KW - sensor fusion KW - multisensory perception KW - fusion KW - representation KW - multisensory processing KW - see KW - implementation KW - perspective KW - multisensory integration KW - population codes Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122253 VL - 7 IS - 148 ER - TY - JOUR A1 - Meule, Adrian T1 - Are certain foods addictive? JF - Frontiers in Psychiatry N2 - A commentary on Lifestyle medicine: the importance of firmgrounding on evidence by Rippe JM. Am J Lifestyle Med (2014) doi:10.1177/ 1559827613520527 Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120257 SN - 1664-0640 VL - 5 IS - 38 ER - TY - JOUR A1 - Sollfrank, Teresa A1 - Hart, Daniel A1 - Goodsell, Rachel A1 - Foster, Jonathan A1 - Tan, Tele T1 - 3D visualization of movements can amplify motor cortex activation during subsequent motor imagery JF - Frontiers in Human Neuroscience N2 - A repetitive movement practice by motor imagery (MI) can influence motor cortical excitability in the electroencephalogram (EEG). This study investigated if a realistic visualization in 3D of upper and lower limb movements can amplify motor related potentials during subsequent MI. We hypothesized that a richer sensory visualization might be more effective during instrumental conditioning, resulting in a more pronounced event related desynchronization (ERD) of the upper alpha band (10–12 Hz) over the sensorimotor cortices thereby potentially improving MI based brain-computer interface (BCI) protocols for motor rehabilitation. The results show a strong increase of the characteristic patterns of ERD of the upper alpha band components for left and right limb MI present over the sensorimotor areas in both visualization conditions. Overall, significant differences were observed as a function of visualization modality (VM; 2D vs. 3D). The largest upper alpha band power decrease was obtained during MI after a 3-dimensional visualization. In total in 12 out of 20 tasks the end-user of the 3D visualization group showed an enhanced upper alpha ERD relative to 2D VM group, with statistical significance in nine tasks.With a realistic visualization of the limb movements, we tried to increase motor cortex activation during subsequent MI. The feedback and the feedback environment should be inherently motivating and relevant for the learner and should have an appeal of novelty, real-world relevance or aesthetic value (Ryan and Deci, 2000; Merrill, 2007). Realistic visual feedback, consistent with the participant’s MI, might be helpful for accomplishing successful MI and the use of such feedback may assist in making BCI a more natural interface for MI based BCI rehabilitation. KW - 3-dimensional visualization KW - motor cortex activation KW - EEG KW - brain-computer interfaces Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126058 VL - 9 IS - 463 ER - TY - JOUR A1 - Körner, Anita A1 - Topolinski, Sascha A1 - Strack, Fritz T1 - Routes to Embodiment JF - Frontiers of Psychology N2 - Research on embodiment is rich in impressive demonstrations but somewhat poor in comprehensive explanations. Although some moderators and driving mechanisms have been identified, a comprehensive conceptual account of how bodily states or dynamics influence behavior is still missing. Here, we attempt to integrate current knowledge by describing three basic psychological mechanisms: direct state induction, which influences how humans feel or process information, unmediated by any other cognitive mechanism; modal priming, which changes the accessibility of concepts associated with a bodily state; sensorimotor simulation, which affects the ease with which congruent and incongruent actions are performed. We argue that the joint impact of these mechanisms can account for most existing embodiment effects. Additionally, we summarize empirical tests for distinguishing these mechanisms and suggest a guideline for future research about the mechanisms underlying embodiment effects. KW - priming KW - simulation KW - grounded cognition KW - embodied cognition KW - metaphors Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125960 VL - 9 IS - 940 ER - TY - THES A1 - Holz, Elisa Mira T1 - Systematic evaluation of non-invasive brain-computer interfaces as assistive devices for persons with severe motor impairment based on a user-centred approach – in controlled settings and independent use T1 - Systematische Evaluation nicht-invasiver Gehirn-Computer Schnittstellen als Hilfsmittel für Personen mit schweren motorischen Einschränkungen auf Basis eines nutzerzentrierten Ansatzes – im kontrollierten Setting und experten-unabhängigen Gebrauch N2 - Brain-computer interfaces (BCIs) are devices that translate signals from the brain into control commands for applications. Within the last twenty years, BCI applications have been developed for communication, environmental control, entertainment, and substitution of motor functions. Since BCIs provide muscle independent communication and control of the environment by circumventing motor pathways, they are considered as assistive technologies for persons with neurological and neurodegenerative diseases leading to motor paralysis, such as amyotrophic lateral sclerosis (ALS), muscular dystrophy, spinal muscular atrophy and stroke (Kübler, Kotchoubey, Kaiser, Wolpaw, & Birbaumer, 2001). Although most researcher mention persons with severe motor impairment as target group for their BCI systems, most studies include healthy participants and studies including potential BCI end-users are sparse. Thus, there is a substantial lack of studies that investigate whether results obtained in healthy participants can be transferred to patients with neurodegenerative diseases. This clearly shows that BCI research faces a translational gap between intense BCI research and bringing BCI applications to end-users outside the lab (Kübler, Mattia, Rupp, & Tangermann, 2013). Translational studies are needed that investigate whether BCIs can be successfully used by severely disabled end-users and whether those end-users would accept BCIs as assistive devices. Another obvious discrepancy exists between a plethora of short-term studies and a sparse number of long-term studies. BCI research thus also faces a reliability gap (Kübler, Mattia, et al., 2013). Most studies present only one BCI session, however the few studies that include several testing sessions indicate high inter- and intra-individual variance in the end-users’ performance due to non-stationarity of signals. Long-term studies, however, are needed to demonstrate whether a BCI can be reliably used as assistive device over a longer period of time in the daily-life of a person. Therefore there is also a great need for reliability studies. The purpose of the present thesis was to address these research gaps and to bring BCIs closer to end-users in need, especially into their daily-lives, following a user-centred design (UCD). The UCD was suggested as theoretical framework for bringing BCIs to end-users by Kübler and colleagues (Kübler et al., 2014; Zickler et al., 2011). This approach aims at the close and iterative interaction between BCI developers and end-users with the final goal to develop BCI systems that are accepted as assistive devices by end-users. The UCD focuses on usability, that is, how well a BCI technology matches the purpose and meets the needs and requirements of the targeted end-users and was standardized with the ISO 9241-210. Within the UCD framework, usability of a device can be defined with regard to its effectiveness, efficiency and satisfaction. These aspects were operationalized by Kübler and colleagues to evaluate BCI-controlled applications. As suggested by Vaughan and colleagues, the number of BCI sessions, the total usage duration and the impact of the BCI on the life of the person can be considered as indicators of usefulness of the BCI in long-term daily-life use (Vaughan, Sellers, & Wolpaw, 2012). These definitions and metrics for usability and usefulness were applied for evaluating BCI applications as assistive devices in controlled settings and independent use. Three different BCI applications were tested and evaluated by in total N=10 end-users: In study 1 a motor-imagery (MI) based BCI for gaming was tested by four end-users with severe motor impairment. In study 2, a hybrid P300 event-related (ERP) based BCI for communication was tested by four severely motor restricted end-users with severe motor impairment. Study 1 and 2 are short-term studies conducted in a controlled-setting. In study 3 a P300-ERP BCI for creative expression was installed for long-term independent use at the homes of two end-users in the locked-in state. Both end-users are artists who had gradually lost the ability to paint after being diagnosed with ALS. Results reveal that BCI controlled devices are accepted as assistive devices. Main obstacles for daily-life use were the not very aesthetic design of the EEG-cap and electrodes (cap is eye-catching and looks medical), low comfort (cables disturb, immobility, electrodes press against head if lying on a head cushion), complicated and time-consuming adjustment, low efficiency and low effectiveness, and not very high reliability (many influencing factors). While effectiveness and efficiency in the MI based BCI were lower compared to applications using the P300-ERP as input channel, the MI controlled gaming application was nevertheless better accepted by the end-users and end-users would rather like to use it compared to the communication applications. Thus, malfunctioning and errors, low speed, and the EEG cap are rather tolerated in gaming applications, compared to communication devices. Since communication is essential for daily-life, it has to be fast and reliable. BCIs for communication, at the current state of the art, are not considered competitive with other assistive devices, if other devices, such as eye-gaze, are still an option. However BCIs might be an option when controlling an application for entertainment in daily-life, if communication is still available. Results demonstrate that BCI is adopted in daily-life if it matches the end-users needs and requirements. Brain Painting serves as best representative, as it matches the artists’ need for creative expression. Caveats such as uncomfortable cap, dependence on others for set-up, and experienced low control are tolerated and do not prevent BCI use on a daily basis. Also end-users in real need of means for communication, such as persons in the locked-in state with unreliable eye-movement or no means for independent communication, do accept obstacles of the BCI, as it is the last or only solution to communicate or control devices. Thus, these aspects are “no real obstacles” but rather “challenges” that do not prevent end-users to use the BCI in their daily-lives. For instance, one end-user, who uses a BCI in her daily-life, stated: “I don’t care about aesthetic design of EEG cap and electrodes nor amplifier”. Thus, the question is not which system is superior to the other, but which system is best for an individual user with specific symptoms, needs, requirements, existing assistive solutions, support by caregivers/family etc.; it is thereby a question of indication. These factors seem to be better “predictors” for adoption of a BCI in daily-life, than common usability criterions such as effectiveness or efficiency. The face valid measures of daily-life demonstrate that BCI-controlled applications can be used in daily-life for more than 3 years, with high satisfaction for the end-users, without experts being present and despite a decrease in the amplitude of the P300 signal. Brain Painting re-enabled both artists to be creatively active in their home environment and thus improved their feelings of happiness, usefulness, self-esteem, well-being, and consequently quality of life and supports social inclusion. This thesis suggests that BCIs are valuable tools for people in the locked-in state. N2 - Gehirn-Computer Schnittstellen (engl. Brain-computer interfaces, Abk.: BCIs) sind technische Systeme, die Gehirnsignale in Kontrollbefehle für Computeranwendungen übersetzen. In den vergangenen zwanzig Jahren wurden verschiedenste BCI Anwendungen entwickelt, beispielsweise zur Kommunikation, Umweltsteuerung, Unterhaltung und Ersatz von Motorfunktionen. Da BCIs muskelunabhängige Kommunikation und Kontrolle ermöglichen, werden sie als mögliche Hilfsmittel für Personen mit neurologischen und neurodegenerativen Krankheiten, die zu motorischen Lähmungen führen, wie beispielsweise bei Amyotrophe Lateralsklerose (ALS), Muskeldystrophie, Spinale Muskelatrophie und Schlaganfall, in Betracht gezogen (Kübler, Kotchoubey, et al., 2001). Auch wenn die meisten BCI Forscher Personen mit starken motorischen Einschränkungen als Zielgruppe für ihre BCI Systeme angeben, so testen sie ihre Systeme nur in Stichproben von gesunden Probanden. BCI Studien, die Patienten einschließen, sind dagegen selten. Daher gibt es einen beträchtlichen Mangel an Studien, die untersuchen, ob die Forschungsergebnisse, die basierend auf einer gesunden Stichprobe verzeichnet wurden, auch auf Patienten mit neurodegenerativen Erkrankungen übertragen werden können. Das macht deutlich, dass es in der BCI Forschung eine erhebliche Translationslücke zwischen der intensiven BCI Grundlagenforschung und dem Transfer von BCI Anwendungen aus dem Labor zu den Patienten, den sogenannten BCI End-Nutzern, gibt (Kübler, Mattia, et al., 2013). Es werden deshalb Translationsstudien benötigt, die untersuchen, ob BCIs von stark motorisch eingeschränkten Patienten verwendet werden können und ob diese sogenannten End-Nutzer BCIs als Hilfsmittel akzeptieren. Zusätzlich ist eine deutliche Diskrepanz zwischen der Vielzahl an Kurzzeitstudien und der geringen Anzahl an Langzeitstudien zu verzeichnen. BCI Forschung ist daher auch mit einer Reliabilitätslücke konfrontiert (Kübler, Mattia, et al., 2013). Die meisten Studien basieren nur auf einer BCI Sitzung, jedoch zeigen die wenigen Studien, die auf mehreren Sitzungen beruhen, hohe inter- und intraindividuelle Varianz in der Performanz der Patienten. Langzeitzeitstudien werden daher benötigt, um aufzuzeigen, ob ein BCI reliabel als Hilfsmittel über einen längeren Zeitraum im Alltagsleben eines Patienten verwendet werden kann. Demzufolge gibt es einen starken Bedarf an Translations- und Reliabilitätsstudien. Das Anliegen der vorliegenden Dissertation war es, diesen Forschungslücken zu begegnen und, basierend auf einem nutzerzentrierten Vorgehen, BCIs näher zu den BCI End-Nutzern zu bringen, besonders in ihr Alltagsleben. Der nutzerzentrierte Ansatz wurde von Kübler und Kollegen (Kübler et al., 2014; Zickler et al., 2011) als theoretisches Gerüst nahegelegt, um BCIs näher zu Patienten zu bringen. Dieser Ansatz beabsichtigt eine enge und iterative Interaktion zwischen BCI Entwicklern und den End-Nutzern mit dem finalen Ziel BCI Systeme zu entwickeln, die von den End-Nutzern als Hilfsmittel akzeptiert werden. Der nutzerzentrierte Ansatz fokussiert auf die Benutzbarkeit, das heißt, wie gut eine BCI Technologie den Bedürfnissen und den Ansprüchen der Zielgruppe entspricht. Dieser Ansatz wurde standardisiert mit dem ISO 9241-210. Demnach ist die Benutzbarkeit eines Gerätes definiert hinsichtlich der Effektivität, Effizienz, und Zufriedenheit. Um BCI Systeme zu evaluieren, wurden diese Aspekte von Kübler und Kollegen operationalisiert. Nach Vaughan und Kollegen können die Anzahl der BCI Sitzungen, die Gesamtnutzungsdauer und der Einfluss eines BCIs auf die Lebensqualität einer Person als Indikatoren der Nützlichkeit eines BCI betrachtet werden (Vaughan et al., 2012). Diese Definitionen und entsprechenden Operationalisierungen wurden in dieser Dissertation verwendet, um BCI Anwendungen hinsichtlich ihrer Benutzbarkeit und Nützlichkeit als Hilfsmittel zu evaluieren. N=10 End-Nutzer testeten und evaluierten drei BCI Anwendungen: In Studie 1 wurde ein auf Bewegungsvorstellung basiertes BCI (engl. motor imagery, Abk: MI) zur Steuerung einer Spielanwendung von vier potentiellen End-Nutzern mit unterschiedlichen neurologischen Erkrankungen getestet. In Studie 2 wurde ein Hybrid BCI, das das P300 ereignis-korrelierte Potential (EKP) und Muskelaktivität als Inputkanäle zur Steuerung eines Kommunikationsprogramms verwendet, von vier potentiellen End-Nutzern getestet. Studie 1 und 2 sind Kurzzeitstudien, welche in einem kontrollierten Design durchgeführt wurden. In Studie 3 wurde ein P300-EKP basiertes BCI zum künstlerischen Ausdruck bei zwei End-Nutzern zuhause für einen experten-unabhängigen und längerfristigen Gebrauch implementiert. Beide End-Nutzer sind Künstler, die, aufgrund der Diagnose ALS und der damit verbundenen fast kompletten körperlichen Lähmung (Locked-in Zustand), nicht mehr in der Lage waren zu malen (Studie 3). Die Ergebnisse zeigen, dass BCI Systeme als Hilfsmittel akzeptiert werden. Das nicht sehr ästhetische Design der EEG-Kappe und der Elektroden (Kappe zu auffällig, sieht medizinisch aus), der geringe Komfort (Kabel stören, Immobilität, Elektroden drücken gegen den Kopf), die komplizierte und zeitaufwändige Einstellung und Anpassung, die geringe Effizienz und geringe Effektivität und die nicht sehr hohe Reliabilität (viele Einflussfaktoren), wurden jedoch für einen Alltagsgebrauch als problematisch angesehen. Obwohl die Effektivität und Effizienz beim MI BCI geringer, verglichen mit beiden P300-EKP BCI Systemen, waren, wurde das MI basierte BCI-Spiel von den End-Nutzern besser akzeptiert und die End-Nutzer konnten sich eher vorstellen es im Alltag zu verwenden, als das Kommunikationsprogramm. Das zeigt, dass Störungen und Fehler, eine geringe Geschwindigkeit, und die EEG Kappe bei BCI Systemen zur Unterhaltung eher toleriert werden, als bei Systemen zur Kommunikation. Da Kommunikation im Leben essentiell ist, muss sie schnell und zuverlässig sein. BCI Systeme zur Kommunikation sind daher zum aktuellen Stand der Technik nicht konkurrenzfähig mit anderen Hilfsmitteln, wenn andere Hilfsmittel zur Kommunikation, wie Augensteuerung, verwendet werden können. BCI Systeme sind aber eine Option im Bereich Unterhaltung, sofern Möglichkeiten zur Kommunikation (noch) bestehen. Die Ergebnisse zeigen, dass ein BCI für einen Alltagsgebrauch übernommen wird, wenn es den Bedürfnissen und Anforderungen des End-Nutzers entspricht. Brain Painting zeigt hierbei beispielhaft, wie negative Facetten, wie die wenig komfortable EEG Kappe, die Abhängigkeit von anderen aufgrund der komplexen Einstellung, und eine subjektiv empfundene geringe Kontrolle toleriert werden, da es genau den Bedürfnissen der Künstler sich kreativ auszudrücken entspricht. Ebenso Patienten, die Bedarf an Kommunikation haben, wie Patienten im Locked-in Zustand, die keine zuverlässigen Augen-Bewegungen aufweisen, oder Patienten, die keine Hilfsmittel zur unabhängigen Kommunikation haben, akzeptieren diese Umstände beim BCI Gebrauch. Das zeigt, dass diese Umstände keine richtigen „Hindernisse“, sondern vielmehr Herausforderungen sind, die eine Übernahme eines BCI im Alltag eines Patienten nicht verhindern. Es ist daher nicht die Frage, welches BCI System überlegen ist, sondern welches BCI System das Beste für ein Individuum mit spezifischen Symptomen, Bedürfnissen, Ansprüchen, vorhandenen Hilfsmitteln, Unterstützung durch Familie und Pflegern, ist; es ist deshalb eine Frage der Indikation. Eine End-Nutzerin, die ein BCI im Alltag verwendet, sagte beispielsweise: „Mir ist das ästhetische Design der EEG-Kappe und der Elektroden, oder des EEG-Verstärkers völlig egal“. Diese Faktoren können als die besten “Prädiktoren” für eine Übernahme eines BCI Systems im Alltag eines Patienten angesehen werden, weniger hingegen die üblichen Kriterien zur Bewertung der Benutzbarkeit, wie Effektivität und Effizienz. Die Ergebnisse hinsichtlich des Alltagsgebrauches belegen ferner, dass ein P300-EKP basiertes BCI mit hoher Zufriedenheit über einen Zeitraum von 3 Jahren, ohne die Hilfe eines BCI Experten, und trotz einer Abnahme der Amplitude des P300-Signales verwendet werden kann. Brain Painting ermöglichte beiden Künstlern sich wieder kreativ auszudrücken und beeinflusste somit positiv das Empfinden von Freude, das Gefühl von Nützlichkeit, das Selbstwertgefühl, das Wohlbefinden und folglich die Lebensqualität der Künstler und förderte ihre soziale Inklusion. Die vorliegende Dissertation zeigt, dass BCIs wertvolle Hilfsmittel für Personen im Locked-in Zustand sein können. KW - Gehirn-Computer-Schnittstelle KW - Benutzerfreundlichkeit KW - brain-computer interface KW - evaluation KW - Evaluation KW - usability KW - Benutzerfreundlichkeit/ Benutzbarkeit KW - assistive device KW - Hilfsmittel KW - user-centred design KW - nutzerzentrierter Ansatz Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126334 ER - TY - THES A1 - Reicherts, Philipp T1 - Cognitive and Emotional Influences on Placebo Analgesia and Nocebo Hyperalgesia T1 - Kognititve und emotionale Einflussfaktoren auf Placeboanalgesie und Nocebohyperalgesie N2 - 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. N2 - Die Wahrnehmung von Schmerz kann durch eine Vielzahl von Faktoren beeinflusst werden, darunter biologische und pharmakologische Interventionen sowie potente kognitive und emotionale Manipulationen. Placebo- und Nocebo-effekte gehören mit zu den eindrucksvollsten Beispielen für die Wirksamkeit derartiger Manipulationen. Placebo- und Nocebo-Behandlungen können zu manifesten psychologischen und physiologischen Veränderungen führen, obwohl die verabreichten Substanzen frei von Wirkstoffen bzw. den angewandten Scheinbehandlungen keine Wirkung zugeschrieben wird. In der vorliegenden Dissertation wurden kognitive und emotionale Einflussfaktoren auf die Induktion von Placebo- und Nocebo-Effekten bei der Wahrnehmung von Schmerz untersucht. Darüber hinaus sollte die Möglichkeit zur Verwendung rein psychologischer Placebo-Nocebo Manipulationen für die Modulation von Schmerz getestet werden. Zwei zentrale Voraussetzungen für die Erzeugung von Placebo und Nocebo-Effekten sind vorherige Erfahrung (z.B. auf Grund früherer Erfahrungen mit einem Medikament) und Erwartung (z.B. eine positive oder negative persönliche Einstellung gegenüber einer Therapie). Bisher basierte die Forschung zu Placebo- und Nocebo-Effekten vornehmlich auf Ergebnissen von Untersuchungen die Schein-Behandlungen oder Leerpräparate einsetzten wie z.B. Tabletten, Cremes oder Injektionen, die herkömmlichen medizinischen Interventionen sehr ähnlich sind. Jedoch ergibt sich bei einem derartigen experimentellen Vorgehen stets das Problem einer Konfundierung der Ergebnisse durch den Einfluss früherer Erfahrungen oder der individuellen Erwartungshaltung an die Behandlung, die aus einer Vorgeschichte medizinischer Therapieerlebnissen herrührt. Daraus leitet sich die Notwendigkeit von anderweitigen, dem Probanden völlig unbekannten Placebo-Interventionen ab, um die jeweilige Beteiligung von Erwartungs- und Erfahrungsprozessen für die Induktion von Placebo- und Nocebo-Effekten bestimmen zu können. Zu diesem Zweck wurden in Experiment 1 Erwartung und Erfahrung in drei Experimentalgruppen stufenweise und unabhängig voneinander manipuliert. Um einer Ähnlichkeit zu früheren Behandlungs-Erfahrungen und dadurch abgeleiteten Erwartungen vorzubeugen, wurde ein rein psychologisches Placebo-Nocebo Verfahren herangezogen, das mit Sicherheit allen Teilnehmern unbekannt war. Sie wurden darüber informiert, dass die Betrachtung von schwarz-weißen Streifenmustern eine wissenschaftlich bestätigte Wirkung auf die Schmerzwahrnehmung hätte. Eine Gruppe der Teilnehmer erhielt lediglich eine Placebo-Nocebo Instruktion (Erwartung), eine zweite Gruppe erlebte tatsächlich die Kopplung von zwei verschiedenen Streifenmustern mit unterschiedlich starken Schmerzreizen während einer Konditionierungs-Phase (Erfahrung) bekam aber keine Instruktion und eine dritte Gruppe erhielt sowohl die Placebo-Nocebo Instruktion als auch die Placebo-Nocebo Konditionierung (Erfahrung + Erwartung). Es konnte gezeigt werden, dass während der anschließenden Testphase lediglich die kombinierte Erfahrung + Erwartung Gruppe signifikant unterschiedliche Schmerzratings und physiologische Reaktionen auf die Schmerzreize während der Placebo- im Vergleich zu den Nocebo-Durchgängen aufwies. Diese Ergebnisse belegen, dass die Induktion eines rein psychologischen Placebo-Nocebo Effektes auf die Schmerzwahrnehmung prinzipiell möglich ist. Besonders hervorzuheben ist dabei die Notwendigkeit beider Prozesse, nämlich einer tatsächlichen Erfahrung der Wirksamkeit der Therapie (Placebo-Nocebo Konditionierung) und einer positiven Erwartung hinsichtlich der Intervention (Placebo-Nocebo Instruktion). Neben Erfahrung und Erwartung, hat die momentane Stimmung entscheidenden Einfluss auf die die Induktion von Placebo- und Nocebo-Effekten einerseits, sowie generell auf die Wahrnehmung von Schmerz andererseits. In diesem Zusammenhang konnte gezeigt werden, dass Placebo-Effekte mit einer Verbesserung der Stimmung einhergehen, Nocebo-Effekte hingegen häufig von gesteigerter Angst begleitet sind. Um die Interaktion von Emotionen und Placebo-Nocebo Manipulationen zu eruieren, wurde das in Experiment 1 etablierte Paradigma angewendet und modifiziert. Anstelle von Streifenmustern, wurden positive und negative emotionale Bilder präsentiert, die entweder eine Schmerz-Verstärkung (Nocebo) oder eine Schmerz-Linderung (Placebo) anzeigten. Zwei Experimentalgruppen wurden miteinander verglichen, die sich hinsichtlich der Kontingenz von positiven Bildern als Placebo- und negativen Bildern als Nocebo-Indikator, bzw. umgekehrt, positiven Bildern als Nocebo- und negativen Bildern als Placebo-Indikator, unterschieden (kongruent vs. inkongruent). Es zeigte, dass die Unterscheidung (Schmerzratings und physiologische Reaktionen auf den Schmerzreiz) zwischen Placebo- und Nocebo-Durchgängen in der kongruenten Gruppe stärker ausgeprägt war als in der inkongruenten Gruppe. Allerdings waren die affektiven Schmerzratings der inkongruenten Gruppe ebenfalls in Nocebo-Durchgängen (positive Bilder) signifikant höher als in Placebo-Durchgängen (negative Bilder), ähnlich zur kongruenten Gruppe. Die Daten zeigen damit, dass eine Placebo-Nocebo Manipulation in der Lage ist, die genuin Schmerz verstärkende Wirkung negativer Emotionen abzuschwächen und sogar umzukehren. Die Befunde aus Experiment 2 konnten zusätzlich in Experiment 3 gestützt werden, welches das zuvor getestete Design ins fMRT überführte und gleichermaßen eine kongruente und eine inkongruente Experimentalgruppe miteinander verglich. Verhaltensmaße sowie physiologische und neurophysiologische Korrelate der Schmerzwahrnehmung ergaben eine eindeutige Differenzierung zwischen Placebo- und Nocebo-Durchgängen, unabhängig von der Experimentalgruppe. Darüber hinaus zeigte sich in der inkongruenten Bedingung eine verstärkte präfrontale Aktivierung für den Vergleich von Nocebo- und Placebo-Durchgängen, was potenziell auf einen zusätzlichen Re- Interpretations- oder Appraisal-Prozess zurückzuführen ist, der sich einstellt, wenn ein positives Bild eine negative Konsequenz vorhersagt. Zusammengefasst zeigen die vorliegenden Studien, dass es (a) möglich ist einen Placebo-Nocebo Effekt mit einer rein psychologischen Manipulation hervorzurufen, dass (b) im Fall rein psychologischer Placebo-Nocebo Manipulationen sowohl Erfahrung als auch positive Erwartung notwendig sind, dass (c) der Einfluss negativer Emotionen auf Schmerz mittels einer Placebo-Nocebo Manipulation reduziert und sogar umgekehrt werden kann und (d) höchstwahrscheinlich ein kognitiver (Neu-) Bewertungsprozess für die Induktion (psychologischer) Placebo-Nocebo Effekte essentiell ist. Die Ergebnisse tragen zum Verständnis der beteiligten psychologischen Prozesse bei der Induktion von Placebo-Nocebo Effekten erheblich bei. Darüber hinaus stellen die verwendeten Paradigmen eine vielseitige Ausgangsposition für zukünftige Studien dar, die klären müssen, ob für die gefunden Ergebnisse vornehmlich Placebo- oder Nocebo-Effekte verantwortlich sind. Perspektivisch könnten die vorliegenden Befunden helfen, die psychologischen Grundlagen der Placebo-Nocebo Antwort näher zu beleuchten und damit sogar im klinischen Kontext zum Ausschöpfen von Placebo- sowie zur Vorbeugung von Nocebo-Effekten beizutragen. KW - Placebo KW - Nocebo-Effekt KW - Psychologie KW - Placebo Hypolagesia KW - Nocebo hyperoalgesia KW - Emotional Pain Modulation Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-106455 ER - TY - JOUR A1 - Simon, Nadine A1 - Käthner, Ivo A1 - Ruf, Carolin A. A1 - Pasqualotto, Emanuele A1 - Kübler, Andrea A1 - Halder, Sebastian T1 - An auditory multiclass brain-computer interface with natural stimuli: Usability evaluation with healthy participants and a motor impaired end user JF - Frontiers in Human Neuroscience N2 - Brain-computer interfaces (BCIs) can serve as muscle independent communication aids. Persons, who are unable to control their eye muscles (e.g., in the completely locked-in state) or have severe visual impairments for other reasons, need BCI systems that do not rely on the visual modality. For this reason, BCIs that employ auditory stimuli were suggested. In this study, a multiclass BCI spelling system was implemented that uses animal voices with directional cues to code rows and columns of a letter matrix. To reveal possible training effects with the system, 11 healthy participants performed spelling tasks on 2 consecutive days. In a second step, the system was tested by a participant with amyotrophic lateral sclerosis (ALS) in two sessions. In the first session, healthy participants spelled with an average accuracy of 76% (3.29 bits/min) that increased to 90% (4.23 bits/min) on the second day. Spelling accuracy by the participant with ALS was 20% in the first and 47% in the second session. The results indicate a strong training effect for both the healthy participants and the participant with ALS. While healthy participants reached high accuracies in the first session and second session, accuracies for the participant with ALS were not sufficient for satisfactory communication in both sessions. More training sessions might be needed to improve spelling accuracies. The study demonstrated the feasibility of the auditory BCI with healthy users and stresses the importance of training with auditory multiclass BCIs, especially for potential end-users of BCI with disease. KW - P300 KW - EEG KW - auditory BCI KW - brain-computer interface KW - communication KW - ALS Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126450 VL - 8 IS - 1039 ER - TY - THES A1 - Wiemer, Julian T1 - Maintaining factors of fear-relevant illusory correlations T1 - Aufrechterhaltende Faktoren von angstbezogenen Zusammenhangsverschätzungen N2 - Biased cognitive processes are very likely involved in the maintenance of fears and anxiety. One of such cognitive processes is the perceived relationship between fear-relevant stimuli and aversive consequences. If this relationship is perceived although objective contingencies have been random, it is called an (a posteriori) illusory correlation. If this relationship is overestimated before objective contingencies are experienced, it is called an (a priori) expectancy bias. Previous investigations showed that fear-relevant illusory correlations exist, but very few is known about how and why this cognitive bias develops. In the present dissertation thesis, a model is proposed based on a review of the literature on fear-relevant illusory correlations. This model describes how psychological factors might have an influence on fear and illusory correlations. Several critical implications of the model were tested in four experiments. Experiment 1 tested the hypothesis that people do not only overestimate the proportion of aversive consequences (startle sounds) following emotionally negative stimuli (pictures of mutilations) relative to neutral stimuli (pictures of household objects), but also following highly arousing positive stimuli (pictures of erotic scenes), because arousal might be an important determinant of illusory correlations. The result was a significant expectancy bias for negative stimuli and a much smaller expectancy bias for positive stimuli. Unexpectedly, expectancy bias was restricted to women. An a posteriori illusory correlation was not found overall, but only in those participants who perceived the aversive consequences following negative stimuli as particularly aversive. Experiment 2 tested the same hypothesis as experiment 1 using a paradigm that evoked distinct basic emotions (pictures inducing fear, anger, disgust or happiness). Only negative emotions resulted in illusory correlations with aversive outcomes (startle sounds), especially the emotions of fear and disgust. As in experiment 1, the extent of these illusory correlations was correlated with the perceived aversiveness of aversive outcomes. Moreover, only women overestimated the proportion of aversive outcomes during pictures that evoked fear, anger or disgust. Experiment 3 used functional Magnetic Resonance Imaging (fMRI) to measure biased brain activity in female spider phobics during an illusory correlation paradigm. Both spider phobics and healthy controls expected more aversive outcomes (painful electrical shocks) following pictures of spiders than following neutral control stimuli (pictures of mushrooms). Spider phobics but not healthy controls overestimated the proportion of aversive outcomes following pictures of spiders in a trial-by-trial memory task. This a posteriori illusory correlation was correlated with enhanced shock aversiveness and activity in primary sensory-motor cortex in phobic participants. Moreover, spider phobics’ brain activity in the left dorsolateral prefrontal cortex was elevated in response to spider images. This activity also predicted the extent of the illusory correlation, which supports the theory that executive and attentional resources play an important role in the maintenance of illusory correlations. Experiment 4 tested the hypothesis that the enhanced aversiveness of some outcomes would be sufficient to causally induce an illusory correlation. Neutral images (colored geometric figures) were paired with differently aversive outcomes (three startle sounds varying in intensity). Participants developed an illusory correlation between those images, which predicted the most aversive sound and this sound, which means that this association was overestimated relative to the other associations. The extent of the illusory correlation was positively correlated with participants’ self-reported anxiety. The results imply that the previously found relationship between illusory correlations and outcome aversiveness might reflect a causal impact of outcome aversiveness or salience on illusory correlations. In sum, the conducted experiments indicate that illusory correlations between fear-relevant stimuli and aversive consequences might persist – among other factors - because of an enhanced aversiveness or salience of aversive consequences following feared stimuli. This assumption is based on correlational findings, a neural measure of outcome perception and a causal influence of outcome aversiveness on illusory correlations. Implications of these findings were integrated into a model of fear-relevant illusory correlations and potential implications are discussed. Future investigations should further elucidate the role of executive functions and gender effects. Moreover, the trial-by-trial assessment of illusory correlations is recommended to increase reliability of the concept. From a clinical perspective, the down-regulation of aversive experiences and the allocation of attention to non-aversive experiences might help to cure anxiety and cognitive bias. N2 - Verzerrte kognitive Prozesse sind sehr wahrscheinlich an der Aufrechterhaltung von Furcht und Angst beteiligt. Ein solcher kognitiver Prozess ist der wahrgenommene Zusammenhang zwischen Reizen, vor denen bereits Angst besteht und unangenehmen Konsequenzen. Wenn so ein Zusammenhang wahrgenommen wird, obwohl die objektiven Kontingenzen zufällig sind, spricht man von einer illusorischen Korrelation (a posteriori). Wenn so ein Zusammenhang überschätzt wird, bevor objektive Kontingenzen erlebt werden, spricht man von einer Erwartungsverzerrung (a priori). Frühere Untersuchungen zeigten, dass angstrelevante illusorische Korrelationen existieren, aber bisher ist nur wenig darüber bekannt, wie und warum diese entstehen. In der vorliegenden Dissertation wird ein Modell vorgeschlagen, dass auf bisherigen Erkenntnissen zu angstrelevanten illusorischen Korrelationen beruht. Das Modell beschreibt, welche psychologischen Faktoren die Entstehung von Angst und illusorischen Korrelationen begünstigen könnten. Mehrere Implikationen dieses Modells wurden in vier Experimenten getestet. Experiment 1 überprüfte die Hypothese, dass Menschen nicht nur die Häufigkeit unangenehmer Konsequenzen (Schreckgeräusche) nach emotional negativen Reizen (Bilder von Verletzungen) überschätzen, verglichen mit neutralen Reizen (Bilder von Haushaltsgegenständen), sondern auch nach sehr aufregenden positiven Reizen (Bilder von erotischen Szenen), weil die allgemeine Erregung einen Einfluss auf illusorische Korrelationen haben sollte. Das Ergebnis war eine signifikante Erwartungsverzerrung bei negativen Reizen und eine sehr viel kleinere Erwartungsverzerrung bei positiven Reizen. Unerwarteter Weise waren Erwartungsverzerrungen auf Frauen beschränkt. Eine illusorische Korrelation (a posteriori) konnte im Allgemeinen nicht festgestellt werden, sondern lediglich bei solchen Probanden, die die unangenehmen Konsequenzen nach negativen Reizen als besonders unangenehm empfanden. Experiment 2 überprüfte die gleiche Hypothese wie Experiment 1 anhand einer Versuchsanordnung, die verschiedene Basisemotionen hervorrufen sollte (durch Bilder, die Angst, Ärger, Ekel oder Freude induzierten). Nur negative Emotionen führten zu illusorischen Korrelationen (a posteriori) mit unangenehmen Ereignissen (Schreckgeräusche), insbesondere die Emotionen Angst und Ekel. Wie auch in Experiment 1 korrelierte das Ausmaß der illusorischen Korrelation mit der wahrgenommenen Unangenehmheit der unangenehmen Ereignisse bei der entsprechenden Bildkategorie. Darüber hinaus überschätzten nur Frauen den Anteil negativer Ereignisse bei Bildern, die Angst, Ekel, oder Ärger hervorriefen. Experiment 3 verwendete funktionelle Magnetresonanztomografie (fMRT), um verzerrte Gehirnaktivität bei Spinnenphobikerinnen während eines Versuchs zu illusorischen Korrelationen zu messen. Sowohl Spinnenphobikerinnen als auch gesunde Kontrollprobandinnen erwarteten mehr unangenehme Konsequenzen (schmerzhafte elektrische Reize) bei Bildern von Spinnen als bei neutralen Kontrollreizen (Bilder von Pilzen). Spinnenphobikerinnen, aber nicht gesunde Kontrollprobandinnen überschätzten jedoch im Nachhinein den Anteil unangenehmer Konsequenzen bei Bildern von Spinnen in einer Trial-by-Trial Gedächtnisaufgabe. Diese illusorische Korrelation (a posteriori) korrelierte mit der erhöhten Unangenehmheit der elektrischen Reize und mit Aktivierung im primären senso-motorischen Kortex der phobischen Teilnehmerinnen. Darüber hinaus wiesen Spinnenphobikerinnen in Reaktion auf die Bilder von Spinnen eine erhöhte Aktivierung im linken dorsolateralen präfrontalen Kortex auf. Diese Aktivität sagte auch das Ausmaß der illusorischen Korrelation vorher, was die These unterstützt, dass exekutive und Aufmerksamkeitsressourcen eine wichtige Rolle in der Aufrechterhaltung illusorischer Korrelationen spielen. Experiment 4 überprüfte die Hypothese, dass die erhöhte Unangenehmheit mancher Konsequenzen hinreichend sein würde, um kausal eine illusorische Korrelation hervorzurufen. Neutrale Bilder (geometrische Figuren in drei verschiedenen Farben) wurden mit unterschiedlich unangenehmen Konsequenzen gepaart (Schreckgeräusche in drei verschiedenen Intensitäten). Bei den Probanden entwickelte sich eine illusorische Korrelation mit der Farbe, die das unangenehmste Geräusch voraussagte und diesem Geräusch, das heißt, der Zusammenhang wurde im Vergleich zu den anderen Zusammenhängen überschätzt. Das Ausmaß der illusorischen Korrelation korrelierte positiv mit der Ängstlichkeit der Teilnehmer. Die Ergebnisse legen nahe, dass der bisher gefundene Zusammenhang zwischen illusorischen Korrelationen und der Unangenehmheit der unangenehmen Konsequenzen auf einen kausalen Einfluss der Unangenehmheit oder Salienz der Konsequenzen auf illusorische Korrelationen zurückgehen könnte. Zusammengefasst zeigten die durchgeführten Experimente, dass illusorische Korrelationen zwischen angstrelevanten Reizen und unangenehmen Konsequenzen – neben anderen Einflussfaktoren – aufgrund einer erhöhten Unangenehmheit oder Salienz unangenehmer Konsequenzen bei gefürchteten Reizen bestehen könnten. Diese Annahme basiert auf korrelativen Ergebnissen, einem neuralen Maß der Konsequenzverarbeitung und dem gefundenen kausalen Einfluss der Unangenehmheit unangenehmer Konsequenzen auf illusorische Korrelationen. Implikationen dieser Befunde werden in ein Modell zu angstrelevanten illusorischen Korrelationen integriert und diskutiert. Zukünftige Studien sollten die Rolle exekutiver Funktionen und Geschlechtsunterschiede genauer untersuchen. Es empfiehlt sich dabei, illusorische Korrelationen Trial-by-Trial zu erfassen, um die Reliabilität des Konzepts zu erhöhen. Aus klinischer Sicht könnten die Beruhigung unangenehmer Erfahrungen und die Aufmerksamkeitsallokation auf nicht-unangenehme Erfahrungen helfen, Ängste und kognitive Verzerrungen zu vermindern. KW - Verzerrte Kognition KW - Angststörung KW - Verzerrte Kognition KW - Illusorische Korrelation KW - Gefahrenlernen KW - Funktionelle Kernspintomografie KW - cognitive bias KW - illusory correlation KW - threat learning KW - functional magnetic resonance imaging KW - Assoziatives Gedächtnis Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116960 ER - TY - JOUR A1 - Reuss, Heiko A1 - Pohl, Carsten A1 - Kiesel, Andrea A1 - Kunde, Wilfried T1 - Instructed illiteracy reveals expertise-effects on unconscious processing JF - Frontiers in Psychology N2 - We used a new methodological approach to investigate whether top-down influences like expertise determine the extent of unconscious processing. This approach does not rely on preexisting differences between experts and novices, but instructs essentially the same task in a way that either addresses a domain of expertise or not. Participants either were instructed to perform a lexical decision task (expert task) or to respond to a combination of single features of word and non-word stimuli (novel task). The stimuli and importantly also the mapping of responses to those stimuli, however, were exactly the same in both groups. We analyzed congruency effects of masked primes depending on the instructed task. Participants performing the expert task responded faster and less error prone when the prime was response congruent rather than incongruent. This effect was significantly reduced in the novel task, and even reversed when excluding identical prime-target pairs. This indicates that the primes in the novel task had an effect on a perceptual level, but were not able to impact on response activation. Overall, these results demonstrate an expertise-based top-down modulation of unconscious processing that cannot be explained by confounds that are otherwise inherent in comparisons between novices and experts. KW - top-down control KW - expertise KW - masked priming KW - unconscious processing KW - lexical decision task Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125332 VL - 6 IS - 239 ER - TY - JOUR A1 - Eder, Andreas B. A1 - Deutsch, Roland T1 - Watch the target! Effects in the affective misattribution procedure become weaker (but not eliminated) when participants are motivated to provide accurate responses to the target JF - Frontiers in Psychology N2 - Previous research showed that priming effects in the affective misattribution procedure (AMP) are unaffected by direct warnings to avoid an influence of the primes. The present research examined whether a priming influence is diminished by task procedures that encourage accurate judgments of the targets. Participants were motivated to categorize the affective meaning of nonsense targets accurately by being made to believe that a true word was presented in each trial and by providing feedback on (allegedly) incorrect responses. This condition produced robust priming effects. Priming was however reduced and less reliable relative to more typical AMP conditions in which participants guessed the meaning of openly presented nonsense targets. Affective judgments of nonsense targets were not affected by advance knowledge of the response mapping during the priming phase, which argues against a response-priming explanation of AMP effects. These findings show that affective primes influence evaluative judgments even in conditions in which the motivation to provide accurate responses is high and a priming of motor responses is not possible. Priming effects were however weaker with high accuracy motivation, suggesting that a focus on accurate judgments is an effective strategy to control for an unwanted priming influence in the AMP. KW - implicit attitude measurement KW - accuracy motivation KW - affect misattribution procedure KW - response priming Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125982 VL - 6 ER - TY - JOUR A1 - Kleih, Sonja C. A1 - Herweg, Andreas A1 - Kaufmann, Tobias A1 - Staiger-Sälzer, Pit A1 - Gerstner, Natascha A1 - Kübler, Andrea T1 - The WIN-speller: a new intuitive auditory brain-computer interface spelling application JF - Frontiers in Neuroscience N2 - The objective of this study was to test the usability of a new auditory Brain-Computer Interface (BCI) application for communication. We introduce a word based, intuitive auditory spelling paradigm the WIN-speller. In the WIN-speller letters are grouped by words, such as the word KLANG representing the letters A, G, K, L, and N. Thereby, the decoding step between perceiving a code and translating it to the stimuli it represents becomes superfluous. We tested 11 healthy volunteers and four end-users with motor impairment in the copy spelling mode. Spelling was successful with an average accuracy of 84% in the healthy sample. Three of the end-users communicated with average accuracies of 80% or higher while one user was not able to communicate reliably. Even though further evaluation is required, the WIN-speller represents a potential alternative for BCI based communication in end-users. KW - Brain-Computer Interface (BCI) KW - communication KW - P300 KW - motor-impaired end-user KW - auditory Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125972 VL - 9 ER - TY - JOUR A1 - Wieser, Matthias J. A1 - Moscovitch, David A. T1 - The effect of affective context on visuocortical processing of neutral faces in social anxiety - An ERP study JF - Frontiers in Psychology N2 - It has been demonstrated that verbal context information alters the neural processing of ambiguous faces such as faces with no apparent facial expression. In social anxiety, neutral faces may be implicitly threatening for socially anxious individuals due to their ambiguous nature, but even more so if these neutral faces are put in self-referential negative contexts. Therefore, we measured event-related brain potentials (ERPs) in response to neutral faces which were preceded by affective verbal information (negative, neutral, positive). Participants with low social anxiety (LSA; n = 23) and high social anxiety (HSA; n = 21) were asked to watch and rate valence and arousal of the respective faces while continuous EEG was recorded. ERP analysis revealed that HSA showed elevated P100 amplitudes in response to faces, but reduced structural encoding of faces as indexed by reduced N170 amplitudes. In general, affective context led to an enhanced early posterior negativity (EPN) for negative compared to neutral facial expressions. Moreover, HSA compared to LSA showed enhanced late positive potentials (LPP) to negatively contextualized faces, whereas in LSA this effect was found for faces in positive contexts. Also, HSA rated faces in negative contexts as more negative compared to LSA. These results point at enhanced vigilance for neutral faces regardless of context in HSA, while structural encoding seems to be diminished (avoidance). Interestingly, later components of sustained processing (LPP) indicate that LSA show enhanced visuocortical processing for faces in positive contexts (happy bias), whereas this seems to be the case for negatively contextualized faces in HSA (threat bias). Finally, our results add further new evidence that top-down information in interaction with individual anxiety levels can influence early-stage aspects of visual perception. KW - context effects KW - face processing KW - social anxiety KW - ERPs (Event-Related Potentials) KW - EEG/ERP Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125148 VL - 6 ER - TY - JOUR A1 - Stippekohl, Bastian A1 - Winkler, Markus H. A1 - Walter, Bertram A1 - Kagerer, Sabine A1 - Mucha, Ronald F. A1 - Pauli, Paul A1 - Vaitl, Dieter A1 - Stark, Rudolf T1 - Neural Responses to Smoking Stimuli Are Influenced by Smokers' Attitudes towards Their Own Smoking Behaviour JF - PLoS One N2 - An important feature of addiction is the high drug craving that may promote the continuation of consumption. Environmental stimuli classically conditioned to drug-intake have a strong motivational power for addicts and can elicit craving. However, addicts differ in the attitudes towards their own consumption behavior: some are content with drug taking (consonant users) whereas others are discontent (dissonant users). Such differences may be important for clinical practice because the experience of dissonance might enhance the likelihood to consider treatment. This fMRI study investigated in smokers whether these different attitudes influence subjective and neural responses to smoking stimuli. Based on self-characterization, smokers were divided into consonant and dissonant smokers. These two groups were presented smoking stimuli and neutral stimuli. Former studies have suggested differences in the impact of smoking stimuli depending on the temporal stage of the smoking ritual they are associated with. Therefore, we used stimuli associated with the beginning (BEGIN-smoking-stimuli) and stimuli associated with the terminal stage (END-smoking-stimuli) of the smoking ritual as distinct stimulus categories. Stimulus ratings did not differ between both groups. Brain data showed that BEGIN-smoking-stimuli led to enhanced mesolimbic responses (amygdala, hippocampus, insula) in dissonant compared to consonant smokers. In response to END-smoking-stimuli, dissonant smokers showed reduced mesocortical responses (orbitofrontal cortex, subcallosal cortex) compared to consonant smokers. These results suggest that smoking stimuli with a high incentive value (BEGIN-smoking-stimuli) are more appetitive for dissonant than consonant smokers at least on the neural level. To the contrary, smoking stimuli with low incentive value (END-smoking-stimuli) seem to be less appetitive for dissonant smokers than consonant smokers. These differences might be one reason why dissonant smokers experience difficulties in translating their attitudes into an actual behavior change. KW - smoking habits KW - addiction KW - amygdala KW - behavioral addiction KW - addicts KW - nicotine addiction KW - drug research and development KW - drug addiction Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124393 VL - 7 IS - 11 ER - TY - JOUR A1 - Sütterlin, Stefan A1 - Paap, Muirne C. S. A1 - Babic, Stana A1 - Kübler, Andrea A1 - Vögele, Claus T1 - Rumination and Age: Some Things Get Better JF - Journal of Aging Research N2 - Rumination has been defined as a mode of responding to distress that involves passively focusing one's attention on symptoms of distress without taking action. This dysfunctional response style intensifies depressed mood, impairs interpersonal problem solving, and leads to more pessimistic future perspectives and less social support. As most of these results were obtained from younger people, it remains unclear how age affects ruminative thinking. Three hundred members of the general public ranging in age from 15 to 87 years were asked about their ruminative styles using the Response Styles Questionnaire (RSQ), depression and satisfaction with life. A Mokken Scale analysis confirmed the two-factor structure of the RSQ with brooding and reflective pondering as subcomponents of rumination. Older participants (63 years and older) reported less ruminative thinking than other age groups. Life satisfaction was associated with brooding and highest for the earlier and latest life stages investigated in this study. Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124356 VL - 2012 IS - 267327 ER -