@article{EidelKuebler2020, author = {Eidel, Matthias and K{\"u}bler, Andrea}, title = {Wheelchair Control in a Virtual Environment by Healthy Participants Using a P300-BCI Based on Tactile Stimulation: Training Effects and Usability}, series = {Frontiers in Human Neuroscience}, volume = {14}, journal = {Frontiers in Human Neuroscience}, issn = {1662-5161}, doi = {10.3389/fnhum.2020.00265}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-207775}, year = {2020}, abstract = {Tactile stimulation is less frequently used than visual for brain-computer interface (BCI) control, partly because of limitations in speed and accuracy. Non-visual BCI paradigms, however, may be required for patients who struggle with vision dependent BCIs because of a loss of gaze control. With the present study, we attempted to replicate earlier results by Herweg et al. (2016), with several minor adjustments and a focus on training effects and usability. We invited 16 healthy participants and trained them with a 4-class tactile P300-based BCI in five sessions. Their main task was to navigate a virtual wheelchair through a 3D apartment using the BCI. We found significant training effects on information transfer rate (ITR), which increased from a mean of 3.10-9.50 bits/min. Further, both online and offline accuracies significantly increased with training from 65\% to 86\% and 70\% to 95\%, respectively. We found only a descriptive increase of P300 amplitudes at Fz and Cz with training. Furthermore, we report subjective data from questionnaires, which indicated a relatively high workload and moderate to high satisfaction. Although our participants have not achieved the same high performance as in the Herweg et al. (2016) study, we provide evidence for training effects on performance with a tactile BCI and confirm the feasibility of the paradigm.}, language = {en} } @article{KueblerHautzingerLudolphetal.2014, author = {K{\"u}bler, Andrea and Hautzinger, Martin and Ludolph, Albert and Dickhaus, Thorsten and Real, Ruben G. L.}, title = {Well-being in amyotrophic lateral sclerosis: a pilot experience sampling study}, doi = {10.3389/fpsyg.2014.00704}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-113057}, year = {2014}, abstract = {Objective: The aim of this longitudinal study was to identify predictors of instantaneous well-being in patients with amyotrophic lateral sclerosis (ALS). Based on flow theory well-being was expected to be highest when perceived demands and perceived control were in balance, and that thinking about the past would be a risk factor for rumination which would in turn reduce well-being. Methods: Using the experience sampling method, data on current activities, associated aspects of perceived demands, control, and well-being were collected from 10 patients with ALS three times a day for two weeks. Results: Results show that perceived control was uniformly and positively associated with well-being, but that demands were only positively associated with well-being when they were perceived as controllable. Mediation analysis confirmed thinking about the past, but not thinking about the future, to be a risk factor for rumination and reduced well-being. Discussion: Findings extend our knowledge of factors contributing to well-being in ALS as not only perceived control but also perceived demands can contribute to well-being. They further show that a focus on present experiences might contribute to increased well-being.}, language = {en} } @article{KueblerBlankertzKleihetal.2014, author = {K{\"u}bler, Andrea and Blankertz, Benjamin and Kleih, Sonja C. and Kaufmann, Tobias and Hammer, Eva M.}, title = {Visuo-motor coordination ability predicts performance with brain-computer interfaces controlled by modulation of sensorimotor rhythms (SMR)}, doi = {10.3389/fnhum.2014.00574}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-113084}, year = {2014}, abstract = {Modulation of sensorimotor rhythms (SMR) was suggested as a control signal for brain-computer interfaces (BCI). Yet, there is a population of users estimated between 10 to 50\% not able to achieve reliable control and only about 20\% of users achieve high (80-100\%) performance. Predicting performance prior to BCI use would facilitate selection of the most feasible system for an individual, thus constitute a practical benefit for the user, and increase our knowledge about the correlates of BCI control. In a recent study, we predicted SMR-BCI performance from psychological variables that were assessed prior to the BCI sessions and BCI control was supported with machine-learning techniques. We described two significant psychological predictors, namely the visuo-motor coordination ability and the ability to concentrate on the task. The purpose of the current study was to replicate these results thereby validating these predictors within a neurofeedback based SMR-BCI that involved no machine learning.Thirty-three healthy BCI novices participated in a calibration session and three further neurofeedback training sessions. Two variables were related with mean SMR-BCI performance: (1) a measure for the accuracy of fine motor skills, i.e., a trade for a person's visuo-motor control ability; and (2) subject's "attentional impulsivity". In a linear regression they accounted for almost 20\% in variance of SMR-BCI performance, but predictor (1) failed significance. Nevertheless, on the basis of our prior regression model for sensorimotor control ability we could predict current SMR-BCI performance with an average prediction error of M = 12.07\%. In more than 50\% of the participants, the prediction error was smaller than 10\%. Hence, psychological variables played a moderate role in predicting SMR-BCI performance in a neurofeedback approach that involved no machine learning. Future studies are needed to further consolidate (or reject) the present predictors.}, language = {en} } @article{KaufmannHerwegKuebler2014, author = {Kaufmann, Tobias and Herweg, Andreas and K{\"u}bler, Andrea}, title = {Toward brain-computer interface based wheelchair control utilizing tactually-evoked event-related potentials}, doi = {10.1186/1743-0003-11-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-110042}, year = {2014}, abstract = {Background People with severe disabilities, e.g. due to neurodegenerative disease, depend on technology that allows for accurate wheelchair control. For those who cannot operate a wheelchair with a joystick, brain-computer interfaces (BCI) may offer a valuable option. Technology depending on visual or auditory input may not be feasible as these modalities are dedicated to processing of environmental stimuli (e.g. recognition of obstacles, ambient noise). Herein we thus validated the feasibility of a BCI based on tactually-evoked event-related potentials (ERP) for wheelchair control. Furthermore, we investigated use of a dynamic stopping method to improve speed of the tactile BCI system. Methods Positions of four tactile stimulators represented navigation directions (left thigh: move left; right thigh: move right; abdomen: move forward; lower neck: move backward) and N = 15 participants delivered navigation commands by focusing their attention on the desired tactile stimulus in an oddball-paradigm. Results Participants navigated a virtual wheelchair through a building and eleven participants successfully completed the task of reaching 4 checkpoints in the building. The virtual wheelchair was equipped with simulated shared-control sensors (collision avoidance), yet these sensors were rarely needed. Conclusion We conclude that most participants achieved tactile ERP-BCI control sufficient to reliably operate a wheelchair and dynamic stopping was of high value for tactile ERP classification. Finally, this paper discusses feasibility of tactile ERPs for BCI based wheelchair control.}, language = {en} } @article{MeuleKueblerBlechert2013, author = {Meule, Adrian and K{\"u}bler, Andrea and Blechert, Jens}, title = {Time course of electrocortical food-cue responses during cognitive regulation of craving}, series = {Frontiers in Psychology}, volume = {4}, journal = {Frontiers in Psychology}, number = {669}, issn = {1664-1078}, doi = {10.3389/fpsyg.2013.00669}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122566}, year = {2013}, abstract = {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.}, language = {en} } @article{KleihHerwegKaufmannetal.2015, author = {Kleih, Sonja C. and Herweg, Andreas and Kaufmann, Tobias and Staiger-S{\"a}lzer, Pit and Gerstner, Natascha and K{\"u}bler, Andrea}, title = {The WIN-speller: a new intuitive auditory brain-computer interface spelling application}, series = {Frontiers in Neuroscience}, volume = {9}, journal = {Frontiers in Neuroscience}, doi = {10.3389/fnins.2015.00346}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125972}, pages = {346}, year = {2015}, abstract = {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.}, language = {en} } @article{KueblerHolzRiccioetal.2014, author = {K{\"u}bler, Andrea and Holz, Elisa M. and Riccio, Angela and Zickler, Claudia and Kaufmann, Tobias and Kleih, Sonja C. and Staiger-S{\"a}lzer, Pit and Desideri, Lorenzo and Hoogerwerf, Evert-Jan and Mattia, Donatella}, title = {The User-Centered Design as Novel Perspective for Evaluating the Usability of BCI-Controlled Applications}, doi = {10.1371/journal.pone.0112392}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111051}, year = {2014}, abstract = {Albeit research on brain-computer interfaces (BCI) for controlling applications has expanded tremendously, we still face a translational gap when bringing BCI to end-users. To bridge this gap, we adapted the user-centered design (UCD) to BCI research and development which implies a shift from focusing on single aspects, such as accuracy and information transfer rate (ITR), to a more holistic user experience. The UCD implements an iterative process between end-users and developers based on a valid evaluation procedure. Within the UCD framework usability of a device can be defined with regard to its effectiveness, efficiency, and satisfaction. We operationalized these aspects to evaluate BCI-controlled applications. Effectiveness was regarded equivalent to accuracy of selections and efficiency to the amount of information transferred per time unit and the effort invested (workload). Satisfaction was assessed with questionnaires and visual-analogue scales. These metrics have been successfully applied to several BCI-controlled applications for communication and entertainment, which were evaluated by end-users with severe motor impairment. Results of four studies, involving a total of N = 19 end-users revealed: effectiveness was moderate to high; efficiency in terms of ITR was low to high and workload low to medium; depending on the match between user and technology, and type of application satisfaction was moderate to high. The here suggested evaluation metrics within the framework of the UCD proved to be an applicable and informative approach to evaluate BCI controlled applications, and end-users with severe impairment and in the locked-in state were able to participate in this process.}, language = {en} } @article{MeuleKuebler2012, author = {Meule, Adrian and K{\"u}bler, Andrea}, title = {The translation of substance dependence criteria to food-related behaviors: different views and interpretations.}, series = {Frontiers in psychiatry}, journal = {Frontiers in psychiatry}, doi = {10.3389/fpsyt.2012.00064}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123092}, year = {2012}, abstract = {No abstract available.}, language = {en} } @article{KleihDahmsBotrelKuebler2021, author = {Kleih-Dahms, Sonja Christina and Botrel, Loic and K{\"u}bler, Andrea}, title = {The influence of motivation and emotion on sensorimotor rhythm-based brain-computer interface performance}, series = {Psychophysiology}, volume = {58}, journal = {Psychophysiology}, number = {8}, doi = {10.1111/psyp.13832}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259664}, year = {2021}, abstract = {While decades of research have investigated and technically improved brain-computer interface (BCI)-controlled applications, relatively little is known about the psychological aspects of brain-computer interfacing. In 35 healthy students, we investigated whether extrinsic motivation manipulated via monetary reward and emotional state manipulated via video and music would influence behavioral and psychophysiological measures of performance with a sensorimotor rhythm (SMR)-based BCI. We found increased task-related brain activity in extrinsically motivated (rewarded) as compared with nonmotivated participants but no clear effect of emotional state manipulation. Our experiment investigated the short-term effect of motivation and emotion manipulation in a group of young healthy subjects, and thus, the significance for patients in the locked-in state, who may be in need of a BCI, remains to be investigated.}, language = {en} } @article{JinAllisonKaufmannetal.2012, author = {Jin, Jing and Allison, Brendan Z. and Kaufmann, Tobias and K{\"u}bler, Andrea and Zhang, Yu and Wang, Xingyu and Cichocki, Andrzej}, title = {The Changing Face of P300 BCIs: A Comparison of Stimulus Changes in a P300 BCI Involving Faces, Emotion, and Movement}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {11}, doi = {10.1371/journal.pone.0049688}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134173}, pages = {e49688}, year = {2012}, abstract = {Background: One of the most common types of brain-computer interfaces (BCIs) is called a P300 BCI, since it relies on the P300 and other event-related potentials (ERPs). In the canonical P300 BCI approach, items on a monitor flash briefly to elicit the necessary ERPs. Very recent work has shown that this approach may yield lower performance than alternate paradigms in which the items do not flash but instead change in other ways, such as moving, changing colour or changing to characters overlaid with faces. Methodology/Principal Findings: The present study sought to extend this research direction by parametrically comparing different ways to change items in a P300 BCI. Healthy subjects used a P300 BCI across six different conditions. Three conditions were similar to our prior work, providing the first direct comparison of characters flashing, moving, and changing to faces. Three new conditions also explored facial motion and emotional expression. The six conditions were compared across objective measures such as classification accuracy and bit rate as well as subjective measures such as perceived difficulty. In line with recent studies, our results indicated that the character flash condition resulted in the lowest accuracy and bit rate. All four face conditions (mean accuracy >91\%) yielded significantly better performance than the flash condition (mean accuracy = 75\%). Conclusions/Significance: Objective results reaffirmed that the face paradigm is superior to the canonical flash approach that has dominated P300 BCIs for over 20 years. The subjective reports indicated that the conditions that yielded better performance were not considered especially burdensome. Therefore, although further work is needed to identify which face paradigm is best, it is clear that the canonical flash approach should be replaced with a face paradigm when aiming at increasing bit rate. However, the face paradigm has to be further explored with practical applications particularly with locked-in patients.}, language = {en} }