@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}
}
@phdthesis{Kopf2018,
  author    = {Kopf, Juliane},
  title     = {Emotion processing and working memory deficits in Bipolar Disorder: interactions and changes from acute to remitted state},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97752},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2018},
  abstract  = {BD is a severe and highly prevalent psychiatric illness characterized by oscillating mood episodes, where patients express either depressed mood, anhedonia, decreased activation along with concentration difficulties and sleep disturbances, or elevated mood with hyperactivity and loss of inhibitions. Between mood episodes, patients return to a relatively normal state of functioning without mood symptoms. Previous research on underlying neuronal mechanisms has led to a model of neuronal dysfunction in BD which states that BD arises from disruption in early development within brain networks that modulate emotional behavior. These abnormalities in the structure and function of key emotional control networks then lead to decreased connectivity among ventral prefrontal networks and limbic brain regions. This in turn creates a loss of emotional homeostasis, putting bipolar patients at risk for developing extreme mood states and switching among mood states. Two core components for BD have been identified, a hyperactive emotion processing system and a hypoactive cognitive functions system. It is controversial whether these deficits are still detectable in euthymia, so it is unclear if hyper- and hypoactivations represent state or trait-like characteristics. The aim of this study was to research both core components of BD with a paradigm eliciting differential activations in both cognitive and emotion processing networks. For this, an emotional word working memory paradigm was constructed to test for differences between manic, depressive, and remitted patients as well as a healthy control group. Differences were assessed in behavior, brain activation (as a correlate for the hypoactive cognitive functions system), measured with near-infrared spectroscopy (fNIRS), and electrophysiological changes in the late positive potential (as a correlate for the hyperactive emotion processing system), an event-related potential (ERP) measured with electroencephalography. 47 patients in the acutely ill phase and 45 healthy controls were measured. Of the 47 patients, 18 returned to the clinic for a second testing while in remission for at least 3 months. Acutely ill patients were classified into 4 groups according to their disorder status: a mildly depressed group, a depressed group, a manic group, and a mixed group along DSM-IV criteria. Analyses were calculated for 3 load conditions (1-back, 2-back and 3-back) and 3 valence conditions (negative, neutral, positive) for behavioral measures reaction time and omission errors, for brain activation and event related potential changes. Results indicate that ill patients differed from controls in their behavioral performance, but the difference in performance was modulated by the mood state they were in. Depressed patients showed the most severe differences in all behavioral measures, while manic and mixed patients differed from controls only upon different valence conditions. Brain activation changes were most pronounced in mildly depressed and manic patients, depressed patients and mixed patients did not differ as much from controls. ERP changes showed a significant difference only between mixed patients and controls, where mixed patients had an overall much higher ERP amplitude. When remitted patients were compared to controls, no differences in behavior, brain activation or ERP amplitude could be found. However, the same was true for differences in patients between acutely ill and remitted state. When looking at the overall data, the following conclusion can be drawn: assuming that the brain activation seen in the prefrontal cortex is part of the dorsal cognitive system, then this is the predominantly disturbed system in depressed patients who show only small changes in the ERP. In contrast, the predominantly disturbed system in manic and mixed patients is the ventral emotion processing system, which can be seen in a hyper-activation of ERP related neural correlates in mixed and hypo-activated neural correlates of the LPP in manic patients. When patients are remitted, the cognitive system regains temporary stability, and can be compared to that of healthy controls, while the emotion processing system remains dysfunctional and underlies still detectable performance deficits.},
  subject      = {Manisch-depressive Krankheit},
  language  = {en}
}
@article{RealKotchoubeyKuebler2014,
  author    = {Real, Ruben G. L. and Kotchoubey, Boris and K{\"u}bler, Andrea},
  title     = {Studentized continuous wavelet transform (t-CWT) in the analysis of individual ERPs: real and simulated EEG data},
  doi       = {10.3389/fnins.2014.00279},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-113581},
  year      = {2014},
  abstract  = {This study aimed at evaluating the performance of the Studentized Continuous Wavelet Transform (t-CWT) as a method for the extraction and assessment of event-related brain potentials (ERP) in data from a single subject. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of the t-CWT were assessed and compared to a variety of competing procedures using simulated EEG data at six low signal-to-noise ratios. Results show that the t-CWT combines high sensitivity and specificity with favorable PPV and NPV. Applying the t-CWT to authentic EEG data obtained from 14 healthy participants confirmed its high sensitivity. The t-CWT may thus be well suited for the assessment of weak ERPs in single-subject settings.},
  language  = {en}
}