TY  - THES
A1  - Leinfelder, Teresa
T1  - Untersuchung von Trainingseffekten bei der Verwendung einer auditorischen P300-basierten EEG Gehirn-Computer Schnittstelle mittels fMRI Analyse
T1  - Investigation of training effects of a P300-based EEG brain-computer interface using fMRI analysis
N2  - In dieser Dissertation untersuchten wir die neuronalen Korrelate des Training-Effektes einer auditorischen P300 Gehirn-Computer Schnittstelle mittels fMRI Analyse in einem prä-post Design mit zehn gesunden Testpersonen. Wir wiesen in drei Trainings-sitzungen einen Trainingseffekt in der EEG-Analyse der P300 Welle nach und fanden entsprechende Kontraste in einer prä-post Analyse von fMRI Daten, wobei in allen fünf Sitzungen das gleiche Paradigma verwendet wurde. In der fMRI Analyse fanden wir fol-gende Ergebnisse: in einem Target-/ Nichttarget Kontrast zeigte sich verstärkte Aktivie-rung in Generatorregionen der P300 Welle (temporale und inferiore frontale Regionen) und interessanterweise auch in motorassoziierten Arealen, was höhere kognitiver Pro-zesse wie Aufmerksamkeitslenkung und Arbeitsspeicher widerspiegeln könnte. Der Kon-trast des Trainingseffektes zeigte nach dem Training einen stärkeren Rebound Effekt im Sinne einer verstärkten Aktivierung in Generatorregionen der P300 Welle, was eine ver-besserte Erkennung und Prozessierung von Target-Stimuli reflektieren könnte. Eine Ab-nahme von Aktivierung in frontalen Arealen in diesem Kontrast könnte durch effizientere Abläufe kognitiver Prozesse und des Arbeitsgedächtnis erklärt werden.
N2  - In this dissertation we investigated the neuronal correlates of the training effect of an auditory P300-based brain-computer interface using fMRI analysis in a prae-post de-sign in a group of ten healthy probands. We showed a training effect during three training sessions with EEG analysis of the P300 wave and found corresponding contrasts in a prae-post analysis of fMRI data, while using the same paradigma in all sessions. In the fMRI analysis we found the following results: in a target / nontarget contrast we found enhancement of activation in generator regions of the P300 wave such as temporal and inferior frontal areas and interestingly also in motor associated areas which could reflect higher cognitive processes such as attention and working memory. In the contrast of the effects of training we found a stronger rebound effect as a correlate of stronger activation after training in generator regions of P300, possibly reflecting better discrimination and processing of stimuli. The decrease of activation in frontal areas in this contrast could be explained by increased efficiency of cognitive processing and working memory through training.
KW  - Gehirn-Computer-Schnittstelle
KW  - Neurofeedback
KW  - Ereigniskorreliertes Potenzial
KW  - Funktionelle Kernspintomografie
KW  - auditorisches Neurofeedback Training
KW  - P300 Welle
KW  - EEG
KW  - BCI
KW  - ALS
KW  - auditory
KW  - fMRI Analyse
KW  - prä-post Design
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-290683
ER  - 
TY  - JOUR
A1  - Rodrigues, Johannes
A1  - Weiß, Martin
A1  - Mussel, Patrick
A1  - Hewig, Johannes
T1  - On second thought … the influence of a second stage in the ultimatum game on decision behavior, electro-cortical correlates and their trait interrelation
JF  - Psychophysiology
N2  - Previous EEG research only investigated one stage ultimatum games (UGs). We investigated the influence of a second bargaining stage in an UG concerning behavioral responses, electro-cortical correlates and their moderations by the traits altruism, anger, anxiety, and greed in 92 participants. We found that an additional stage led to more rejection in the 2-stage UG (2SUG) and that increasing offers in the second stage compared to the first stage led to more acceptance. The FRN during a trial was linked to expectance evaluation concerning the fairness of the offers, while midfrontal theta was a marker for the needed cognitive control to overcome the respective default behavioral pattern. The FRN responses to unfair offers were more negative for either low or high altruism in the UG, while high trait anxiety led to more negative FRN responses in the first stage of 2SUG, indicating higher sensitivity to unfairness. Accordingly, the mean FRN response, representing the trait-like general electrocortical reactivity to unfairness, predicted rejection in the first stage of 2SUG. Additionally, we found that high trait anger led to more rejections for unfair offer in 2SUG in general, while trait altruism led to more rejection of unimproving unfair offers in the second stage of 2SUG. In contrast, trait anxiety led to more acceptance in the second stage of 2SUG, while trait greed even led to more acceptance if the offer was worse than in the stage before. These findings suggest, that 2SUG creates a trait activation situation compared to the UG.
KW  - bargaining behavior
KW  - two-stage ultimatum game
KW  - reward positivity/FRN/MFN/N2
KW  - trait activation in two-stage ultimatum game,
KW  - midfrontal theta
KW  - fairness evaluation vs. cognitive effort
KW  - EEG
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318983
VL  - 59
IS  - 7
ER  -