@phdthesis{Weiss2020,
  author    = {Weiß, Martin},
  title     = {The neural principles of behavior modification using socioemotional facial feedback cues in economic decision-making},
  doi       = {10.25972/OPUS-20865},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-208654},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2020},
  abstract  = {The present dissertation aims to shed light on different mechanisms of socio-emotional feedback in social decision-making situations. The objective is to evaluate emotional facial expressions as feedback stimuli, i.e., responses of interaction partners to certain social decisions. In addition to human faces, artificial emojis are also examined due to their relevance for modern digital communication. Previous research on the influence of emotional feedback suggests that a person's behavior can be effectively reinforced by rewarding stimuli. In the context of this dissertation, the differences in the feedback processing of human photographs and emojis, but also the evaluation of socially expected versus socially unexpected feedback were examined in detail in four studies. In addition to behavioral data, we used the electroencephalogram (EEG) in all studies to investigate neural correlates of social decision-making and emotional feedback. As the central paradigm, all studies were based on a modified ultimatum game. The game is structured as follows: there is a so-called proposer who holds a specific amount of money (e.g., 10 cents) and offers the responder a certain amount (e.g., 3 cents). The responder then decides whether to accept or reject the offer. In the version of the ultimatum game presented here, different types of proposers are introduced. After the participants have accepted or rejected in the role of the responder, the different proposers react to the participant's decision with specific emotional facial expressions. Different feedback patterns are used for the individual experiments conducted in the course of this dissertation. In the first study, we investigated the influence of emotional feedback on decision-making in the modified version of the ultimatum game. We were able to show that a proposer who responds to the acceptance of an offer with a smiling face achieves more accepted offers overall than a control proposer who responds to both accepted and rejected offers with a neutral facial expression. Consequently, the smile served as a positive reinforcement. Similarly, a sad expression in response to a rejected offer also resulted in higher acceptance rates as compared to the control identity, which could be considered an expression of compassion for that proposer. On a neuronal level, we could show that there are differences between simply looking at negative emotional stimuli (i.e., sad and angry faces) and their appearance as feedback stimuli after rejected offers in the modified ultimatum game. The so-called feedback-related negativity was reduced (i.e., more positive) when negative emotions appeared as feedback from the proposers. We argued that these findings might show that the participants wanted to punish the proposers by rejecting an offer for its unfairness and therefore the negative feedback met their expectations. The altered processing of negative emotional facial expressions in the ultimatum game could therefore indicate that the punishment is interpreted as successful. This includes the expectation that the interaction partner will change his behavior in the future and eventually make fairer offers. In the second study we wanted to show that smiling and sad emojis as feedback stimuli in the modified ultimatum game can also lead to increased acceptance rates. Contrary to our assumptions, this effect could not be observed. At the neural level as well, the findings did not correspond to our assumptions and differed strongly from those of the first study. One finding, however, was that the neural P3 component showed how the use of emojis as feedback stimuli particularly characterizes certain types of proposers. This is supported by the fact that the P3 is increased for the proposer who rewards an acceptance with a smile as well as for the proposer who reacts to rejection with a sad emoji compared to the neutral control proposer. The third study examined the discrepancy between the findings of the first and second study. Accordingly, both humans and emojis representing the different proposers were presented in the ultimatum game. In addition, emojis were selected that showed a higher similarity to known emojis from common messenger services compared to the second study. We were able to replicate that the proposers in the ultimatum game, who reward an acceptance of the offer with a smile, led to an increased acceptance rate compared to the neutral control proposers. This difference is independent of whether the proposers are represented by emojis or human faces. With regard to the neural correlates, we were able to demonstrate that emojis and human faces differ strongly in their neural processing. Emojis showed stronger activation than human faces in the face-processing N170 component, the feedback-related negativity and the P3 component. We concluded that the results of the N170 and feedback-related negativity could indicate a signal for missing social information of emojis compared to faces. The increased P3 amplitude for emojis might imply that emojis appear unexpectedly as reward stimuli in a social decision task compared to human faces. The last study of this project dealt with socially unexpected feedback. In comparison to the first three studies, new proposer identities were implemented. In particular, the focus was on a proposer who reacted to the rejection of an offer unexpectedly with a smile and to the acceptance with a neutral facial expression. According to the results, participants approach this unexpected smile through increased rejection, although it is accompanied by financial loss. In addition, as reported in studies one and three, we were able to show that proposers who respond to the acceptance of an offer with a smiling face and thus meet the expectations of the participants have higher offer acceptance rates than the control proposer. At the neuronal level, especially the feedback from the socially unexpected proposer led to an increased P3 amplitude, which indicates that smiling after rejection is attributed a special subjective importance. The experiments provide new insights into the social influence through emotional feedback and the processing of relevant social cues. Due to the conceptual similarity of the studies, it was possible to differentiate between stable findings and potentially stimulus-dependent deviations, thus creating a well-founded contribution to the current research. Therefore, the novel paradigm presented here, and the knowledge gained from it could also play an important role in the future for clinical questions dealing with limited social competencies.},
  subject      = {Entscheidungsverhalten},
  language  = {en}
}
@phdthesis{Rodrigues2016,
  author    = {Rodrigues, Johannes},
  title     = {Let me change your mind… Frontal brain activity in a virtual T-maze},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-143280},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {Frontal asymmetry, a construct invented by Richard Davidson, linking positive and negative valence as well as approach and withdrawal motivation to lateralized frontal brain activation has been investigated for over thirty years. The frontal activation patterns described as relevant were measured via alpha-band frequency activity (8-13 Hz) as a measurement of deactivation in electroencephalography (EEG) for homologous electrode pairs, especially for the electrode position F4/ F3 to account for the frontal relative lateralized brain activation. Three different theories about frontal activation patterns linked to motivational states were investigated in two studies. The valence theory of Davidson (1984; 1998a; 1998b) and its extension to the motivational direction theory by Harmon-Jones and Allen (1998) refers to the approach motivation with relative left frontal brain activity (indicated by relative right frontal alpha activity) and to withdrawal motivation with relative right frontal brain activation (indicated by relative left frontal alpha activity). The second theory proposed by Hewig and colleagues (2004; 2005; 2006) integrates the findings of Davidson and Harmon - Jones and Allen with the reinforcement sensitivity theory of Jeffrey A. Gray (1982, 1991). Hewig sees the lateralized frontal approach system and withdrawal system proposed by Davidson as subsystems of the behavioral activation system proposed by Gray and bilateral frontal activation as a biological marker for the behavioral activation system. The third theory investigated in the present studies is the theory from Wacker and colleagues (2003; 2008; 2010) where the frontal asymmetrical brain activation patterns are linked to the revised reinforcement sensitivity theory of Gray and McNaughton (2000). Here, right frontal brain activity (indicated by lower relative right frontal alpha activity) accounts for conflict, behavioral inhibition and activity of the revised behavioral inhibition system, while left frontal brain activation (indicated by lower relative left frontal alpha activity) stands for active behavior and the activity of the revised behavioral activation system as well as the activation of the revised flight fight freezing system. In order to investigate these three theories, a virtual reality T-maze paradigm was introduced to evoke motivational states in the participants, offering the opportunity to measure frontal brain activation patterns via EEG and behavior simultaneously in the first study. In the second study the virtual reality paradigm was additionally compared to mental imagery and a movie paradigm, two well-known state inducing paradigms in the research field of frontal asymmetry. In the two studies, there was confirming evidence for the theory of Hewig and colleages (2004; 2005; 2006), showing higher bilateral frontal activation for active behavior and lateralized frontal activation patterns for approach (left frontal brain activation) and avoidance (right frontal brain activation) behavior. Additionally a limitation for the capability model of anterior brain asymmetry proposed by Coan and colleagues (2006), where the frontal asymmetry should be dependent on the relevant traits driving the frontal asymmetry pattern if a relevant situation occurs, could be found. As the very intense virtual reality paradigm did not lead to a difference of frontal brain activation patterns compared to the mental imagery paradigm or the movie paradigm for the traits of the participants, the trait dependency of the frontal asymmetry in a relevant situation might not be given, if the intensity of the situation exceeds a certain level. Nevertheless there was an influence of the traits in the virtual reality T-maze paradigm, because the shown behavior in the maze was trait-dependent. The implications of the findings are multifarious, leading from possible objective personality testing via diversification of the virtual reality paradigm to even clinical implications for depression treatments based on changes in the lateralized frontal brain activation patterns for changes in the motivational aspects, but also for changes in bilateral frontal brain activation when it comes to the drive and preparedness for action in patients. Finally, with the limitation of the capability model, additional variance in the different findings about frontal asymmetry can be explained by taking the intensity of a state manipulation into account.},
  subject      = {Electroencephalographie},
  language  = {en}
}
@phdthesis{Ulrich2016,
  author    = {Ulrich, Natalie},
  title     = {Processing of Near Outcomes and Outcome Sequences in Gambling: Implications for the Biopsychological Basis of Problem Gambling},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-139612},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2016},
  abstract  = {Gambling is a popular activity in Germany, with 40\% of a representative sample reporting having gambled at least once in the past year (Bundeszentrale f{\"u}r gesundheitliche Aufkl{\"a}rung, 2014). While the majority of gamblers show harmless gambling behavior, a subset develops serious problems due to their gambling, affecting their psychological well-being, social life and work. According to recent estimates, up to 0.8\% of the German population are affected by such pathological gambling. People in general and pathological gamblers in particular show several cognitive distortions, that is, misconceptions about the chances of winning and skill involvement, in gambling. The current work aimed at elucidating the biopsychological basis of two such kinds of cognitive distortions, the illusion of control and the gambler's and hot hand fallacies, and their modulation by gambling problems. Therefore, four studies were conducted assessing the processing of near outcomes (used as a proxy for the illusion of control) and outcome sequences (used as a proxy for the gambler's and hot hand fallacies) in samples of varying degrees of gambling problems, using a multimethod approach. The first study analyzed the processing and evaluation of near outcomes as well as choice behavior in a wheel of fortune paradigm using electroencephalography (EEG). To assess the influence of gambling problems, a group of problem gamblers was compared to a group of controls. The results showed that there were no differences in the processing of near outcomes between the two groups. Near compared to full outcomes elicited smaller P300 amplitudes. Furthermore, at a trend level, the choice behavior of participants showed signs of a pattern opposite to the gambler's fallacy, with longer runs of an outcome color leading to increased probabilities of choosing this color again on the subsequent trial. Finally, problem gamblers showed smaller feedback-related negativity (FRN) amplitudes relative to controls. The second study also targeted the processing of near outcomes in a wheel of fortune paradigm, this time using functional magnetic resonance imaging and a group of participants with varying degrees of gambling problems. The results showed increased activity in the bilateral superior parietal cortex following near compared to full outcomes. The third study examined the peripheral physiology reactions to near outcomes in the wheel of fortune. Heart period and skin conductance were measured while participants with varying degrees of gambling problems played on the wheel of fortune. Near compared to full outcomes led to increased heart period duration shortly after the outcome. Furthermore, heart period reactions and skin conductance responses (SCRs) were modulated by gambling problems. Participants with high relative to low levels of gambling problems showed increased SCRs to near outcomes and similar heart period reactions to near outcomes and full wins. The fourth study analyzed choice behavior and sequence effects in the processing of outcomes in a coin toss paradigm using EEG in a group of problem gamblers and controls. Again, problem gamblers showed generally smaller FRN amplitudes compared to controls. There were no differences between groups in the processing of outcome sequences. The break of an outcome streak led to increased power in the theta frequency band. Furthermore, the P300 amplitude was increased after a sequence of previous wins. Finally, problem gamblers compared to controls showed a trend of switching the outcome symbol relative to the previous outcome symbol more often. In sum, the results point towards differences in the processing of near compared to full outcomes in brain areas and measures implicated in attentional and salience processes. The processing of outcome sequences involves processes of salience attribution and violation of expectations. Furthermore, problem gamblers seem to process near outcomes as more win-like compared to controls. The results and their implications for problem gambling as well as further possible lines of research are discussed.},
  subject      = {Spielsucht},
  language  = {en}
}