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The Role of Attentional Control and Fear Acquisition and Generalization in Social Anxiety Disorder
(2020)
Although Social Anxiety Disorder (SAD) is one of the most prevalent mental disorders, still little is known about its development and maintenance. Cognitive models assume that deviations in attentional as well as associative learning processes play a role in the etiology of SAD. Amongst others, deficits in inhibitory attentional control as well as aberrations during fear generalization, which have already been observed in other anxiety disorders, are two candidate mechanisms that might contribute to the onset and retention of SAD. However, a review of the literature shows that there is a lack of research relating to these topics. Thus, the aim of the present thesis was to examine in which way individuals with SAD differ from healthy controls regarding attentional control and generalization of acquired fear during the processing of social stimuli.
Study 1 tested whether impairment in the inhibitory control of attention is a feature of SAD, and how it might be influenced by emotional expression and gaze direction of an interactional partner. For this purpose, individuals with SAD and healthy controls (HC) participated in an antisaccade task with faces displaying different emotional expressions (angry, neutral and happy) and gaze directions (direct and averted) serving as target stimuli. While the participants performed either pro- or antisaccades in response to the peripherally presented faces, their gaze behavior was recorded via eye-tracking, and ratings of valence and arousal were obtained. Results revealed that both groups showed prolonged latencies and increased error rates in trials with correct anti- compared to prosaccades. However, there were no differences between groups with regard to response latency or error rates, indicating that SAD patients did not exhibit impairment on inhibitory attentional control in comparison to HC during eye-tracking. Possible explanations for this finding could be that reduced inhibitory attentional control in SAD only occurs under certain circumstances, for example, when these individuals currently run the risk of being negatively evaluated by others and not in the mere presence of phobic stimuli, or when the cognitive load of a task is so high that it cannot be unwound by compensatory strategies, such as putting more effort into a task.
As not only deviations in attentional, but also associative learning processes might be pathogenic markers of SAD, these mechanisms were further addressed in the following experiments. Study 2 is the first that attempted to investigate the generalization of conditioned fear in patients with SAD. To this end, patients with SAD and HC were conditioned to two neutral female faces serving as conditioned stimuli (CS+: reinforced; CS-: non-reinforced) and a fearful face paired with a loud scream serving as unconditioned stimulus (US). Fear generalization was tested by presenting morphs of the two faces (GS: generalization stimuli), which varied in their similarity to the original faces. During the whole experiment, self-report ratings, heart rate (HR) and skin conductance responses (SCR) were recorded. Results demonstrated that SAD patients rated all stimuli as less pleasant and more arousing, and overestimated the occurrence of the US compared to HC, indicating a general hyperarousal in individuals with SAD. In addition, ratings and SCR indicated that both groups generalized their acquired fear from the CS+ to intermediate GSs as a function of their similarity to the CS+. However, except for the HR data, which indicated that only SAD patients but not HC displayed a generalization response in this measure, most of the results did not support the hypothesis that SAD is characterized by overgeneralization. A plausible reason for this finding could be that overgeneralization is just a key characteristic of some anxiety disorders and SAD is not one of them. Still, other factors, such as comorbidities in the individuals with SAD, could also have had an influence on the results, which is why overgeneralization was further examined in study 3.
The aim of study 3 was to investigate fear generalization on a neuronal level. Hence, high (HSA) and low socially anxious participants (LSA) underwent a conditioning paradigm, which was an adaption of the experimental design used study 2 for EEG. During the experiment, steady-state visually evoked potentials (ssVEPs) and ratings of valence and arousal were recorded. Analyses revealed significant generalization gradients in all ratings with highest fear responses to the CS+ and a progressive decline of these reactions with increasing similarity to the CS-. In contrast, the generalization gradient on a neuronal level showed highest amplitudes for the CS+ and a reduction in amplitude to the most proximal, but not distal GSs in the ssVEP signal, which might be interpreted as lateral inhibition in the visual cortex. The observed dissociation among explicit and implicit measures points to different functions of behavioral and sensory cortical processes during fear generalization: While the ratings might reflect an individual’s consciously increased readiness to react to threat, the lateral inhibition pattern in the occipital cortex might serve to maximize the contrast among stimuli with and without affective value and thereby improve adaptive behavior. As no group differences could be observed, the finding of study 2 that overgeneralization does not seem to be a marker of SAD is further consolidated.
In sum, the conducted experiments suggest that individuals with SAD are characterized by a general hyperarousal during the exposition to disorder-relevant stimuli as indicated by enhanced arousal and reduced valence ratings of the stimuli compared to HC. However, the hypotheses that reduced inhibitory attentional control and overgeneralization of conditioned fear are markers of SAD were mostly not confirmed. Further research is required to elucidate whether they only occur under certain circumstances, such as high cognitive load (e.g. handling two tasks simultaneously) or social stress (e.g. before giving a speech), or whether they are not characteristics of SAD at all. With the help of these findings, new interventions for the treatment of SAD can be developed, such as attentional bias modification or discrimination learning.
Both specific stimulus valence and unspecific processing dynamics can influence evaluative responses. Eight experiments investigated their respective influence on evaluative judgments in the domain of stereotyping. Valence of stereotypic information and consistency-driven fluency were manipulated in an impression formation paradigm. When information about the to-be-evaluated target person was strongly valenced, no effects of consistency-driven fluency were observed. Higher cognitive processes, valence of inconsistent attributes, processing priority of category information, and impression formation instructions were ruled out as possible factors responsible for the non-occurrence of fluency effects. However, consistency-driven fluency did influence the evaluative judgment, if the information about a target person was not strongly valenced. It is therefore concluded that both stimulus valence and consistency-driven processing fluency play a role in evaluative judgments in the domain of stereotyping. The respective impact of stimulus valence is much stronger than the impact of unspecific processing dynamics, however. Implications for fluency research and the applied field of stereotype change are discussed.
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.
The aim of this study was both to investigate the influence of cognitive control on unconscious processing, and to investigate the influence of unconscious processing on cognitive control. At first, different mechanisms and accounts to explain unconscious priming are presented. Here, perceptual and motor processes, as well as stimulus-response learning, semantic categorization, and the action trigger account as theories to explain motor priming are discussed. Then, the issue of the potential limits of unconscious processing is presented. Findings that indicate that active current intentions and expertise modulate unconscious processing are illustrated. Subsequently, results that imply an influence of unconsciously presented stimuli that goes beyond motor processes are discussed, with a special focus on inhibition processes, orienting of attention, task set activation, and conflict adaptation. Then I present the results of my own empirical work. Experiment 1 shows that the effective processing of unconsciously presented stimuli depends on expertise, even when potentially confounding difference between the expert and novice groups are controlled. The results of Experiments 2 and 3 indicate that the intention to use particular stimuli is a crucial factor for the effectiveness of these stimuli when they are presented unconsciously. Additionally, these findings show that shifts of attention can be triggered by centrally presented masked arrow cues. Experiments 4 and 5 broaden these results to cue stimuli that are not inherently associated with a spatial meaning. The finding corroborate that typically endogenously controlled shifts of attention can also be induced by unconscious stimuli. Experiments 6 and 7 demonstrate that even a central cognitive control process like task set activation is not contingent on conscious awareness, but can in contrast be triggered through unconscious stimulation. Finally, these results are integrated and I discuss how the concept of cognitive control and the limits of unconscious processing may have to be reconsidered. Furthermore, potential future research possibilities in this field are presented.
Trust carries the capacity to shift the focus from risks to opportunities of a situation. Scientific studies from the field of trust research point out that besides situation-specific factors (i.e., stimuli of the environment), cross-situationally stable interindividual differences (i.e., personality) are involved in the emergence of trust. Stable interindividual differences are particularly influential to the subjective experience of situational conditions when crucial information is incomplete. The online shopping environment classifies as a prime example of markets with asymmetric information. Research has examined online consumer trust in the light of signaling theory to understand the effects of trust-enhancing signals. Previous research largely neglects interindividual differences in the perception, processing and reaction to these signals. Against this background, this scientific work has two primary objectives: the investigation of (1) interindividual differences in the evaluation of trust-enhancing signals and (2) a personality-based personalization of trust-enhancing signals in its effect on cognition and behavior. For this purpose, an interactive online shop setup was created, which served as realistic environmental framework. First, the results show a trust-enhancing effect of both objective and subjective personalization, with a superiority of subjective over objective personalization. Second, results suggest a particular susceptibility of the beliefs component of trust. Third, the results suggest that personalization exerts a specifically strong effect in what is, by definition, the particularly uncertain environment of credence goods. Fourth, results indicate that while the trust-enhancing effects of personalization operate (largely) independently of personality, the effect of personality on trust seems to depend on the condition of signal presentation. Taken together, the present work makes a contribution to understanding the effect of personality-adapted signaling environments on the emergence of trust and decision making in the specific context of B2C e-commerce.
Research on the deployment and use of technology to assist learning has seen a significant
rise over the last decades (Aparicio et al., 2017). The focus on course quality, technology,
learning outcome and learner satisfaction in e-learning has led to insufficient attention by
researchers to individual characteristics of learners (Cidral et al., 2017 ; Hsu et al., 2013). The current work aims to bridge this gap by investigating characteristics identified by previous works and backed by theory as influential individual differences in e-learning. These learner characteristics have been suggested as motivational factors (Edmunds et al., 2012) in decisions by learners to interact and exchange information (Luo et al., 2017).
In this work e-learning is defined as interaction dependent information seeking and sharing enabled by technology. This is primarily approached from a media psychology perspective. The role of learner characteristics namely, beliefs about the source of knowledge (Schommer, 1990), learning styles (Felder & Silverman, 1988), need for affect (Maio & Esses, 2001), need for cognition (Cacioppo & Petty, 1982) and power distance (Hofstede, 1980) on interactions to seek and share information in e-learning are investigated. These investigations were shaped by theory and empirical lessons as briefly mentioned in the next paragraphs. Theoretical support for investigations is derived from the technology acceptance model(TAM) by psychologist Davis (1989) and the hyper-personal model by communication scientist Walther (1996). The TAM was used to describe the influence of learner characteristics on decisions to use e-learning systems (Stantchev et al., 2014). The hyper-personal model described why computer-mediated communication thrives in e-learning (Kaye et al., 2016) and how learners interpret messages exchanged online (Hansen et al., 2015). This theoretical framework was followed by empirical reviews which justified the use of interaction and information seeking-sharing as key components of e-learning as well as the selection of learner characteristics. The reviews provided suggestions for the measurement of variables (Kühl et al., 2014) and the investigation design (Dascalau et al., 2015). Investigations were designed and implemented through surveys and quasi experiments which were used for three preliminary studies and two main studies. Samples were selected from Germany and Ghana with same variables tested in both countries. Hypotheses were tested with interaction and information seeking-sharing as dependent variables while beliefs about the source of knowledge, learning styles, need for affect, need for cognition and power distance were independent variables. Firstly, using analyses of variance, the influence of beliefs about the source of knowledge on interaction choices of learners was supported. Secondly, the role of need for cognition on interaction choices of learners was supported by results from a logistic regression. Thirdly, results from multiple linear regressions backed the influence of need for cognition and power distance on information seeking-sharing behaviour of learners. Fourthly, the relationship between need for affect and need for cognition
was supported. The findings may have implications for media psychology research, theories used in this work, research on e-learning, measurement of learner characteristics and the design of e-learning platforms. The findings suggest that, the beliefs learners have about the source of knowledge, their need for cognition and their power distance can influence decisions to interact and seek or share information. The outlook from reviews and findings in this work predicts more research on learner characteristics and a corresponding intensity in the use of e-learning by individuals. It is suggested that future studies investigate the relationship between learner autonomy and power distance. Studies on inter-cultural similarities amongst e-learners in different populations are also
suggested.
This thesis consists of three studies investigating the influence media literacy has on political variables, cognitive variables, and learning. Adolescents from 13 years of age and young adults are included in the studies. This thesis is divided into three chapters. Study I and II are one comprehensive study, but will be presented separately for better readability. Chapter I provides the reader with background knowledge for the original studies presented in chapter II includes information about media use, different conceptualizations of media literacy and its development over the lifetime, as well as media literacy’s impact on cognitive and political variables. Additionally, current literature on the comparison of the learning outcomes of different kinds of texts (written, auditory, and audiovisual) is presented, with a differentiation between text-based information and inferences. In chapter II, the original studies are placed in the current state of research and presented in detail. In chapter III, a critical discussion of the studies is conducted, and a general model of the influence media literacy has on the investigated cognitive and political factors is presented, followed by a conclusion of the research.
The theoretical foundation of this thesis is three models of media literacy proposed by Groeben (2002, 2004), Hobbs (1997), and Potter (1998, 2016). These three models are similar in that they define media literacy as a multifactorial construct with skills that develop further in the course of life. Their ideas are integrated and developed further, leading to our own model of media literacy. It encompasses five scales: media sign literacy, distinction between reality and fiction, knowledge of media law, knowledge of media effects, and production skills. Thereupon, the assessment tool Würzburg Media Literacy Test (WMK; Würzburger Medienkompetenztest) is designed.
There is evidence that media use and media literacy influence socio-political factors. Young adults name the internet as the main source of information on political topics (see Pasek et al., 2006), and knowledge demonstrably fosters political participation (Delli Carpini & Keeter, 1996). However, the kind of participation activity regarded is important (Quintelier & Vissers, 2008), as sometimes real-life participation is supplemented by online activities (Quan-Haase & Wellman, 2002). Media literacy is the key to evaluating the quality of information from media. Whether or not a direct link between media literacy and political interest exists has, as far as I know, not yet been investigated. Several studies have shown that precursors and subcomponents of media literacy have the capacity to influence cognitive variables. For instance, children with higher media sign literacy possess better reading proficiency (Nieding et al., 2017) and are better at collecting information and drawing inferences from hypermedia and films (Diergarten et al., 2017) as compared to children with low literacy. These precursors and subcomponents are more efficient in processing medial sign systems, reducing cognitive load, and consequently, liberating cognitive capacity for other mental tasks (Sweller, 1988). Paino and Renzulli (2012) showed that highly computer-proficient adolescents exhibit better mathematics and reading abilities. Different types of media influence the learning process differently, and the learning process can be enhanced by combining these different types of media, if the material is prepared according to the research findings and Mayer’s (2002) cognitive theory of multimedia learning. Similarly, a reduction in cognitive load takes place and more resources can be invested in the learning process itself (Mayer & Moreno, 2003; Sweller, 1988). It is not easy to answer the question of whether one medium is superior for learning to another. Generally, adults learn best from written texts (e.g., Byrne & Curtis, 2000), and audiovisual and auditory texts are comparable (e.g., Hayes et al., 1986); however, there is little research regarding the comparison of the latter two.
Study I examined whether media literacy has a positive impact on interest in politics and the political self-concept. A sample of 101 13-to 20-year-olds was drawn. The control variables were intelligence, socio-economic status (SES), openness to experiences, perspective-taking, age, and sex. Additionally, an evaluation of the WMK was conducted, which indicated good construct validity and excellent overall reliability. Media literacy was positively associated with interest in politics, political self-concept, and perspective-taking but not with openness. In hierarchical regressions and path analysis, a direct influence of media literacy and openness on interest in politics could be found. Political self-concept was solely influenced by interest in politics. Although media literacy had no direct influence on political self-concept, it influenced its precursor interest in politics and was thus expected to have distal influence. The results of the first study confirm previous findings (e.g., Vecchione & Caprara, 2009), where political self-concept is regarded as a precursor of political participation. In conclusion, the findings of study I suggested that by stimulating political interest, media literacy could, mediated through political self-concept, foster political participation.
Study II (which was conducted on the same sample as study I) was concerned with the question of whether highly media-literate adolescent and young adult participants exhibit better academic skills (mathematics; reading) and academic achievement (grades) compared to less media-literate participants. Additionally, to obtain information about potential development during adolescence, a group of 50 13-year-olds was compared with a group of 51 19-year-olds in terms of their media literacy. The control variables were intelligence, SES, sex, and age. The results showed that a significant development of media literacy took place during adolescence (∆M = .17), agreeing with Potter’s (1998, 2013) development theory of media literacy. Media literacy was significantly correlated with reading skills and school grades. Regarding adults, media literacy was also significantly correlated with mathematical skills; the association was greater than that with reading skills. However, no connection with mathematical skills was found for adolescents. To control for the influence of age and intelligence, which were both associated with media literacy, hierarchical regressions and path analyses were conducted. The results revealed that media literacy had a greater impact on grades and academic abilities than intelligence. These results are in line with those obtained by Paino and Renzulli (2012).
Study III investigated whether media literacy helps young adults to better learn from three kinds of media, a written, an auditory, and an audio-visual text, and which medium achieves the best learning results. Three groups of 91 young adults were compared (written, auditory, and audio-visual text) in terms of their learning outcomes. These outcomes were conceptualized as directly stated information in the text (assessed by text-based questions) and inferential learning (inference questions). A computer-based short version of the WMK was applied to assess media literacy, which should be optimized in the future. The control variables were intelligence, verbal ability, media usage, prior knowledge, and SES. In hierarchical regression, media literacy turned out to be a significant predictor of text inferences, even when other relevant variables, such as intelligence, were controlled for. Inferences foster the building of the situation model, which is believed by many authors to be true comprehension of a text (Zwaan & Radvansky, 1998). The outcomes of study III support Ohler’s (1994) assumption that media literacy fosters the creation of a more elaborated situational model. Text-based questions were only influenced by prior knowledge. As assumed by Potter (1998, 2016), the media literacy of young adults in the Western world suffices to extract relevant facts from educational learning material. Both subjects were best in the written text condition for text-based and inference question results. Audiovisual and auditory texts showed no significant differences. The written text condition did not excel in the auditory text condition for inferences. The results accord with those obtained by, for instance, Byrne and Curtis (2000).
Taken together, these studies show that media literacy can influence several cognitive and political variables. It stimulates political interest, reading comprehension, school grades, and mathematical abilities in young adults, as well as drawing inferences from different kinds of texts. Additionally, media literacy develops further during adolescence.
Anxiety research is one of the major psychological research domains and looks back on decades of research activity. Traditionally, novel theories and approaches are tested utilizing animal models. One way to study inherent anxiety in rodents is the elevated plus-maze (EPM). The EPM is a plus-shaped platform with two closed, i.e., walled, arms and two open unwalled arms. If given the opportunity to freely explore the apparatus, rodents instinctively avoid the open arms to protect themselves from predators. Hence, they spent less time on open and more time on closed arms, which is behaviorally associated with general anxiety. In the course of the pharmacological validation, it was found that this exploratory pattern can be reversed by anxiolytic substances, e.g., benzodiazepines, or potentiated by anxiogenics. One of the significant advantages of the EPM is that no prior training session is required in contrast to conditioning studies, thus allowing to observe natural behavior. Therefore, together with the economic and uncomplicated setup, the EPM has become a standard preclinical rodent anxiety test over the decades. In order to validate these rodent anxiety tests, there have recently been attempts to retranslate them to humans. A paramount of cross-species validation is not only the simple transferability of these animal tests but also the observation of anxiety behaviors that are evolutionarily conserved across species. Accordingly, it could be possible to conclude various factors associated with the etiology and maintenance of anxiety disorders in humans. So far, convincing translations of the EPM to humans are still lacking. For that reason, the primary aim of this dissertation is to retranslate the EPM throughout three studies and to evaluate cross-species validity critically. Secondly, the undertaken studies are set out to observe ambulatory activity equivalent to rodent EPM behavior, i.e., open arm avoidance. Thirdly, the undertaken studies aimed to assess the extent to which trait anxiety influences human exploratory activity on the platform to associate it with the assumption that rodent EPM-behavior is a reflection of general anxiety. Finally, virtual reality (VR) was the method of choice to maintain the economic advantage and adjust the EPM size to humans. Study 1 (N = 30) was set up to directly transfer the rodent EPM regarding test design and experimental procedure using a Computer Automatic Virtual Environment (CAVE). The results revealed that humans unlike rodents display a general open arms approach during free exploration. However, open arm avoidance was associated with high trait anxiety and acrophobia (fear of height), which was initially assessed as a control variable due to the virtual platform height. Regression analyses and subjective anxiety ratings hinted at a more significant influence of acrophobia on open arm avoidance. In addition, it was assumed that the open arms approach might have resulted from claustrophobic tendencies experienced in the closed arms due to the high walls. Study 2 (N = 61) sought to differentiate the influence of trait anxiety and acrophobia and adapt the virtual EPM to humans. Therefore, parts of the platform held a semi-transparent grid-floor texture, and the wall height on the closed arms was reduced to standard handrail level. Moreover, participants were priorly screened to exclude clinically significant levels of acrophobia, claustrophobia, and agoraphobia. The data on general exploratory activity showed no arm preference. Regression analyses confirmed that acrophobia is related to open arm avoidance, corroborating the finding of Study 1. Surprisingly, for trait anxiety, the result of Study 1 could not be replicated. Instead, for trait anxiety, no significant effect was found indicating that predominantly fear of heights shapes human EPM behavior even on a subclinical stage. In Study 3 (N = 57), the EPM was embedded into a city setting to 1) create a more natural human environment and 2) eliminate height. Furthermore, a head-mounted display was utilized for VR presentation, and arousal ratings were introduced. Participants were screened for high and low levels of trait anxiety and agoraphobia, and claustrophobia. Replicating the findings of Study 2, no difference in open and closed arm activity was observed, and no effect was found in relationship with trait anxiety. The data on anxiety ratings and claustrophobia suggest a positive correlation indicating that in this city EPM, claustrophobic tendencies might play a role in closed arm avoidance. In summary, this thesis added valuable insights into the retranslation of a well-established standard anxiety test used in rodents. However, it also majorly challenges current findings on the cross-species validity of the EPM. Various explanatory models for the results are critically discussed and associated with clinical implications concerning future research.
The present work comprises four studies dealing with the investigation of the auditory event-related potentials (ERP) Mismatch Negativity (MMN), P300, and N400 under different attentional instructions, and with their application in patients with disorders of consciousness (DOC) to assess residual cognitive functioning. In guided interviews (study 1), practitioners working with DOC patients stated their general interest in and an objective need for the complementation of current diagnostic procedures by reliable and valid ERP-based methods. Subsequently, in study 2, simple oddball and semantic paradigms were applied to 19 behaviorally non-responsive DOC patients revealing the presence of at least one ERP in eight patients investigated. In the third and fourth study, specific attentional effects on ERPs were investigated in healthy participants to define optimal instructions and stimulus parameters. In study 3, MMN and N400 amplitudes were assessed in 18 participants, and in study 4, MMN and P300 amplitudes were assessed in 32 participants. Both studies included an ignore task (attention on simultaneous visual stimuli), a passive task, and a focused task and revealed distinct attentional effects on P300 and N400 with largest amplitudes in the focused task, smaller ones in the passive task and no ERP in the ignore task. An MMN was elicited in all tasks, but still, amplitudes differed as a function of task. In addition, study 4 included oddball paradigms comprising several deviants in different dimensions. Higher amplitudes were found in this multifeature paradigm compared to traditional oddball paradigms and larger amplitudes were elicited by deviants highly different from standards. It is concluded that ERPs represent a promising tool to complement clinical assessment of DOC patients. Application of ERP paradigms should include focused instructions, especially when using semantic material. Furthermore, multifeature paradigms have been proven especially useful eliciting large amplitudes and allowing for the investigation of several dimensions of deviants at the same time.
One primary source for self-knowledge is social comparison. Often objective criteria for self-evaluations are not available or useful and therefore comparisons with other people play a crucial role in self-evaluations. But the question is whether social comparisons could indeed provide information about the self without consuming too much cognitive resources or time. Therefore, in this research I wanted to look at practice effects in social comparison and the particular significance of routine standards. Whereas traditional research on standard selection mostly focused on goal-oriented and strategic standard selection processes, this research sets out to integrate social cognitive knowledge, ideas, and methods. Researchers from many different fields agree that people’s behavior and thinking is not fully determined by rational choices or normative considerations. Quite the contrary, factors like knowledge accessibility, habits, procedural practice, stereotyping, categorization, and many more cognitive processes play an important role. The same may be true in social comparison and standard selection. In my research I demonstrate that efficiency concerns play an important role in social comparison. Since people may not be able to engage in a strategic standard selection whenever they engage in social comparison processes, there has to be a more efficient alternative. Using routine standards would be such an alternative. The efficiency advantage of routine standards may thereby be founded not only in the abandonment of a strategic but arduous standard selection process, but also in a higher efficiency of the comparison process itself. I therefore set out to show how the use of routine standards facilitates the social comparison processes. This was done in three steps. First, I replicated and improved our former research (Mussweiler & Rüter, 2003, JPSP) indicating that people really do use their best friends as routine standards to evaluate themselves. Second, I demonstrated that it is more efficient to compare with a routine standard than with another standard. In Studies 2 and 3 I therefore show that comparisons between the self and a routine standard (either a natural routine standard like the best friend or a experimentally induced routine standard based on practice) are faster and more efficient than comparisons with other standards. Finally, I looked at the underlying mechanism of the efficiency advantage of routine standards. The results of Studies 4 and 5 point out, that both general as well as specific practice effects occur with repeated comparisons. Whereas a specific practice effect implies the repeated processing of the same content (i.e., knowledge about the routine standard), general practice effects indicate that the pure process (i.e., comparing the self with a routine standard) becomes more efficient regardless whether new content (i.e., comparison relevant knowledge) has to be processed. Taken together, the efficiency advantage of routine standards during self-evaluation is based not only on the lack of necessity for an arduous standard selection, but is additionally supported by the facilitation of the comparison process itself. The efficiency of routine standards may provide an explanation as to why people base self-evaluations on comparisons with these standards and dispense with strategic considerations to select the most suitable standard.