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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Affektive und kognitive Desensibilisierung als Konsequenz von Mediengewaltkonsum : eine experimentelle Untersuchung auf Basis lerntheoretischer Überlegungen / Affective and cognitive desensitization as a consequence of violent media exposure : an experimental investigation based on learning theories

Busching, Robert January 2014 (has links)
NutzerInnen von gewalthaltigen Medien geben einerseits oftmals zu, dass sie fiktionale, gewalthaltige Medien konsumieren, behaupten jedoch gleichzeitig, dass dies nicht ihr Verhalten außerhalb des Medienkontexts beeinflusst. Sie argumentieren, dass sie leicht zwischen Dingen, die im fiktionalen Kontext und Dingen, die in der Realität gelernt wurden, unterscheiden können. Im Kontrast zu diesen Aussagen zeigen Metanalysen Effektstärken im mittleren Bereich für den Zusammenhang zwischen Gewaltmedienkonsum und aggressivem Verhalten. Diese Ergebnisse können nur erklärt werden, wenn MediennutzerInnen gewalthaltige Lernerfahrungen auch außerhalb des Medienkontexts anwenden. Ein Prozess, der Lernerfahrungen innerhalb des Medienkontexts mit dem Verhalten in der realen Welt verknüpft, ist Desensibilisierung, die oftmals eine Reduktion des negativen Affektes gegenüber Gewalt definiert ist. Zur Untersuchung des Desensibilisierungsprozesses wurden vier Experimente durchgeführt. Die erste in dieser Arbeit untersuchte Hypothese war, dass je häufiger Personen Gewaltmedien konsumieren, desto weniger negativen Affekt zeigen sie gegenüber Bildern mit realer Gewalt. Jedoch wurde angenommen, dass diese Bewertung auf Darstellungen von realer Gewalt beschränkt ist und nicht bei Bildern ohne Gewaltbezug, die einen negativen Affekt auslösen, zu finden ist. Die zweite Hypothese bezog sich auf den Affekt während des Konsums von Mediengewalt. Hier wurde angenommen, dass besonders Personen, die Freude an Gewalt in den Medien empfinden weniger negativen Affekt gegenüber realen Gewaltdarstellungen zeigen. Die letzte Hypothese beschäftigte sich mit kognitiver Desensibilisierung und sagte vorher, dass Gewaltmedienkonsum zu einem Transfer von Reaktionen, die normalerweise gegenüber gewalthaltigen Reizen gezeigt werden, auf ursprünglich neutrale Reize führt. Das erste Experiment (N = 57) untersuchte, ob die habituelle Nutzung von gewalthaltigen Medien den selbstberichteten Affekt (Valenz und Aktivierung) gegenüber Darstellungen von realer Gewalt und nichtgewalthaltigen Darstellungen, die negativen Affekt auslösen, vorhersagt. Die habituelle Nutzung von gewalthaltigen Medien sagte weniger negative Valenz und weniger allgemeine Aktivierung gegenüber gewalthalten und nichtgewalthaltigen Bildern vorher. Das zweite Experiment (N = 103) untersuchte auch die Beziehung zwischen habituellem Gewaltmedienkonsum und den affektiven Reaktionen gegenüber Bildern realer Gewalt und negativen affektauslösenden Bildern. Als weiterer Prädiktor wurde der Affekt beim Betrachten von gewalthaltigen Medien hinzugefügt. Der Affekt gegenüber den Bildern wurde zusätzlich durch psychophysiologische Maße (Valenz: C: Supercilii; Aktivierung: Hautleitreaktion) erhoben. Wie zuvor sagte habitueller Gewaltmedienkonsum weniger selbstberichte Erregung und weniger negative Valenz für die gewalthaltigen und die negativen, gewalthaltfreien Bilder vorher. Die physiologischen Maßen replizierten dieses Ergebnis. Jedoch zeigte sich ein anderes Muster für den Affekt beim Konsum von Gewalt in den Medien. Personen, die Gewalt in den Medien stärker erfreut, zeigen eine Reduktion der Responsivität gegenüber Gewalt auf allen vier Maßen. Weiterhin war bei drei dieser vier Maße (selbstberichte Valenz, Aktivität des C. Supercilii und Hautleitreaktion) dieser Zusammenhang auf die gewalthaltigen Bilder beschränkt, mit keinem oder nur einem kleinen Effekt auf die negativen, aber nichtgewalthaltigen Bilder. Das dritte Experiment (N = 73) untersuchte den Affekt während die Teilnehmer ein Computerspiel spielten. Das Spiel wurde eigens für dieses Experiment programmiert, sodass einzelne Handlungen im Spiel mit der Aktivität des C. Supercilii, dem Indikator für negativen Affekt, in Bezug gesetzt werden konnten. Die Analyse des C. Supercilii zeigte, dass wiederholtes Durchführen von aggressiven Spielzügen zu einem Rückgang von negativen Affekt führte, der die aggressiven Spielhandlungen begleitete. Der negative Affekt während gewalthaltiger Spielzüge wiederum sagte die affektive Reaktion gegenüber Darstellungen von gewalthaltigen Bildern vorher, nicht jedoch gegenüber den negativen Bildern. Das vierte Experiment (N = 77) untersuchte kognitive Desensibilisierung, die die Entwicklung von Verknüpfungen zwischen neutralen und aggressiven Kognitionen beinhaltete. Die Teilnehmer spielten einen Ego-Shooter entweder auf einem Schiff- oder einem Stadtlevel. Die Beziehung zwischen den neutralen Konstrukten (Schiff/Stadt) und den aggressiven Kognitionen wurde mit einer lexikalischen Entscheidungsaufgabe gemessen. Das Spielen im Schiff-/Stadt-Level führte zu einer kürzen Reaktionszeit für aggressive Wörter, wenn sie einem Schiff- bzw. Stadtprime folgten. Dies zeigte, dass die im Spiel enthaltenen neutralen Konzepte mit aggressiven Knoten verknüpft werden. Die Ergebnisse dieser vier Experimente wurden diskutiert im Rahmen eines lerntheoretischen Ansatzes um Desensibilisierung zu konzeptualisieren. / Users of violent media often state that they consume fictional violent media and claim that this does not influence their behavior outside of the media context. Media users reason that they can easily distinguish between things learned in a fictional context and things learned in reality. In contrast to these claims, meta-analyses report medium-sized effects between media violence consumption and aggressive behavior. These effects can only be explained if media users also apply learning experiences from the media outside the media context. One of the processes linking learning experiences in the media context to behavior in the real word is desensitization, which is often defined as a reduction of negative affect towards violence. To investigate the process of desensitization, four experiments were conducted. The first hypothesis investigated in these experiments was that persons who have a higher level of violent media exposure show less negative affect towards depictions of real violence compared to persons with a lower level. However, it was assumed that this reduction in reaction would be limited to depictions of real violence and would not be found in response to depictions of nonviolent pictures electing negative affect. The second hypothesis referred to the role of affect experienced during exposure to media depictions of violence, assuming that especially people who enjoy the violence while consuming the media show less negative affect towards depictions of real violence. The final hypothesis addressed cognitive desensitization effects and predicted that media violence use leads to transfer effects from responses to violent cues to initially neutral stimuli The first experiment (N = 57) examined to what extent the habitual use of media violence predicts the self-reported affect (Valence and Arousal) towards depictions of real violence and nonviolent pictures eliciting negative affect. Habitual media violence exposure predicted less negative valence and less arousal toward violent pictures and negative nonviolent pictures. The second experiment (N = 103) also examined the relationship between habitual media violence exposure and the affective reactions towards images of real violence as well as negative, nonviolent scenes. Additionally, affect while watching violent media was added as a second predictor. The affect toward the images was also obtained by psychophysical measures (Valence: activity of C. Supercilii; Activation: skin conductance). As in experiment 1, habitual media violence exposure predicted less self-reported negative valence and less self-reported arousal for the violent pictures and the negative nonviolent pictures. The physiological measures replicated this result. However, a different pattern emerged for the enjoyment of violent media. People who enjoyed violent media more showed a reduction of affective responsivity toward violence on all four different measures. Additionally, for three of the four measures (skin conductance, self-reported negative valence and the activity on the C. Supercilii) this relationship was limited to the violent pictures, with no or little effect on the negative, but nonviolent pictures. A third experiment (N = 73) studied affect while participants played a violent computer game. A game was specially programmed in which specific actions could be linked to the activity of the C. Supercilii, an indicator for negative affect. The analysis of the C. Supercilii showed that repeatedly performing aggressive actions during the game led to a decline in negative affect accompanying the aggressive actions. The negative affect during aggressive actions in turn predicted less negative affective responses to violent images of real-life violence but not to nonviolent, negative images. The fourth experiment (N=77) showed cognitive desensitization effects, which involved the formation of links between neutral and aggressive cognitions. Participants played a first-person shooter game either on a ship or a city level. The relationship between neutral constructs (ship/city) and aggressive cognitions was measured using a lexical decision task. Playing the game in a ship/city level led to shorter reaction time for aggressive words following ship/city primes respectively. This indicated that the neutral concepts introduced in the game had become associated with aggressive cognitions. The findings of these four experiments are discussed in terms of a learning theory approach to conceptualizing desensitization.
2

Empirical Evaluation of Machine Learning Algorithms based on EMG, ECG and GSR Data to Classify Emotional States

Pandey, Amare Ketsela Tesfaye and Amrit January 2013 (has links)
The peripheral psychophysiological signals (EMG, ECG and GSR) of 13 participants were recorded in the well planned Cognition and Robotics lab at BTH University and 9 participants data were taken for further processing. Thirty(30) pictures of IAPS were shown to each participant individually as stimuli, and each picture was displayed for five-second intervals. Signal preprocessing, feature extraction and selection, models, datasets formation and data analysis and interpretation were done. The correlation between a combination of EMG, ECG and GSR signal and emotional states were investigated. 2- Dimensional valence-arousal model was used to represent emotional states. Finally, accuracy comparisons among selected machine learning classification algorithms have performed. Context: Psychophysiological measurement is one of the recent and popular ways to identify emotions when using computers or robots. It can be done using peripheral signals: Electromyography (EMG), Electrocardiography (ECG) and Galvanic Skin Response (GSR). The signals from these measurements are considered as reliable signals and can produce the required data. It is further carried out by preprocessing of data, feature selection and classification. Classification of EMG, ECG and GSR data can be conducted with appropriate machine learning algorithms for better accuracy results. Objectives: In this study, we investigate and analyzed with psychophysiological (EMG, ECG and GSR) data to find best classifier algorithm. Our main objective is to classify those data with appropriate machine learning techniques. Classifications of psychophysiological data are useful in emotion recognition. Therefore, our ultimate goal is to provide validated classified psychological measures for the automated adoption of human robot performance. Methods: We conducted a literature review in order to answer RQ1. The sources used are Inspec/ Compendex, IEEE, ACM Digital Library, Google Scholar and Springer Link. This helps us to identify suitable features required for the classification after reading the articles and papers that are peer reviewed as well as lie relevant to the area. Similarly, this helps us to select appropriate machine learning algorithms. We conducted an experiment in order to answer RQ2 and RQ3. A pilot experiment, then after main experiment was conducted in the Cognition and Robotics lab at the university. An experiment was conducted to take measures from EMG, ECG and GSR signal. Results: We obtained different accuracy results using different sets of datasets. The classification accuracy result was best given by the Support Vector Machine algorithm, which gives up to 59% classified emotional states correctly. Conclusions: The psychophysiological signals are very inconsistent with individual participant for specific emotion. Hence, the result we got from the experiment was higher with a single participant than all participants were together. Although, having large number of instances are good to train the classifier well. / The thesis is focused to classify emotional states from physiological signals. Features extraction and selection of the physiological signal was done, which was used for dataset formation and then classification of those emotional states. IAPS pictures were used to elicit emotional/affective states. Experiment was conducted with 13 participants in cognition and Robotics lab using biosensors EMG, ECG and GSR at BTH University. Nine participants data were taken for further preprocessing. We observed in our thesis the classification of emotions which could be analyzed by a combination of psychophysiological signal as Model A and Model B. Since signals of subjects are different for same emotional state, the accuracy was better for single participant than all participants together. Classification of emotional states is useful for HCI and HRI to manufacture emotional intelligence robot. So, it is essential to provide best classifier algorithms which can be helpful to detect emotions for developing emotional intelligence robots. Our work contribution lies in providing best algorithms for emotion recognition for psychophysiological data and selected features. Most of the results showed that SVM performed best with classification accuracy up to 59 % for single participant and 48.05 % for all participants together. For a single dataset and single participant, we found 60.17 % accuracy from MLP but it consumed more time and memory than other algorithms during classification. The rest of the algorithms like BNT, Naive Bayes, KNN and J48 also gave competitive accuracy to SVM. We conclude that SVM algorithm for emotion recognition from a combination of EMG, ECG and GSR is capable of handling and giving better classification accuracy among others. Tally between IAPS pictures with SAM helped to remove less correlated signals and to obtain better accuracies. Still the obtained results are small in percentage. Therefore, more participants are probably needed to get a better accuracy result over the whole dataset. / amarehenry@gmail.com ; Mobile: 0767042234 amrit.pandey111@gmail.com ; Mobile : 0704763190
3

Validating User Engagement and Effectiveness of Training Simulations : A mixed-methods approach informed by embodied cognition and psychophysiological measures / Validering av användarengagemang och effektivitet hos träningssimulatorer : En kombinerad metodansats informerad av kroppslig kognition och psyko-fysiologiska mått

Ekanayake, Hiran B. January 2015 (has links)
Simulation-based training has gained widespread attention recently as a response to drawbacks associated with traditional training approaches, such as high training costs (instructors, equipment, etc.), high risks (e.g. pilot training), and ethical issues (e.g. medical training), as well as a lack of availability of certain training environments (e.g. space exploration). Apart from their target training domains, many of aspects of simulations differ, such as their degree of physical realism (fidelity), scenarios (e.g. story), and pedagogical aspects (e.g. after-action reviews and collaborative learning). Among those aspects, designers have mostly focused on developing high-fidelity simulations with the expectation of increasing the effectiveness of training. However, some authors suggest that the above belief is a myth as researchers have failed to identify a linear relationship between the (physical) fidelity and training effectiveness of simulations.  Most researchers have therefore evaluated the correspondence between the behaviours of trainees in both real world and simulated contexts, however, the existing methods of simulation validation using behavioural measures have a number of drawbacks, such as the fact that they do not address certain complex phenomena of skills acquisition. Bridging the above knowledge gap, this research reports on empirical investigations using an improved methodology for validating training simulations. This research includes an investigation of the user experience of trainees, with respect to the acceptance of virtual scenarios provoking a similar psychophysiological response as in real world scenarios, and the training potential of simulations with respect to the positive transfer of training from a simulator to real world operational contexts. The most prominent features of the proposed methodology include the use of psychophysiological measures in addition to traditional behavioural measures and the use of natural (quasi-) experiments. Moreover, its conceptual framework was influenced by contemporary theories in cognitive science (e.g. constructivism and embodied cognition). The results of this research have several important theoretical and methodological implications, involving, for example, the dependency of the effectiveness of simulations on the perceived realism of trainees, which is more embodied than has been predicted by previous researchers, and the requirement of several different types/levels of adaptive training experience, depending on the type of trainee. / Träning i simulatorer har på senare år fått ökad uppmärksamhet som en respons på problem och svårigheter förknippade med traditionella träningsansatser, såsom höga kostnader (instruktörer och utrustning, etc.), hög risk (t.ex. träning av piloter), och etiska aspekter (t.ex. träning av kirurger), likaväl som avsaknaden av träningsmöjligheter och miljöer (t.ex. forskning om rymden). Bortsett från vad som specifikt tränas så skiljer sig simuleringar åt i ett flertal olika aspekter såsom fysisk realism (eng. fidelity), scenarier (handling) och pedagogiska aspekter (t.ex. genomgång efter övning och kollaborativt lärande).  Bland dessa aspekter så har designers ofta fokuserat att utveckla simuleringar med hög realism med förväntningen att detta ska göra träningen mer effektiv. Litteraturen antyder dock att denna föreställning inte stämmer och att de flesta simuleringar med hög realism inte har lyckats uppnå denna målsättning. En slutsats är därför att det finns ett behov av metoder som kan validera potentialen hos simuleringar avsedda att stödja träning – redan innan dessa används. Enligt litteraturen så är utbildningspotentialen hos en simulering starkt kopplad till hur väl den psykologiska effekten en simulering har, stämmer överens med en verklig upplevelse. Forskning har emellertid identifierat ett flertal svagheter hos existerande ansatser för att validera simuleringar; de är oftast baserade på prestations- och/eller subjektiva mätningar; de har fokuserat en eller ett fåtal psykologiska aspekter; och de bygger på traditionella teorier. Baserat på resultat från studier av en kör-simulator presenteras och föreslås i denna avhandling ett förbättrat ramverk för utvärdering. De mest centrala egenskaperna hos det föreslagna ramverket inbegriper användandet av psyko-fysiologiska mått tillsammans med mer traditionella mått; det konceptuella ramverket bygger på samtida teoretiska ansatser (tex konstruktivism och kroppslig kognition); samt användandet av fält (kvasi-) experiment. Utöver uppnåendet av uppsatta mål för forskningen så har resultaten ett flertal teoretiska och metodologiska implikationer. Bland dessa återfinns beroendet mellan effektiviteten hos en simulering och den upplevelse av realitet som de tränade har, vilken är mer grundläggande än vad som rapporterats i tidigare forskning, samt kravet på flera och olika typer av anpassning av träningsupplevelse för den tränade för att förhöja potentialen hos träningssimulatorer. / SIDA Funded National e-Learning Centre Project at the University of Colombo School of Computing, Sri Lanka

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