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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.
41

Strategische Interaktion realer Agenten: ganzheitliche Konzeptualisierung und Softwarekomponenten einer interdisziplinären Forschungsinfrastruktur

Tagiew, Rustam 11 February 2011 (has links)
Zum Verständnis menschlichen sozialen, administrativen und wirtschaftlichen Verhaltens, das als Spiel bzw. strategische Interaktion aufgefasst werden kann, reichen die rein analytischen Methoden nicht aus. Es ist nötig, Daten menschlichen strategischen Verhaltens zu sammeln. Basierend auf Daten lässt sich solches Verhalten modellieren, simulieren bzw. vorhersagen. Der theoretische Teil der Zielsetzung wird über praxisorientierte Konzeptualisierung strategischer Interaktion realer Agenten - Menschen und Maschinen - und gegenseitige Integration der Konzepte aus Spieltheorie und Multiagentensysteme erreicht, die über die bisherigen Ansätze hinausgehen. Der praktische Teil besteht darin, ein allgemein verwendbares System zu entwerfen, das strategische Interaktionen zwischen realen Agenten mit maximalen wissenschaftlichen Nutzen durchführen kann. Die tatsächliche Implementation ist eines der Ergebnisse der Arbeit. Ähnliche vorhandene Systeme sind GDL-Server (für Maschinen) [Genesereth u.a., 2005] und z-Tree (für Menschen) [Fischbacher, 2007]. Die Arbeit ist in drei Bereiche unterteilt - (1) Entwicklung von Sprachen für die Beschreibung eines Spiels, (2) ein auf diesen Sprachen basierendes Softwaresystem und (3) eine Offline-Analyse der u.a. mit dem System bereits gesammelten Daten als Beitrag zur Möglichkeiten der Verhaltensbeschreibung. Die Innovation dieser Arbeit besteht nicht nur darin ,einzelne Bereiche mit einander zu kombinieren, sondern auch Fortschritte auf jedem Bereich für sich allein zu erreichen. Im Bereich der Spielbeschreibungssprachen, werden zwei Sprachen - PNSI und SIDL - vorgeschlagen, die beide Spiele bei imperfekter Information in diskreter Zeit definieren können. Dies ist ein Fortschritt gegenüber der bisherigen Sprachen wie Gala und GDL. Speziell die auf Petrinetzen basierende Sprache PNSI kann gleichermaßen für Gameserver und für spieltheoretische Algorithmen von z.B. GAMBIT verwendet werden. Das entwickelte System FRAMASI basiert auf JADE [Bellifemine u.a., 2001] und ist den bisherigen Client-Server-Lösungen durch Vorteile der Multiagentensysteme voraus. Mit dem entstandenen System wurde bereits ein Experiment entsprechend den Standards der experimentellen Spieltheorie durchgeführt und somit die Praxistauglichkeit nachgewiesen. Das Experiment hatte als Ziel, Daten zur menschlichen Unvorhersagbarkeit und zur Vorhersagefähigkeit anderer zu liefen. Dafür wurden Varianten von \"Knobeln\" verwendet. Die Daten dieses Experiments sowie eines Experiments einer externen Arbeitsgruppe mit ähnlicher Motivation wurden mit Hilfe von Datamining analysiert. Dabei wurden die in der Literatur berichteten Gesetzmäßigkeiten des Verhaltens nachgewiesen und weitere Gesetzmäßigkeiten entdeckt.:Einführung Grundlagen Verwandte Arbeiten Sprachen für Spielbeschreibung Implementation der Spielinfrastruktur Beschreibung Strategischen Verhaltens Resümee Ergebnisse Ausblick / To understand human social, administrative and economic behavior, which can be considered as a game or strategic interaction, the purely analytical methods do not suffice. It is necessary to gather data of human strategic behavior. Based on data, one can model, simulate and predict such behavior. The theoretical part of the objective is achieved using a practice oriented conceptualization of the real agents\' - humans and machines - strategic interaction and mutual integration of the concepts from game theory and multi-agent systems, which go beyond the related work. The practical part is the design of an universally usable system that can perform the strategic interactions between real agents with maximum scientific benefit. The current implementation is one of the results of the work. Similar existing systems are GDL-server (for machines) [Genesereth et al., 2005] and z-Tree (for humans) [Fischbacher, 2007]. The work is divided in three fields - (1) development of languages for the description of a game, (2) a software system based on these languages and (3) an offline analysis of the data already gathered among other things using the system as a contribution to behavior definition facilities. The innovation of this work does not consist only in combining of the several fields to each other, but also in achieving of improvements in every field on its own. In the field of game definition languages, two languages are proposed - PNSI and SIDL, which both can define games of imperfect information in discrete time. It is an improvement comparing with hitherto languages as Gala and GDL. Especially, the Petri net based language PNSI can likewise be used for game servers and game theoretic algorithms like GAMBIT. The developed system FRAMASI is based on JADE [Bellifemine et al., 2001] and is ahead of the hitherto client-server solutions through the advantages of the multi-agent systems. Using the originated system, an experiment has been conducted according to the standards from the experimental game theory, and thus demonstrated the practicability. The experiment had the objective to provide data on the human unpredictability and the ability to predict others. Therefore, variants of Roshambo were used. The data from this experiment and from an experiment of an external workgroup with a similar motivation were analyzed using data mining. As results, the regularities of the behavior reported in literature have been demonstrated and further regularities have been discovered.:Einführung Grundlagen Verwandte Arbeiten Sprachen für Spielbeschreibung Implementation der Spielinfrastruktur Beschreibung Strategischen Verhaltens Resümee Ergebnisse Ausblick
42

Virtuelle Nothilfe - Ein Experiment zum Effekt von virtueller Hilfe, Gewalt und Nothilfe auf Hilfe- und Gewaltverhalten / Virtual Emergency Assistance - The Effect of Virtual Helping, Aggression and Emergency Assistance on Helping and Aggressive Behavior

Mohseni, M. Rohangis 23 July 2013 (has links)
A recent meta-analysis of Anderson and colleagues (2010) shows that violent behavior in computer games promotes violent behavior in real-life and inhibits prosocial behavior. A couple of studies conducted by Greitemeyer and Osswald (2010) lead to the conclusion that helping behavior in computer games furthers helping behavior in real-life. There exist no studies examining the combined effect of violence and helping in computer games, although this combination is typical for violent video games (Anderson et al., 2010). In violent RPGs, a lot of tasks consist of helping someone by using violence. The present study addresses this issue and bridges the current empirical gap by investigating if violent emergency assistance furthers helping behavior and/or violent behavior in real-life. To accomplish that, the role-playing game “Oblivion” was modified to create four different experimental conditions: (1) violent emergency assistance, (2) killing, (3) helping, and (4) treasure hunting. Comparing these conditions, violent emergency assistance seemingly reduces helping behavior in real-life and at the same time furthers violent behavior. The results are in unison with the moral management model (Hartmann & Vorderer, 2010; Hartmann, in press), which is based on Banduras Theory of Moral Disengagement (Bandura, 2002).
43

Context Effects in Early Visual Processing and Eye Movement Control

Nortmann, Nora 29 April 2015 (has links)
There is a difference between the raw sensory input to the brain and our stable perception of entities in the environment. A first approach to investigate perception is to study relationships between properties of currently presented stimuli and biological correlates of perceptual processes. However, it is known that such processes are not only dependent on the current stimulus. Sampling of information and the concurrent neuronal processing of stimulus content rely on contextual relationships in the environment, and between the environment and the body. Perceptual processes dynamically adjust to relevant context, such as the current task of the organism and its immediate history. To understand perception, we have to study how processing of current stimulus content is influenced by such contextual factors. This thesis investigates the influence of such factors on visual processing. In particular, it investigates effects of temporal context in early visual processing and the effect of task context in eye movement control. To investigate effects of contextual factors on early visual processing of current stimulus content, we study neuronal processing of visual information in the primary visual cortex. We use real-time optical imaging with voltage sensitive dyes to capture neuronal population activity in the millisecond range across several millimeters of cortical area. To characterize the cortical layout concerning the mapping of orientation, previous to further investigations, we use smoothly moving grating stimuli. Investigating responses to this stimulus type systematically, we find independent encoding of local contrast and orientation, and a direct mapping of current stimulus content onto cortical activity (Study 1). To investigate the influence of the previous stimulus as context on processing of current stimulus content, we use abrupt visual changes in sequences of modified natural images. In earlier studies, investigating relatively fast timescales, it was found that the primary visual cortex continuously represents current input (ongoing encoding), with little interference from past stimuli. We investigate whether this coding scheme generalizes to cases in which stimuli change more slowly, as frequently encountered in natural visual input. We use sequences of natural scene contours, comprised of vertically and horizontally filtered natural images, their superpositions, and a blank stimulus, presented with 10 or 33 Hz. We show that at the low temporal frequency, cortical activity patterns do not encode the present orientations but instead reflect their relative changes in time. For example, when a stimulus with horizontal orientation is followed by the superposition of both orientations, the pattern of cortical activity represents the newly added vertical orientations instead of the full sum of orientations. Correspondingly, contour removal from the superposition leads to the representation of orientations that have disappeared rather than those that remain. This is in sharp contrast to more rapid sequences for which we find an ongoing representation of present input, consistent with earlier studies. In summary, we find that for slow stimulus sequences, populations of neurons in the primary visual cortex are no longer tuned to orientations within individual stimuli but instead represent the difference between consecutive stimuli. Our results emphasize the influence of the temporal context on early visual processing and consequentially on information transmission to higher cortical areas (Study 2). To study effects of contextual factors on the sampling of visual information, we focus on human eye movement control. The eyes are actively moved to sample visual information from the environment. Some traditional approaches predict eye movements solely on simple stimulus properties, such as local contrasts (stimulus-driven factors). Recent arguments, however, emphasize the influence of tasks (task context) and bodily factors (spatial bias). To investigate how contextual factors affect eye movement control, we quantify the relative influences of the task context, spatial biases and stimulus-driven factors. Participants view and classify natural scenery and faces while their eye movements are recorded. The stimuli are composed of small image patches. For each of these patches we derive a measure that quantifies stimulus-driven factors, based on the image content of a patch, and spatial viewing biases, based on the location of the patch. Utilizing the participants’ classification responses, we additionally derive a measure, which reflects the information content of a patch in the context of a given task. We show that the effect of spatial biases is highest, that task context is a close runner-up, and that stimulus-driven factors have, on average, a smaller influence. Remarkably, all three factors make independent and significant contributions to the selection of viewed locations. Hence, in addition to stimulus-driven factors and spatial biases, the task context contributes to visual sampling behavior and has to be considered in a model of human eye movements. Visual processing of current stimulus content, in particular visual sampling behavior and early processing, is inherently dependent on context. We show that already in the first cortical stage, temporal context strongly affects the processing of new visual information and that visual sampling by eye movements is significantly influenced by the task context, independently of spatial factors and stimulus-driven factors. The empirical results presented provide foundations for an improved theoretical understanding of the role of context in perceptual processes.
44

I can't let go: Personality, Behavioral, and Neural Correlates of Persistent, Intrusive Thought in Depression

Eggert, Lucas 24 April 2013 (has links)
Though a major illness in modern society, depression is still not completely understood. A number of empirical observations point to the importance of basic cognitive processes as well as personality variables as antecedents of a depressive disorder. In this work it is argued that “state orientation”, a personality style characterized by the inability to actively influence one’s focus of thought, plays an important role in the development of at least some forms of major depressive disorder. In the present work, it is suggested that (1) state-oriented cognitions are equivalent to sustained information processing, that (2) depressed individuals are characterized in particular by state-oriented cognitions related to prior failure experiences, that (3) sustained processing of affective information will interfere with normal executive cognitive functioning in depressed individuals resulting in impairments of normal behavior, and that (4) both sustained information processing and “affective interference” will be associated with specific dysfunctional patterns of brain activity in depressed individuals. In the first chapter of this thesis, theorizing pertaining to “action control” and the relationship between action control and state orientation are reviewed. After having established the potential functional significance of state-oriented cognitions, their possible link to depression is developed by introducing the “degenerated-intention hypothesis”. Afterwards, the role of state orientation in the advent of the depressive state is discussed against the background of the “functional helplessness” model of depression. Next, recent empirical findings related to executive dysfunction associated with state-oriented cognitions in major depressive disorder and related dysfunctional patterns of brain activity are reviewed. By considering evidence from studies on executive functioning, brain imaging, and neurophysiological studies, support is found for a possible frontocingulate dysfunction associated with a state-oriented cognitive style underlying a major depressive disorder. Consistent with the proposed link between depression and state orientation, in the second chapter of the thesis, Studies 1a – 1c demonstrate that subclinically and clinically depressed individuals are specifically characterized by failure-related state orientation. Moreover, the results of Study 2, described in Chapter 3, reveal that sustained processing of affectively valenced information may indeed interfere with subsequent executive cognitive functioning, especially in individuals demonstrating relatively high levels of depression. Finally, in line with the idea that sustained information processing and affective interference will be related to an individual’s level of state orientation and will be reflected in specific patterns of neural activity, Study 3, presented in Chapter 4, provides considerable evidence for disturbed brain function in clinically depressed individuals during processing of affective information as well as subsequent executive cognitive functioning and its relation to state-oriented thought. The current research supports the idea that state orientation, in particular its failure-focused form, is a crucial process involved in the development and maintenance of a depressive disorder. Specifically, the present findings suggest that certain forms of major depressive disorder are associated with sustained processing of affective information and with the resulting affective interference with executive cognitive functioning. Findings further suggest that sustained information processing is experienced by affected individuals as ruminative, state-oriented thought on past aversive experiences, and that both sustained information processing and affective interference are associated with distinct patterns of brain activity, which are related to early stimulus evaluation, conflict monitoring, and conflict resolution. The processes possibly underlying some forms of depression, as proposed in this thesis, comprise what may be called “the spinning mind”, whose important functional significance is to hinder an individual from adaptive behavior by impairing the ability to direct thought. Although state orientation may therefore appear to be maladaptive per se, it may be argued instead that this mode of action control is also an adaptive process as long as critical limits of certain parameters are met and the spinning mind is prevented. These and similar considerations are addressed in the concluding discussion in Chapter 5.
45

Shaping the field

Perlina, Anna 18 November 2016 (has links)
Die vorliegende wissenschaftliche Arbeit rekonstruiert die Entwicklung der deutschen Psychologie zwischen der Eröffnung des ersten psychologischen Labors in 1879 und der Gleichschaltung durch das Nazi-Regime in den 1930er Jahren. Die Dissertation stellt den konzeptuellen und methodologischen Rahmen der psychologischen Disziplin anhand von drei Generationen von Pionierforschung dar. Hierbei wird herausgearbeitet, wie sich die frühe experimentelle Psychologie einen eigenen Platz zwischen den Natur- und Geisteswissenschaften kreiert. Die gestaltpsychologische Schule spielt darin eine entscheidende Rolle. Der zentrale Fokus der Arbeit liegt in der historischen Periode zwischen 1922 und 1936, über welche sich Kurt Lewins Untersuchungen zur Handlungs- und Affektpsychologie erstrecken. In dieser deutschen Schaffensperiode wurden der theoretische und methodologische Rahmen, sowie praktische experimentelle Designs erschaffen, welche die amerikanische Arbeit Lewins entscheidend prägten. Der Aufbau von Lewins berühmter Feldtheorie wird im Detail rekonstruiert. Die Dissertation zeigt auf, wie Lewin originelle psychologische Konzepte aus interdisziplinärer Erfahrung formte, und wie experimentelle Praktiken der Zeit die Entstehung eines immer komplexer werdenden Konzeptgerüstes herbeiführten. Anschließend wird die Bedeutung des Gestalt-Lewin-Falles für die Psychologiegeschichte erörtert. In die langfristige Wissenschaftsgeschichte ist Lewins Arbeit nicht etwa als gebündeltes Forschungsgebiet eingegangen. Stattdessen ist sie in so unterschiedliche Bereiche wie Entwicklungs- und Persönlichkeitspsychologie, Soziologie und Wirtschaftsmanagement eingeflossen und hat diese geprägt. / This dissertation represents a historical reconstruction of the development and transformation of German experimental psychology between the emergence of the first experimental laboratory in 1879 and its Gleichschaltung by the Nazi regime in the 1930s. It traces the evolution of the conceptual as well as the experimental framework of psychology over the course of these years following three generations of experimental research. Hereby, the work attempts to grasp how early experimental psychology negotiated its place between the humanities and the natural sciences. The project’s major focus lies in the period between 1922 and 1936, in which Kurt Lewin’s Berlin Experimental Program on Action and Emotions took place. The work specifically investigates the process of constitution of Lewin’s field theory, a system of concepts coined by Lewin in order to study psychological processes underlying human conduct. The dissertation shows how Lewin’s concepts emerged out of interdisciplinary sources, and how experimental practices in psychology triggered the emergence of new knowledge. Eventually, it is shown how the investigated historical case of Gestalt psychology in Berlin fits into and plays a decisive role in the long-term development of experimental psychology.

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