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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.
511

How brain images reveal cognition an ethnographic study of meaning-making in brain mapping practice /

Alač, Morana. January 2006 (has links)
Thesis (Ph. D.)--University of California, San Diego, 2006. / Title from first page of PDF file (viewed September 19, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
512

Neurobiological aspect of suicide; a review of low cerebrospinal 5 hydroxyindoleacetic acid concentration and prediction of suicidality

Osmanovic, Almira January 2007 (has links)
<p>Finding an indicator that can point to a high risk group for suicide has long been a desirable aid for the prevention of completed suicides. The studies reviewed in this essay presume that a biological aspect can point out the high risk individual. The focus of the studies lies on the serotonin 5-hydroxytryptamine (5-HT) monoamine neurotransmitter and cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5-HIAA) which is the principal metabolite of 5-HT in depression. The studies on 5-HT metabolites have led to the belief that these may play a key role in the neurochemistry of suicidal behaviour. It is suggested that the core behavioural effect of low CSF 5-HIAA concentration might result in an increase in impulsive and violent behaviour to self and others. The predictability is based on the fact that patients with low CSF 5-HIAA are more prone to reattempt and complete suicide by violent means. A number of well-designed studies concerning suicidal individuals and control subjects have however not shown any difference in concentration of CSF 5-HIAA in suicide attempters compared to non-suicide attempters which could be explained by methodological flaws. Low CSF 5-HIAA does seem to characterize the high risk individual, but it is not yet determined what role it plays in actual suicidality.</p>
513

Evolutionary Psychology - Sex Differences in Spatial Abilities

Wendelholt, Erica January 2008 (has links)
<p>Sex differences in spatial ability, especially mental rotation, navigation and object-location memory are described in this essay. Biological differences in brain morphology, hormones and genes between men and women are presented as explanations for the sex differences. Another level of explanations offered are evolutionary, hence the most influential evolutionary psychological theories are summarized and evaluated. These theories are Gaulin’s and Fitzgerald’s male range theory, Silverman’s and Eals’s hunter-gatherer theory, and Ecuyer-Dab’s and Robert’s twofold selection theory. The hunter-gatherer theory at present seems to be of the most importance, though the twofold selection theory may in the future challenge it. Regardless, united biological and evolutionary explanations would create the best comprehensive theory.</p>
514

Individual pains and social gains : the personal and social consequences of collective dysphoric rituals

Kavanagh, Christopher January 2016 (has links)
This thesis presents the results of a multi-method exploration of the effects of collective dysphoric rituals on self-identification, group affiliation, and prosocial behaviour. Findings are presented from a worldwide sample of martial artists, student participants in artificial ritual experiments, and observers and performers of Shinto firewalking festivals in Japan. The thesis tests recent predictions of the Modes of Religiosity theory in regards to the psychological processes that underpin shared dysphoric rituals and various costly signalling theories concerning the group orientated consequences of participating in extreme ritual events. The results from the studies raise questions with the broader generalisability of recent findings linking collective dysphoric rituals and inclusive self- identification and urge for a more nuanced appraisal of associations with prosocial behaviour. Furthermore, the role of subjective positive assessment of dysphoric experiences is shown to be a topic that has been unduly overlooked and preliminary evidence is provided for a potential relationship with identity fusion. Methodologically the thesis presents a series of novel artificial ritual studies that offer initial evidence in support of shared dysphoria's ability to enhance cooperation and promote positive ingroup association.
515

Ritual in development : improving children's ability to delay gratification

Rybanska, Veronika January 2016 (has links)
To be accepted into social groups, individuals must internalise and reproduce appropriate group conventions, such as rituals. The high fidelity copying of such rigid and socially stipulated behavioural sequences places heavy demands on executive function abilities. Given previous research showing that challenging executive functioning also improves it, it was hypothesised that prolonged engagement in ritualistic behaviours would improve executive functioning in children, in turn improving their ability to delay gratification. A three month circle-time-games intervention with primary school children in two contrasting cultural environments (Slovakia and Vanuatu) was conducted. In both environments we found the intervention improved children's executive function and in turn their ability to delay gratification. Moreover, these effects were amplified when the intervention task was imbued with ritual, rather than instrumental, cues. The findings presented in this thesis have potentially far-reaching implications for child-rearing and educational practices, suggesting ritual participation may be necessary for the cultivation of future mindedness.
516

Simulation tools for the study of the interaction between communication and action in cognitive robots

Ferrauto, Tomassino January 2017 (has links)
In this thesis I report the development of FARSA (Framework for Autonomous Robotics Simulation and Analysis), a simulation tool for the study of the interaction between language and action in cognitive robots and more in general for experiments in embodied cognitive science. Before presenting the tools, I will describe a series of experiments that involve simulated humanoid robots that acquire their behavioural and language skills autonomously through a trial-and-error adaptive process in which random variations of the free parameters of the robots’ controller are retained or discarded on the basis of their effect on the overall behaviour exhibited by the robot in interaction with the environment. More specifically the first series of experiments shows how the availability of linguistic stimuli provided by a caretaker, that indicate the elementary actions that need to be carried out in order to accomplish a certain complex action, facilitates the acquisition of the required behavioural capacity. The second series of experiments shows how a robot trained to comprehend a set of command phrases by executing the corresponding appropriate behaviour can generalize its knowledge by comprehending new, never experienced sentences, and by producing new appropriate actions. Together with their scientific relevance, these experiments provide a series of requirements that have been taken into account during the development of FARSA. The objective of this project is that to reduce the complexity barrier that currently discourages part of the researchers interested in the study of behaviour and cognition from initiating experimental activity in this area. FARSA is the only available tools that provide an integrated framework for carrying on experiments of this type, i.e. it is the only tool that provides ready to use integrated components that enable to define the characteristics of the robots and of the environment, the characteristics of the robots’ controller, and the characteristics of the adaptive process. Overall this enables users to quickly setup experiments, including complex experiments, and to quickly start collecting results.
517

Uma Rede Neural Auto-Organizável Construtiva para Aprendizado Perpétuo de Padrões Espaço-Temporais / A growing self-organizing neural network for lifelong learning of spatiotemporal patterns

Bastos, Eduardo Nunes Ferreira January 2007 (has links)
O presente trabalho propõe um novo modelo de rede neural artificial voltado a aplicações robóticas, em especial a tarefas de natureza espaço-temporal e de horizonte infinito. Este modelo apresenta três características que o tornam único e que foram tomadas como guia para a sua concepção: auto-organização, representação temporal e aprendizado construtivo. O algoritmo de aprendizagem auto-organizada incorpora todos os mecanismos que são básicos para a auto-organização: competição global, cooperação local e auto-amplificação seletiva. A rede neural é suprida com propriedades dinâmicas através de uma memória de curto prazo. A memória de curto prazo é inserida na estrutura da rede por meio de integradores e diferenciadores, os quais são implementados na camada de entrada da rede. Nesta abordagem existe uma evidente separação de papéis: a rede é responsável pela não-linearidade e a memória é responsável pelo tempo. A construção automática da arquitetura da rede neural é realizada de acordo com uma unidade de habituação. A unidade de habituação regula o crescimento e a poda de neurônios. O procedimento de inclusão, adaptação e remoção de conexões sinápticas é realizado conforme o método de aprendizado hebbiano competitivo. Em muitos problemas práticos, como os existentes na área da robótica, a auto-organização, a representação temporal e o aprendizado construtivo são fatores imprescindíveis para o sucesso da tarefa. A grande dificuldade e, ao mesmo tempo, a principal contribuição deste trabalho consiste em integrar tais tecnologias em uma arquitetura de rede neural artificial de maneira eficiente. Estudos de caso foram elaborados para validar e, principalmente, determinar as potencialidades e as limitações do modelo neural proposto. Os cenários abrangeram tarefas simples de classificação de padrões e segmentação temporal. Os resultados preliminares obtidos demonstraram a eficiência do modelo neural proposto frente às arquiteturas conexionistas existentes e foram considerados bastante satisfatórios com relação aos parâmetros avaliados. No texto são apresentados, também, alguns aspectos teóricos das ciências cognitivas, os fundamentos de redes neurais artificiais, o detalhamento de uma ferramenta de simulação robótica, conclusões, limitações e possíveis trabalhos futuros. / The present work proposes a new artificial neural network model suitable for robotic applications, in special to spatiotemporal tasks and infinite horizon tasks. This model has three characteristics which make it unique and are taken as means to guide its conception: self-organization, temporal representation and constructive learning. The algorithm of self-organizing learning incorporates all the mechanisms that are basic to the self-organization: global competition, local cooperation and selective self-amplification. The neural network is supplied with dynamic properties through a short-term memory. The short-term memory is added in the network structure by means of integrators and differentiators, which are implemented in the input layer of the network. In this approach exists an evident separation of roles: the network is responsible for the non-linearity and the memory is responsible for the time. The automatic construction of the neural network architecture is carried out taking into account habituation units. The habituation unit regulates the growing and the pruning of neurons. The procedure of inclusion, adaptation and removal of synaptic connections is carried out in accordance with competitive hebbian learning technique. In many practical problems, as the ones in the robotic area, self-organization, temporal representation and constructive learning are essential factors to the success of the task. The great difficulty and, at the same time, the main contribution of this work consists in the integration of these technologies in a neural network architecture in an efficient way. Some case studies have been elaborated to validate and, mainly, to determine the potentialities and the limitations of the proposed neural model. The experiments comprised simple tasks of pattern classification and temporal segmentation. Preliminary results have shown the good efficiency of the neural model compared to existing connectionist architectures and they have been considered sufficiently satisfactory with regard to the evaluated parameters. This text also presents some theoretical aspects of the cognitive science area, the fundamentals of artificial neural networks, the details of a robotic simulation tool, the conclusions, limitations and possible future works.
518

Cultural Parameters for "Man On the Loop" Paradigm in the context of Intelligence, Surveillance, and Reconnaissance

Tuli, Gaurav Yash Pal 01 January 2008 (has links)
Social reasoning and norms of a group of individuals that share a set of cultural traits are largely fashioned by those traits. We explored a few predominant sociological, cultural traits and developed a methodology for parametrically adjusting them. This exploratory study shows promise toward a capability to deliberately tune cultural group traits in order to produce desired group behavior. In order to validate our methodology, we implemented a prototypical agent based simulated intelligence, surveillance, and reconnaissance scenario. In this simulation, a group of simulated agents traverse a hostile territory while a user adjusts cultural group trait values. The group and individual utilities are dynamically observed against values of selected cultural traits. Uncertainty avoidance index and individualism are the cultural traits we explored in depth. Upon user's training of the correspondence between cultural values and system utilities, the user is able to deliberately produce desired system utilities by issuing changes to trait values. Appropriateness of specific cultural values is not universal but determined by the domain and scenarios. This work heralds a path for control of large systems via parametric cultural adjustments.
519

Behavioral and neurological studies in tactile map reading and training by persons who are blind or visually impaired

Lawrence, Megan McNally, 1977- 06 1900 (has links)
xiii, 103 p. : ill. (some col.) / This research investigates the relationship between map use tasks, spatial abilities and training-based effects in persons who are blind or visually impaired. A mixed-method approach using theories and methods in behavioral geography, tactile cartography and functional magnetic resonance imaging have produced finds that identify both behaviorally-based as well as biologically-based impacts resulting from systematic tactile map use and spatial thinking training. The neurological results indicate that prior to training a dominant egocentric/route strategy is used to answer all experimental map tasks, while after training an allocentric/survey strategy is used. The current study demonstrates that the adoption of an allocentric perspective is coupled with improved behavioral performance. The findings provide supporting evidence that people who are blind are capable of learning and applying sophisticated spatial strategies. The systematic progression from egocentric/route processing to allocentric/survey processing in the participant population follows traditional developmental models of spatial knowledge. / Committee in charge: Amy Lobben, Chairperson; Andrew Marcus, Member; Patrick Bartlein, Member; Michal Young, Outside Member
520

Skill and scepticism : an enquiry concerning the nature and epistemic value of intuitive judgement

Greve, Sebastian January 2018 (has links)
This thesis concerns two main questions: What is intuition? And can it be a source of knowledge or justification? In addressing these questions, it advances several ongoing philosophical debates, and does so in two main ways: firstly, by formulating a general account of the nature of intuitive judgement that establishes common ground amongst the often disparate views of scholars working on intuition (or intuitions) in psychology, linguistics, philosophy and various other disciplines; and, secondly, by developing a new epistemological position that combines scepticism about the evidential value of intuition with a new account of philosophical skill. The general account of the nature of intuitive judgement mainly consists in drawing a distinction between intuitive judgement and intuitive appearance which is analogous to a distinction that can be drawn between perceptual judgement and perceptual appearance. It is argued that a common type of paradox entails the distinction for the non-perceptual case; it is then demonstrated how various related notions, such as intuitive belief, intuitive thinking and intuition as a cognitive faculty, can be derived from the notion of intuitive judgement. The epistemological account receives additional support from a new theory regarding the objects of intuition, according to which the analogy between intuition and perception holds specifically for what is sometimes called 'aspect perception': it is argued that some intuitive appearances are partially constituted by an appearance of meaning and that, consequently, the analysis of intuitive judgement must distinguish between two types of object, an intentional object (typically, a thought) and a causal one (typically, an expression of thought). It is further argued that the focus on evidential value that has been prevalent in the philosophical literature is too restrictive. By contrast with the prevalent view, it is demonstrated that intuition plays a significant role in human thinking, including in philosophical and scientific enquiry, independently of whether intuition is of great or only of minimal evidential value.

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