Goal-directed behavior is based on representations of contingencies between a certain situation (S), a certain (re)action (R) and a certain outcome (O). These S-R-O representations enable flexible response selection in different situations according to the currently pursued goal. Importantly however, the successful formation of such representations is a necessary but not sufficient precondition for goal-directed behavior which additionally requires the actual usage of the contingency information for action control. The present fMRI study aimed at identifying the neural basis of each of these two aspects: representing vs. explicitly using experienced S-R-O contingencies. To this end, we created three experimental conditions: S-R-O contingency present and used for outcome-based response selection, S-R-O contingency present but not used, and S-R-O contingency absent. The comparison between conditions with and without S-R-O contingency revealed that the angular gyrus is relevant for representing S-R-O contingencies. The explicit usage of learnt S-R-O representations in turn was associated with increased functional coupling between angular gyrus and several subcortical (hippocampus, caudate head), prefrontal (lateral orbitofrontal cortex (OFC), rostrolateral prefrontal cortex (RLPFC)) and cerebellar areas, which we suggest represent different explicit and implicit processes of goal-directed action control. Hence, we ascribe a central role to the angular gyrus in associating actions to their sensory outcomes which is used to guide behavior through coupling of the angular gyrus with multiple areas related to different aspects of action control.

Moderne Theorien der Verhaltenskontrolle unterscheiden zwei Systeme, wobei das Handeln gesunder Individuen von beiden geprägt ist: Das retrospektiv agierende habituelle, sog. modellfreie Verhalten zeichnet sich durch Wiederholung zuvor belohnter Entscheidungen aus. Es passt sich nur langsam an möglicherweise veränderte Umweltbedingungen an. Die verstärkte Nutzung des habituellen Systems gilt als assoziiert mit verschiedenen psychischen Erkrankungen. Dem gegenüber steht das zielgerichtete, sog. modellbasierte Verhalten, das sich durch vorausschauende Entscheidungen auszeichnet. Hierbei werden die möglichen Konsequenzen einer Handlung berücksichtigt, um ein gewünschtes Ergebnis zu erreichen. Dazu wird ein „mentales“ Modell der Umwelt- bedingungen erstellt. In einer Verhaltensstudie mit 39 Versuchspersonen wurde untersucht, ob biopsychologischer Stress zu einer Reduktion von modellbasiertem hin zu mehr modellfreiem Verhalten führt. Dazu absolvierten 39 Versuchspersonen eine sequentielle Entscheidungsaufgabe, nachdem sie psychosozialem Stress ausgesetzt wurden. Subjektive und physiologische Stress-Parameter wurden über das Experiment hinweg wiederholt erhoben. Ein direkter Effekt von akutem Stress auf das Gleichgewicht modellfreien vs. modellbasierten Verhaltens konnte nicht beobachtet werden. Allerdings zeigten diejenigen Versuchspersonen, die in den letzten zwei Jahren eine hohe Anzahl an stressbehafteten Lebensereignissen aufwiesen (chronischer Stress), signifikant weniger modellbasiertes Verhalten nach der Exposition von akutem Stress als in der Kontrollbedingung. Darüber hinaus korrelierte physiologische Stressreaktivität (stressbedingte Cortisol- Ausschüttung) negativ mit modellbasiertem Entscheidungsverhalten, während subjektive Stressreaktivität (basierend auf Fragebögen) positiv mit modellbasiertem Verhalten assoziiert war. Der in der Forschung beschriebene Einfluss von akutem und chronischem Stress auf die Entstehung und Aufrechterhaltung psychischer Erkrankungen könnte demnach teilweise über ein solches Ungleichgewicht der beiden Entscheidungsstrategien vermittelt sein.

No description available.

Prior evidence suggests that sensorimotor regions play a crucial role in habit formation. Yet, whether and how their global functional network properties might contribute to a more comprehensive characterization of habit formation still remains unclear. Capitalizing on advances in Elastic Net regression and predictive modeling, we examined whether learning-related functional connectivity alterations distributed across the whole brain could predict individual habit strength. Using the leave-one-subject-out cross-validation strategy, we found that the habit strength score of the novel unseen subjects could be successfully predicted. We further characterized the contribution of both, individual large-scale networks and individual brain regions by calculating their predictive weights. This highlighted the pivotal role of functional connectivity changes involving the sensorimotor network and the cingulo–opercular network in subject-specific habit strength prediction. These results contribute to the understanding the neural basis of human habit formation by demonstrating the importance of global functional network properties especially also for predicting the observable behavioral expression of habits.

Uma meta procurada em inteligência artificial (IA) é o desenvolvimento de mecanismos inteligentes capazes de cumprir com objetivos preestabelecidos, de forma totalmente independente, em ambientes dinâmicos e complexos. Uma recente vertente das pesquisas em IA, os agentes autônomos, vem conseguindo resultados cada vez mais promissores para o cumprimento desta meta. A motivação deste trabalho é a proposição e implementação de um agente que aprenda a executar tarefas, sem a interferência de um tutor, em um ambiente não estruturado. A tarefa prática proposta para testar o agente é a navegação de um robô móvel em ambientes com diferentes configurações, e cujas estruturas são inicialmente desconhecidas pelo agente. O paradigma de aprendizagem por reforço, através de variações dos métodos de diferença temporal, foi utilizado para implementar o agente descrito nesta pesquisa. O resultado final obtido foi um agente autônomo que utiliza um algoritmo simples para desempenhar propriedades como: aprendizagem a partir de tabula rasa, aprendizagem incremental, planejamento deliberativo, comportamento reativo, capacidade de melhoria do desempenho e habilidade para gerenciar múltiplos objetivos. O agente proposto também apresenta um desempenho promissor em ambientes cuja estrutura se altera com o tempo, porém diante de certas situações seus comportamentos em tais ambientes tendem a se tornar inconsistentes. / One of the current goals of research in Artificial Intelligence is the proposition of intelligent entities that are able to reach a particular target in a dynamic and complex environment without help of a tutor. This objective has been becoming reality through the propositions of the autonomous agents. Thus, the main motivation of this work is to propose and implement an autonomous agent that can match the mentioned goals. This agent, a mobile robot, has to navigate in environments which are initially unknown and may have different structures. The agent learns through one of the main reinforcement learning strategies: temporal difference. The proposed autonomous employs a simple learning mechanisms with the following features: learns incrementally from tabula rasa, executes deliberative and reactive planning, improves its performance through interactions with the environment, and manages multiple objectives. The agent presented promising results when moving in a dynamic environment. However, there are situations in which the agent do not follow this last property.

過去網站設計相關研究大多強調網站介面設計、導覽設計或消費者使用之易 用性…等，較少研究關注於視覺設計對消費者態度之影響，但學者Gitte, Gary, Cathy & Brown(2006)研究發現，一般瀏覽者在接觸到網頁的0.05 秒內就已經對 於網頁設計的好惡下了決定其實，因此，留住消費者網站的第一印象非常重要。 Holter(2006)認為以動畫組成的片頭首頁(Splash page)就好像是網站的封面，不但 能呈現出網站整體之基本元素與風格，還能表現出網站整體之策略，更是表現企 業創意的最佳所在。因此，本研究主要是探討網站設計中片頭首頁(Splash pages) 之有無、生動性程度與時間長短對消費者態度之影響。 本研究採用實驗法，以2x2x2(實驗組)+1x2(控制組)之多因子設計，主要的 自變項為「片頭首頁有無(有vs.無)」、「片頭首頁生動性(高vs.低)」和「片頭首 頁時間(10 秒vs.20 秒)」；依變項是「消費者態度」，其中又分為「片頭首頁態度 度」、「網站態度」和「品牌態度」；調節變項是「網路使用目的(目標導向vs.經 驗導向」。研究結果發現： 1. 片頭首頁之有無，不會影響消費者對網站及品牌態度之偏好。 2. 片頭首頁生動性高低，不會影響消費者對片頭首頁、網站及品牌態度之偏好。 3. 片頭首頁時間長短，不會影響消費者對片頭首頁、網站及品牌態度之偏好。 4. 消費者網路使用目的之差異，不會影響消費者對片頭首頁、網站及品牌態度 之偏好。 5. 片頭首頁生動性與時間長短之間具有交互效果：當消費者在瀏覽高生動片頭 首頁時，10 秒片頭首頁比20 秒片頭首頁會有較高的品牌態度偏好。

Uma meta procurada em inteligência artificial (IA) é o desenvolvimento de mecanismos inteligentes capazes de cumprir com objetivos preestabelecidos, de forma totalmente independente, em ambientes dinâmicos e complexos. Uma recente vertente das pesquisas em IA, os agentes autônomos, vem conseguindo resultados cada vez mais promissores para o cumprimento desta meta. A motivação deste trabalho é a proposição e implementação de um agente que aprenda a executar tarefas, sem a interferência de um tutor, em um ambiente não estruturado. A tarefa prática proposta para testar o agente é a navegação de um robô móvel em ambientes com diferentes configurações, e cujas estruturas são inicialmente desconhecidas pelo agente. O paradigma de aprendizagem por reforço, através de variações dos métodos de diferença temporal, foi utilizado para implementar o agente descrito nesta pesquisa. O resultado final obtido foi um agente autônomo que utiliza um algoritmo simples para desempenhar propriedades como: aprendizagem a partir de tabula rasa, aprendizagem incremental, planejamento deliberativo, comportamento reativo, capacidade de melhoria do desempenho e habilidade para gerenciar múltiplos objetivos. O agente proposto também apresenta um desempenho promissor em ambientes cuja estrutura se altera com o tempo, porém diante de certas situações seus comportamentos em tais ambientes tendem a se tornar inconsistentes. / One of the current goals of research in Artificial Intelligence is the proposition of intelligent entities that are able to reach a particular target in a dynamic and complex environment without help of a tutor. This objective has been becoming reality through the propositions of the autonomous agents. Thus, the main motivation of this work is to propose and implement an autonomous agent that can match the mentioned goals. This agent, a mobile robot, has to navigate in environments which are initially unknown and may have different structures. The agent learns through one of the main reinforcement learning strategies: temporal difference. The proposed autonomous employs a simple learning mechanisms with the following features: learns incrementally from tabula rasa, executes deliberative and reactive planning, improves its performance through interactions with the environment, and manages multiple objectives. The agent presented promising results when moving in a dynamic environment. However, there are situations in which the agent do not follow this last property.

The purpose of this thesis was to develop methodology by which treatments for the cognitive impairments in Huntington's disease (HD) could be tested. As such, the thesis focused mainly on evaluating rats with quinolinic acid (QA) lesions of the striatum, as this manipulation mimics some aspects of the neural damage in Huntington's disease, to try to identify cognitive deficits of HD resulting from cell loss in the striatum. In the first part (Chapters 3-5), the role of the striatum in implicit memory was investigated. Chapter 3 compared the performance of rats and humans on a reaction time task that evaluated implicit memory by presenting visual stimuli with differing probabilities which change over time. Although rats made higher percentage of incorrect responses and late errors, both groups showed a similar pattern of reaction times. Chapter 4 investigated whether implicit memory (the computation of probabilities to predict the location of a stimulus) was affected by selective blockade of dopaminergic transmission at the D1 or D2 receptors by SCH-23390 and raclopride, respectively. Reaction times were slower with SCH-23390 and raclopride, but only SCH-23390 reduced errors to the least probable target location. Chapter 5 used the same task to evaluate implicit memory in rats with QA lesions of the dorsomedial striatum (DMS). Implicit memory was not affected by lesions of the DMS, which suggested that once a task that requires implicit memory has been learned, the DMS was not involved in sustaining the performance of the task. The second part of this thesis (Chapter 6), explored the contribution of the DMS in habit formation. DMS lesioned rats did not show habitual responding, and were not impaired in learning a new goal-directed behaviour. The third part (Chapters 7 and 8), investigated the role of the dorsal striatum in reversal learning, attentional set-formation, and set-shifting. Dorsal striatum lesioned rats were not impaired in reversal learning, but had a diminished shift-cost, which suggested that dorsal striatum lesions disrupted the formation of attentional sets. These results showed that although QA lesions of the dorsal striatum mimic some aspects of the neural damage in HD, they did not result in the same cognitive deficits observed in patients with HD, at least using the tasks presented in this thesis. However, other animal models of HD could be evaluated using the different tasks presented in this thesis to continue the search of a reliable animal model of HD in which treatments for the disease could be evaluated.

This thesis is based on design theory about how to build an application for the mobile platform, a scientific analysis and an application for grocery shopping and meal planning. The thesis also contains a valuation of the research and of the application. The valuation of the application was done by a usability test and an analysis of the results of the test. The application of the thesis has an easy navigation system, which is time saving and simple to use. Finding recipes with the associated ingredients is a quick fix. The search function can be used for searching freely after recipes as well as for separate ingredients. That makes it possible for the user to create own recipes from available ingredients. One can also compose a recipe from scratch and add to the recipe bank. It´s also possible to see which ingredients that is needed for a certain recipe. The application is direct and easy to use and because of that it can be used outside the home in environments where there are a lot of distractions, for example in the food store, where all the ingredients is purchased and checked off from the list. The application is competent. The user can save recipes and create own recipes without having to login. From the added information the app is able to suggest menus, at the same time it enables for the user to compose his or her own menus with lunch and dinner. Gradually a big and varying recipe bank is built which is formed after the family´s specific priorities of good, easy to cook, healthy food and it also sends a warning if a recipe contains food that someone in the family is allergic to. Each and every recipe can also be illustrated with drawings which could improve the overview. The application can be synced with a web site where more information can be extracted. / Den här uppsatsen består av en designteori för hur en applikation för den mobila plattformen ska byggas, samt en vetenskaplig analys och en färdig applikation som ska användas vid inköp av mat och planering av måltider. Uppsatsen innehåller också en utvärdering av forskningen och av applikationen. Utvärderingen av applikationen utfördes genom en användarbarhetstestning och en analys av testningens resultat. Uppsatsens applikation en har smidig navigering, som är tidseffektiv och enkel att använda. Det går snabbt att ta fram recept och vilka ingredienser som krävs för receptet. Det är möjligt att söka fritt både på recept och enskilda ingredienser. Det innebär att användaren kan forma egna recept utifrån tillgängliga ingredienser. Man kan även komponera egna recept och lägga in i receptbanken. Det är också möjligt att se vilka ingredienser som behövs för att ett visst recept ska kunna tillagas. Applikationen är tydlig och lättanvänd och fungerar därför i miljöer med många distraherande inslag utanför hemmet, exempelvis direkt i butiken, där alla ingredienser kan köpas in och bockas av från en lista. Applikationen är kompetent. Användaren kan spara recept och lägga till egna recept utan att behöva logga in. Med utgångspunkt från inlagd information kan applikationen föreslå menyer, samtidigt som den möjliggör komposition av egna menyer för lunch och middag.  Efter hand byggs det upp en stor och varierande receptbank som formas efter familjens egna prioriteringar av god, lättlagad, nyttig mat och även varnar för exempelvis mat som kan framkalla allergireaktioner om allergi förekommer i familjen. Vart och en av recepten kan också illustreras med tecknade bilder vilket skulle kunna förbättrar överblicken. Applikationen kan samsynkas med en hemsida där mer utförlig information kan hämtas.

Au cours des dernières années, les communautés virtuelles de patients se sont énormément développées sur l'Internet. Ces communautés permettent des échanges fréquents entre les patients, qui peuvent partager des informations liées à la santé dans un environnement interactif. Alors que beaucoup s'accordent sur l'opportunité représentée par ces communautés pour ses utilisateurs, les connaissances sur ce qui détermine l'action collective en ligne des patients ainsi que sur les fondamentaux de l'action collective en ligne dans ces espaces virtuels sont relativement peu développées. En conséquence, ce travail doctoral examine les raisons pour lesquelles les patients interagissent entre eux et comment ils procèdent. En nous appuyant sur le modèle du comportement orienté vers un but, la théorie de la valeur de l'attente, la théorie des forces du champ, les concepts de dons et les interviews menées, nous avons développé un modèle qui examine les interactions en ligne des patients dans un contexte d'action collective en ligne. Une approche multi-méthode, qualitative et quantitative, permet d'explorer les interactions des patients et de mesurer les déterminants de l'action collective en ligne sur ces espaces virtuels. L'analyse qualitative de 54 entretiens menés avec des patients, des proches de patients, des professionnels de la santé 2.0, des médecins et des soignants permet d'affiner le modèle de recherche, qui a ensuite été testé au travers d'une enquête quantitative auprès de 269 patients. Cette recherche contribue à la recherche en systèmes d'information en augmentant nos connaissances sur la dynamique individuelle et les interactions qui entourent les communautés de patients en ligne. / Over the last few years, virtual patients’communities have been developing tremendously over the Internet. These Web 2.0 communities allow frequent interactions among patients, who can share health-related information within an interactive environment. While many agree on the opportunity represented by those communities for its users, we know very little about what determines patients’ online collective action, specifically on virtual communities as well as the fundamentals of online collective action in these virtual spaces. Accordingly, this doctoral work examines why patients interact with others and how they interact on topics related to their disease through these virtual communities. Drawing on the goal-directed behavior (MGB), the expectancy-value (EVT) theories, the field force theory, gift concepts and field interviews, we have developed a model for examining patients’ online interactions and identified gift-giving behaviors in the context of online collective action. A multi-method, qualitative and quantitative approaches, enables us to explore patients’ interactions and measures the determinants of online collective action on these virtual spaces. The qualitative analysis of 54 interviews conducted with patients, patient’s relatives, Health 2.0 professionals, doctors and caregivers allows refining the research model, which has then been tested through a survey handled with 269 patients, members of patient’s communities. This research contributes to IS research by increasing our knowledge regarding the individual dynamics and interactions that surround online patients’ communities.