In this dissertation, I investigate how differences in the manner via which individuals pursue goals (judging effort from outcome or outcome from effort) influences expectations (effort vs. outcome). In particular, I focus on the role of self-efficacy, and show that when individuals focus on outcomes, they take self-efficacy into consideration when assessing how much effort is needed. However, when focusing on effort, individuals do not take self-efficacy into consideration when making judgments of outcomes. Thus, I find that irrespective of differences in self-efficacy, individuals expect similar outcomes when effort invested is the same. I report findings from six studies, and discuss theoretical and managerial implications. / Ph. D.

This thesis presents distribution strategies for pursuit evasion games of networked multi-agent systems. The strategies are designed for both obstacle-free and obstacle-cluttered environments, leveraging potential maps as a method. The effectiveness of the proposed strategies was eval- uated through simulation and analysis, and the result is that combining a potential map and position extrapolation for obstacle avoidance was very successful at producing competent autonomous agents, and very com- patible when combined with specifically tailored pursuer algorithms for seeking and capture

Reduzir a dimensão de bancos de dados é um passo importante em processos de reconhecimento de padrões e aprendizagem de máquina. Projection Pursuit (PP) tem emergido como uma técnica relevante para tal fim, a qual busca projeções dos dados em espaços de baixa dimensão onde estruturas interessantes sejam reveladas. Apesar do relativo sucesso de PP em vários problemas de redução dimensional, a literatura mostra uma aplicação limitada da mesma em bancos de dados com elevada quantidade de atributos e poucas amostras, tais como os gerados em biologia molecular. Nesta tese, estudam-se formas de aproveitar o potencial de PP em problemas de alta dimensão e poucas amostras a fim de facilitar a posterior construção de classificadores. Entre as principais contribuições deste trabalho tem-se: i) Sequential Projection Pursuit Modified (SPPM), um método de busca sequencial de espaços de projeção baseado em Algoritmo Genético (AG) e operadores de cruzamento especializados; ii) Block Sequential Projection Pursuit Modified (Block-SPPM) e Whitened Sequential Projection Pursuit Modified (W-SPPM), duas estratégias de aplicação de SPPM em problemas com mais atributos do que amostras, sendo a primeira baseada e particionamento de atributos e a segunda baseada em pré-compactação dos dados. Avaliações experimentais sobre bancos de dados públicos de expressão gênica mostraram a eficácia das propostas em melhorar a acurácia de algoritmos de classificação populares em relação a vários outros métodos de redução dimensional, tanto de seleção quanto de extração de atributos, encontrando-se que W-SPPM oferece o melhor compromisso entre acurácia e custo computacional. / Reducing the dimension of datasets is an important step in pattern recognition and machine learning processes. PP has emerged as a relevant technique for that purpose. PP aims to find projections of the data in low dimensional spaces where interesting structures are revealed. Despite the success of PP in many dimension reduction problems, the literature shows a limited application of it in dataset with large amounts of features and few samples, such as those obtained in molecular biology. In this work we study ways to take advantage of the potential of PP in order to deal with problems of large dimensionalities and few samples. Among the main contributions of this work are: i) SPPM, an improved method for searching projections, based on a genetic algorithm and specialized crossover operators; and ii) Block-SPPM and W-SPPM, two strategies of applying SPPM in problems with more attributes than samples. The first strategy is based on partitioning the attribute space while the later is based on a precompaction of the data followed by a projection search. Experimental evaluations over public gene-expression datasets showed the efficacy of the proposals in improving the accuracy of popular classifiers with respect to several representative dimension reduction methods, being W-SPPM the strategy with the best compromise between accuracy and computational cost.

Reduzir a dimensão de bancos de dados é um passo importante em processos de reconhecimento de padrões e aprendizagem de máquina. Projection Pursuit (PP) tem emergido como uma técnica relevante para tal fim, a qual busca projeções dos dados em espaços de baixa dimensão onde estruturas interessantes sejam reveladas. Apesar do relativo sucesso de PP em vários problemas de redução dimensional, a literatura mostra uma aplicação limitada da mesma em bancos de dados com elevada quantidade de atributos e poucas amostras, tais como os gerados em biologia molecular. Nesta tese, estudam-se formas de aproveitar o potencial de PP em problemas de alta dimensão e poucas amostras a fim de facilitar a posterior construção de classificadores. Entre as principais contribuições deste trabalho tem-se: i) Sequential Projection Pursuit Modified (SPPM), um método de busca sequencial de espaços de projeção baseado em Algoritmo Genético (AG) e operadores de cruzamento especializados; ii) Block Sequential Projection Pursuit Modified (Block-SPPM) e Whitened Sequential Projection Pursuit Modified (W-SPPM), duas estratégias de aplicação de SPPM em problemas com mais atributos do que amostras, sendo a primeira baseada e particionamento de atributos e a segunda baseada em pré-compactação dos dados. Avaliações experimentais sobre bancos de dados públicos de expressão gênica mostraram a eficácia das propostas em melhorar a acurácia de algoritmos de classificação populares em relação a vários outros métodos de redução dimensional, tanto de seleção quanto de extração de atributos, encontrando-se que W-SPPM oferece o melhor compromisso entre acurácia e custo computacional. / Reducing the dimension of datasets is an important step in pattern recognition and machine learning processes. PP has emerged as a relevant technique for that purpose. PP aims to find projections of the data in low dimensional spaces where interesting structures are revealed. Despite the success of PP in many dimension reduction problems, the literature shows a limited application of it in dataset with large amounts of features and few samples, such as those obtained in molecular biology. In this work we study ways to take advantage of the potential of PP in order to deal with problems of large dimensionalities and few samples. Among the main contributions of this work are: i) SPPM, an improved method for searching projections, based on a genetic algorithm and specialized crossover operators; and ii) Block-SPPM and W-SPPM, two strategies of applying SPPM in problems with more attributes than samples. The first strategy is based on partitioning the attribute space while the later is based on a precompaction of the data followed by a projection search. Experimental evaluations over public gene-expression datasets showed the efficacy of the proposals in improving the accuracy of popular classifiers with respect to several representative dimension reduction methods, being W-SPPM the strategy with the best compromise between accuracy and computational cost.

In order to grasp an object in their visual field, humans orient their visual axis to targets of interest. While scanning their environment, humans perform multiple saccades (rapid eye movements that correct for a position error between eye and target) to align their visual axis with objects of interest. Humans are also able to track objects that move in their environment by means of smooth pursuit eye movements (slow eye movements that correct for any velocity error between eye and target, i.e. for any retinal slip). The appearance of a moving stimulus in the environment elicits smooth pursuit eye movements with a latency of around 100ms. Accordingly, the smooth pursuit system accounts for a change in the trajectory of a moving target with a similar delay. Due to this delay, the oculomotor system needs to develop strategies to avoid the build up of position error during tracking of a moving target. To do so, the oculomotor system uses prediction to try and anticipate the future target trajectory. However, this strategy is limited to conditions where target trajectory is predictable. Otherwise, primates have to combine pursuit and saccades in visual tracking of unpredictable moving targets to avoid large position error. This thesis focuses on both the prediction mechanisms and the interactions between saccades and pursuit. In order to investigate prediction mechanisms, we asked human subjects to pursue a moving target when it was transiently occluded. During occlusions, subjects continued to pursue the invisible target. This thesis demonstrates that this predictive pursuit response is based on a dynamic internal representation of target motion, i.e. a representation that evolves with time. This internal representation could be either built up by repetition of the same target motion or extrapolated on the basis of the pre-occlusion target motion. In addition, it is shown that during occlusions, saccades are adjusted in order to account for the large variability of the smooth pursuit response. As a consequence, it shows that the smooth pursuit command is used by internal models in order to predict future smooth pursuit response. These results demonstrate that both prediction and internal models are necessary to track the invisible and the visible.

In this thesis, a model of motion integration is described which is based on a recursive Bayesian estimation process. The model displays a dynamic behaviour qualitatively similar to the dynamics of the motion integration process observed experimentally in smooth eye pursuit and plaid perception. The computer simulations of the model applied to smooth pursuit eye movements confirm the psychophysical data both in humans and monkeys, and the physiological data in monkeys. The temporal dynamics of motion integration is demonstrated together with its dependence on contrast, size of the stimulus and added noise. A new theoretical approach to explaining plaid perception has been developed, based on both the application of the model and a novel geometrical analysis of the plaid’s pattern. It is shown that the results from simulating the model are consistent with the psychophysical data about the plaid motion. Furthermore, by formulating the model as an approximate version of a Kalman filter algorithm, it is shown that the model can be put into a neurally plausible, distributed recurrent form which coarsely corresponds to the recurrent circuitry of visual cortical areas V1 and MT. The model thus provides further support for the notion that the motion integration process is based on a form of Bayesian estimation, as has been suggested by many psychophysical studies, and moreover suggests that the observed dynamic properties of this process are the result of the recursive nature of the motion estimation.

<p>Smooth pursuit eye movements are movements of the eyes that are used to foveate moving objects. Their precision and adaptation is believed to depend on a constellation of sites across the cerebellum, but only one region’s contribution is well characterized, the floccular complex. Here, I characterize the response properties of neurons in the oculomotor vermis, another major division of the oculomotor cerebellum whose role in pursuit remains unknown. I recorded Purkinje cells, the output neurons of this region, in two monkeys as they executed pursuit eye movements in response to step ramp target motion. The responses of these Purkinje cells in the oculomotor vermis were very different from responses that have been documented in the floccular complex. The simple spikes of these cells encoded movement direction in retinal, as opposed to muscle coordinates. They were less related to movement kinematics, and had smaller values of trial-by-trial correlations with pursuit speed, latency, and direction than their floccular complex counterparts. Unlike Purkinje cells in the floccular complex, simple spike firing rates in the oculomotor vermis remained unchanged over the course of pursuit adaptation, likely excluding the oculomotor vermis as a site of directional plasticity. Complex spikes of these Purkinje cells were only partially responsive to target motion, and did not fall into any clear opponent directional organization with simple spikes, as has been found in the floccular complex. In general, Purkinje cells in the oculomotor vermis were responsive to both pursuit and to saccadic eye movements, but maintained tuning for the direction of these movements along separate directions at a population level. Predictions of caudal fastigial nucleus activity, generated on the basis of our population of oculomotor vermal Purkinje cells, faithfully tracked moment-by-movement changes in pursuit kinematics. By contrast, these responses did not faithfully track moment-by-moments changes in saccade kinematics. These results suggest that the oculomotor vermis is likely to play a smaller role in influencing pursuit eye movements by comparison to the floccular complex.</p> / Dissertation

Thesis advisor: Diana C. Pullin / Framed in the context of increased media attention focused on a shortage of qualified candidates for the superintendency of public school districts, this study examines the thought process of educational leaders who are in a position to pursue the superintendency. A review of the literature explored the increasing challenges of the position itself, and examined business and psychology literature concerning applicant attraction and the concept of fit including the factors that may attract and deter potential applicants. Qualitative research methods were used to illuminate the thought process that accompanies consideration of the superintendency. The following research questions were considered: what factors, including job desirability and accessibility, influence the pursuit intentions of individuals qualified to be superintendent, and, how does the mix of motivators and inhibitors impact the decision to pursue or not to pursue the position? Twelve in-depth interviews were conducted with graduates of a doctoral program in educational leadership, all currently working as educational leaders in public school districts. Coded transcripts from the interviews highlighted the importance of perceived positional and organizational fit, the use of a common mental checklist to conceptualize fit, and the weight that is applied to different factors. Data also pointed to the ways in which female and racial/ethnic minorities experience the pursuit process differently, especially in terms of their access to pipeline networks. Recommendations are made for professional associations of educational leaders, search agencies and school districts, and higher education. / Thesis (EdD) — Boston College, 2012. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.

The current study explored the impact of intellectual versus physical affirmations received over Instagram, either directly or indirectly, on females’ physical acceptance, intellectual pursuits during leisure and financial decision making. A total of 256 female students of the Claremont Colleges were recruited through advertisement of the study on the colleges’ designated Facebook page, and flyers posted around the campuses. The longitudinal, quasi- experimental study used a 2 (Type of Affirmation: Physical or Intellectual) x 2 (Mode of Exposure: Feed or Direct Message) x 3 (Phase: 1, 2, 3) fully crossed factorial design. Participants who voluntarily agreed to participate were randomly assigned to one of the four conditions. Participants exposed to physical affirmations, via Instagram’s direct messaging feature, reported significantly lower levels of physical acceptance, were less likely to engage in intellectual activities during leisure, and made financial decisions that reflected a greater desire to attend to their appearance than to their intellect, compared to participants exposed to physical affirmations, via feed. The opposite pattern of interaction was found for participants exposed to intellectual affirmations. The results support previous psychological literature on social role theory, stereotype threat, self-objectification theory, social comparison theory, and affirmation theory. The implications of this study concern female leadership development, specifically how exposure to intellectual affirmations over social media has the potential to attenuate the negative effects living in a patriarchal society has on females.

The purpose of this study was to examine the impact of religiosity on the pursuit of education and the perceptions towards education among college students at Utah State University (USU). The study focused on what religious variables were useful in predicting postsecondary educational pursuit and either positive or negative educational perceptions among students at USU. From a systematic random sample of 1,460 USU students, a correlational research design was used for this study. Multiple linear regression (MLR) techniques were used to determine which of the various measures of religiosity provided the greatest degree of predictive value for ascertaining educational pursuit and educational perception. A stepwise multiple regression model was used to determine statistical significance of the predictors. Survey methods were used to gather the necessary data. From the results of MLR, seven independent variables (gender, religious practice, parental education, marital status, religious affiliation, positive religious experience, and ethnicity) correlate significantly with four constructs concerning educational perceptions and pursuits (school experience, academic attainments, family pressure, and influences). Of the seven independent variables revealed by MLR to be significant predictors of educational pursuits and perceptions, the measured constructs concerning religiosity were found to be generally less important than the demographic factors.