Teses / dissertações sobre o tema "Subjective experiment"

Les images de champs de lumière (LFI) suscitent un intérêt et une fascination remarquables en raison de leur importance croissante dans les applications immersives. Étant donné que les LFI peuvent être déformés à différentes étapes, de l'acquisition à la visualisation, l'évaluation de la qualité des images de champs de lumière (LFIQA) est d'une importance vitale pour surveiller les dégradations potentielles de la qualité des LFI.La première contribution (Chapitre 3) de ce travail se concentre sur le développement de deux métriques LFIQA sans référence (NR) fondées sur des caractéristiques ad-hoc, dans lesquelles les informations de texture et les coefficients ondelettes sont exploités pour l'évaluation de la qualité.Puis dans la deuxième partie (Chapitre 4), nous explorons le potentiel de la technologie de l’apprentissage profond (deep learning) pour l'évaluation de la qualité des LFI, et nous proposons quatre métriques LFIQA basées sur l’apprentissage profond, dont trois métriques sans référence (NR) et une métrique Full-Reference (FR).Dans la dernière partie (Chapitre 5), nous menons des évaluations subjectives et proposons une nouvelle base de données normalisée pour la LFIQA. De plus, nous fournissons une étude comparative (benchmark) de nombreuses métriques objectives LFIQA de l’état de l’art, sur la base de données proposée<br>Light Field Image (LFI) has garnered remarkable interest and fascination due to its burgeoning significance in immersive applications. Since LFIs may be distorted at various stages from acquisition to visualization, Light Field Image Quality Assessment (LFIQA) is vitally important to monitor the potential impairments of LFI quality. The first contribution (Chapter 3) of this work focuses on developing two handcrafted feature-based No-Reference (NR) LFIQA metrics, in which texture information and wavelet information are exploited for quality evaluation. Then in the second part (Chapter 4), we explore the potential of combining deep learning technology with the quality assessment of LFIs, and propose four deep learning-based LFIQA metrics according to different LFI characteristics, including three NR metrics and one Full-Reference (FR) metric. In the last part (Chapter 5), we conduct subjective experiments and propose a novel standard LFIQA database. Moreover, a benchmark of numerous state-of-the-art objective LFIQA metrics on the proposed database is provided

This dissertation which consists of three essays investigates the influence of subjective probabilities on decision making processes under conditions of risk. In particular, it examines whether subjects adjust new risk information on their prior subjective estimates, and, to what extent this adjustment affects their choices. In the first essay, by using an artefactual field experiment, I examine the potential correlation between incentive compatibility and validity of subjective probabilities elicited via the Exchangeability Method, an innovative elicitation mechanism which consists of several chained questions. Here, validity is investigated using de Finetti’s notion of coherence under which subjective probabilities are coherent if and only if they obey all axioms and theorems of probability theory. Experimental results suggest that subjects provided with monetary incentives and randomized questions more likely express valid subjective probabilities than others because they are not aware of the chaining which undermines the incentive compatibility of the Exchangeability Method. In the second essay, by using the same experimental data, I show that valid subjective probabilities do not significantly diverge from invalid ones, indicative of little effect of internal validity on the actual magnitude of subjective probabilities. In the third essay, by using a field Choice Experiment, I investigate to what extent subjects adjust risk information given in the status quo alternative on their subjective probability estimates. An innovative two-stage approach that incorporates subjective probabilities into Choice Experiments’ design is developed to investigate this phenomenon, known as the scenario adjustment. In the first stage, subjective probabilities that given outcomes will occur are elicited using the Exchangeability Method. In the second stage, two treatment groups are designed: in the first group, each subject is presented with a status quo alternative which incorporates her/his subjective probabilities, and, hence, no adjustment is required; in the second group, each subject faces a status quo alternative where the presented risk is not consistent with her/his probability estimates, and, hence, a mental adjustment to the scenario might take place. By comparing willingness to pay across the treatment groups, my results suggest that, when subjects are provided with SQ alternatives in which the risk is lower than the perceived one, the mental adjustment takes place, but, when subjects are provided with SQ alternatives in which the risk is higher than their own estimates, these subjects appear to make irrational choices.

This dissertation which consists of three essays investigates the influence of subjective probabilities on decision making processes under conditions of risk. In particular, it examines whether subjects adjust new risk information on their prior subjective estimates, and, to what extent this adjustment affects their choices. In the first essay, by using an artefactual field experiment, I examine the potential correlation between incentive compatibility and validity of subjective probabilities elicited via the Exchangeability Method, an innovative elicitation mechanism which consists of several chained questions. Here, validity is investigated using de Finetti’s notion of coherence under which subjective probabilities are coherent if and only if they obey all axioms and theorems of probability theory. Experimental results suggest that subjects provided with monetary incentives and randomized questions more likely express valid subjective probabilities than others because they are not aware of the chaining which undermines the incentive compatibility of the Exchangeability Method. In the second essay, by using the same experimental data, I show that valid subjective probabilities do not significantly diverge from invalid ones, indicative of little effect of internal validity on the actual magnitude of subjective probabilities. In the third essay, by using a field Choice Experiment, I investigate to what extent subjects adjust risk information given in the status quo alternative on their subjective probability estimates. An innovative two-stage approach that incorporates subjective probabilities into Choice Experiments’ design is developed to investigate this phenomenon, known as the scenario adjustment. In the first stage, subjective probabilities that given outcomes will occur are elicited using the Exchangeability Method. In the second stage, two treatment groups are designed: in the first group, each subject is presented with a status quo alternative which incorporates her/his subjective probabilities, and, hence, no adjustment is required; in the second group, each subject faces a status quo alternative where the presented risk is not consistent with her/his probability estimates, and, hence, a mental adjustment to the scenario might take place. By comparing willingness to pay across the treatment groups, my results suggest that, when subjects are provided with SQ alternatives in which the risk is lower than the perceived one, the mental adjustment takes place, but, when subjects are provided with SQ alternatives in which the risk is higher than their own estimates, these subjects appear to make irrational choices.

Les maillages 3D polygonaux sont largement utilisés dans diverses applications telles que le divertissement numérique, la conception assistée par ordinateur et l'imagerie médicale. Un maillage peut être soumis à différents types d'opérations comme la compression, le tatouage ou la simplification qui introduisent des distorsions géométriques (modifications) à la version originale. Il est important de quantifier ces modification introduites au maillage d'origine et d'évaluer la qualité perceptuelle des maillages dégradés. Dans ce cadre, on s'intéresse dans cette thèse à l'évaluation de la qualité perceptuelle des maillages 3D statiques et dynamiques. On présente des études expérimentales pour l'évaluation subjective de la qualité des maillages 3D dynamiques.On présente également de nouvelles métriques objectives, de type avec-référence complète ou de type avec référence-réduite, qui sont efficaces pour l'estimation de la qualité perçue des maillages statiques et dynamiques<br>3D mesh animations have been increasingly used in various applications, e.g., in digital entertainment, computer-aided design and medical imaging. It is possible that a mesh model undergoes some lossy operations, e.g., compression, watermarking or simplification, which can impair the original mesh surface and introduce geometric distortions. An important task is to quantify such distortions and assess the perceptual quality of impaired meshes. In this manuscript, we focus on the perceptual quality assessment of 3D static and dynamic meshes. We present psychometric experiments that we conducted to measure the subjective perceptual quality of dynamic meshes. We also present new full-reference and reduced-reference objective metrics capable of faithfully evaluating the perceptual quality of 3D static and dynamic meshes

As mentioned in the introduction, the objective of this work has been to get a more realistic understanding of economic decision making processes by adopting an interdisciplinary approach which takes into consideration at the same time economic and psychological issues. The research in particular has been focused on the psychological concept of categorization, which in the standard economic theory has received until now no attention, and on its implications for decision making. The three experimental studies conducted in this work provide empirical evidence that individuals don not behave according to the perfect rationality and maximization assumptions which underly the SEUT, but rather as bounded rational satisfiers who try to simplify the decision problems they face through the process of categorization. The results of the first experimental study, on bilateral integrative negotiation, show that most of the people categorize a continuum of outcomes in two categories (satisfying/not satisfying), and treat all the options within each category as equivalent. This process of categorization leads the negotiators to make suboptimal agreements and to what I call the ?Zone of Agreement Bias? (ZAB). The experimental study on committees? decision making with logrolling provides evidence of how the categorization of outcomes in satisfying/not satisfying can affect the process of coalition formation in multi-issue decisions. In the first experiment, involving 3-issues and 3-parties decisions under majority rule, the categorization of outcomes leads most of the individuals to form suboptimal coalitions and make Pareto-dominated agreements. The second experiment, aimed at comparing the suboptimizing effect of categorization under majority and unanimity rule, shows that the unanimity rule can lead to a much higher rate of optimal agreements than the majority rule. The third experiment, involving 4-issues and 4-parties decisions provides evidence that the results of experiments 1 and 2 hold even when the level of complexity of the decision problem increases.

Subjective contours provide an opportunity to explore the limits of correspondence matching in motion. A new class of subjective contour which is a by-product of motion processing is examined within the context of the dual process models of retinal motion processing proposed by Braddick (1980) and Anstis (1980), as well as the more recent first-order/second-order formulation proposed by Cavanagh and Mather (1989). These kinetically induced figures are created by displacing a surface defined by dots which change randomly from frame to frame over a static random dot background. Despite the fact that local form information is uncorrelated throughout the motion sequence, the resulting phenomenal percept is that of a "sparkling" surface which translates across the background. The results of five experiments were not, however, fully consistent with predictions based on either model. An extension of the criteria necessary for the long-range system to be operative would accommodate the data within the context of the short-range/long-range model, whereas a more detailed definition of the properties and relationships between second-order attributes would accommodate the data within the framework of the first-order/second-order model.

Cognitive fatigue refers to the decline in mental efficiency and accompanying feelings of strain and weariness that occur over time-on-task. This study extends previous research on the determinants of cognitive fatigue by evaluating the independent and joint effects of individual differences in extraversion and performance context (individual vs. team) on reports of fatigue. Using a within-subjects counterbalanced design, 92 undergraduate participants performed a three-hour series of problem-solving tasks alone and as part of a four-person team. Results indicated main effects for context, such that all participants report greater fatigue in the solitary performance context compared to the team context. Extraversion was also negatively related to fatigue across time-on-task. However, no extraversion X context interaction was observed. I conclude that task engagement provides a specific source of variance in fatigue-reduction, and suggest that extraverts benefit more from task-related arousal or state positive affect.

This thesis is an investigation into the microeconomic mechanisms that govern some of the occupational choices faced by workers in Sub-Saharan Africa, and into the monetary and non-monetary returns to their decisions. Chapter 1 begins by exploring the decision process that leads workers to allocate themselves to different occupations within the economy. In particular, I investigate the role of risk-aversion in the allocation of workers between formal and informal jobs in Ghana, hence attempting to explain a fundamental dimension of duality through an investigation into workers' preferences. In my model of sectoral allocation risk-averse workers can opt between entering the free-entry informal sector and queuing for formal occupations. Conditional on identifying the riskier option, the model yields testable implications on the relationship between risk-aversion and workers' allocation. My testing strategy proceeds in two steps. First, using the first three waves of the Ghana Household Urban Panel Survey (GHUPS) dataset, I estimate expected income uncertainty and find it considerably higher in the informal sector than in formal employment. Second, using experimental data to elicit risk-attitudes I estimate the effect of risk-aversion on occupational choices and I find that, in line with the first result, more risk-averse workers are more likely to queue for formal jobs and less likely to be in the informal sector. The conclusion of the first chapter is that attitudes to risk should feature more prominently in models of sector allocation and in the design of labour market policies, in particular when those policies aim to impact workers' vulnerability to risk and uncertainty. Chapter 2 focuses on the largest occupational category in the Developing world, self-employed workers with small productive activities, and it tries to estimate the returns to different productive assets, namely physical capital, labour and human capital. These are the workers that form most of the informal sector analysed in chapter 1, which allows me to draw a direct link with the analysis so far. The chapter begins by specifying a model for the income-generating process grounded in the literature on firms' production and hence abridging the gap between the analysis of individual earnings and the study of firms' value added. Identification in the empirics is achieved by means of panel estimators that are suitable to address the endogeneity of input choices, which derives from both time-varying and time-invariant unobservable heterogeneity. The use of these estimators is made feasible by the length of the Ghanaian Household Urban Panel Survey dataset at CSAE. I also explore issues of endogeneity in the selection of different technologies, defined by their relative capital and labour intensity. Finally, I analyse the shape of returns to capital, with the aim to detect potential non-convexities in technology. The results show that capital and work-experience play the strongest role in income-generation, while the shares of value added attributed to labour and to formal schooling are low. Marginal returns to investment are high at low capital levels and they decrease very rapidly, pointing against the existence of non-convexities due to minimum scale requirements, but implying that real income gains resulting form micro-investment are modest. Chapter 3 returns to the issue of earnings uncertainty and risk-aversion explored in Chapter 1, but it now takes the allocation choice as given and explores the direct welfare implications of income uncertainty for worker's well-being. Namely, the chapter explores the relationship between income and welfare, with a particular attention on the link between income vulnerability and happiness. Using unique longitudinal data on life-satisfaction and labour market outcomes, I estimate an individual measure of vulnerability (defined as the probability of falling below a low-income threshold) and investigate its effect on well-being. After controlling for unobservable individual fixed effects, work-satisfaction, relative income and other relevant worker characteristics, I find a sizable impact of vulnerability, over and above the income effect. When I explore the mechanisms behind my results, I find that aspiration adaptation to current income may result in a transitory income effect. Moreover, using my direct measure of attitudes to risk from field-experiments (already used in chapter 1), I can test directly the hypothesis that more risk-averse agents suffer more heavily from a given increase in income vulnerability. Overall, my findings support policy interventions that aim to reduce vulnerability, as I expect such policies to have a 'direct' impact on agents' happiness given the prevailing attitudes to risk and uncertainty in the population. Finally, from the point of view of overall social welfare, my results suggest that non-Rawlsian growth models, whereby 'someone may be left behind', may fail to enhance general welfare, for high enough levels of risk-aversion in the population, if the risk of falling behind is sufficiently widespread.

Researchers have struggled with the problem of obtaining an "accurate" operational definition of drowsiness. Drowsiness is difficult to define because it may involve many different indicators, such as different physiological measures. This thesis consists of two separate, but related, experiments to determine an optimal method of determining whether or not an individual is drowsy via physiological and observed measures. The first part of the experiment used behaviorally trained observers to rate different subjects on the level of drowsiness observed. The data collected showed that trained raters are relatively consistent when rating drowsiness. The second part of the experiment tried to determine if there is a good physiological model to predict performance impairment due to drowsiness by collecting data on sleep deprived subjects. The subjects were given two interleaved tasks, low level and high level cognitive tasks, to perform while twenty-one performance and behavioral measures were collected. The results show that a regression model can be developed using eyelid closure measures, simple EEG measures and simple heart-rate measures to predict performance impairment due to drowsiness.<br>Master of Science

There is a sizeable economic literature dedicated to understanding trust and the extent to which it influences decision making. Although trust is difficult to measure, experimental economics has commonly used the 'amount sent’ in the Berg, Dickhaut and McCabe (1995) investment game to elicit levels of trust from players of the game. However, there is a growing body of literature suggesting that factors such as risk preferences, altruism, and subjective beliefs may confound this measure of trust, thereby questioning the validity of using the 'amount sent’ to elicit people’s levels of trust. To understand these factors, we designed and conducted an incentive-compatible economic experiment with students from the University of Cape Town. These participants completed the investment game, the dictator game (to measure levels of altruism), and a random lottery pair risk preferences task (to gauge risk preferences). We also included an information treatment where students were shown the conditional distributions of amount sent decisions made by students in the previous, baseline treatment. This was done to evaluate whether knowledge of the actions taken by other students would ground students’ beliefs and influence the decisions they made. We estimate a set of standard statistical models to gauge determinants of the amount sent and a complementary maximum likelihood estimation approach to estimate Expected Utility models and Rank-Dependent Utility models in order to further evaluate our data. Our results show that caution needs to be taken when using the amount sent as a measure of trust as the relationship between risk preferences and the amount sent is a nuanced one. Moreover, altruism has a statistically significant association with the amount sent and with risk preferences. We also found that those who were part of the information treatment sent significantly more than those who were not, and they were on average also less risk averse. This indicates that while subjective beliefs do influence behaviour in the investment game, they also affect risk preferences. Thus, our results suggest that researchers should not use the amount sent in the investment game as a pure measure of trust because its measurement is confounded empirically by altruism and subjective beliefs, and theoretically by risk preferences.

Social-communication impairments in autism spectrum disorder (ASD) are often ascribed to deficits in empathy. I argue that social-communicative deficits in ASD stem from impairments in specific aspects of empathy, rather than a general empathy impairment. Empathy is defined as the sharing of another's emotion (affective empathy), understanding others' mental states (cognitive empathy), and regulation of one's own emotional state (self-regulation). Empathy can also lead to muscle mimicry and empathic concern for another's wellbeing. I argue that empathy should be measured on multiple levels: cognitive, subjective and physiological. Particularly, measurement of autonomic regulation can contribute to characterising the empathy profile in ASD. Furthermore, confounding factors such as lack of understanding of one's own emotions, or alexithymia, must be accounted for when measuring empathy. I measured subjective trait empathy ratings in people with varying levels of autism traits (N₁ = 519 & N₂ = 98, ages 14 - 45). I also investigated the association between physiological arousal, trait empathy, and empathic concern for (1) sensory pain and (2) facial pain expressions, controlling for alexithymia (N = 98); and examined the evidence for atypical autonomic arousal at rest and during empathy-induction in individuals with ASD. Autism traits were negatively correlated with cognitive empathy and self-regulation, but were not associated with atypical affective empathy per se. However, individuals with poor self-regulation showed heightened subjective affective states, whereas alexithymic individuals showed reduced affective empathy to facial pain expressions. Regarding the autonomic regulation of empathy, there was a significant association between autonomic arousal and affect regulation: Low sympathetic arousal and concurrent high parasympathetic arousal at rest predicted smaller changes in personal distress during pain observation than did autonomic co-inhibition. However, resting state arousal did not predict absolute affective state levels or dispositional empathy, and was not associated with amount of autism traits. In conclusion, the findings do not support the hypothesis of global empathy deficits in ASD. The results suggest that interventions focusing on own-emotion identification and self-regulation skills are important, but caution against the over-hasty adoption of interventions targeting resting state autonomic arousal, which was not related to either ASD or dispositional empathy.

The overwhelming trend of the usage of multimedia services has raised the consumers&apos; awareness about quality. Both service providers and consumers are interested in the delivered level of perceptual quality. The perceptual quality of an original video signal can get degraded due to compression and due to its transmission over a lossy network. Video quality assessment (VQA) has to be performed in order to gauge the level of video quality. Generally, it can be performed by following subjective methods, where a panel of humans judges the quality of video, or by using objective methods, where a computational model yields an estimate of the quality. Objective methods and specifically No-Reference (NR) or Reduced-Reference (RR) methods are preferable because they are practical for implementation in real-time scenarios. This doctoral thesis begins with a review of existing approaches proposed in the area of NR image and video quality assessment. In the review, recently proposed methods of visual quality assessment are classified into three categories. This is followed by the chapters related to the description of studies on the development of NR and RR methods as well as on conducting subjective experiments of VQA. In the case of NR methods, the required features are extracted from the coded bitstream of a video, and in the case of RR methods additional pixel-based information is used. Specifically, NR methods are developed with the help of suitable techniques of regression using artificial neural networks and least-squares support vector machines. Subsequently, in a later study, linear regression techniques are used to elaborate the interpretability of NR and RR models with respect to the selection of perceptually significant features. The presented studies on subjective experiments are performed using laboratory based and crowdsourcing platforms. In the laboratory based experiments, the focus has been on using standardized methods in order to generate datasets that can be used to validate objective methods of VQA. The subjective experiments performed through crowdsourcing relate to the investigation of non-standard methods in order to determine perceptual preference of various adaptation scenarios in the context of adaptive streaming of high-definition videos. Lastly, the use of adaptive gain equalizer in the modulation frequency domain for speech enhancement has been examined. To this end, two methods of demodulating speech signals namely spectral center of gravity carrier estimation and convex optimization have been studied.

Aims: Opioid use disorder (OUD) is associated with significant morbidity and mortality, and opioid agonist treatment (OAT) with methadone or buprenorphine represents the most efficacious treatment. However, data suggest that chronic administration of opioids may be associated with significant weight gain, possibly by altering an organism’s perception of and preference for sweet foods. The primary aim of this laboratory study was to rigorously examine sucrose subjective response among adults receiving OAT and a comparison sample without OUD. As secondary outcomes, we also sought to compare the groups on additional baseline characteristics that may influence subjective sucrose response and weight gain during treatment. Methods: Participants were 40 adults receiving treatment for OUD (OUD+) and a comparison sample of 40 adults without OUD (OUD-). All participants completed an initial screening visit that included questionnaires on eating behaviors, diet and nutrition, recent substance use, and measurement of body mass index. Eligible participants completed two, same-day outpatient laboratory sessions during which they sampled six experimenter-administered concentrations of sucrose solution (0, 0.1, 0.25, 0.5, 0.75, and 1.0M in distilled water) each three times under double-blind counterbalanced conditions. Following each exposure, participants rated the pleasantness and intensity of each sample using 100-point visual analog scales. Results: OUD+ participants rated sucrose solutions as less pleasant than OUD- participants (p<0.001). However, this effect was limited to the three lowest sucrose concentrations (0, 0.1, 0.25M), and at higher concentrations there were no group differences. There were no between-group differences on ratings of intensity (p=0.35). Given these baseline group differences in placebo (0M) responding, sucrose response was also examined in terms of change from baseline. In this analysis, there was a significant group effect, with a higher magnitude of change in pleasantness ratings and a lower magnitude of change in intensity ratings from 0M in OUD+ vs. OUD- participants (p’s<0.05). With regard to baseline characteristics that may influence sucrose response and eating behavior more generally, the OUD+ group had a higher prevalence of obesity, food insecurity, unhealthy eating behaviors, high sugar consumption, and nutrition knowledge deficits compared to the OUD- group (p’s<0.05). Conclusion: Data from preclinical and clinical research have suggested that opioid agonist medications may enhance subjective response to sweet flavors. In the present study, OUD+ participants exhibited a higher magnitude of change in pleasantness ratings from placebo compared to OUD- participants. However, this effect was largely driven by pronounced group differences in perceived pleasantness of essentially unsweet solutions. On the outcome of sucrose intensity, findings were more mixed with no consistent differences between OUD+ and OUD- participants. In contrast, group differences were far more pronounced in participants’ daily eating behaviors and nutrition knowledge, with OUD+ participants presenting with a consistently more severe profile. These data highlight the significant risk factors experienced by OUD+ individuals that extend beyond drug-related risks and may inform future scientific and clinical efforts to improve health outcomes in this vulnerable population.

The alleged privacy paradox states that individuals report high values for personal privacy, while at the same time they report behavior that contradicts a high privacy value. This is a misconception. Reported privacy behaviors are explained by asymmetric subjective beliefs. Beliefs may or may not be uncertain, and non-neutral attitudes towards uncertainty are not necessary to explain behavior. This research was conducted in three related parts. Part one presents an experiment in individual decision making under uncertainty. Ellsberg s canonical two-color choice problem was used to estimate attitudes towards uncertainty. Subjects believed bets on the color ball drawn from Ellsberg s ambiguous urn were equally likely to pay. Estimated attitudes towards uncertainty were insignificant. Subjective expected utility explained subjects choices better than uncertainty aversion and the uncertain priors model. A second treatment tested Vernon Smith s conjecture that preferences in Ellsberg s problem would be unchanged when the ambiguous lottery is replaced by a compound objective lottery. The use of an objective compound lottery to induce uncertainty did not affect subjects choices. The second part of this dissertation extended the concept of uncertainty to commodities where quality and accuracy of a quality report were potentially ambiguous. The uncertain priors model is naturally extended to allow for potentially different attitudes towards these two sources of uncertainty, quality and accuracy. As they relate to privacy, quality and accuracy of a quality report are seen as metaphors for online security and consumer trust in e-commerce, respectively. The results of parametric structural tests were mixed. Subjects made choices consistent with neutral attitudes towards uncertainty in both the quality and accuracy domains. However, allowing for uncertainty aversion in the quality domain and not the accuracy domain outperformed the alternative which only allowed for uncertainty aversion in the accuracy domain. Finally, part three integrated a public-goods game and punishment opportunities with the Becker-DeGroot-Marschak mechanism to elicit privacy values, replicating previously reported privacy behaviors. The procedures developed elicited punishment (consequence) beliefs and information confidentiality beliefs in the context of individual privacy decisions. Three contributions are made to the literature. First, by using cash rewards as a mechanism to map actions to consequences, the study eliminated hypothetical bias as a confounding behavioral factor which is pervasive in the privacy literature. Econometric results support the  privacy paradox at levels greater than 10 percent. Second, the roles of asymmetric beliefs and attitudes towards uncertainty were identified using parametric structural likelihood methods. Subjects were, in general, uncertainty neutral and believed  bad events were more likely to occur when their private information was not confidential. A third contribution is a partial test to determine which uncertain process, loss of privacy or the resolution of consequences, is of primary importance to individual decision-makers. Choices were consistent with uncertainty neutral preferences in both the privacy and consequences domains.<br>Ph.D.<br>Department of Economics<br>Business Administration<br>Economics PhD

This dissertation investigates the effects of price, brand, and store information on buyers perception of product quality and value, as well as the buyers' willingness to buy. It reviews the dissimilar paradigms developed by economists and behaviorists to explain the influence of price on consumer behavior. Hypotheses are derived from a conceptual model to posit the relationship that the extrinsic cues of information, price, brand name and store name, individually have with the constructs of perceived quality, perceived value, and willingness to buy. Additionally, the combined effects of the extrinsic cues on the three constructs are examined. The research was conducted in two phases. The first phase was necessary to determine products, price levels, brand names and store names to use in the second phase. A 5x3x3 factorial design, with a student sample was used in phase two to test the research hypotheses. Each of the three independent variables had no information treatment that allowed partial replication of past price-perceived quality studies, and examination of price, brand name, and store name main effects in many different cue combinations. Additionally, this research design allowed exploratory research of the marginal effects of combining cue information. Reliability of the measures was assessed using exploratory and confirmatory factor analysis and Cronbach's alpha. Analysis of variance, Duncans' multiple range tests, and trend analysis were used to analyze the data. In general the analysis gave good support for the hypothesized effects. The principal exception was finding only the downward sloping relationships for perceived value and willingness to buy as affected by price information. Also, there was a lack of support for the hypothesized combined cues when all the information were perceived to be low. The research results are discussed with respect to the major findings, significance to theoretical and methodological knowledge as well as marketing practice. Limitations of the research are discussed as well as directions for future research in this paradigm.<br>Ph. D.

This thesis explores subjective and objective understandings of civic duty, obligation and good citizenship. Despite the importance of these drivers of behaviour, a lack of empirical understanding about what these drivers are and how they are understood has left a significant gap in our understanding of voting behaviour. My research contributes to the field by examining three central themes; Are duty, obligation and good citizenship understood the same? Are one or more of these traits suitable for cross-national research? Can a new conceptual model of civic duty help further the use of civic duty in studies of voting behaviour? In order to do this, this thesis analyses the following issues: (1) objectively exploring duty, obligation and good citizenship (2) analysing subjective understandings of these concepts (3) demonstrating individual level drivers of these concepts (4) demonstrating the impact of institutions, and cross-national differences have upon duty, obligation and good citizenship (5) showing how these concepts relate to voting behaviour (6) by testing and proving that a new approach to measuring civic duty can provide a model that explains not only long term immutable voting habits, but why individuals may vote out of duty sometimes, and abstain at others and (7) finally providing substantial evidence from what is an exploratory study to help in the formation of future representative research and to demonstrate the importance of taking civic duty seriously in forthcoming voting behaviour research. Using the theoretical and philosophical literature, I argue that despite the empirical literature treating obligation, good citizenship and civic duty as the same concept and driver of voting behaviour, that individuals understand these traits uniquely, and that they are all separate motivators, with duty being contingent on external forces (social capital) and obligation being contingent on personal or inward pressures. I argue that given the limited literature on good citizenship, there is no clear idea of what it means and that good citizenship will be contingent on what an individual deems to be "good". Finally, I argue that old models of civic duty are outdated, and that a new conceptual framework of duty needs to be introduced to accurately demonstrate how individuals understand it, and actually demonstrate its impact upon individual level voting behaviour. Using data from a pilot study, with an embedded survey experiment (N=735) collected in the United Kingdom, the United States, New Zealand, Australia and Ireland, I demonstrate that not only are duty, obligation and good citizenship understood differently, but the drivers of the concepts are significantly different. While obligation shows no relationship to voting behaviour within or across countries, good citizenship appears to be a good driver of second order elections while civic duty appears to drive first order and high saliency elections. Duty appears to be contingent upon external factors, while good citizenship appears to be contingent upon the behaviour of politicians, and citizenship education suggesting a social contract type relationship. Institutional factors appear to indirectly impact voting behaviour with a mediating effect on the strengths of duty and good citizenship. Finally, evidence suggests that previous notions of an "immutable" sense of duty are unfounded, and that an individuals’ sense of duty is contingent on a range of internal and external pressures. The first empirical chapter focuses on individual level understandings of duty, obligation and good citizenship, before the second empirical chapter expands this to look at cross-national differences in the understanding of, and drivers of duty obligation and good citizenship. Finally, the third empirical analyses a new model of civic duty and suggests that its previous use has been limited by ineffective measures. While the evidence presented in this thesis is exploratory and not generalisable or representative of any of the countries sampled, the evidence from the sample strongly suggests that future development of the study of civic duty, and further analysis of how duty, obligation and good citizenship are understood in representative samples are needed to confirm the findings presented in this thesis, and build upon what is a successful pilot study. This research finds its limitations in the number of survey items available to build a complete picture of all drivers of individual understandings of duty, obligation and good citizenship.

As mentioned in the introduction, the objective of this work has been to get a more realistic understanding of economic decision making processes by adopting an interdisciplinary approach which takes into consideration at the same time economic and psychological issues. The research in particular has been focused on the psychological concept of categorization, which in the standard economic theory has received until now no attention, and on its implications for decision making. The three experimental studies conducted in this work provide empirical evidence that individuals don not behave according to the perfect rationality and maximization assumptions which underly the SEUT, but rather as bounded rational satisfiers who try to simplify the decision problems they face through the process of categorization. The results of the first experimental study, on bilateral integrative negotiation, show that most of the people categorize a continuum of outcomes in two categories (satisfying/not satisfying), and treat all the options within each category as equivalent. This process of categorization leads the negotiators to make suboptimal agreements and to what I call the ?Zone of Agreement Bias? (ZAB). The experimental study on committees? decision making with logrolling provides evidence of how the categorization of outcomes in satisfying/not satisfying can affect the process of coalition formation in multi-issue decisions. In the first experiment, involving 3-issues and 3-parties decisions under majority rule, the categorization of outcomes leads most of the individuals to form suboptimal coalitions and make Pareto-dominated agreements. The second experiment, aimed at comparing the suboptimizing effect of categorization under majority and unanimity rule, shows that the unanimity rule can lead to a much higher rate of optimal agreements than the majority rule. The third experiment, involving 4-issues and 4-parties decisions provides evidence that the results of experiments 1 and 2 hold even when the level of complexity of the decision problem increases.

The dissertation employs laboratory experimental methodology to study decision-making when people face trade-offs between ethical and economic values. More explicitly, the three chapters investigate 1) consumer behaviour when a substantially equivalent version of a product is more expensive because it was produced without child labour, 2) the interaction between an expert advisor and an ignorant decision-maker, when the former may gain from lying and the latter has to decide whether or not to trust in the advice, and 3) fairness in divisions of an economic gain between two people who were both involved in creating the gain, but only one of them provided real effort. Here, a focus is on the impact of power structure, i.e. who decides, on divisions and fairness judgments. All studies discuss implications of experimental behaviour for market and business domains. In addition, the thesis emphasizes ethical theories as complementary to normative benchmark from economic and psychological theory.<br>La tesis utiliza una metodología experimental para investigar las decisiones de los individuos cuando hay un conflicto entre valores éticos y económicos. Mas específicamente, los tres capítulos investigan sobre 1) el comportamiento del consumidor cuando se enfrenta a dos versiones de un mismo producto, siendo una de ellas más cara por ser producida sin trabajo infantil, 2) la interacción entre un agente experto y un agente desinformado que debe tomar una decisión confiando o no en el consejo del experto, el cuál puede mentir para ganar más dinero, y 3) el reparto justo de una ganancia económica entre dos personas de las cuales sólo una ha contribuido trabajando en un ejercicio. Este último estudio se centra en el impacto de la estructura de poder, es decir quién decide, en el reparto y en los juicios de que es lo justo. Los estudios analizan las implicaciones del comportamiento experimental sobre los mercados y las empresas. Además, la tesis propone teorías éticas para complementar las teorías económicas y psicológicas.

In this work I present several studies, which might appear rather heterogeneous for both experimental questions and methodological approaches, and yet are linked by a common leitmotiv: spatial attention. I will address issues related to the assessment of attentional asymmetries, in the healthy individual as in patients with neurological disorders, their role in various aspects of human cognition, and their neural underpinning, driven by the deep belief that spatial attention plays an important role in various mental processes that are not necessarily confined to perception. What follows is organized into two distinct sections. In the first I will focus on the evaluation of visuospatial asymmetries, starting from the description of a new paradigm particularly suitable for this purpose. In the first chapter I will describe the effects of multitasking in a spatial monitoring test; the main result shows a striking decreasing in detection performance as a function of the introduced memory load. In the second chapter I will apply the same paradigm to a clinical population characterized by a brain lesion affecting the left hemisphere. Despite a standard neuropsychological battery failed to highlight any lateralized attentional deficit, I will show that exploiting concurrent demands might lead to enhanced sensitivity of diagnostic tests and consequently positive effects on patients’ diagnostic and therapeutic management. Finally, in the third chapter I will suggest, in light of preliminary data, that attentional asymmetries also occur along the sagittal axis; I will argue, in particular, that more attentional resources appear to be allocated around peripersonal space, the resulting benefits extending to various tasks (i.e., discrimination tasks). Then, in the second section, I will follow a complementary approach: I will seek to induce attentional shifts in order to evaluate their role in different cognitive tasks. In the fourth and fifth chapters this will be pursued exploiting sensory stimulations: visual optokinetic stimulation and galvanic vestibular stimulation, respectively. In the fourth chapter I will show that spatial attention is highly involved in numerical cognition, this relationship being bidirectional. Specifically, I will show that optokinetic stimulation modulates the occurrence of procedural errors during mental arithmetics, and that calculation itself affects oculomotor behaviour in turn. In the fifth chapter I will examine the effects of galvanic vestibular stimulation, a particularly promising technique for the rehabilitation of lateralized attention disorders, on spatial representations. I will discuss critically a recent account for unilateral spatial neglect, suggesting that vestibular stimulations or disorders might indeed affect the metric representation of space, but not necessarily resulting in spatial unawareness. Finally, in the sixth chapter I will describe an attentional capture phenomenon by intrinsically rewarding distracters. I will seek, in particular, to predict the degree of attentional capture from resting-state functional magnetic resonance imaging data and the related brain connectivity pattern; I will report preliminary data focused on the importance of the cingulate-opercular network, and discuss the results through a parallel with clinical populations characterized by behavioural addictions.<br>In questo lavoro presenterò una serie di ricerche che possono sembrare piuttosto eterogenee per quesiti sperimentali e approcci metodologici, ma sono tuttavia legate da un filo conduttore comune: i costrutti di ragionamento e attenzione spaziale. Affronterò in particolare aspetti legati alla valutazione delle asimmetrie attenzionali, nell'individuo sano come nel paziente con disturbi neurologici, il loro ruolo in vari aspetti della cognizione umana, e i loro substrati neurali, guidato dalla convinzione che l’attenzione spaziale giochi un ruolo importante in svariati processi mentali non necessariamente limitati alla percezione. Quanto segue è stato dunque organizzato in due sezioni distinte. Nella prima mi soffermerò sulla valutazione delle asimmetrie visuospaziali, iniziando dalla descrizione di un nuovo paradigma particolarmente adatto a questo scopo. Nel primo capitolo descriverò gli effetti del doppio compito e del carico attenzionale su un test di monitoraggio spaziale; il risultato principale mostra un netto peggioramento nella prestazione al compito di detezione spaziale in funzione del carico di memoria introdotto. Nel secondo capitolo applicherò lo stesso paradigma ad una popolazione clinica contraddistinta da lesione cerebrale dell’emisfero sinistro. Nonostante una valutazione neuropsicologica standard non evidenziasse alcun deficit lateralizzato dell’attenzione, mostrerò che sfruttare un compito accessorio può portare ad una spiccata maggiore sensibilità dei test diagnostici, con evidenti ricadute benefiche sull'iter clinico e terapeutico dei pazienti. Infine, nel terzo capitolo suggerirò, tramite dati preliminari, che asimmetrie attenzionali possono essere individuate, nell'individuo sano, anche lungo l’asse sagittale; argomenterò, in particolare, che attorno allo spazio peripersonale sembrano essere generalmente concentrate più risorse attentive, e che i benefici conseguenti si estendono a compiti di varia natura (ad esempio compiti di discriminazione). Passerò dunque alla seconda sezione, in cui, seguendo una logica inversa, indurrò degli spostamenti nel focus attentivo in modo da valutarne il ruolo in compiti di varia natura. Nei capitoli quarto e quinto sfrutterò delle stimolazioni sensoriali: la stimolazione visiva optocinetica e la stimolazione galvanico vestibolare, rispettivamente. Nel quarto capitolo mostrerò che l’attenzione spaziale è coinvolta nella cognizione numerica, con cui intrattiene rapporti bidirezionali. Nello specifico mostrerò da un lato che la stimolazione optocinetica può modulare l’occorrenza di errori procedurali nel calcolo mentale, dall'altro che il calcolo stesso ha degli effetti sull'attenzione spaziale e in particolare sul comportamento oculomotorio. Nel quinto capitolo esaminerò gli effetti della stimolazione galvanica vestibolare, una tecnica particolarmente promettente per la riabilitazione dei disturbi attentivi lateralizzati, sulle rappresentazioni mentali dello spazio. Discuterò in modo critico un recente modello della negligenza spaziale unilaterale, suggerendo che stimolazioni e disturbi vestibolari possano sì avere ripercussioni sulle rappresentazioni metriche dello spazio, ma senza comportare necessariamente inattenzione per lo spazio stesso. Infine, nel sesto capitolo descriverò gli effetti di cattura dell’attenzione visuospaziale che stimoli distrattori intrinsecamente motivanti possono esercitare nell'adulto sano. Cercherò, in particolare, di predire l’entità di questa cattura attenzionale partendo da immagini di risonanza magnetica funzionale a riposo: riporterò dati preliminari focalizzati sull'importanza del circuito cingolo-opercolare, effettuando un parallelismo con popolazioni cliniche caratterizzate da comportamenti di dipendenza.

With the growth of fashion consumption through websites and e-tailers, the question of when and why consumers engage in shopping without the intent to purchase has gained new relevance. A novel framework for understanding this phenomenon comes from studies examining the neural basis of aesthetic appreciation. Previous studies in neuroaesthetics have identified brain regions associated with value and reward, including the nucleus accumbens (NAcc) and ventromedial prefrontal cortex (VMPFC), as involved during attractiveness judgments even when no physical product is consumed. Along with research demonstrating that attractive stimuli can serve as economic incentives to motivate behavior, these results suggest that the experience of aesthetic appreciation can have value in and of itself, similar to the hedonic value previously proposed to explain shopping without the intent to purchase. The proposed study examines whether fashion browsing can be considered a type of aesthetic experience. Functional magnetic resonance imaging (fMRI) will be used to measure neural activation as female subjects (N=50) view fashion images. If fashion browsing is a type of aesthetic experience, we would expect it serve as an economic incentive and motivate work. Additionally, the NAcc and VMPFC during browsing should show increasing activation with increasing attractiveness of fashion content. Individual differences in self-reported fashion browsing behavior will correlate with the degree of neural differentiation to fashion content such that individuals who spend more time per week browsing will have higher BOLD signal NAcc and VMPFC activation during the experimental task. Fashion browsing as an aesthetic experience could serve as a crucial mechanism to develop a greater understanding of an important aspect of the consumer shopping experience.

This dissertation aims to examine the causal effect of education on happiness and satisfaction with several life domains using data from the Turkish Life Satisfaction Survey. To tackle possible endogeneity of education, we implement the method of instrumental variables (IV) and make use of the 1997 education reform, which prolonged compulsory schooling from 5 to 8 years in Turkey, as a source of exogeneous variation in education. The IV estimates indicate that education has no statistically significant effect on happiness for both genders. Moreover, the impact of education on various life satisfaction domains differs between men and women. The IV results provide evidence that for females, having at least a middle school degree increases the likelihood of being satisfied with household income, health, and housing quality. Among males, we find that education has a negative and statistically significant effect on job satisfaction.<br>Esta dissertação tem como objetivo examinar o efeito causal da educação na felicidade e na satisfação com diversos domínios da vida pessoal usando dados obtidos do Turkish Life Satisfaction Survey. Para responder a um possível problema de endogeneidade da educação, implementamos o método das variáveis instrumentais (VI) e usamos a reforma educacional introduzida em 1997, que prolongou a escolaridade obrigatória de 5 para 8 anos na Turquia, como fonte de variação exógena na educação. As estimativas VI indicam que a educação não tem um efeito estatisticamente significativo sobre a felicidade para ambos os géneros. Os resultados demonstram também que o impacto da educação em vários domínios da satisfação com a vida difere entre homens e mulheres. Os resultados VI fornecem evidências de que, para as mulheres, ter pelo menos o ensino médio aumenta a probabilidade de estarem satisfeitas com o rendimento familiar, saúde e qualidade de habitação. Entre os homens, descobrimos que a educação tem um efeito negativo e estatisticamente significativo na satisfação com o emprego atual.

The impact of self awareness during sexual activity has been widely discussed. However, research has been largely focused on the effects of performance anxiety in male erectile functioning. Based on research linking sexual difficulties to lower levels of body image, it has been suggested that physical appearance concerns may have a similar influence on sexual functioning in women as does men's self-awareness about erectile functioning. On the other hand, research has also shown that in some cases self awareness can improve sexual functioning among women. The role that physical appearance or awareness of one's body specifically may play in female sexual response has received little empirical attention. The aim of the current study was to examine the impact of body image on sexual arousal response to erotica among 48 women with Female Sexual Arousal Disorder (FSAD). Women were randomized to one of two Body Image conditions: Positive Body Image or Negative Body Image. Each woman participated in two sessions: Experimental and Control. In the experimental sessions, participants were asked to adopt and attend to their positive or negative body parts, and a full-length mirror was placed in front of them. Self-reported mental arousal, perceptions of physical arousal, body awareness, body image, anxiety, and cognitive distraction were assessed. Results showed that in the negative and positive experimental sessions, women experienced increased mental and perceptions of physical sexual arousal compared to the control session. Findings were mainly accounted for by levels of body image and body awareness. There were no differences in anxiety or cognitive distraction. Findings suggest that body image and body awareness, whether positive or negative, can result in increased subjective sexual arousal response.<br>text

The utilisation of navigation systems in cars has given rise to road safety concerns, and the design and functionality of such systems must therefore be adjusted to the users’ needs, since they have to divide their attention between driving and the operation of the navigation system. The study was aimed at finding the optimum system response time (SRT) which would enable a driver to focus as much as possible on the road while attaining an efficient task completion time using an electronic navigational system. The research project consists of two separate experiments and was completed by 10 subjects. Experiment 1 included a temporal reproduction task and a secondary memory task. The subjects had to memorise two symbols and then reproduce six time spans ranging from 1 to 30 s to provide a baseline measurement of their time estimation abilities. Experiment 2 consisted of a simulated automobile driving task. While driving in the simulator the subjects completed a memorising task displayed on a touch screen. The task was presented with seven different system response times (SRTs) ranging from 0 to 30 s. The effects of different SRTs on the eye movement from road to monitor, regarding the duration of fixation and the frequency of change were evaluated. The distribution of gazes to the secondary task was analysed to provide information about the time estimation performance in the driving simulator. Other dependent variables tested were the accuracy of selected items, memory game performance, drive performance and the subjective state of the test person. The results of this study can be employed to find the optimum duration of inter-task delays for in-vehicle technical devices.<br>Psychology<br>M.A. (Psychology)

碩士<br>國立臺灣大學<br>會計學研究所<br>99<br>This study examines the effects of the superior’s subjective discretion on bonus allocation on the subordinates’ perceived justice, job satisfaction, and job performance. This study recruits 70 undergraduates and graduates as the participants in an experiment in which they are paired to form a two-person team to perform the decoding task independently for eight periods. Adopting a 3x1 between-subjects design by which the participants are randomly assigned to one of three bonus allocation methods: compensation based on actual individual-performance, compensation based on equal share of the actual team performance, and compensation based on the superior’s subjective judgment which deviates from actual individual-performance. Using structural equation modeling to test the hypotheses, this study finds that the superior’s subjective discretion has a direct effect on the subordinate’s perceived justice as well as job performance, but does not has a direct effect on job satisfaction. Perceived justice has a direct effect on job satisfaction but not job performance. Job satisfaction has a direct effect on job performance. In terms of mediating effects, the superior’s subjective discretion has an indirect effect on job satisfaction via perceived justice. Also, perceived justice has an indirect effect on job performance via job satisfaction. Implications for performance evaluation and incentive contracts are discussed.

O estudo procura explorar as práticas de bullying nas escolas angolanas, tendo como suporte teórico o modelo ecológico de Bronfenbrenner (1994) e o modelo tripartido da influência familiar na regulação emocional (Morris, Silk, Steinberg, Myers & Robinson, 2007). Pretende-se analisar o papel da regulação emocional na relação entre a família (estilos parentais) e o (des)ajustamento (bullying e bem-estar subjetivo) e a moderação das características dos pais e das crianças. Os participantes são 544 estudantes angolanos, de ambos os sexos, entre os 10 e os 16 anos, das províncias de Benguela, Huíla e Luanda. O instrumento é um questionário de autorrelato, adaptado ao contexto angolano. O estudo foi aprovado pelas Direções Provinciais da Educação e consideraram todos os procedimentos éticos, de acordo com a OPP e a APA. De acordo com os resultados, o desenvolvimento da regulação emocional, através de práticas parentais mais adequadas, poderá prevenir o bullying e promover um maior bem-estar das crianças e jovens.<br>This research attempts to explore bullying practices in Schools of Angola, based on the technical support of the theoretic ecologic method of Bronfenbrenner (1994) and the tripartite model of family influence in emotional regulation of the family (Morris, Silk, Steinberg, Myers & Robinson, 2007). It intends to analyze the role of emotional regulation in the relationship between the family (parental styles) and the (mal)adjustment (bullying and subjective well-being) and the moderation of the parents and children characteristics. The participants are 544 (five hundred and forty four) Angolan students, both genders, between 10 to 16 years old, from the provinces of Benguela, Huila and Luanda. The applied instrument is a self-report questionnaire, adapted to the Angola Context. This research has received approval from Provincial Directions of Education in respective provinces, having considered all the ethic procedures as being in accordance with the OPP and the APA. The results of the study showed that the emotional development regulation, throughout the most adequate practices, might prevent bullying and promote well-being of children and young people.