11,815 research outputs found

    Preference purification and the inner rational agent:A critique of the conventional wisdom of behavioural welfare economics

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    Neoclassical economics assumes that individuals have stable and context-independent preferences, and uses preference-satisfaction as a normative criterion. By calling this assumption into question, behavioural findings cause fundamental problems for normative economics. A common response to these problems is to treat deviations from conventional rational-choice theory as mistakes, and to try to reconstruct the preferences that individuals would have acted on, had they reasoned correctly. We argue that this preference purification approach implicitly uses a dualistic model of the human being, in which an inner rational agent is trapped in an outer psychological shell. This model is psychologically and philosophically problematic

    Thurstonian Scaling of Compositional Questionnaire Data

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    To prevent response biases, personality questionnaires may use comparative response formats. These include forced choice, where respondents choose among a number of items, and quantitative comparisons, where respondents indicate the extent to which items are preferred to each other. The present article extends Thurstonian modeling of binary choice data (Brown & Maydeu-Olivares, 2011a) to “proportion-of-total” (compositional) formats. Following Aitchison (1982), compositional item data are transformed into log-ratios, conceptualized as differences of latent item utilities. The mean and covariance structure of the log-ratios is modelled using Confirmatory Factor Analysis (CFA), where the item utilities are first-order factors, and personal attributes measured by a questionnaire are second-order factors. A simulation study with two sample sizes, N=300 and N=1000, shows that the method provides very good recovery of true parameters and near-nominal rejection rates. The approach is illustrated with empirical data from N=317 students, comparing model parameters obtained with compositional and Likert scale versions of a Big Five measure. The results show that the proposed model successfully captures the latent structures and person scores on the measured traits

    Phase control and measurement in digital microscopy

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    The ongoing merger of the digital and optical components of the modern microscope is creating opportunities for new measurement techniques, along with new challenges for optical modelling. This thesis investigates several such opportunities and challenges which are particularly relevant to biomedical imaging. Fourier optics is used throughout the thesis as the underlying conceptual model, with a particular emphasis on three--dimensional Fourier optics. A new challenge for optical modelling provided by digital microscopy is the relaxation of traditional symmetry constraints on optical design. An extension of optical transfer function theory to deal with arbitrary lens pupil functions is presented in this thesis. This is used to chart the 3D vectorial structure of the spatial frequency spectrum of the intensity in the focal region of a high aperture lens when illuminated by linearly polarised beam. Wavefront coding has been used successfully in paraxial imaging systems to extend the depth of field. This is achieved by controlling the pupil phase with a cubic phase mask, and thereby balancing optical behaviour with digital processing. In this thesis I present a high aperture vectorial model for focusing with a cubic phase mask, and compare it with results calculated using the paraxial approximation. The effect of a refractive index change is also explored. High aperture measurements of the point spread function are reported, along with experimental confirmation of high aperture extended depth of field imaging of a biological specimen. Differential interference contrast is a popular method for imaging phase changes in otherwise transparent biological specimens. In this thesis I report on a new isotropic algorithm for retrieving the phase from differential interference contrast images of the phase gradient, using phase shifting, two directions of shear, and non--iterative Fourier phase integration incorporating a modified spiral phase transform. This method does not assume that the specimen has a constant amplitude. A simulation is presented which demonstrates good agreement between the retrieved phase and the phase of the simulated object, with excellent immunity to imaging noise

    A Methodology for Investigating Heat Stress Selectivity Effects on Mental Performance

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    This paper outlines a methodology that can be used to investigate the selectivity patterns of heat stress effects. The adopted view is that heat stress causes performance to deteriorate because it depletes attentional resources. The term “selectivity” refers to the extent to which certain individual resource pools (the existence of which is postulated by multiple resource theories) are more susceptible to heat stress effects than others. The methodology consists of plotting performance of two time-shared tasks over time on the Performance Operating Characteristic (POC) space. Manipulating the difficulties of the paired tasks under the same environmental conditions (i.e., temperature level and exposure duration) produces a predictable change of the POC path. In particular, if the heat stress effects are non-selective, the POC path will rotate either clockwise or counter-clockwise depending on the task whose difficulty is increased. On the contrary, if the heat stress effects are selective, increasing the difficulty of a task will have no effect on the orientation of the POC path.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

    Modality-specific attention in foraging bumblebees

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    V.N. was funded by a Marie Curie Incoming International Fellowship. L.C. was funded by a Royal Society Wolfson Research Merit Award and an ERC Advanced Grant

    Subjective well‐being and valuation of future health states : discrepancies between anticipated and experienced life satisfaction

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    One way of informing health policy decisions is to ask people about the impact that different health states would have on their future subjective well‐being. The present research explored the relation between anticipated and experienced changes in health‐related subjective well‐being, and examined whether affective forecasting errors could be reduced by psychological distancing manipulations. Using survey methodology, we tested whether people can accurately estimate the impact of different possible health states on their subjective well‐being. We also manipulated psychological distance: Forecasts were made about present self, future self, or others. Based on construal level theory and past work on affective forecasting errors, our prediction was that increasing psychological distance may reduce the mismatch between anticipated and experienced impact of health states on subjective well‐being. We found that the impact of ill health on subjective well‐being was greatly overpredicted and that this overprediction was not eliminated when participants were asked to make predictions about themselves in the future or about other people. Consistent with past work, we found that our participants correctly expected that their subjective well‐being would deteriorate more if they experienced the highest levels of mental illness as compared to the highest intensities of pain or most severe limitations to physical functioning

    PII: S1364-6613(02)01974-5

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    Counterfactual thoughts about what might have been ('if only…') are pervasive in everyday life. They are related to causal thoughts, they help people learn from experience and they influence diverse cognitive activities, from creativity to probability judgements. They give rise to emotions and social ascriptions such as guilt, regret and blame. People show remarkable regularities in the aspects of the past they mentally 'undo' in their counterfactual thoughts. These regularities provide clues about their mental representations and cognitive processes, such as keeping in mind true possibilities, and situations that are false but temporarily supposed to be true

    Back to Bentham? Explorations of Experienced Utility

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    Two core meanings of “utility” are distinguished. “Decision utility” is the weight of an outcome in a decision. “Experienced utility” is hedonic quality, as in Bentham’s usage. Experienced utility can be reported in real time (instant utility), or in retrospective evaluations of past episodes (remembered utility). Psychological research has documented systematic errors in retrospective evaluations, which can induce a preference for dominated options. We propose a formal normative theory of the total experienced utility of temporally extended outcomes. Measuring the experienced utility of outcomes permits tests of utility maximization and opens other lines of empirical research

    Game On? Smoking Cessation Through the Gamification of mHealth: A Longitudinal Qualitative Study

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    BACKGROUND: Finding ways to increase and sustain engagement with mHealth interventions has become a challenge during application development. While gamification shows promise and has proven effective in many fields, critical questions remain concerning how to use gamification to modify health behavior. OBJECTIVE: The objective of this study is to investigate how the gamification of mHealth interventions leads to a change in health behavior, specifically with respect to smoking cessation. METHODS: We conducted a qualitative longitudinal study using a sample of 16 smokers divided into 2 cohorts (one used a gamified intervention and the other used a nongamified intervention). Each participant underwent 4 semistructured interviews over a period of 5 weeks. Semistructured interviews were also conducted with 4 experts in gamification, mHealth, and smoking cessation. Interviews were transcribed verbatim and thematic analysis undertaken. RESULTS: Results indicated perceived behavioral control and intrinsic motivation acted as positive drivers to game engagement and consequently positive health behavior. Importantly, external social influences exerted a negative effect. We identified 3 critical factors, whose presence was necessary for game engagement: purpose (explicit purpose known by the user), user alignment (congruency of game and user objectives), and functional utility (a well-designed game). We summarize these findings in a framework to guide the future development of gamified mHealth interventions. CONCLUSIONS: Gamification holds the potential for a low-cost, highly effective mHealth solution that may replace or supplement the behavioral support component found in current smoking cessation programs. The framework reported here has been built on evidence specific to smoking cessation, however it can be adapted to health interventions in other disease categories. Future research is required to evaluate the generalizability and effectiveness of the framework, directly against current behavioral support therapy interventions in smoking cessation and beyond
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