Good Athlete – Bad Athlete? on the ‘Role-Model Argument’ for Banning Performance-Enhancing Drugs

The paper critically discusses a role-model argument (RMA) in favour of banning performance-enhancing drugs in sport. The argument concludes that athletes should be banned from using performance-enhancing drugs because if they are allowed to use such drugs they will encourage, or cause, youngsters who look up to them to use drugs in a way that would be harmful. In Section 2 the structure of the argument and some versions of it are presented. In Section 3 a critical discussion of RMA is presented. It is argued that we should be reluctant to accept the argument as it stands for at least three reasons: (i) it rests on an unsupported empirical claim; (ii) it also makes a false empirical claim; and (iii) the normative premise of the argument is too demanding morally. Further objections to the RMA are also discussed, but argued to be beside the point     

Negation: A theory of its meaning,representation, and use

This article presents a model-based theory of what negation means, how it is mentally represented, and how it is understood. The theory postulates that negation takes a single argument that refers to a set of possibilities and returns the complement of that set. Individuals therefore tend to assign a small scope to negation in order to minimize the number of models of possibilities that they have to consider. Individuals untrained in logic do not know the possibilities corresponding to the negation of compound assertions formed with if, or, and and, and have to infer the possibilities one by one. It follows that negations are easier to understand, and to formulate, when individuals already have in mind the possibilities to be negated. The paper shows that the evidence, including the results of recent studies, corroborates the theory.     

Grounding Bayesian accounts of numerosity and variability effects in a similarity-based framework: the case of self-organising maps

ABSTRACT

In this paper, we propose self-organising maps as possible candidates to explain the psychological mechanisms underlying category generalisation. Self-organising maps are psychologically and biologically plausible neural network models that can learn after limited exposure to positive category examples, without any need of contrastive information. They reproduce human behaviour in category generalisation, in particular, the Numerosity and Variability effects, which are usually explained with Bayesian tools. Where category generalisation is concerned, self-organising maps deserve attention to bridge the gap between the computational level of analysis in Marr's hierarchy (where Bayesian models are often situated) and the algorithmic level of analysis in which plausible mechanisms are described.     

The role of body image in the prevention of eating disorders

This article reviews theory and research pertaining to prevention of negative body image and eating disorders. Research derived from the social cognitive model (SCM) and non-specific vulnerability-stressor (NSVS) model indicates that sustained prevention effects for attitudes and behaviors are possible, but not easy to achieve or explain. These limitations are considered in the context of promising research derived from a third model, critical social perspectives (CSP). We conclude that (1) research on practice should aim beyond the examination of efficacy in order to clarify the active ingredients contributing to prevention; and (2) research informed by each of the divergent perspectives can be used to enrich theory and practice in the field of eating disorders prevention.     

Constituent-morpheme priming: Implications from the morphology of two-kanji compound words

Abstract: The diversity in the morphological structure of two‐kanji compound words is a matter of special concern for models of the Japanese mental lexicon. This study discusses two proposals for models of the Japanese mental lexicon – Hirose’s (1992, 1994, 1996 ) hypotheses and a Japanese lemma‐unit version of the multilevel interactive‐activation framework – in terms of their ability to cope with this diversity. As the proposals make different predictions concerning constituent‐morpheme priming, patterns of facilitation were examined in two experiments with five word‐formation principles as experimental conditions. Experiment 1, using the long stimulus onset asynchrony (SOA) of 3000 ms employed by Hirose (1992 ), only found significant differences between the first‐ and second‐element conditions in one of the word‐formation conditions. Experiment 2, using a short SOA of 250 ms, confirmed the pattern of priming obtained in Experiment 1. These results are more consistent with the prediction from the Japanese lemma‐unit model.     

Heterogeneous factor analysis models: A bayesian approach

Multilevel factor analysis models are widely used in the social sciences to account for heterogeneity in mean structures. In this paper we extend previous work on multilevel models to account for general forms of heterogeneity in confirmatory factor analysis models. We specify various models of mean and covariance heterogeneity in confirmatory factor analysis and develop Markov Chain Monte Carlo (MCMC) procedures to perform Bayesian inference, model checking, and model comparison.We test our methodology using synthetic data and data from a consumption emotion study. The results from synthetic data show that our Bayesian model perform well in recovering the true parameters and selecting the appropriate model. More importantly, the results clearly illustrate the consequences of ignoring heterogeneity. Specifically, we find that ignoring heterogeneity can lead to sign reversals of the factor covariances, inflation of factor variances and underappreciation of uncertainty in parameter estimates. The results from the emotion study show that subjects vary both in means and covariances. Thus traditional psychometric methods cannot fully capture the heterogeneity in our data.     

Agonistic behavior and growth in newly emerged brown trout (Salmo trutta L) of sea‐ranched and wild origin

Selection experiments and game theory models have revealed that the changes in agonistic behavior following selection for rapid growth rate of fish depend on the access of food. If food is spatially restricted and in excess of demand, the intensity of agonistic behaviors will decrease. This prediction was tested in an experiment on wild and sea‐ranched brown trout (Salmo trutta L.) fry originating from a common stock. Agonistic behavior, activity, and specific growth rate were studied in tanks (56 × 56 cm) at high (159.4 fry/m²) and low (9.6 fry/m²) stocking densities given either a large or small food ration (3.0% and 1.5%, respectively, food per total body weight and day). Observations were done during 4 days in each trial. Generally, fry of sea‐ranched origin had a higher growth rate. No differences in activity were found. Intensity of agonistic behavior was higher among wild groups. There was a tendency for interaction between density and strain, e.g., wild fish were relatively more aggressive at higher densities. Food ration had no effect on level of agonistic behavior. These results indicate that the selection for rapid growth in hatcheries may indirectly select for reduced aggressiveness. Genetic integrity and diversity of wild populations may be threatened when interbreeding occurs between wild and hatchery fish. Aggr. Behav. 28:145–153, 2002. © 2002 Wiley‐Liss, Inc.     

A Latent Variable Framework for Power Estimation Within Intervention Contexts

This paper presents a latent growth SEM approach for the estimation of treatment effects, and power to detect such effects, within a true experimental design setting in which subjects are randomly assigned to treatment and control conditions. Power estimation is a critical component of intervention experiment design and the testing of their results. Although researchers have become increasingly sophisticated in applying tests for statistical significance in intervention contexts, few are aware of the power of these tests. The issues raised in this paper are not new; however, reminding researchers to consider these points is important. Exactly how the researcher handles these issues will depend on the questions asked and the resources available, as well as other considerations. Discussion underscores the relationship between the reliability of a study's measures and concomitant increases in power obtained within the SEM framework.