The normative development of child and adolescent problem behavior

The aim of this study was to identify normative developmental trajectories of parent-reported problems assessed with the Child Behavior Checklist (CBCL; T. M. Achenbach, 1991) in a representative sample of 2,076 children aged 4 to 18 years from the general population. The trajectories were determined by multilevel growth curve analyses on the CBCL syndromes in a Longitudinal multiple birth-cohort sample that was assessed 5 times with 2-year intervals. Most syndromes showed a linear increase or decrease with age or a curvilinear trajectory, except for thought problems. Trajectories for most syndromes differed for boys versus girls, except those for withdrawn, social problems, and thought problems. These normative developmental trajectories provide information against which developmental deviance in childhood and adolescence can be detected.     

From symptoms to causes: Diversity effects in diagnostic reasoning

A single causal agent can often give rise to a cascade of consequences that can be envisioned as a branching pathway in which symptoms are the terminal nodes. In three studies, we investigated whether reasoning about root causes on the basis of such symptoms would conform to a diversity effect analogous to that found in inductive reasoning about properties of hierarchically organized categories. A strong diversity effect was found both for reasoning about medical diseases that drew on existing background knowledge and for reasoning that did not. Specifically, the presence of a root cause was more likely to be induced when the symptoms present were further apart in the branching structure.     

Basic-level visual similarity and category specificity

The role of visual crowding in category deficits has been widely discussed (e.g.,;; ). Most studies have measured overlap at the superordinate level (compare different examples of 'animal') rather than at the basic level (compare different examples of 'dog'). In this study, we therefore derived two measures of basic-level overlap for a range of categories. The first was a computational measure generated by a self-organising neural network trained to process pictures of living and non-living things; the second was a rating of perceived visual similarity generated by human subjects to the item names. The computational measure indicated that the pattern of crowded/uncrowded does not honour a living/non-living distinction. Nevertheless, different superordinates showed varied degrees of basic-level overlap, suggesting that specific token choice affects some superordinates more than others e.g., individual fruit and vegetable tokens show greater variability than any other items, while tools and vehicles produce more reliable or overlapping basic-level visual representations. Finally, subject ratings correlated significantly with the computational measures indicating that the neural model represents structural properties of the objects that are psychologically meaningful.     

A nonlinear mixed model framework for item response theory

Mixed models take the dependency between observations based on the same cluster into account by introducing 1 or more random effects. Common item response theory (IRT) models introduce latent person variables to model the dependence between responses of the same participant. Assuming a distribution for the latent variables, these IRT models are formally equivalent with nonlinear mixed models. It is shown how a variety of IRT models can be formulated as particular instances of nonlinear mixed models. The unifying framework offers the advantage that relations between different IRT models become explicit and that it is rather straightforward to see how existing IRT models can be adapted and extended. The approach is illustrated with a self-report study on anger.     

Folkscience: coarse interpretations of a complex reality

The rise of appeals to intuitive theories in many areas of cognitive science must cope with a powerful fact. People understand the workings of the world around them in far less detail than they think. This illusion of knowledge depth has been uncovered in a series of recent studies and is caused by several distinctive properties of explanatory understanding not found in other forms of knowledge. Other experimental work has shown that people do have skeletal frameworks of expectations that constrain richer ad hoc theory construction on the fly. These frameworks are supplemented by an ability to evaluate and rely on the division of cognitive labour in one's culture, an ability shown to be present even in young children.     

On the Concept of the Scale

The theory of linear arrays provides a definition of linear order from the reflexive, symmetric, but non-transitive relation of matching. However, a distance function is not generally available for the elements of a linear array. Given the original intended interpretation of the matching predicate as holding between phenomenal qualia, this result presents an apparent contradiction to the existence of human practices, specifically the tradition of musical practice described by common-practice music theory, that involve precise judgments of phenomenal distance. This paper resolves that seeming contradiction by constructing a notion of the musical scale out of the theory of linear arrays. First, the theory of linear arrays is briefly reviewed. Then, criteria of adequacy for the construction are adduced from common-practice music theory, the theory of measure and the semiotic theory of notation. The construction is presented along with results indicating its fulfillment of the criteria of adequacy. Finally, the relations between several variables introduced in the course of the construction are investigated.     

How to discover that the real is unreal

The measurement problem in quantum mechanics is presented in a completely non-technical way by means of the results of some very simple experiments. These experimental results themselves, rather than the formalism of quantum theory, are shown to be extremely hard to incorporate in a sensible state-space picture of the world. A novel twist is then added which makes the problem even harder than it appears to be in other presentations of the measurement problem.     

Visual acuity improvement following fading and feedback training—I. Comparison of myopic and emmetropic volunteers

18 myopes and 18 emmetropes were randomly assigned in pairs to either Fading and Feedback training or a no-treatment control condition. The emmetropes were fitted with plus lenses equivalent to the spherical correction of the paired myope to simulate myopic visual acuity. Extensive visual acuity measures were obtained pre- and post-training. Data analyses indicated significant increases in recognition visual acuity for trained subjects, compared to no-treatment controls. The myopia/emmetropia variable did not interact with training even though there were noticably greater increases in visual acuity for trained myopes compared to the other conditions. Resolution visual acuity did not change as a function of training. These data are discussed in terms of their implications for better understanding the mechanisms responsible for visual acuity increases following behavioural training.