ON FUNCTIONAL FIXEDNESS: Some critical remarks

The interpretation of functional fixedness as a fixation of behavior or inhibiting of behavior tendencies is challenged. As an alternative is proposed 'perceptual emphasis' in which the effect of past experience with the use of objects is viewed in agreement with van de Geer as a change in the perception of the objects. Some recent experiments are reviewed in the light of this phenomenological interpretation.     

General mixture item response models with different item response structures: Exposition with an application to Likert scales

This article proposes a general mixture item response theory (IRT) framework that allows for classes of persons to differ with respect to the type of processes underlying the item responses. Through the use of mixture models, nonnested IRT models with different structures can be estimated for different classes, and class membership can be estimated for each person in the sample. If researchers are able to provide competing measurement models, this mixture IRT framework may help them deal with some violations of measurement invariance. To illustrate this approach, we consider a two-class mixture model, where a person’s responses to Likert-scale items containing a neutral middle category are either modeled using a generalized partial credit model, or through an IRTree model. In the first model, the middle category (“neither agree nor disagree”) is taken to be qualitatively similar to the other categories, and is taken to provide information about the person’s endorsement. In the second model, the middle category is taken to be qualitatively different and to reflect a nonresponse choice, which is modeled using an additional latent variable that captures a person’s willingness to respond. The mixture model is studied using simulation studies and is applied to an empirical example.     

Right-sided human prefrontal brain activation during acquisition of conditioned fear

This H2(15)O positron emission tomography (PET) study reports on relative regional cerebral blood flow (rCBF) alterations during fear conditioning in humans. In the PET scanner, subjects viewed a TV screen with either visual white noise or snake videotapes displayed alone, then with electric shocks, followed by final presentations of white noise and snakes. Autonomic nervous system responses confirmed fear conditioning only to snakes. To reveal neural activation during acquisition, while equating sensory stimulation, scans during snakes with shocks and white noise alone were contrasted against white noise with shocks and snakes alone. During acquisition, rCBF increased in the right medial frontal gyrus, supporting a role for the prefrontal cortex in fear conditioning to unmasked evolutionary fear-relevant stimuli.     

Validity and reliability of self-assessed physical fitness using visual analogue scales

To test the validity and reliability of self-assessed physical fitness samples included healthcare assistants working at a hospital (women=170, men=17), persons working with physically and mentally handicapped patients (women=530, men= 123), and two separate groups of healthcare students (a) women=91 and men=5 and (b) women=159 and men=10. Five components of physical fitness were self-assessed by Visual Analogue Scales with illustrations and verbal anchors for the extremes: aerobic fitness, muscle strength, endurance, flexibility, and balance. Convergent and divergent validity were evaluated by age-adjusted correlations stratified by sex with performance-based measures of physical fitness. Self-assessed aerobic fitness (r = .36 - .64) (women/men), muscle strength (r = .30 - .51), and flexibility (r = .36 - .31) showed moderate convergent validity. The divergent validity was satisfactory except for flexibility among men. The reliability was moderate to good (ICC = .62 - .80). Self-assessed aerobic fitness, muscle strength, and flexibility showed moderate construct validity and moderate to good reliability using visual analogues.     

Bootstrap and rollback: generalizing epistemic circularity

Reliabilists accept the possibility of basic knowledge??knowledge that p in virtue of the reliability of some belief-producing process r without antecedent knowledge that r is reliable. Cohen (Philos Phenomenol Res 65:309?C329, 2002, Philos Phenomenol Res 70:417?C430, 2005) and Vogel (J Philos 97:602?C623, 2000, J Philos 105:518?C539, 2008) have argued that one can bootstrap knowledge that r is reliable from basic knowledge. This paper provides a diagnosis of epistemic bootstrapping, and then shows that recent attempts at embracing bootstrapped knowledge are found wanting. Instead it is argued that such arguments are afflicted by a novel kind of generalized epistemic circularity. The ensuing view is defended against various objections, and an explanation of the source of that circularity is offered.     

Testing Manifest Monotonicity Using Order-Constrained Statistical Inference

Most dichotomous item response models share the assumption of latent monotonicity, which states that the probability of a positive response to an item is a nondecreasing function of a latent variable intended to be measured. Latent monotonicity cannot be evaluated directly, but it implies manifest monotonicity across a variety of observed scores, such as the restscore, a single item score, and in some cases the total score. In this study, we show that manifest monotonicity can be tested by means of the order-constrained statistical inference framework. We propose a procedure that uses this framework to determine whether manifest monotonicity should be rejected for specific items. This approach provides a likelihood ratio test for which the p-value can be approximated through simulation. A simulation study is presented that evaluates the Type I error rate and power of the test, and the procedure is applied to empirical data.     

Invariant Ordering of Item-Total Regressions

A new observable consequence of the property of invariant item ordering is presented, which holds under Mokken’s double monotonicity model for dichotomous data. The observable consequence is an invariant ordering of the item-total regressions. Kendall’s measure of concordance W and a weighted version of this measure are proposed as measures for this property. Karabatsos and Sheu proposed a Bayesian procedure (Appl. Psychol. Meas. 28:110–125, 2004), which can be used to determine whether the property of an invariant ordering of the item-total regressions should be rejected for a set of items. An example is presented to illustrate the application of the procedures to empirical data.     

Punishing War Crimes,Genocide, and Crimes against Humanity: Introduction

The purpose of this paper is to direct attention to a challenge—referred to as the threshold challenge—facing a non-absolutist retributivist view on international criminal justice. It is argued, on the one hand, that this challenge constitutes a practically pertinent problem for the retributivist approach to the punishment of mass crimes and, on the other, that it is very hard to imagine any principled way of meeting this challenge.     

The Causal Exclusion Argument

Jaegwon Kim’s causal exclusion argument says that if all physical effects have sufficient physical causes, and no physical effects are caused twice over by distinct physical and mental causes, there cannot be any irreducible mental causes. In addition, Kim has argued that the nonreductive physicalist must give up completeness, and embrace the possibility of downward causation. This paper argues first that this extra argument relies on a principle of property individuation, which the nonreductive physicalist need not accept, and second that once we get clear on overdetermination, there is a way to reject the exclusion principle upon which the causal exclusion argument depends, but third that this should not lead to the belief that mental causation is easily accounted for in terms of counterfactual dependencies.