Sample size determinations for the two rater kappa statistic

This paper gives a method for determining a sample size that will achieve a prespecified bound on confidence interval width for the interrater agreement measure,. The same results can be used when a prespecified power is desired for testing hypotheses about the value of kappa. An example from the literature is used to illustrate the methods proposed here.     

No attentional bias for pictoral stimuli in spider-fearful subjects

A number of experiments have shown that (spider) fearful subjects direct their attention to fear-relevant words, even when these words are irrelevant to the completion of a target task (e.g., color naming). The present study examined whether subjects with an intense fear of spiders also display such attentional bias for a fear-relevant pictoral stimulus. Female spider-fearful (n=13) and control subjects (n=13) saw neutral patterns (i.e., horizontal and vertical bars). One pattern served as target for a reaction time, while the other pattern served as nontarget. Targets and nontargets were accompanied by either fear-relevant or neutral pictoral material (i.e., a picture of a spider or a picture of a flower, respectively). The fear-relevant picture did not selectively delibate reaction time performance of spider-fearful subjects. Thus, no evidence was found for an attentional bias for fear-relevant pictoral material in subjects with an intense fear of spiders. Instead, fearful subjects exhibited a general inhibition of performance which became stronger over trials. This suggests that the fear-relevant picture induced a state of anxious arousal or defensive withdrawal that interfered with reaction time performance on both fear-relevant and neutral trials.     

Is the match/mismatch model based on a statistical artefact?

In the match/mismatch model, recently formulated by Rachman and coworkers, it is stated that incorrectly predicted aversive experiences are generally followed by an immediate adjustment of the predictions concerning aversiveness of the next experience. This model can be considered to reflect a psychological process of the formation of expectations. In the present article it is argued that a simple H0 model, assuming that predictions are completely randomly generated by the subject, may account for the same effects. This H0 model is used in a stringent test of empirical data to determine if there are any effects of the discrepancy between prediction and experience on next prediction that exceed the effects explained by the H0 model. Although the H0 model produces effects very similar to the empirically observed effects, there is clear support for the hypothesized influence of the discrepancy between prediction and experience. Therefore, the model appears to reflect 'real' psychological processes and not chance findings.     

Reliability and Validity of a Paper-and-Pencil Test Measuring Hemisphere Preference

The present studies examined the reliability and validity of the Preference Test (PT), a widely used self-report index of preferred hemisphere thinking styles. The PT consists of items that intend to tap left-hemisphere and right-hemisphere cognitions. In the first study (N=47), PT scores were found to have reasonable test–retest stability. In the second study (N=334), a factor analysis of PT scores showed that the PT has a two-factor solution that can best be interpreted in terms of putative left- and right-hemisphere items. In the third study (N=29), background EEG activity (F3, F4, P3 and P4) of subjects was recorded. PT scores were found to be related to EEG asymmetry patterns for frontal, but not for parietal, recording sites. More specifically, subjects with a left-hemisphere preference displayed relatively stronger left frontal activity than subjects with a right-hemisphere preference. By and large, the present findings provide strong support for the reliability and some suggestive evidence for the validity of the PT.     

Beliefs in personality disorders: a test with the personality disorder belief questionnaire

The hypothesis that each personality disorder (PD) is characterized by a specific set of beliefs was tested in a sample of 643 subjects, including non-patient controls, axis-I and axis-II patients, diagnosed with SCID-I and -II interviews. Beliefs of six PDs (avoidant, dependent, obsessive-compulsive, paranoid, histrionic, borderline) were assessed with the Personality Disorder Belief Questionnaire (PDBQ). Factor analyses supported the existence of six hypothesized sets of beliefs. Structural equation modeling (SEM) supported the hypothesis that each PD is characterized by a specific set of beliefs. Path coefficients were however in the medium range, suggesting that PDs are not solely determined by beliefs. Nevertheless, empirically derived cutoff scores of the six belief subscales were reasonably successful in classifying subjects, percentages ranging form 51% to 83%. It appeared that there was a monotonical increase in scores on each belief subscale from non-patient controls, to patients without any PD, to patients with PDs (other than the pertinent PD), to patients with the pertinent PD. This suggests that PD-related beliefs are at least partly associated with (personality) psychopathology in general. Another explanation is that many patients' position on the underlying dimensions is not high enough to lead to a DSM PD diagnosis, but high enough to lead to an elevated belief score.     

Psychometric qualities of the White Bear Suppression Inventory in a Dutch sample of children and adolescents

The White Bear Suppression Inventory [WBSI; Wegner and Zanakos (1994)] was developed to assess the tendency to suppress unwanted thoughts. Most psychometric studies of the WBSI have included healthy students and adults with obsessive-compulsive disorder. There has been increasing interest in thought suppression in children and adolescents, especially after a traumatic event, but little is known about the psychometric properties of the WBSI for children. The aim of this research was to examine the psychometric qualities of the WBSI in a Dutch sample of children and adolescents. Two studies were conducted. First, the WBSI’s factor structure, internal consistency and test-retest stability were examined in a sample of 203 primary school children (9-13 years). Second, the factor structure and content validity were assessed in 89 children and adolescents (8-18 years) who attended the emergency room after a road traffic accident. Results demonstrated that the WBSI items contribute to a single factor measuring the suppression of unwanted thoughts and that the reliability is satisfactory. Associations between the WBSI and PTSD-symptoms demonstrated sufficient content validity. The findings suggest that the WBSI can appropriately be used in child and adolescent samples.     

Mental Disorders,Personality Traits,and Grievance-Fueled Targeted Violence: The Evidence Base and Implications for Research and Practice

This article aims to move away from intuitive appeals that link mental disorder with violence such as terrorism, mass murder, and other targeted violence. The article synthesizes the existing evidence base regarding the relationship between mental disorders and personality traits and (a) attitudinal affinities with violent causes, and (b) a number of violent behaviors (including mass murder and terrorism). The evidence base is mixed and the research focus changed across time: from simple and unempirical assertions of causation to an almost complete rejection of their presence to a finer grained and disaggregated understanding. Empirical research examining mental disorder in crime and violence highlights that the commission of such events is a complex synthesis of psychopathology, personal circumstance, and environment. The article concludes with several suggestions regarding future research and practice.     

Theism, Dualism, and the Scientific Image of Humanity

Recently, some philosophers of religion have suggested that a reduction of the classical image of humanity may jeopardize classical theism. To obstruct reductionism, some theologians have argued for dualism on the basis of the argument of consciousness. In this essay, I argue that even consciousness must be considered a brain-based phenomenon. This does not commit one to reductionism, however. Nonreductive physicalism appears to offer a promising alternative to either dualism or reductionism, without necessarily compromising more traditional views of humanity. I do suggest that a modification of the classical image of God may be inevitable.     

Researchers discover what they already knew about validity: The case of the family-of-Origin Scale

This article is concerned with two recnet studies of the Family-of-Origin Scale (FOS), Gavin and Wamboldt (1992) and Ryan, Kawash, Fine, and Powel (1994). The external validity analyses conducted for the FOS in these studies assumed the scale to be a unidemsional measure. The present discussion centers on methodological decisions and interpretive strategies that may have prevented a more complete understanding of the scale's dimensional structure and theoretical meaning. It is concluded that a unidimensional view of the FOS is an oversimplification that is inconsistent with the available data. A case is made for a more comprehensive and technically adequate evaluation of the FOS. Specific suggestions are offered.     

Brightness indention: A novel compression mechanism in the luminance-brightness mapping

In a previous study, Schouten and Blommaert (1995) explicitly showed that brightness constancy implies a substantial compression in the luminance-brightness mapping. Here it is argued that additional compression mechanisms are required for scenes with large luminance ranges. To trace these, a series of experiments was conducted which involved expansion of the luminance range. We used a simple spatial configuration consisting of a disk on a contourless homogeneous surround (Ganzfeld). The contrast between the disk and Ganzfeld acted as the independent variable, while the size of the disk was parametrically varied. Sequential dichoptical brightness matches with a reference were carried out for both the disk and the surround. The results reveal a compression mechanism which we termbrightness indention. This indention, which has not previously been reported in the literature, only occurs if the Ganzfeld is less luminous than the disk, and it takes the form of a brightness decrease of the immediate surroundings of the disk.