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.     

The aesthetic attractivity of the golden section

Summary It is hypothesized that the presence of a golden section does not in and of itself add to the aesthetic attractivity of a pattern. Only as far as the realization of a golden section entails equivalences between parts of a pattern, will the aesthetic appeal of a pattern be enhanced. An experiment is reported in which this hypothesis is tested and confirmed.     

Bayesian inference for psychology. Part II: Example applications with JASP

Bayesian hypothesis testing presents an attractive alternative to p value hypothesis testing. Part I of this series outlined several advantages of Bayesian hypothesis testing, including the ability to quantify evidence and the ability to monitor and update this evidence as data come in, without the need to know the intention with which the data were collected. Despite these and other practical advantages, Bayesian hypothesis tests are still reported relatively rarely. An important impediment to the widespread adoption of Bayesian tests is arguably the lack of user-friendly software for the run-of-the-mill statistical problems that confront psychologists for the analysis of almost every experiment: the t-test, ANOVA, correlation, regression, and contingency tables. In Part II of this series we introduce JASP (http://www.jasp-stats.org), an open-source, cross-platform, user-friendly graphical software package that allows users to carry out Bayesian hypothesis tests for standard statistical problems. JASP is based in part on the Bayesian analyses implemented in Morey and Rouder’s BayesFactor package for R. Armed with JASP, the practical advantages of Bayesian hypothesis testing are only a mouse click away.     

Partial support from a non-replication: comment on Roma, Silberberg, Ruggiero, and Suomi (2006)

A purported replication by P. G. Roma, A. Silberberg, A. M. Ruggiero, and S. J. Suomi of the authors' previous study claims to contradict their finding that capuchin monkeys (Cebus apella) refuse to exchange with an experimenter if their partner receives a superior reward. Roma et al. used no exchange task, however, or any other task. Roma et al. offered frustration as explanation of their findings, yet failed to statistically prove that the effect of frustration is stronger than that of inequity. They also misrepresented the dependent measure of the authors' study. Reanalysis of the authors' own data indicated no role of frustration, that is, no effect of previous experience with a superior reward. The authors conclude that Roma et al.'s study is not a replication and does not disprove the authors' findings.     

Visual kin recognition and family resemblance in chimpanzees (Pan troglodytes)

The male-offspring biased visual kin recognition in chimpanzees (Pan troglodytes) reported by L. A. Parr and F. B. M. de Waal (1999) was replicated with human (Homo sapiens) participants and a principal components analysis (PCA) of pixel maps of the chimpanzee face photos. With the same original materials and methods, both humans and the PCA produced the same asymmetry in kin recognition as found with the chimpanzees. The PCA suggested that the asymmetry was a function of differences in the distribution of global characteristics associated with the framing of the faces in the son and daughter test sets. Eliminating potential framing biases, either by cropping the photos tightly to the faces or by rebalancing the recognition foils, eliminated the asymmetry but not human participants' ability to recognize chimpanzee kin.     

Developmental dyslexia and discrimination in speech perception: a dynamic model study

At the behavioral level one of the primary disturbances involved in congenital dyslexia concerns phonological processing. At the neuroarchitectural level autopsies have revealed ectopies, e.g., a reduced number of neurons in the upper layers of the cortex and an increased number in the lower ones. In dynamic models of interacting neuronal populations the behavioral level can be related to the neurophysiological level. In this study an attempt is made to do so at the cortical level. The first focus of this model study are the results of a Finnish experiment assessing geminate stop perception in quasi speech stimuli by 6 month old infants using a head turning paradigm and evoked potentials. The second focus of this study are the results of a Dutch experiment assessing discrimination of transients in speech stimuli, by adult dyslexics and controls and 2 month old infants. There appears to be a difference in the phonemic perceptual boundaries of children at genetic risk for dyslexia and control children as revealed in the Finnish study. Assuming a lowered neuronal density in the 'dyslexic' model, reflecting ectopies, it may be postulated that less neuronal surface is available for synaptic connections resulting in a lowered synaptic density and thus a lowered amount of available neurotransmitter. A lowered synaptic density also implies a reduced amount of membrane surface available for neurotransmitter metabolism. By assuming both, a reduced upper bound of neurotransmitter and a reduced metabolic transmitter rate in the dynamic model, the Finnish experimental results can be approximated closely. This applies both to data from behavioral head turning and that of the evoked potential study. In the Dutch study adult dyslexics show poor performance in discriminating transients in the speech signal compared to the controls. The same stimuli were used in a a study comparing infants from dyslexic families and controls. Using the same transmitter parameters as in modeling the results of the Finnish study, also in this case the experimental results for adults and infants can be approximated closely. Simulation of behavioral and pharmaceutical interventions with the model provide predictions which can be put to the test in experiments.     

Changes in personality pathology after pharmacotherapy and combined therapy for depressed patients

The central question addressed by this article is whether courses of treatment consisting of pharmacotherapy or pharmacotherapy combined with psychotherapy (combined therapy) produce different changes in personality pathology at follow-up after 40 weeks. We also examined whether recovery from depression has an influence on outcome. The study population consisted of 128 outpatients in whom personality pathology and severity of depression were determined at the start of the study. For 72 patients, personality pathology and severity of depression were determined again after 40 weeks. Of the group of 72 patients, 25 patients received only pharmacotherapy for 6 months, and 47 patients received combined treatment (pharmacotherapy and psychodynamic supportive psychotherapy). The antidepressant protocol provides for three successive steps in case of intolerance or inefficacy: fluoxetine, amitriptyline, and moclobemide. The combined therapy condition consisted of 16 sessions of Short Psychodynamic Supportive Psychotherapy in addition to pharmacotherapy. In the combined therapy condition there was a significant reduction in personality pathology in patients who recovered from depression but also in patients who had not. In the pharmacotherapy condition the significant decrease was restricted to patients who recovered from depression. The results were most striking for Cluster C psychopatology. Patients with cluster B pathology changed the least. Depressed patients with comorbid personality pathology appear to benefit most from a combination of pharmacotherapy and a form of short, psychodynamic, supportive psychotherapy.     

Police communication programmes aimed at burglary victims: A review of studies and an experimental evaluation

The effects and side-effects of a victim assistance project aimed at victims of burglary are experimentally evaluated. Key features of the programme included the provision of burglary prevention information by police officers during a personal interaction with the victim through a positive and limitative communication strategy. Results suggest that important programme goals (for example, stronger satisfaction with police performance, a more internal risk orientation concerning victimization, stronger preventive intentions) were met. One of the positive effects for which experimental support was found was an improvement in police-victim relations. As regards side-effects the programme led neither to response generalization, nor to increased fear of crime outside the home. However, the side-effects of increased fear in the home did occur in female victims and victims with an external risk-orientation. The implications for future victim assistance projects in this domain are finally discussed.     

Rhetorical Analysis Within a Pragma-Dialectical Framework

The paper reacts against the strict separation between dialectical and rhetorical approaches to argumentation and argues that argumentative discourse can be analyzed and evaluated more adequately if the two are systematically combined. Such an integrated approach makes it possible to show how the opportunities available in each of the dialectical stages of a critical discussion have been used strategically to further the rhetorical aims of the speaker or writer. The approach is illustrated with the help of an analysis of an `advertorial' published by R. J. Reynolds Tobacco Company.