We identify two aspects of the problem of maintaining perceptual stability despite an observer's eye movements. The first, visual direction constancy, is the (egocentric) stability of apparent positions of objects in the visual world relative to the perceiver. The second, visual position constancy, is the (exocentric) stability of positions of objects relative to each other. We analyze the constancy of visual direction despite saccadic eye movements.Three information sources have been proposed to enable the visual system to achieve stability: the structure (...) of the visual field, proprioceptive inflow, and a copy of neural efference or outflow to the extraocular muscles. None of these sources by itself provides adequate information to achieve visual direction constancy; present evidence indicates that all three are used.Our final question concerns how information processing operations result in a stable world. The three traditionally suggested means have been elimination, translation, or evaluation. All are rejected. From a review of the physiological and psychological evidence we conclude that no subtraction, compensation, or evaluation need take place. The problem for which these solutions were developed turns out to be a false one. We propose a “calibration” solution: correct spatiotopic positions are calculated anew for each fixation. Inflow, outflow, and retinal sources are used in this calculation: saccadic suppression of displacement bridges the errors between these sources and the actual extent of movement. (shrink)

The phenomena referred to by the term attention were not discovered by scientific psychology. They were discovered and described within philosophy and gently handed over to the emerging academic psychology of the nineteenth century. The main contributors and contributions to the delineation and construction of attention as an empirical phenomenon and a topic for theorizing were Aristotle, who noticed that not all that reaches the senses is clearly perceived; Augustine, who interpreted attention as an effort of the soul; Descartes, who (...) distinguished active attention from passive attention; and Leibniz, who discussed the relation between attention, perception, and consciousness. (For further information on attention's philosophical past the reader is referred to Neumann's (in press) brief history of this philosophical past that is badly in need of an English translation.). (shrink)

The explanatory gap refers to the lack of concepts for understanding “how it is that . . . a state of consciousness comes about as a result of irritating nervous tissue.” By assuming that there are colours in the outside world, Block needlessly widens this gap and Lycan and Kitcher simply fail to see the gap. When such assumptions are abandoned, an unnecessary and incomprehensible constraint disappears. It then becomes clear that the brain can use its own neural language for (...) representing aspects of the outside world. While this may not close the gap, it becomes clearer where we need new concepts. (shrink)

Everybody knows the phenomena summarized with the term attention: concentration, focalization, limitation, selection, and intensification . The explanation of these phenomena is, however, a different matter. Problems easily arise with regard towhathas to be explained and with regard to thestyleof explanation. A problem of the first kind is the “methodology of ‘bad focus’”: the explanation starts with and is fixated on an intuitively striking but nonessential behavioral feature or cognitive achievement. A problem of the second kind is a “virtus dormitiva” (...) explanation: the explanation starts with emphasizing one aspect of the observed phenomena, the emphasized aspect receives an interesting and suggestive name, and that name with its connotations is used as a concept in the explanation. At the start of contemporary, behavior-based, information processing psychology, avirtus dormitivaexplanation infiltrated the functional accounts of the phenomena of attention; the empirical observation that people show performance limitations was translated into the theoretical concept of a communication channel with a limited capacity. That limited capacity notion became the core concept in what can be called the standard theory of attention. This standard theory of attention faced severe difficulties in explaining the guidance of attention by the information processor's goals and intentions. Subsequent modifications, concerned with removing these difficulties, revealed that selection, guided by goals and intentions, is the essential behavioral feature and that the observed performance limitations are a result of this selection. So, the limited capacity theorizing was not only plagued by avirtus dormitivaexplanation, it also suffered from the methodology of bad focus. (shrink)

BackgroundRelatives have no formal position in the practice of euthanasia and physician-assisted suicide (EAS) according to Dutch legislation. However, research shows that physicians often involve relatives in EAS decision-making. It remains unclear why physicians do (not) want to involve relatives. Therefore, we examined how many physicians in the Netherlands involve relatives in EAS decision-making and explored reasons for (not) involving relatives and what involvement entails.MethodsIn a mixed-methods study, 746 physicians (33% response rate) completed a questionnaire, and 20 were interviewed. The (...) questionnaire included two statements on relatives’ involvement in EAS decision-making. Descriptive statistics were used, and multivariable logistic regression analyses to explore characteristics associated with involving relatives. In subsequent interviews, we explored physicians’ views on involving relatives in EAS decision-making. Interviews were thematically analysed.ResultsThe majority of physicians want to know relatives’ opinions about an EAS request (80%); a smaller group also takes these opinions into account in EAS decision-making (35%). Physicians who had ever received an explicit EAS request were more likely to want to know opinions and clinical specialists and elderly care physicians were more likely to take these opinions into account. In interviews, physicians mentioned several reasons for involving relatives: e.g. to give relatives space and help them in their acceptance, to tailor support, to be able to perform EAS in harmony, and to mediate in case of conflicting views. Furthermore, physicians explained that relatives’ opinions can influence the decision-making process but cannot be a decisive factor. If relatives oppose the EAS request, physicians find the process more difficult and try to mediate between patients and relatives by investigating relatives’ objections and providing appropriate information. Reasons for not taking relatives’ opinions into account include not wanting to undermine patient autonomy and protecting relatives from a potential burdensome decision.ConclusionsAlthough physicians know that relatives have no formal role, involving relatives in EAS decision-making is common practice in the Netherlands. Physicians consider this important as relatives need to continue with their lives and may need bereavement support. Additionally, physicians want to perform EAS in harmony with everyone involved. However, relatives’ opinions are not decisive. (shrink)

This systematic review aimed to provide an overview of earlier research on the relationships between age conceptualizations and indicators of employability. We have conducted a systematic literature search using PsycINFO, Academic Search Premier, Business Source Complete, CINAHL, ERIC, MEDLINE, and Science Direct. Two raters evaluated the articles and subsequently distinguished k = 41 studies that met the inclusion criteria for this systematic review. Our review revealed that many researchers adopted different operationalizations to measure employability. Moreover, most studies included calendar age (...) as indicator of aging at work, and were based on a cross-sectional design. Based on the Standardized Index of Convergence method, different types of evidence were found for the relationships between age and the employability measures. For relationships between psychosocial age and lifespan age, on the one hand, and employability measures, on the other hand, too few studies were found to draw conclusions. Yet, for relationships between calendar age and labor market-based measures strong consistent negative relationships were found across the studies, and moderately strong positive relationships were found for functional age and labor market- based measures. For organizational age and both competence-based as well as labor market-based measures moderately strong negative relationships were found. We discuss the implications of these results and propose a research agenda for future studies. (shrink)

In view of the aging and dejuvenation of the working population and the expected shortages in employees’ skills in the future, it is of utmost importance to focus on older workers’ employability in order to prolong their working life until, or even beyond, their official retirement age. The primary aim of the current study was to examine the relationship between elderly workers’ employability (self-)perceptions and their intention to continue working until their official retirement age. In addition, we studied the role (...) of potential antecedents of their perceived employability at three different levels: training and education in current expertise area as well as in an adjacent expertise area (individual level factor), learning value of the job (job level factor), and organizational career management practices (organizational level factor). Data were collected by means of e-questionnaires that were distributed among two groups of Dutch older (45-plus) white collar workers. The samples consisted of 223 employees of an insurance company, and 325 university workers, respectively. Our research model was tested separately in each sample using Structural Equation Modelling; in our analyses, we controlled for the effects of respondents’ (self-)perceived health and (self-)perceived financial situation. Similar results were found for both samples. First, the relationship of perceived employability with the intention to continue working until one’s retirement age was positive, whereas the relationship between a perceived good financial situation with the intention to continue working until one’s retirement age was negative. Secondly, as regards the potential antecedents, results showed that the learning value of the job was positively related to perceived employability. In addition, an employee’s perception of good health is a relevant correlate of perceived employability. So, whereas perceived employability contributes to the intention to continue working until one’s retirement age, a perceived good financial situation is a push factor to retire early. In order to promote the labour participation of older workers, this study indicates that organizations should focus on the learning possibilities that are inherent to one’s job rather than on providing additional training or career management. Further research is needed to test the generalizability of our results to other samples. (shrink)

Using the Job Demands-Resources model literature and the life-span theory as scholarly frameworks, we examined the effects of job demands and job resources as mediators in the relationship between bundles of used HRM practices and employee outcomes. In addition, we tested for age differences in our research model. Findings confirmed the hypothesized original 2-factor structure representing maintenance and development HRM practices. Structural Equation Modeling analyses showed that the maintenance HRM bundle related directly and negatively to employee outcomes, without moderating effects (...) of age. However, job resources appeared to mediate this relationship in a positive way as it also did for the development HRM bundle. Whereas this study showed the ‘driving power’ of the actual use of HRM bundles through job resources, regardless of the employee’s age, this study also suggests a ‘dark side’ of HRM. In particular, we found that development HRM bundles may also increase job demands, which, in turn, may result in lower levels of beneficial employee outcomes. These empirical outcomes demonstrate the strength of the driving power eliciting from job resources preceded by any HRM bundle. Moreover, this effect appears to apply to employees of all ages. Our moderated-mediation model appeared robust for several control variables. Overall, this study provides an extension of the well-known Job Demands-Resources model by including maintenance and development bundles of HRM practices used by employees that have a differential effect on job demands and job resources which in turn have an impact on employee outcomes. (shrink)

The participation of vulnerable patients in clinical research poses apparent ethical dilemmas. Depending on the nature of the vulnerability, their participation may challenge the ethical principles of autonomy, non-maleficence, or justice. On the other hand, non-participation may preclude the building of a knowledge base that is a prerequisite for defining the optimal clinical management of vulnerable patients. Such clinical uncertainty may also incur substantial economic costs. We present the participation of pre-menopausal women with atrial fibrillation in trials of novel oral (...) anticoagulant drugs as a case study. Due to their non-participation in pivotal trials, it is uncertain whether for them, the risks that are associated with these drugs are outweighed by the advantages compared with conventional treatment. We addressed the question whether research of this new class of drugs in this subgroup would be appropriate from both, an ethical as well an economic perspective. We used the method of specifying norms as a wider framework to resolve the apparent ethical dilemma, while incorporating the question whether research of oral anticoagulants in premenopausal women with atrial fibrillation can be justified on economic grounds. For the latter, the results of a value-of-information analysis were used. Further clinical research on NOACs in premenopausal women with atrial fibrillation can be justified on both, ethical and economic grounds. Addressing apparent ethical dilemmas by invoking a method such as specifying norms can improve the quality of public practical reasoning. As such, the method should also prove valuable to committees that have formally been granted the authority to review trial protocols and proposals for scientific research. (shrink)

Les décisions politiques sur les risques environnementaux complexes font fréquemment intervenir des éléments scientifiques contestés. Il n’y a généralement pas de « faits » qui conduisent à une politique correcte unique. Les éléments de preuve qui sont intégrés dans les avis scientifiques destinés à une décision politique nécessitent une évaluation de leur qualité. En 2003, l’Agence néerlandaise d’évaluation environnementale a adopté une méthode standardisée, désignée sous le nom de « guide », dans le cadre de laquelle les principaux aspects de (...) la production et de l’utilisation des connaissances sont présentés grâce à une liste de contrôle visant à l’évaluation et à la communication des incertitudes. Dans cet article, nous présentons des résultats de l’application de ce guide à la controverse sur les risques des particules en suspension. La délibération active sur l’incertitude dans un contexte d’expertise entraîne un processus d’apprentissage commun entre les experts et les décideurs politiques, ce qui conduit à une meilleure prise de conscience du phénomène d’incertitude et de ses implications politiques.Policy decisions on complex environmental risks often involve disputed science. Typically, there are no “ facts” to support a single unequivocally correct policy. The evidence provided in scientific studies for policy-making decisions requires high-quality assessment. In 2003, the Netherlands Environmental Assessment Agency adopted a standardized method, referred to as “guidelines”, whereby key quality aspects of knowledge production and use are presented in the form of a checklist for uncertainty assessments and communication. In this article, we present the outcomes of applying the guidelines in controversies on the risks of ambient particulate matter. In the policy–advisory context, active deliberation on uncertainty produces a common learning process for advisors and policy makers, which leads to a deeper understanding and increased awareness of the phenomenon of uncertainty and its policy implications. (shrink)

Colour has been shown to facilitate the recognition of scene images, but only when these images contain natural scenes, for which colour is ‘diagnostic’. Here we investigate whether colour can also facilitate memory for scene images, and whether this would hold for natural scenes in particular. In the first experiment participants first studied a set of colour and greyscale natural and man-made scene images. Next, the same images were presented, randomly mixed with a different set. Participants were asked to indicate (...) whether they had seen the images during the study phase. Surprisingly, performance was better for greyscale than for coloured images, and this difference is due to the higher false alarm rate for both natural and man-made coloured scenes. We hypothesized that this increase in false alarm rate was due to a shift from scrutinizing details of the image to recognition of the gist of the image. A second experiment, utilizing images without a nameable gist, confirmed this hypothesis as participants now performed equally on greyscale and coloured images. In the final experiment we specifically targeted the more detail-based perception and recognition for greyscale images versus the more gist-based perception and recognition for coloured images with a change detection paradigm. The results show that changes to images are detected faster when image-pairs were presented in greyscale than in colour. This counterintuitive result held for both natural and man-made scenes and thus corroborates the shift from more detailed processing of images in greyscale to more gist-based processing of coloured images. (shrink)

This article reports the findings of a study into the role of Dutch nurses in the alleviation of pain and symptoms with a life-shortening intention, conducted as part of a study into the role of nurses in medical end-of-life decisions. A questionnaire survey was carried out using a population of 1509 nurses who were employed in hospitals, home care organizations and nursing homes. The response rate was 82.0%; 78.1% (1179) were suitable for analysis. The results show that in about half (...) of the cases (55.8%) nurses were involved in the decision making by the physician and that nurses were frequently (81.5%) involved in administering the medication. The authors' conclusion is that alleviation of pain and symptoms with a life-shortening intention represents a `grey' area, in which physicians and nurses act on the basis of personal ethical norms rather than legal rules, professional guidelines or shared moral values. (shrink)

Research suggests that sedentary behavior is negatively associated with cognitive outcomes. Interrupting prolonged sitting has been shown to improve cognitive functions, including executive functioning, which is important for academic performance. No research has been conducted on the effect of standing on EF in VET students, who make up a large proportion of the adolescent population and who are known to sit more than other students of this age. In this study, we investigated the acute effects of reducing SB by short (...) time standing on EF in vocational education and training students. In a randomized crossover study, 165 VET students were first taught for 15 min in seated position. After this, they performed while seated the Letter Memory Test for updating, and the Color Shape Test for shifting and inhibition. Students were randomly assigned to a sitting or standing condition. All students were taught again for 15 min and then took the same tests in the condition they were allocated to, respectively, standing or seated. After 1 week, the test procedure was repeated, in which students switched conditions. Mixed model analyses showed no significant effect of sitting or standing on updating, shifting, or inhibition. Also, no significant differences were found for the order of condition on updating, shifting, or inhibition. Our results suggest that 40 min of standing does not significantly influence EF among VET students. (shrink)

The Dutch law states that a physician may perform euthanasia according to a written advance euthanasia directive when a patient is incompetent as long as all legal criteria of due care are met. This may also hold for patients with advanced dementia. We investigated the differing opinions of physicians and members of the general public on the acceptability of euthanasia in patients with advanced dementia.

Introduction: The Dutch Euthanasia Act states that euthanasia is not punishable if the attending physician acts in accordance with the statutory due care criteria. These criteria hold that: there should be a voluntary and well-considered request, the patient’s suffering should be unbearable and hopeless, the patient should be informed about their situation, there are no reasonable alternatives, an independent physician should be consulted, and the method should be medically and technically appropriate. This study investigates whether physicians experience problems with these (...) criteria in medical practice.Methods: In 2006, questionnaires were sent to a random, stratified sample of 2100 Dutch physicians . Physicians were asked about problems in their decision-making related to requests for euthanasia or assisted suicide after enforcement of the 2002 Euthanasia Act.Results: Of all physicians who had received a request for euthanasia or assisted suicide , 25% had experienced problems in the decision-making with regard to at least one of the criteria of due care. Physicians who had experienced problems mostly indicated to have had problems related to evaluating whether or not the patient’s suffering was unbearable and hopeless and whether or not the patient’s request was voluntary or well considered .Discussion: Physicians in The Netherlands most frequently reported problems related to aspects in which they have to evaluate the patient’s subjective perspective. However, it can be questioned whether placing emphasis on these subjective aspects is an adequate fulfilment of the duties imposed on physicians, as laid down in the Dutch Euthanasia Act. (shrink)

Van Gelder presents the distinction between dynamical systems and digital computers as the core issue of current developments in cognitive science. We think this distinction is much less important than a reassessment of cognition as a neurally, bodily, and environmentally embedded process. Embedded cognition lines up naturally with dynamical models, but it would also stand if combined with classic computation.

Introduction In 2007, a national review committee was instituted in The Netherlands to review cases of active ending of life for newborns. It was expected that 15–20 cases would be reported. To date, however, only one case has been reported to this committee. Reporting is essential to obtain societal control and transparency; the possible explanations for this lack of reporting were therefore explored. Methods Data on end-of-life decision-making were scrutinised from Dutch nation-wide studies (1995, 2001 and 2005), before institution of (...) the committee. Physicians received a questionnaire about their medical decision-making for stratified samples of deceased infants up to 1 year, drawn from the central death registry. Results In 2005, 58% of all deaths were preceded by an end-of-life decision, compared with 68% in 2001 and 62% in 1995. The use of drugs with a possible life-shortening effect tended to be lower. In 2005, all four cases in the study in which an infants' life was actively ended were preceded by a decision to forego life-prolonging treatment. In three cases, the infant's life expectancy was short; one case involved a longer life expectancy. Discussion The expected number of cases is probably an overestimation due to changes in medical practice such as the tendency to attribute less life-shortening effects to opioids. The lack of reports is probably also associated with requirements in the regulation; it may be difficult to fulfil them due either to time constraints or the nature of the suffering that is addressed. If societal control of active ending of life is considered useful, changes in the regulation may be needed. (shrink)