Facilitating effects of exercise on information processing

The aim of this study was to examine the facilitating effects of moderate physical exercise on the reaction process to gain a better understanding of the interaction between physiological and cognitive processes. Sixteen participants with specific expertise in decision-making sports performed a double task consisting of choice reaction time while cycling. Signal quality, stimulus-response compatibility and time uncertainty were manipulated. Participants were tested at rest and while cycling at 20% and at 50% of their maximal aerobic power. A mood assessment questionnaire and a critical flicker fusion test were administered before and after the choice reaction time task. The results showed that moderate-intensity exercise (50% maximal aerobic power) improves cognitive performance and that low-intensity exercise (20% maximal aerobic power) enables participants to compensate the negative dual-task effect.     

Employing Travel Time to Compare the Value of Competing Cultural Organizations

A number of studies have applied non-market valuation techniques to measure the value of cultural goods. Virtually all of these studies are single case applications and rely mostly on stated preferences, such as contingent valuation techniques. We compare the relative value of multiple, competing goods and show how revealed preferences, in particular travel time, may be used for this. In addition, we account for heterogeneity. Using a unique transaction database with the visiting behavior of 80,821 Museum Cardholders to 108 Dutch museums, we propose a latent class application of a logit model to account for the different distances of museums to the population and for differences in willingness-to-travel.     

Cultural barriers to the international transfer of information

The recent debates on such issues as the transborder data flow or the new information order have brought to light the cultural implications of information activities. This is fortunate since information science used to consider them only as aspects of language barrier.Information has recently been qualified as a humankind's heritage. Sharing it requires not only the international flow of information, but also its unimpeded creation and use. Considering that humankind is not limited to the inhabitants of Europe and North America, this paper discusses the various ways in which objective and subjective cultural traits affect the generation, presentation, transfer and use of information in different societies.It emphasizes that all presently available information products and services are culture dependent, and primarily dependent upon the “northern” culture, what drastically limits their international value, but for “occidentalized” elite groups.     

The role of education in health system performance

I investigate the role of education on health, using country-level data and the production frontier framework suggested by the World Health Organization (WHO) to assess performances of health care systems. I find that the impact of human capital on health is much smaller than suggested by the WHO frontier model, and the relationship exhibits diminishing return in the observed range of education. Taking into account the heterogeneity in this relationship generates a different ranking of the efficiency of health care systems internationally. This suggests that the method currently used by the WHO favors health care systems operating in countries that underinvested in education in the past.     

From declarative and procedural knowledge to the management of declarative and procedural knowledge

Research on domain-specific knowledge and general knowledge such as strategies has shown that information can indeed be available to a subject and still not be used. Several hypothesis have been set forth to explain this phenomenon; they as briefly exposed. An alternative, complementary hypothesis is then presented. It is assumed that most activities have several components organized in the form of a complex hierarchy. These interdependent components require monitoring because, at certain times, they are competing with one another for resources. Competition for resources and problems in component coordination may lead to a drop in performance. Several studies dealing with diverse knowledge domains are reviewed, which provide evidence for such resource problems. The same theoretical framework is then applied to explain several facts concerning teaching and learning: the impact of advance organizers; the instability of performance across repeated executions; some effects of social variables; the efficiency of tutoring and of taking into account the ‘proximal zone of development’. The limited cognitive capacity construct proves extremely useful in interpreting a large number of phenomena in a wide variety of domains.     

Examining genetic and environmental effects on social aggression: a study of 6-year-old twins

Using a genetic design of 234 six-year-old twins, this study examined (a) the contribution of genes and environment to social versus physical aggression, and (b) whether the correlation between social and physical aggression can be explained by similar genetic or environmental factors or by a directional link between the phenotypes. For social aggression, substantial (shared and unique) environmental effects but only weak genetic effects were found. For physical aggression, significant effects of genes and unique environment were found. Bivariate modeling suggests that social and physical aggression share most of their underlying genes but only very few overlapping environmental factors. The correlation between the two phenotypes can also be explained by a directional effect from physical to social aggression.