Limits of dynamic object perception in pigeons: Dynamic stimulus presentation does not enhance perception and discrimination of complex shape

A go/no-go procedure was used to train pigeons to discriminate pictures of human faces differing only in shape, with either static images or movies of human faces dynamically rotating in depth. On the basis of experimental findings in humans and some earlier studies on three-dimensional object perception in pigeons, we expected dynamic stimulus presentation to support the pigeon’s perception of the complex morphology of a human face. However, the performance of the subjects presented with movies was either worse than (AVI format movies) or did not differ from (uncompressed dynamic presentation) that of the subjects trained with a single or with multiple static images of the faces. Furthermore, generalization tests to other presentation conditions and to novel static views revealed no promoting effect of dynamic training. Except for the subjects trained on multiple static views, performance dropped to chance level with views outside the training range. These results are in contrast to some prior reports from the literature, since they suggest that pigeons, unlike humans, have difficulty using the additional structural information provided by the dynamic presentation and integrating the multiple views into a three-dimensional object.     

Comparisons of the ski turn techniques of experienced and intermediate skiers

We compared selected kinematic variables for four different ski turn techniques performed by five experienced and five intermediate male skiers. The four ski turn techniques were the upstem turn, the downstem turn, the parallel turn and the parallel step turn. Each turn was divided into the initiation phase and the first and second steering phases. Most of the statistically significant differences (P < 0.05) between the two groups were found for the initiation phases of the four turns. Both the hip axis-hand axis angle and the edging angle of the uphill ski were significantly different between the two groups for the upstem turn at the beginning of the initiation phase. For the downstem turn, significant differences between the groups were found at the start of the initiation phase for the hip axis-hand axis angle, the shoulder axis-fall line angle, and the edging angle of the uphill ski. The standard deviation of the distance between the tips of the two skis over the second steering phase also differed significantly between the two groups. For the parallel step turn, significant differences were found at the start of the initiation phase for the edging angle of the downhill ski and the downhill ski to movement direction angle. Significant differences were also found for the edging angle of the downhill ski in the middle of the second steering phase and the shoulder axis to movement direction angle at the end of this phase. For the initiation phase of the parallel turn, significant differences were found for the timing of setting the ski pole, the uphill knee angle at the start of this phase and the range of the knee angle of the uphill leg from the start to the end of this phase. For this turn, significant differences between the two groups were also found for the edging angle of the downhill ski in the middle of the second steering phase and the shoulder axis to movement direction angle at the end of this phase. One of the reasons it was possible to identify a few significant differences only for the turns analysed, was the variability within the intermediate group: for most of the variables analysed, the standard deviation was much higher for the intermediate than for the experienced group.     

Exklusive Bildungseinrichtungen in Deutschland. Entwicklungstendenzen und Identifizierungshürden

Point of departure of the contribution are current public debates about the expansion of private educational institutions and multi-located discussions about the feared accompanied increase of educational inequalities. Especially the theses, that increasing refoundations of privately owned educational institutions are coincide with enhanced social segregation, is in the center of attention. The contribution also amplifies the verified phenomena of increasing distinction of educational and founding/supporting landscapes at all levels of the educational system. It also requests apart from debates about the pros and cons of an “elite education” in Germany, how exclusive educational institutions with stratifying impact can be identified. With reference to the national and international research, criteria and dimensions of the study for the different levels of education from the elementary education to higher education are developed.     

Target-defining features in a “people-present/people-absent” discrimination task by pigeons

Aust and Huber (2001) demonstrated that in apeople-present/people-absentdiscrimination task, pigeons actually attended to properties of the target (i.e., the human figure). The aim of the present effort was to specify what sort of information contained in the target was used for classification, as well as to investigate whether and in what way the target-defining features interacted. Six pigeons were trained in a go/no-go procedure to discriminate between color photographs characterized by the presence or absence of people. They were then presented with various types of test stimuli that contained some category-relevant features but lacked others. The results showed that properties related to target size and internal structure played an important role and that human silhouettes were insufficient for eliciting a people-present response. Furthermore, some properties of the human figure (e.g., hands/arms) made good predictors of the people-present category, whereas others (e.g., feet/legs or skin color) did not. Responses to test stimuli that belonged to the people-absent category but nevertheless contained some features normally typical for humans (e.g., nonhuman primates) provided evidence that various category-relevant features contributed to classification in an additive way. Taken together, the results suggest that the pigeons made use of a polymorphous class rule involving collections of differently weighted target features.     

Food leadership: Leadership and adult learning for global food systems transformation

International Review of Education -     

Does social labelling encourage child schooling and discourage child labour in Nepal?

This paper explores the determinants of child labour vis-à-vis child schooling. It further examines the influence of non-governmental organisations (NGOs) which are engaged in social labelling, on the incidence of child labour and schooling trade-off. The empirical results show that the probability of child schooling increases as well as child labour decreases if a carpet firm has adopted a labelling scheme. It can also be shown that labelling NGOs have a significant positive influence on sending the ex-child labourers to school.     

Dynamics of mental model construction from text and graphics

When students read for learning, they frequently are required to integrate text and graphics information into coherent knowledge structures. The following study aimed at analyzing how students deal with texts and how they deal with graphics when they try to integrate the two sources of information. Furthermore, the study investigated differences between students from different school types and grades. Forty students from grades 5 and 8 from higher track and lower track of the German school system were asked to process and integrate texts and graphics in order to answer items from different levels of a text–picture integration taxonomy. Students’ eye movements were recorded and analyzed. Results suggest fundamentally different functions of text and graphics, which are associated with different processing strategies. Texts are more likely to be used according to a coherence-formation strategy, whereas graphics are more likely to be used on demand as visual cognitive tools according to an information-selection strategy. Students from different tracks of schooling revealed different adaptivity with regard to the requirements of combining text and graphic information.     

The interplay between individual and collective knowledge: technologies for organisational learning and knowledge building

This article presents a framework model that defines knowledge building as a co-evolution of cognitive and social systems. Our model brings together Nonaka's knowledge-creating theory and Luhmann's systems theory. It is demonstrated how collaborative knowledge building may occur – in an ideal situation – within an organisation, when people interact with each other using shared digital artefacts. For this purpose, three different technologies are introduced as examples: social-tagging systems, pattern-based task-management systems, and wikis. These examples have been chosen to demonstrate that knowledge building can occur with respect to both declarative and procedural knowledge. The differences and similarities between these technologies, as far as their potential for organisational knowledge building is concerned, are discussed in the light of the framework model.