Symptom perception in childhood asthma: the role of anxiety and asthma severity.

This study tested the relationship of anxiety and asthma severity to symptom perception. Eighty-six children diagnosed with mild or moderate asthma had symptom perception and pulmonary function measured throughout methacholine challenge (to induce bronchoconstriction). Higher trait anxiety was associated with heightened symptom perception (controlling for pulmonary function) at baseline. Greater asthma severity was associated with blunted symptom perception (controlling for pulmonary function) at the end of methacholine challenge and with a slower rate of increase in symptom perception across methacholine challenge. These results suggest that anxiety plays a role when children's symptoms are mild, whereas medical variables such as severity play a role in perception of changes in asthma symptomatology as bronchoconstriction worsens.     

Kooperatives Lernen auf der Grundlage komplementären Vorwissens: ein Experiment und eine Simulationsstudie

Summary. Knowledge acquisition in collaborative problem solving is mainly realized by two activities: (1) when participants mutually impart their knowledge and (2) when they elaborate their knowledge together. Both activities are favoured by differences in the participants' prior knowledge. To support this thesis, an experimental study and a cognitive simulation are described. In the study, pairs of students were systematically taught complementary knowledge about qualitative resp. quantitative aspects of classical mechanics. During the subsequent collaborative problem solving the students successfully exchanged information about their complementary knowledge. Students who had been taught knowledge about qualitative aspects of physics gained more from their partners than students who had been taught knowledge about quantitative aspects. A cognitive model simulates problem solving and learning under the conditions set up in the study. In a simulation study based on the cognitive model it was possible to reconstruct the main results of the experimental study. Finally, the role of dialogue analysis and external representations are discussed and conclusions for the design of computer systems supporting collaborative problem solving are drawn. Zusammenfassung. Wissenserwerb bei der Kooperation vollzieht sich vor allem durch zwei Aktivitäten: (1) gegenseitige Wissensvermittlung und (2) gemeinsame Elaboration des Wissens. Für beides ist unterschiedliches Vorwissen der Beteiligten eine günstige Voraussetzung. Um diese These zu unterstützen, wird im vorliegenden Artikel eine experimentelle Studie dargestellt, in der Paaren von Schülerinnen systematisch komplementäres Vorwissen über qualitative bzw. quantitative Aspekte der klassischen Mechanik vermittelt wurde. Beim anschließenden kooperativen Problemlösen vermittelten die Schülerinnen sich gegenseitig erfolgreich Teile ihres Wissens. Schülerinnen, die zuvor Wissen über qualitative Aspekte der Physik erworben hatten, lernten dabei mehr von ihren Partnerinnen als Schülerinnen, die zuvor Wissen über quantitative Aspekte erworben hatten. Ein nachfolgend implementiertes kognitives Modell simuliert kooperatives Lernen und Problemlösen unter den Bedingungen der Studie und ist in der Lage, die zentralen Befunde der Studie zu rekonstruieren. In der Diskussion wird auf die Rolle des Dialogverhaltens und der Nutzung externer Repräsentationen für das kooperative Lernen und Problemlösen eingegangen. Abschließend werden Schlußfolgerungen für die Gestaltung von Computersystemen zur Unterstützung kooperativen Lernens und Problemlösens gezogen.     

Das ABC der farbigen Außenarchitektur

Ohne Zusammenfassung     

Content‐specific gender differences in emotion ratings from early to late adulthood

The investigation of gender differences in emotion has attracted much attention given the potential ramifications on our understanding of sexual differences in disorders involving emotion dysregulation. Yet, research on content‐specific gender differences across adulthood in emotional responding is lacking. The aims of the present study were twofold. First, we sought to investigate to what extent gender differences in the self‐reported emotional experience are content specific. Second, we sought to determine whether gender differences are stable across the adult lifespan. We assessed valence and arousal ratings of 14 picture series, each of a different content, in 94 men and 118 women aged 20 to 81. Compared to women, men reacted more positively to erotic images, whereas women rated low‐arousing pleasant family scenes and landscapes as particularly positive. Women displayed a disposition to respond with greater defensive activation (i.e., more negative valence and higher arousal), in particular to the most arousing unpleasant contents. Importantly, significant interactions between gender and age were not found for any single content. This study makes a novel contribution by showing that gender differences in the affective experiences in response to different contents persist across the adult lifespan. These findings support the “stability hypothesis” of gender differences across age.     

Intentional fixation of behavioural learning,or how R-O learning blocks S-R learning

Four experiments deal with the acquisition of knowledge for the control of voluntary behaviour. Subjects had to accomplish a computer-controlled learning task that required them to learn which one of four actions (R) had to be performed in order to attain a certain one of four outcomes (O) in the presence of one of four situational contexts (S). Reinforcements were assigned to actions according to two schedules: In the S-R condition each of the four actions was consistently reinforced in the presence of a certain situation, whereas in the R-O condition each of the actions was either always (Experiments 1-3) or mostly (Experiment 4) reinforced if a certain outcome was required. Furthermore, the type of feedback was varied. In Experiment 1, only positive or negative reinforcements were fed back, whereas in Experiments 2-4 the actions resulted in outcomes that had to be compared with the required outcomes in order to determine successes and failures. The results indicate a preference for learning R-O contingencies over learning S-R contingencies. Most subjects were so fixated on learning R-O relations that they remained completely blind to the consistent reinforcement of S-R mappings. The data suggest that, in line with the ideomotor principle, the acquisition of behavioural competence is based primarily on the formation of bidirectional action-outcome relations. Specifications of the underlying learning mechanisms are discussed.     

Entstehung und Aufrechterhaltung von chronischen Schmerzen

Chronic pain has previously been defined as lasting longer than 3 or 6 months. This criterion, however, does not adequately describe the process of pain becoming chronic. Consequently, pain chronicity is not only assessed by pain duration but by consideration of other factors, such as disability or intensity. A number of learning processes affect pain chronicity as they mediate changes in neural networks involved in pain processing. Furthermore, a number of psychosocial risk factors have been identified that affect not only the transition from acute to chronic pain but also the maintenance of chronic pain. The fear-avoidance model takes into account many of these risk factors to explain the development and maintenance of chronic musculoskeletal pain.     

On the microstructures of equilibrated and quenched spinel-containing nickel titanates

Electron microscopy has been used to study the microstructures of equilibrated and quenched NiO-TiO₂ mixtures containing 5, 10, 15, 20 and 25wt% TiO₂. All the specimens contained rocksalt- and spinel-structured phases on a nanometre scale. The microstructure suggests that a nonstoichiometric spinel decomposed during quenching. The 25wt% TiO₂ specimen exhibited a lamellar microstructure composed of NiTiO₃ and spinelNiO. These phases had the usual orientation relationships, i.e., (111)_cubic||(0001)_hex and (110)_cubic|| (1100>_hex. Faceted NiO solid-solution regions with coherent cube-on-cube interfaces with the spinel were found in the four specimens of lower TiO₂ contents. When large (15 and 20wt% TiO₂), these regions were faceted cuboidal particles. With lower TiO₂ contents, these regions were no longer equiaxed and could be interconnected. The specimens were chemically homogeneous on a length scale of about 1mum. Morphological evidence is presented to explain which part of the microstructure most probably already existed in this form during equilibration. In particular, the large-scale NiTiO₃ and the spinel lamella in the 25wt% TiO₂ material form during long-term equilibration.     

Affective mediators of intergroup contact: a three-wave longitudinal study in South Africa

Intergroup contact (especially cross-group friendship) is firmly established as a powerful strategy for combating group-based prejudice (Pettigrew & Tropp, 2006). Great advances have been made in understanding how contact reduces prejudice (Brown & Hewstone, 2005), highlighting the importance of affective mediators (Pettigrew & Tropp, 2008). The present study, a 3-wave longitudinal study undertaken among minority-status Colored high school children in South Africa (N = 465), explored the full mediation of the effects of cross-group friendships on positive outgroup attitudes, perceived outgroup variability, and negative action tendencies via positive (affective empathy) and negative (intergroup anxiety) affective mediators simultaneously. The target group was the majority-status White South African outgroup. As predicted, a bidirectional model described the relationship between contact, mediators, and prejudice significantly better over time than either autoregressive or unidirectional longitudinal models. However, full longitudinal mediation was only found in the direction from Time 1 contact to Time 3 prejudice (via Time 2 mediators), supporting the underlying tenet of the contact hypothesis. Specifically, cross-group friendships were positively associated with positive outgroup attitudes (via affective empathy) and perceived outgroup variability (via intergroup anxiety and affective empathy) and were negatively associated with negative action tendencies (via affective empathy). Following Pettigrew and Tropp (2008), we compared two alternative hypotheses regarding the relationship between intergroup anxiety and affective empathy over time. Time 1 intergroup anxiety was indirectly negatively associated with Time 3 affective empathy, via Time 2 cross-group friendships. We discuss the theoretical and empirical contributions of this study and make suggestions for future research.