Transmission electron microscopy study of a new silicon nitride phase

An abnormally large phase, which was found in the precursor-derived Si 3.0 B 1.1 C 5.3 N 3.0 ceramics after crystallization under a nitrogen pressure of 100bar at 1800C for 3h, has been characterized by means of transmission electron microscopy and electron-energy-loss spectroscopy (EELS). EELS analysis shows that this phase consists of only silicon and nitrogen, no other elements being detected. The analysis of selected-area diffraction and convergent-beam electron diffraction in conjunction with EELS reveals that the unknown phase is a variant of silicon nitride. It has a hexagonal structure with lattice parameters a =0.737nm and c =0.536nm, and the space group P62c. .     

Adaptive memory: enhanced source memory for animate entities

ABSTRACT

The animacy effect refers to enhanced memory for animate over inanimate items. In two studies, we examined whether this memory advantage generalises to source memory. A multinomial processing tree model was used to disentangle item recognition, source memory, and guessing processes. In Study 1, animate and inanimate words were presented at different spatial locations on the screen. Animacy was associated with enhanced source memory for the spatial locations of the items. In Study 2, pseudowords were associated with animate and inanimate properties. Replicating previous results, the pseudowords were better remembered when they were associated with animate properties than when they were associated with inanimate properties. What is more, participants had enhanced source memory for the association between the pseudowords and the animate properties. The results strengthen the idea that animate items are associated with richer mnemonic representations than inanimate items.     

Coping in relationships: the interplay between individual and dyadic coping and their effects on relationship satisfaction

The main aim of the present study was to determine how individual and dyadic coping efforts are related in the context of relationships. This aim was achieved by studying partners simultaneously and taking into account the interdependent nature of couple data. Specifically tested was whether dyadic coping mediates the influence of individual coping, and whether there is a mutual influence of partners' dyadic coping. Cross-sectional data of 240 German couples were analyzed using structural equation modeling. Results indicated that dyadic coping is a stronger predictor of relationship satisfaction than individual coping, and that it mediates the individual coping efforts. Mutual influence could be demonstrated for pragmatic coping but not for emotional coping. This research highlights the importance of dyadic coping by focusing on the ways in which couples cope together.     

Gender differences in the mean level,variability, and profile shape of student achievement: Results from 41 countries

A domain-specific hierarchical conceptualization of mathematics achievement can be represented by the standard psychometric model in which a single latent dimension accounts for observed individual differences in scores on the respective subdomains (e.g., quantity). Alternatively, a fully hierarchical conceptualization of achievement can be represented by a nested-factor model in which individual differences in subdomain-specific scores are explained by both general student achievement and specific mathematics achievement. The authors applied both models to study the gender similarity hypothesis, the greater male variability hypothesis, and the masking hypothesis, which predicts that gender differences in general student achievement mask gender differences in both the means and the variability of specific mathematics achievement. Representative data were obtained from 275,369 15-year-old students in 41 countries. The results supported these hypotheses in most countries, demonstrating that a fully hierarchical conceptualization of achievement in terms of the nested-factor model significantly contributes to a better understanding of gender differences in the mean level, variability, and shape of students' achievement profiles.     

Relations between Preschool Children’s Fine Motor Skills and General Cognitive Abilities

ABSTRACT

An increasing number of findings suggest that cognition is grounded in sensorimotor experiences. Research suggests that fine motor skills (FMS) link to cognitive abilities. Existing studies, however, lack conceptual and methodological differentiation regarding FMS and little is known about the directional nature of links. In study 1, we measured three types of FMS, namely dexterity, grapho-motor skill, speed-dominated FMS in a sample of preschool children (n = 78) aged 4.42 years, and analyzed their links with nonverbal reasoning and general knowledge. Factor analyses verified the existence of these three distinct subsets of FMS. A unique link was found for dexterity and reasoning after controlling for age, attention and processing speed. In study 2, using a cross-lagged-panel design with two measurement points one year apart in preschool (n = 84), a cross-lagged link from four-year-old children’s dexterity to their reasoning skills at age five was demonstrated. Findings support the idea of FMS being involved in the development of cognitive abilities.     

Implicit expectations influence target detection in children and adults

When a sound occurs at a predictable time, it gets processed more efficiently. Predictability of the temporal structure of acoustic inflow has been found to influence the P3b of event‐related potentials in young adults, such that highly predictable compared to less predictable input leads to earlier P3b peak latencies. In our study, we wanted to investigate the influence of predictability on target processing indexed by the P3b in children (10–12 years old) and young adults. To do that, we used an oddball paradigm with two conditions of predictability (high and low). In the High‐predictability condition, a high‐pitched target tone occurred most of the time in the fifth position of a five‐tone pattern (after four low‐pitched non‐target sounds), whereas in the Low‐predictability condition, no such rule was implemented. The target tone occurred randomly following 2, 3, 4, 5, or 6 non‐target tones. In both age groups, reaction time to predictable targets was faster than to non‐predictable targets. Remarkably, this effect was largest in children. Consistent with the behavioral responses, the onset latency of the P3b response elicited by targets in both groups was earlier in the predictable than the unpredictable conditions. However, only the children had significantly earlier peak latency responses for predictable targets. Our results demonstrate that target stimulus predictability increases processing speed in children and adults even when predictability was only implicitly derived by the stimulus statistics. Children did have larger effects of predictability, seeming to benefit more from predictability for target detection.     

How to get really smart: Modeling retest and training effects in ability testing using computer-generated figural matrix items

The interpretation of retest scores is problematic because they are potentially affected by measurement and predictive bias, which impact construct validity, and because their size differs as a function of various factors. This paper investigates the construct stability of scores on a figural matrices test and models retest effects at the level of the individual test taker as a function of covariates (simple retest vs. training, use of identical vs. parallel retest forms, and general mental ability). A total of N = 189 subjects took two tests of matrix items that were automatically generated according to a strict construction rationale. Between test administrations, participants in the intervention groups received training, while controls did not. The Rasch model fit the data at both time points, but there was a lack of item difficulty parameter invariance across time. Training increased test performance beyond simple retesting, but there was no large difference between the identical and parallel retest forms at the individual level. Individuals varied greatly in how they profited from retest experience, training, and the use of identical vs. parallel retest forms. The results suggest that even with carefully designed tasks, it is problematic to directly compare scores from initial tests and retests. Test administrators should emphasize learning potential instead of state level assessment, and inter-individual differences with regard to test experience should be taken into account when interpreting test results.     

Gewalt und Vertrauen

Puzzles are often the result of wrong questions. Not the question is interesting, how it is possible that “quite normal men” are capable of extreme violence, rather the question why in face of world history this question persists and is still considered as being interesting. This article is an attempt to find an answer to this question by discussing the special relation developed by the cultural formation named “modern age” to violence in general and last but not least to its own violence. Violence underlies in modern age a pressure of legitimation which strongly differs from other cultures, and the trust in modern age is to a great extent based on the – all too often counterfactual – assumption that it is non-violent or at least on the way to that. In the course of these considerations it should be examined why there is no satisfying sociology of violence although just this lack is known and bemoaned –, as well as the question on which bases such a sociology could be established: systematically, considering a phenomenology of physical violence and the analysis of the relation of power and violence as well as the communicative function of violence; historically, considering the question how the special relation of modern age to violence was developing and to which changes it is subjected in face of the excesses of violence of the 20th century.     

Lipopolysaccharide-induced experimental immune activation does not impair memory functions in humans

Reconsolidation studies have led to the hypothesis that memory, when labile, would be modified in order to incorporate new information. This view has reinstated original propositions suggesting that short-term memory provides the organism with an opportunity to evaluate and rearrange information before storing it, since it is concurrent with the labile state of consolidation. The Chasmagnathus associative memory model is used here to test whether during consolidation it is possible to change some attribute of recently acquired memories. In addition, it is tested whether these changes in behavioral memory features can be explained as modifications on the consolidating memory trace or as a consequence of a new memory trace. We show that short-term memory is, unlike long-term memory, not context specific. During this short period after learning, behavioral memory can be updated in order to incorporate new contextual information. We found that, during this period, the cycloheximide retrograde amnesic effect can be reverted by a single trial in a new context. Finally, by means of memory sensitivity to cycloheximide during consolidation and reconsolidation, we show that the learning of a new context (CS) during this short-term memory period builds up a new memory trace that sustains the behavioral memory update.