An information-theory approach to geometry for animal groups

Animal Cognition - One of the hardest problems in studying animal behaviour is to quantify patterns of social interaction at the group level. Recent technological developments in global positioning...     

Activation of multiple phoneme associates of graphemes in visual word recognition

One general issue in the domain of visual word recognition is to delineate the nature of readers' knowledge of the print-sound mapping. A more specific question is to determine whether multiple grapheme-phoneme associations are available and activated during the phonological transcoding of a letter string. Evidence for the activation of irregular associations during print-to-sound transcoding, independently from lexical influences, was assessed in a letter detection task by examining performance on target-absent pseudowords. We contrasted two types of pseudowords that could be considered homophone with a real word by application of either grapheme-phoneme correspondence rules or of multiple phonemic activation. Performance on both types of homophones was compared to nonhomophone control pseudowords, strictly equivalent in terms of orthographic similarity to the base words. The finding of a homophony disadvantage for the homophones by multiple activation was interpreted as evidence for multiple phonemic activation in the print-to-sound conversion system.     

Promoting perspective coordination by dilemma discussion. The effectiveness of classroom group discussion on interpersonal negotiation strategies of 12-year-old students

Promoting social competence and social cognition is an important aim of education and socialization. According to theories of social cognitive and moral development, social cognition may be promoted by adolescent peer interaction. In this study, social cognition is theoretically conceptualized by the interpersonal negotiation strategies model of Selman which distinguishes levels of perspective coordination and steps of information processing (identification of a problem, generating negotiation strategies, selection of a strategy, evaluation). In a pre-post control group design this study investigated whether dilemma discussions among peers lead to higher individual levels of perspective coordination compared to an individualistic condition. Members of the discussion-condition exhibited higher gain scores in perspective coordination compared to the control group regarding the information processing steps generating strategies and strategy selection. In order to analyze verbal interaction in the discussion groups, an integrative coding schedule was developed. In addition, trait-like argumentative motives of the participants were assessed. The results of multilevel analyses suggest that progress in posttest-perspective coordination is mediated by the groups consensual solution of the dilemma as well as by an explanation-oriented discussion style, but only if the latter is accompanied by a trait-like subject- and consensus-oriented argumentative motive. Theoretical and practical conclusions are drawn.     

Effects of methylphenidate on kinematic aspects of handwriting in hyperactive boys

Poor handwriting in hyperactive children often contributes to academic failure. Beneficial effects of methylphenidate on the quality of handwriting have been shown. Using a digitizing tablet, the handwriting of 21 hyperactive boys was examined both during methylphenidate treatment and following withdrawal of the drug. Half of the hyperactive boys were tested first on methylphenidate and then following withdrawal of the drug and the remaining hyperactive boys were examined in the reverse order. Twenty-one control boys underwent the same examination. Velocity and acceleration of handwriting movements were measured. Furthermore, every writing specimen was independently rated by four examiners regarding the quality of handwriting. Following withdrawal of the drug, the quality of handwriting specimens of hyperactive boys was poorer than during treatment with methylphenidate. Statistical comparison of writing movements of hyperactive boys on and off methylphenidate revealed that the medication resulted in a deterioration in handwriting fluency. The results showed that following withdrawal of medication, hyperactive children did not differ from control boys in handwriting movements. The improvement in hyperactive behavior through methylphenidate was associated with increased legibility and greater accuracy of handwriting. The intention to write neatly may interfere with the fluent writing process.     

Morningness in German and Spanish students: a comparative study

Humans show pronounced individual differences in circadian orientation. Transcultural comparisons are interesting since biological (or environmental) factors together with cultural ones may contribute to differences in morningness–eveningness. We compared Spanish and German undergraduates using the Composite Scale of Morningness (CSM) to assess circadian preferences. Confirmatory and multiple groups confirmatory factor analysis were used to assess factor structure and structural invariance across countries. The results showed that a three‐factor model of morningness best characterises the CSM structure of both samples. Partial factorial invariance (factor loadings) across countries was demonstrated for the factors ‘morningness’ and ‘morning alertness’. Scores of both factors were higher in German students. Potential cultural and biological explanations for the differences are discussed. Copyright © 2007 John Wiley & Sons, Ltd.     

On how high performers keep cool brains in situations of cognitive overload

What happens in the brain when we reach or exceed our capacity limits? Are there individual differences for performance at capacity limits? We used functional magnetic resonance imaging (fMRI) to investigate the impact of increases in processing demand on selected cortical areas when participants performed a parametrically varied and challenging dual task. Low-performing participants respond with large and load-dependent activation increases in many cortical areas when exposed to excessive task requirements, accompanied by decreasing performance. It seems that these participants recruit additional attentional and strategy-related resources with increasing difficulty, which are either not relevant or even detrimental to performance. In contrast, the brains of the high-performing participants “keep cool” in terms of activation changes, despite continuous correct performance, reflecting different and more efficient processing. These findings shed light on the differential implications of performance on activation patterns and underline the importance of the interindividual-differences approach in neuroimaging research.     

E-mailed standardized cognitive behavioural treatment of work-related stress: a randomized controlled trial

The aim of this study was to assess the effects of a 7-week standardized cognitive behavioural treatment of work-related stress conducted via e-mail. A total of 342 people applied for treatment in reaction to a newspaper article. Initial screening reduced the sample to a heterogeneous (sub)clinical group of 239 participants. Participants were assigned randomly to a waiting list condition (n = 62), or to immediate treatment (n = 177). A follow-up was conducted 3 years after inception of the treatment. The outcome measures used were the Depression Anxiety Stress Scales (DASS-42) and the Emotional Exhaustion scale of the Maslach Burnout Inventory - General Survey (MBI-GS). Fifty participants (21%) dropped out. Both groups showed statistically significant improvements. Intention-to-treat analysis of covariance (ANCOVAs) revealed that participants in the treatment condition improved significantly more than those in the waiting control condition (0.001

or = d > or = 0.5 (anxiety)). The between-group effects ranged from d = 0.6 (stress) to d = 0.1 (anxiety). At follow-up, the effects were more pronounced, but this result requires replication in view of high attrition at follow-up. The results warrant further research on Internet-driven standardized cognitive behavioural therapy for work-related stress. Such research should include the direct comparison of this treatment with face-to-face treatment, and should address the optimal level of therapist contact in Internet-driven treatment.     

Assessing automatic activation of valence: a multinomial model of EAST performance

The Extrinsic Affective Simon Task (EAST; De Houwer, 2003) has been introduced as an indirect measure of automatic activation of valence. EAST effects provide nonrelative valence measures of single stimuli compared to relative measures (e.g., Implicit Association Test) that imply a comparison between two stimuli or concepts. However, EAST effects can be biased by response tendencies. A multinomial process dissociation model of EAST performance is proposed and successfully validated in four experiments. Its parameters provide pure and unbiased measures of automatic valence activation, controlled processing of task-relevant features, and response tendency. A first application of latent-class hierarchical multinomial models reveals a significant amount of parameter heterogeneity resulting from interindividual differences in accuracy motivation.