The Chemnitz LogAnalyzer: A tool for analyzing data from hypertext navigation research

Computer-based studies usually produce log files as raw data. These data cannot be analyzed adequately with conventional statistical software. The Chemnitz LogAnalyzer provides tools for quick and comfortable visualization and analyses of hypertext navigation behavior by individual users and for aggregated data. In addition, it supports analogous analyses of questionnaire data and reanalysis with respect to several predefined orders of nodes of the same hypertext. As an illustration of how to use the Chemnitz LogAnalyzer, we give an account of one study on learning with hypertext. Participants either searched for specific details or read a hypertext document to familiarize themselves with its content. The tool helped identify navigation strategies affected by these two processing goals and provided comparisons, for example, of processing times and visited sites. Altogether, the Chemnitz LogAnalyzer fills the gap between log files as raw data of Web-based studies and conventional statistical software.     

What makes words sound similar?

Although similarity plays an important role in accounts of language processing, there are surprisingly few direct empirical studies of the phonological similarity between words, and it is therefore not clear whether similarity comparisons between words involve processes similar to those involved in other cognitive domains. In five experiments, participants chose which of two monosyllabic pseudo-words sounded more similar to a target pseudo-word. Our results are generally consistent with the structural alignment theory of comparisons between complex mental representations, suggesting that phonological word similarity parallels similarity involving other kinds of information including visual objects and scenes, events, and word meanings. We use our results to test new metrics of word similarity, and identify predictions for future similarity research both in the domain of word sounds and in other cognitive domains.     

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

Aust and Huber (2001) demonstrated that in a people-present/people-absent discrimination 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.     

Lactation and stress: protective effects of breast-feeding in humans

Whilst most research on breast-feeding has been designed to assess its importance for infant health or to find a human nutrient replacement for infant formula, the effects of breast-feeding on maternal health have received little scientific attention. In several animal studies lactation has been shown to be associated with a marked blunting of physiological and behavioral responses to physical and psychological stress. However, the literature on the effects of lactation on stress in humans remains limited. This review focuses primarily on recent findings on the effects of breast-feeding on neuroendocrine and behavioral responses to acute stress exposure in lactating women. The available data suggest that breast-feeding suppresses the hypothalamic-pituitary-adrenal (HPA) axis response to physical and psychosocial stress. However, lactation in women, in contrast to lactating rats, does not seem to result in a general restraint of the endocrine stress response during the whole period of lactation. Recent data strongly suggest that the blunted HPA axis response to stress in women seems to be counterbalanced if the acute stressor, at least when of a psychosocial nature, occurs later than 1 h after suckling. Further elucidation of the underlying psychobiological mechanisms involved in suppressed stress responses during lactation will no doubt lead to new insights into improved health sequelae of breast-feeding in women and to a better understanding of the psychobiology of human stress protection in general.     

Types of boredom: An experience sampling approach

The present study investigated different types of boredom as proposed in a four-categorical conceptual model by Goetz and Frenzel (2006; doi:10.1026/0049-8637.38.4.149). In this model, four types of boredom are differentiated based on degrees of valence and arousal: indifferent, calibrating, searching, and reactant boredom. In two studies (Study 1: university students, N = 63, mean age 24.08 years, 66 % female; Study 2: high school students, grade 11, N = 80, mean age 17.05 years, 58 % female), real-time data were obtained via the experience-sampling method (personal digital assistants, randomized signals). Boredom experiences (N = 1,103/1,432 in Studies 1/2) were analyzed with respect to the dimensions of valence and arousal using multilevel latent profile analyses. Supporting the internal validity of the proposed boredom types, our results are in line with the assumed four types of boredom but suggest an additional, fifth type, referred to as “apathetic boredom.” The present findings further support the external validity of the five boredom types in showing differential relations between the boredom types and other affective states as well as frequency of situational occurrence (achievement contexts vs. non-achievement contexts). Methodological implications as well as directions for future research are discussed.     

Generalisierte Angststörung

The core features of generalized anxiety disorder (GAD) are excessive worry about various topics which are perceived as uncontrollable and mostly last for at least 6 months. Worrying is accompanied by a number of symptoms (e.g. muscle tension and irritability). Various etiological models suggest that avoidance of internal processes (e.g. cognitive, emotional, and physical) by worrying is central to the development and maintenance of GAD. Empirically well supported cognitive-behavioral interventions are worry exposure, applied relaxation, treating metacognitions, intolerance of uncertainty and negative problem orientation. Initial studies indicate the efficacy of mindfulness and acceptance-based approaches as well as psychodynamic approaches to treat GAD. The present article reports central diagnostic procedures, important differential diagnoses and illustrates actual (psycho) therapeutic treatment options.