The chronic psychosocial stress paradigm in male tree shrews: evaluation of a novel animal model for depressive disorders

To improve our knowledge of the causal mechanisms of stress-related disorders such as depression, we need animal models that mirror the situation in patients. One promising model is the chronic psychosocial stress paradigm in male tree shrews, which is based on the territorial behaviour of these animals that can be used to establish naturally occurring challenging situations under experimental control in the laboratory. Co-existence of two males in visual and olfactory contact leads to a stable dominant-subordinate relationship, with subordinates showing distinct stress-induced behavioural and neuroendocrine alterations that are comparable to the symptoms observed during episodes of depression in patients such as constantly elevated circulating glucocorticoid hormones due to a chronic hyperactivity of the hypothalamic-pituitary-adrenal axis. To elucidate whether the chronic psychosocial stress model in tree shrews besides its "face validity" for depression also has "predictive validity", we treated subordinate tree shrews with the tricyclic antidepressant clomipramine and found a time-dependent restoration of both endocrine and behavioural parameters. In contrast, the anxiolytic diazepam was ineffective. Although the chronic psychosocial stress model in tree shrews requires further validation, it has sufficient face, predictive, and construct validity to become an interesting non-rodent model for research on the etiology and pathophysiology of depression.     

Early detection of core deficits in autism

The goal of this review of the research literature is to discuss approaches to the early detection of autism in infancy. Early detection would enable diagnoses to be made before 18 months of age rather than at 24-30 months, the age where diagnoses start to be made now. After summarizing the criteria for a deficit to be considered "core" to the disorder, the literature on research strategies used in early detection is examined. In order to guide the design of future studies, the review then turns to an overview of what is known about the processes of early social development in typically developing children that underlie the domains in which core deficits are manifested in young children with autism. The social domains covered in the review are those that show development in typically developing infants below 18 months of age: dyadic interaction and imitation; emotion discrimination; and attachment. The review concludes that all of these areas are worthy of investigation in young children, particularly those at higher risk of showing some of the core deficits of autism such as the infant siblings of children with autism.     

Tasks determine what is learned in visual statistical learning

Visual statistical learning (VSL), the unsupervised learning of statistical contingencies across time and space, may play a key role in efficient and predictive encoding of the perceptual world. How VSL capabilities vary as a function of ongoing task demands is still poorly understood. VSL is modulated by selective attention and faces interference from some secondary tasks, but there is little evidence that the types of contingencies learned in VSL are sensitive to task demands. We found a powerful effect of task on what is learned in VSL. Participants first completed a visual familiarization task requiring judgments of face gender (female/male) or scene location (interior/exterior). Statistical regularities were embedded between stimulus pairs. During a surprise recognition phase, participants showed less recognition for pairs that had required a change in response key (e.g., female followed by male) or task (e.g., female followed by indoor) during familiarization. When familiarization required detection of “flicker” or “jiggle” events unrelated to image content, there was weaker, but uniform, VSL across pair types. These results suggest that simple task manipulations play a strong role in modulating the distribution of learning over different pair combinations. Such variations may arise from task and response conflict or because the manner in which images are processed is altered.     

Associations Between Fathers’ and Mothers’ Psychopathology Symptoms,Parental Emotion Socialization,and Preschoolers’ Social-Emotional Development

In this study we tested whether the relation between fathers’ and mothers’ psychopathology symptoms and child social-emotional development was mediated by parents’ use of emotion talk about negative emotions in a sample of 241 two-parent families. Parents’ internalizing and externalizing problems were measured with the Adult Self Report and parental emotion talk was observed while they discussed a picture book with their children (child age: 3 years). Children’s parent-reported internalizing and externalizing problems and observed prosocial behaviors were assessed at the age of 3 years and again 12 months later. We found that mothers’ use of emotion talk partially mediated the positive association between fathers’ internalizing problems and child internalizing problems. Fathers’ internalizing problems predicted more elaborative mother–child discussions about negative emotions, which in turn predicted more internalizing problems in children a year later. Mothers’ externalizing problems directly predicted more internalizing and externalizing problems in children. These findings emphasize the importance of examining the consequences of parental psychological difficulties for child development from a family-wide perspective.     

Commitment to family roles: effects on managers' attitudes and performance

The authors tested the premise that family role commitment (i.e., marital role commitment, parental role commitment) has simultaneous negative and positive effects on managers' (N = 346) life satisfaction, career satisfaction, and performance through family-to-work interference and enhancement. The authors also explored whether psychological strain mediates the effects of interference and enhancement on outcomes. The authors expected family role commitment to reduce the favorability of outcomes by increasing interference. To the contrary, they found that neither marital nor parental role commitment was associated with increased interference. The authors expected family role commitment to improve outcomes by increasing enhancement. As expected, marital role commitment was associated with increased enhancement, which, in turn, seemed to reduce strain and strengthen outcomes. Parental role commitment was also associated with increased enhancement. However, parental role commitment had direct positive effects on outcomes that were more substantial than its indirect effects through enhancement. Overall, marital and parental role commitment had more benefits than costs.     

Corticosterone time-dependently modulates beta-adrenergic effects on long-term potentiation in the hippocampal dentate gyrus

Previous experiments in the hippocampal CA1 area have shown that corticosterone can facilitate long-term potentiation (LTP) in a rapid non-genomic fashion, while the same hormone suppresses LTP that is induced several hours after hormone application. Here, we elaborated on this finding by examining whether corticosterone exerts opposite effects on LTP depending on the timing of hormone application in the dentate gyrus as well. Moreover, we tested rapid and delayed actions by corticosterone on β-adrenergic-dependent changes in LTP. Unlike the CA1 region, our in vitro field potential recordings show that rapid effects of corticosterone do not influence LTP induced by mild tetanization in the hippocampal dentate gyrus, unless GABA_A receptors are blocked. In contrast, the β-adrenergic agonist isoproterenol does initiate a slow-onset, limited amount of potentiation. When corticosterone was applied concurrently with isoproterenol, a further enhancement of synaptic strength was identified, especially during the early stage of potentiation. Yet, treatment with corticosterone several hours in advance of isoproterenol fully prevented any effect of isoproterenol on LTP. This emphasizes that corticosterone can regulate β-adrenergic modulation of synaptic plasticity in opposite directions, depending on the timing of hormone application.     

How to Measure and Explain Achievement Change in Large-Scale Assessments: A Rejoinder

In this rejoinder, we discuss substantive and methodological validity issues of large-scale assessments of trends in student achievement, commenting on the discussion paper by Van den Heuvel-Panhuizen, Robitzsch, Treffers, and Köller (2009). We focus on methodological challenges in deciding what to measure, how to measure it, and how to foster stability. Next, we discuss what to do with trends that are found. Finally, we reflect on how the research findings were received.