Neuronal nitric oxide synthase gene inactivation reduces the expression of vasopressin in the hypothalamic paraventricular nucleus and of catecholamine biosynthetic enzymes in the adrenal gland of the mouse

The impact of a lifelong absence of the neuronal nitric oxide synthase (nNOS) in the neuroendocrine stress response was investigated in nNOS knockout (KO) and wild type (WT) mice under basal conditions and in response to forced swimming. In the hypothalamic paraventricular nucleus oxytocin and corticotropin-releasing-hormone mRNA levels did not differ between these genotypes under resting conditions, whereas vasopressin mRNA levels were significantly lower in nNOS KO than in WT animals. Also, in the adrenal glands basal levels of tyrosine hydroxylase protein, the rate-limiting enzyme for catecholamine biosynthesis, and of phenylethanolamine N-methyltransferase, which converts norepinephrine to epinephrine, were significantly reduced in nNOS KO mice. Plasma adrenocorticotropin, corticosterone, norepinephrine and epinephrine levels were similar in the KO and WT genotypes under resting conditions. In response to forced swimming, a similar increase in plasma adrenocorticotropin and corticosterone was observed in KO and WT animals. Stressor exposure triggered also an increased epinephrine release in WT animals, but did not significantly alter plasma epinephrine levels in KO mice. These data suggest that the chronic absence of nNOS reduces the capacity of epinephrine synthesising enzymes in the adrenal gland to respond to acute stressor exposure with an adequate epinephrine release.     

Exemplars and prototypes in natural language concepts: A typicality-based evaluation

Are natural language categories represented by instances of the category or by a summary representation? We used an exemplar model and a prototype model, both derived within the framework of the generalized context model (Nosofsky, 1984, 1986), to predict typicality ratings for 12 superordinate natural language concepts. The models were fitted to typicality ratings averaged across participants and to the typicality judgments of individual participants. Both analyses yielded results in favor of the exemplar model. These results suggest that higher-level natural language concepts are represented by their subordinate members, rather than by a summary representation.     

Linderung depressiver Symptomatik

Standard interventions, such as antidepressive medication or psychotherapy, show only medium effect sizes in the reduction of depressive symptomatology. In addition, medication has problematic and not well accepted side-effects therefore it seems reasonable to look for alternative, cost-effective, easily available treatments which show no side-effects. A large number of studies have demonstrated similar neurophysiological effects of sport as antidepressants or psychotherapies but the crucial question remains unanswered: does sport show antidepressive effects by alleviating depressive symptomatology? Some randomized, controlled studies and all available recent meta-analysis addressing this question are reviewed. This review concludes that randomized control trials including sport activities have similar positive effect sizes as psychotherapy or antidepressant studies. The pre-post effects are in the medium to high range. Such a conclusion is jeopardized by a limited number of methodolically sound studies. It is too early to make evidence-based recommendations about the antidepressive effect of sport. Currently, it can only be speculated about moderators and mechanisms mediating outcome.     

Maternal attachment representations after very preterm birth and the effect of early intervention

Objective

For very preterm infants the mother-infant relationship may be compromised. Maternal attachment representations 18 (corrected) months after very preterm birth and the effect of the post-discharge Infant Behavioral Assessment and Intervention Program (IBAIP) were studied. The IBAIP is designed to assist parents to support and enhance their infant's regulatory competence and development. The intervention consisted of 6-8 home visits during the first 8 months after birth.

Method

Seventy-eight mothers of very preterm infants (<32 weeks and/or <1500 g) were interviewed, who participated in a randomized controlled trial: 41 from the intervention group and 37 from the control group. Maternal attachment representations were assessed with the Working Model of the Child Interview (WMCI). The interviews resulted in a classification of the attachment representations into balanced or non-balanced.

Results

30% of the mothers had non-balanced attachment representations. Qualitative content analysis of the answers showed that negative feelings when first seeing their baby and negative or ambivalent feelings in the first weeks at home with their baby are related to non-balanced attachment representations. The WMCI revealed no differences between the intervention and control group.

Conclusion

Early support for mothers of very preterm born infants to develop a healthy mother-infant relationship is recommended especially for mothers who report negative first experiences.     

A General and Maladaptive Personality Perspective on Youth Obsessive–Compulsive Symptoms

Based on Krueger's (2005) conceptual model of the personality-psychopathology relationship, this study examines how personality predicts different youth obsessive–compulsive symptoms, comparing the relative contribution of general and maladaptive personality traits. Three-hundred forty-four adolescents provided self-reports on an obsessive–compulsive scale, and their mothers rated their child's general and maladaptive personality. Hierarchical regression analyses revealed that personality differentially predicts obsessive–compulsive symptomatology, and that the relative significance of general versus maladaptive personality predictors differs across various forms of obsessive–compulsive pathology. The results are discussed in terms of the value of including both general and maladaptive personality measures in the assessment of early obsessive–compulsive difficulties.     

Need to train your rat? There is an App for that: A touchscreen behavioral evaluation system

The increasing demand for highly automated and flexible tasks capable of assessing visual learning and memory in nonhuman animals has led to the exciting development of a wide array of prefabricated touchscreen-equipped systems. However, the high cost of these prefabricated systems has led many researchers to develop or modify their own preexisting equipment. We developed a freely downloadable App, the Touchscreeen Behavioral Evaluation System (TBES) for use in conjunction with an iPad (Apple, Cupertino, California) as an alternative to prefabricated touchscreen systems. TBES allows for stimulus presentation and data collection on an iPad. The touchscreen technology offered by the iPad is attractive to researchers due to its affordability, reliability, and resistance to false inputs. We highlight these, as well as the feasibility and procedural flexibility of TBES, in an effort to promote our system as a competitive alternative to those currently available.     

Determining informative priors for cognitive models

The development of cognitive models involves the creative scientific formalization of assumptions, based on theory, observation, and other relevant information. In the Bayesian approach to implementing, testing, and using cognitive models, assumptions can influence both the likelihood function of the model, usually corresponding to assumptions about psychological processes, and the prior distribution over model parameters, usually corresponding to assumptions about the psychological variables that influence those processes. The specification of the prior is unique to the Bayesian context, but often raises concerns that lead to the use of vague or non-informative priors in cognitive modeling. Sometimes the concerns stem from philosophical objections, but more often practical difficulties with how priors should be determined are the stumbling block. We survey several sources of information that can help to specify priors for cognitive models, discuss some of the methods by which this information can be formalized in a prior distribution, and identify a number of benefits of including informative priors in cognitive modeling. Our discussion is based on three illustrative cognitive models, involving memory retention, categorization, and decision making.     

Leveling up the analysis of the reminiscence bump in autobiographical memory: A new approach based on multilevel multinomial models

In many studies of autobiographical memory, participants are asked to generate more than one autobiographical memory. The resulting data then have a hierarchical or multilevel structure, in the sense that the autobiographical memories (Level 1) generated by the same person (Level 2) tend to be more similar. Transferred to an analysis of the reminiscence bump in autobiographical memory, at Level 1 the prediction of whether an autobiographical memory will fall within the reminiscence bump is based on the characteristics of that memory. At Level 2, the prediction of whether an individual will report more autobiographical memories that fall in the reminiscence bump is based on the characteristics of the individual. We suggest a multilevel multinomial model that allows for analyzing whether an autobiographical memory falls in the reminiscence bump at both levels of analysis simultaneously. The data come from 100 older participants who reported up to 33 autobiographical memories. Our results showed that about 12% of the total variance was between persons (Level 2). Moreover, at Level 1, memories of first-time experiences were more likely to fall in the reminiscence bump than were emotionally more positive memories. At Level 2, persons who reported more emotionally positive memories tended to report fewer memories from the life period after the reminiscence bump. In addition, cross-level interactions showed that the effects at Level 1 partly depended on the Level 2 effects. We discuss possible extensions of the model we present and the meaning of our findings for two prominent explanatory approaches to the reminiscence bump, as well as future directions.