Transient activation of the CA3 Kappa opioid system in the dorsal hippocampus modulates complex memory processing in mice

The hippocampus plays a central role in various forms of complex learning and memory. Opioid peptides and receptors are abundant in the hippocampus. These peptides are co-released with glutamate from mossy fiber- and lateral perforant path-synapses. In this study, we evaluated the functional relevance of the CA3 Kappa opioid receptors (KOR) by transient pharmacological activation or inactivation using single bilateral intrahippocampal microinjections of a selective agonist (U50,488H, 1 or 2.5 nmol), a selective antagonist (nor-binaltorphimine, norBNI 5 nmol) or a mixture of both. C57Bl/6J mice were tested in a fear conditioning paradigm (FC) or in a modified version of the water maze task thought to reveal how flexibly animals can learn and manipulate spatial information (WM). In FC, the agonist (2.5 nmol) decreased context-induced (but not tone-induced) freezing whereas norBNI had no effect. The impairment caused by the agonist U50,488H was blocked by the injection of norBNI, suggesting that overstimulation of CA3-KOR impairs the acquisition and consolidation of contextual fear-related memory. In the WM task, mice were trained repeatedly each day to find a hidden platform. After having reached this goal, the platform position was changed the next day for a new task. U50,488H injection before the last task abolished the previously acquired ability to find rapidly a new platform location, whereas adding norBNI reversed this impairment. Thus, in the mouse, even partial and topographically restricted activation of CA3-KOR entails impairments in two different hippocampus-dependent tasks, indicating functional relevance of the kappa opioid system.     

How children with facial differences are perceived by non-affected children and adolescents: Perceiver effects on stereotypical attitudes

Children with a facial difference are presumed to be at risk of social stigmatization. The purposes of this study were twofold: (1) to assess the effect of facial differences on social perceptions by unaffected children and adolescents; and (2) to identify perceiver characteristics that predict stereotypical attitudes toward facial differences. Participants were 344 non-affected children and adolescents, ages 8–17 years. Participants rated digitally altered images of 12 children depicted either with or without a facial difference. Results show that participants attributed less favorable characteristics to children with a facial difference than to those without. Moreover, participants reported less willingness to interact with or befriend a child with a facial difference. Significant predictors of low discriminative attitudes were older participant age and previous contact with someone with a facial difference. Our data call attention to the need for public education programs targeted at reducing negative attitudes toward facial differences.     

Asymmetric prefrontal cortex functions predict asymmetries in number space

Little is known about the neuropsychological factors that contribute to individual differences in the asymmetric orientation along the mental number line. The present study documents healthy subjects’ preference for small numbers over large numbers in a random number generation task. This preference, referred to as “small-number bias” (SNB), varied with prefrontal functional lateralization: it was larger in participants with over-proportionately better performance in design fluency compared to letter fluency than in participants with over-proportionately better performance in letter fluency when compared to design fluency. Asymmetries in learning and memory tasks (verbal vs. non-verbal) were not related to direction or size of the SNB. We conclude that hemispheric asymmetries of specifically prefrontal executive functions are predictive of an individual’s lateral orientation bias along the mental number line. Therefore, the focus on parietal contributions to spatial-numerical associations may not be justified. Random number generation may be a helpful method to further explore these associations uncontaminated by the asymmetric involvement of response effectors.     

Personality of children with accident‐related injuries

Previous studies based on a variety of behaviour, temperament, and personality measures identified a pattern of over‐activity, impulsiveness, emotional instability, and aggressiveness in children who are prone to accidents. The present study is the first to study accident‐prone children by means of a comprehensive test for the assessment of the Five Factor model (Hierarchical Personality Inventory for Children (HiPIC) (Mervielde & De Fruyt, 1999 ). 118 children, aged 6–15 years, who were hospitalized due to an accident‐related injury, were contrasted with 184 school‐children of the same age. Lower socio‐economic status was under‐represented in both groups. Children who were exposed to accidents had higher scores on the facets of energy, optimism, and non‐shyness (Extraversion domain), and lower scores on the facets of concentration and achievement striving (Conscientiousness domain). There was no indication of higher aggressiveness, impulsiveness, or emotional instability in the group exposed to accidents, and there were no gender‐by‐accident interactions. Results suggest that there is a relatively benign pattern of personality traits that is related to greater accident hazard in children. Copyright © 2003 John Wiley & Sons, Ltd.     

Circular vection as a function of foreground-background relationships

It has previously been reported that illusory self-rotation (circular vection) is most effectively induced by the more distant of two moving displays. Experiments are reported in which the relative effectiveness of two superimposed displays in generating circular vection as a function of (i) the separation in depth between them, (ii) their perceived relative distances, and (iii) which display was in the plane of focus was investigated. Circular vection was governed by the motion of the display that was perceived to be the more distant, even when it was actually nearer. However, actual or perceived distance was found to be not the crucial factor in circular vection because even when the distance between the two displays was virtually zero, vection was controlled by the display perceived to be in the background. When the displays were well separated in depth, vection was not affected by whether the near or the far display was in the plane of focus, nor by which display was fixed or pursued by the eyes.     

Heuristic processing of distinctiveness information in minority and majority influence

The role of distinctiveness information in majority and minority influence was studied. Students read a message containing strong or weak arguments advocated by a minority or majority source. The communicator's minority (majority) status was said to be either distinctive to the target topic or nondistinctive across topics. Major dependent variables were attitude judgments and cognitive responses. Across conditions, messages were processed systematically, and a majority communicator tended to be more persuasive than a minority communicator. Most importantly, high distinctiveness led to greater influence than low distinctiveness, and this effect was independent of argument strength and minority versus majority status. Theoretical and applied implications of these findings are discussed. © 1998 John Wiley & Sons, Ltd.     

Motivational determinants of systematic processing: expectancy moderates effects of desired confidence on processing effort

Extending the motivational assumptions of the heuristic-systematic model (Chaiken, Liberman, & Eagly, 1989), the authors hypothesized that a discrepancy between desired and actual judgmental confidence raises processing effort only if the expectancy that processing will increase confidence is high. In Experiment 1, university students expected to review information for upcoming social judgments. Desired confidence was varied through low versus high task importance. To manipulate expectancy, low versus high perceived processing efficacy was induced via feedback. As predicted, high- (as compared to low-) importance participants expressed greater interest in receiving information and selected more information when perceived efficacy was high, and this effect was mediated via a heightened discrepancy between desired and actual confidence. These effects were not obtained under low perceived efficacy. In Experiment 2, students processed a persuasive message. Only high importance conditions were studied; processing efficacy and argument strength were manipulated. As predicted, high- (but not low-) efficacy participants processed the message systematically, as indicated by a different impact of argument strength and by mediational path analyses. It is argued that the precision of social judgment models would benefit from an explicit consideration of processing- and outcome-related expectancy variables. © 1998 John Wiley & Sons, Ltd.     

Narzißtische Persönlichkeitsstörungen

Zusammenfassung Der Begriff des Narzi?mus wird aus historischen, soziologischen, anthropologischen, mythologischen und etymologischen Quellen hergeleitet und dann in die verschiedenen psychoanalytischen Theorien eingeordnet. Die theoretischen Grundpositionen zum Narzi?mus und zur Auffassung narzi?tischer Pers?nlichkeitsst?rungen werden ausführlich erl?utert. Die Annahme eines prim?ren Narzi?mus wird anhand der theoretischen Vorstellungen von Freud, Grunberger, Mahler und Kohut erkl?rt, die Annahme einer prim?ren Objektbeziehung durch die Theorien von Ferenczi, Balint, Klein und Winnicott illustriert. Anschlie?end werden die Konzeptionen des Narzi?mus im Rahmen der Triebtheorie bzw. als eigenst?ndige Entwicklungslinie (Kohut) erl?utert. Grunberger nimmt dabei eine Mittelstellung ein. Kohut und Kernberg stehen sich gegenüber, wenn es um die Einordnung des Narzi?mus als pathologisches Ph?nomen (Kernberg) oder als Entwicklungsarretierung (Kohut) geht. Es schlie?t sich ein Abschnitt über die klassifikatorisch-deskriptive Erfassung des Narzi?mus an, in dem die Auffassungen der narzi?tischen Pers?nlichkeitsst?rung im Rahmen der g?ngigen Klassifikationssysteme (DSM-IV, ICD-10, OPD) beschrieben werden. Ebenso finden die Testdiagnostik sowie interpersonelle Ans?tze Berücksichtigung. Danach werden die Befunde der modernen S?uglingsforschung und deren Auswirkungen auf ein ver?ndertes Verst?ndnis der narzi?tischen Pers?nlichkeitsst?rung dargestellt. Die übersicht schlie?t mit einer differenzierten Betrachtung der unterschiedlichen therapeutischen Vorgehensweisen.