EEG theta phase coupling during executive control of visual working memory investigated in individuals with schizophrenia and in healthy controls

In healthy humans, it has been shown that executive functions are associated with increased frontal-midline EEG theta activity and theta phase coupling between frontal and posterior brain regions. In individuals with schizophrenia, central executive functions are supposed to be heavily impaired. Given that theta phase coupling is causally involved in central executive functions, one would expect that patients with an executive function deficit should display abnormal EEG theta synchronization. We therefore investigated executive functioning in 21 healthy controls and 21 individuals with schizophrenia while they performed a visuospatial delayed match to sample task. The task required either high executive demands (manipulation of content in working memory [WM]) or low executive demands (retention of WM content). In addition, WM load (one vs. three items) was varied. Results indicated higher frontal theta activity for manipulation processes than for retention processes in patients with schizophrenia, as compared with healthy controls, independently of WM load. Furthermore, individuals with schizophrenia revealed a reduction in theta phase coupling during early stages of the delay period for retention, as well as for manipulation processes at high-WM loads. Deviations in theta phase coupling in individuals with schizophrenia were mainly characterized by aberrant fronto-posterior connections, but also by attenuated posterior connections during manipulation of high-WM load. To conclude, fronto-parietal theta coupling seems to be substantially involved in executive control, whereas frontal theta activity seems to reflect general task demands, such as deployment of attentional resources during WM.     

A comparison of impulsivity and sensation seeking in pathological gamblers and skydivers

The aim of this study was to compare pathological gamblers and skydivers in relation to measures of impulsivity and sensation seeking. The Eysenck Impulsivity Scale - Narrow Impulsiveness Subscale and the Arnett Inventory of Sensation Seeking were administered to pathological gamblers (n = 29), skydivers (n = 93), and a control group (n = 43). A two-way multivariate analysis of variance was conducted to explore differences in impulsivity and sensation seeking between the groups and possible group by gender and group by age interaction effects. The significant effects were further investigated using follow-up univariate analysis of variance. The results showed significant main effects of Group, Gender and Age, and a significant Group by Gender interaction effect. The results showed no statistically significant differences in impulsivity between pathological gamblers and skydivers; however, both groups scored higher than the controls. The skydivers scored higher compared to the pathological gamblers and controls on both sensation seeking subscales. Pathological gamblers scored higher than the controls on the subscale Need for Stimulus Intensity, although lower than the controls on the subscale Need for Novelty. We conclude that skydivers and pathological gamblers do not seem to differ in terms of impulsivity, but that the two groups differ in terms of sensation seeking. Skydivers are hence characterized by more sensation seeking compared to pathological gamblers. Skydiving, as opposed to pathological gambling, is not considered a psychiatric disorder, and skydiving may represent a more non-pathological way to fulfill the need for stimulus intensity.     

Falsche Geständnisse

Although false confessions would seem to run counter to their own interests, innocent suspects do occasionally admit to having committed even serious crimes. This article describes individual differences in susceptibility to interrogative influence and mechanisms through which interrogation tactics can induce false confessions. It will also show that there is no simple way of distinguishing false from true confessions, which is partly due to the lack of verbatim records of interviews with suspects. In some cases false confessions can even negatively impact on the gathering and evaluation of further evidence and in turn this seemingly independent evidence seems to validate the false confession if this is later retracted. Psychological expertise may well help to clarify individual cases; however, any uncritical transfer of the credibility assessment developed to evaluate witness testimony, without taking the specific conditions of interviews with suspects into account, may well lead to false results.     

Modernization and the logic of interorganizational networks

In this paper an attempt is made to widen the perspective under which interorganizational networks are generally seen. It is argued that both in the economy and in policy making, network phenomena are in fact becoming more prominent. This is linked to functional differentiation, a core process of societal modernization, which implies the existence of partly autonomous societal subsystems. Their emergence is closely connected with the ascendance of formal organizations, which in turn enjoy a certain measure of autonomy. In this structural context, interorganizational network following a logic of negotiation, which extends to “constitutional” issues can provide a solution to coordination problems typical of modern societies. Her research interests include sociological macro-theory, comparative social and political research, organizational and administrative sociology, and sociology of technology.     

Evidence for a Data-Based Environmental Policy: Induction of a Behavior-Based Decision Support System

To advise policy‐makers about possible courses of action in the environmental domain, psychological science should employ a support system that allows for evidence‐based decisions with respect to the three generic policy questions: what, where, and how. The key to such a system is a measurement instrument in which environmental motivation becomes tangible in individual actions. In this article, we provide empirical examples of such a decision support system in the environmental domain. It consists of (a) evidence about environmental motivation of persons, (b) evidence about motivation's spatial distribution, (c) knowledge about the socio‐cultural conditions that affect individuals when they translate motivation into action (i.e. structural information), and (d) a forecast of the environmental impact—the concrete conservation potential of various behaviors. Pour conseiller les décideurs à propos de lignes de conduite possibles dans le domaine de l’environnement, la science psychologique devrait utiliser un système qui tienne compte des décisions provenant des trois questions génériques suivantes: quoi, ou et comment? La clé d’un tel système consiste en un instrument de mesure dans lequel la motivation environnementale devient tangible dans les actions individuelles. Dans cet article, nous prenons des exemples empiriques de telles aides à la décision dans le domaine de l’environnement. Peut être ainsi montré a) la motivation environnementale des personnes, b) la distribution spatiale de la motivation, c) l’influence de la connaissance des conditions socioculturelles des individus quand ils transforment motivation en action (i.e. information structurale) et (d) la prévision de l’impact environnemental sur le maintien potentiel de divers comportements.     

Gustatory plasticity in C. elegans involves integration of negative cues and NaCl taste mediated by serotonin, dopamine, and glutamate

While na?ve Caenorhabditis elegans individuals are attracted to 0.1-200 mM NaCl, they become strongly repelled by these NaCl concentrations after prolonged exposure to 100 mM NaCl. We call this behavior gustatory plasticity. Here, we show that C. elegans displays avoidance of low NaCl concentrations only when pre-exposure to NaCl is combined with a negative stimulus, e.g., a repellent, or in the absence of food. By testing serotonin and/or dopamine signaling mutants and rescue by exogenously supplying these neurotransmitters, we found that serotonin and dopamine play a role during the plasticity response, while serotonin is also required during development. In addition, we also show that glutamate plays an important role in the response to NaCl, both in chemoattraction to NaCl and in gustatory plasticity. Thus, C. elegans can associate NaCl with negative stimuli using dopaminergic, serotonergic, and glutamatergic neurotransmission. Finally, we show that prolonged starvation enhances gustatory plasticity and can induce avoidance of NaCl in most gustatory plasticity mutants tested. Only mutation of the glutamate-gated Cl(-) channel gene avr-15 affected starvation-enhanced gustatory plasticity. These results suggest that starvation induces avoidance of NaCl largely independent of the normal gustatory plasticity mechanism.     

Children report suggested events even when interviewed in a non-suggestive manner: what are its implications for credibility assessment?

An important question in the legal context is how suggested statements about fictitious events develop over a course of various interviews. Sixty-seven first-graders were interviewed four times about one real and one fictitious event, applying various suggestive techniques. A fifth, non-suggestive, interview was conducted by blind experts. Over the course of the interviews there was a considerable increase in assents to the fictitious events. Moreover, few significant differences in criteria-based content analysis-criteria were revealed between true and fictitious statements in the fifth interview. Accordingly, experts had difficulties in discriminating between true and suggested accounts. Furthermore, several children were convinced of the truth of their reports, even after having been partially debriefed in a sixth interview. Implications for statement validity assessment are discussed. Copyright © 2004 John Wiley & Sons, Ltd.