Offline consolidation of memory varies with time in slow wave sleep and can be accelerated by cuing memory reactivations

Memory representations are reactivated during slow-wave sleep (SWS) after learning, and these reactivations cause a beneficial effect of sleep for memory consolidation. Memory reactivations can also be externally triggered during sleep by associated cues which enhance the sleep-dependent memory consolidation process. Here, we compared in humans the influence of sleep periods (i) of 40min and (ii) of 90min without externally triggered reactivations and (iii) of externally triggered reactivations by an associated odor cue during a 40-min sleep period on the consolidation of previously learned hippocampus-dependent visuo-spatial memories. We show that external reactivation by an odor cue during the 40-min sleep period enhanced memory stability to the same extent as 90min of sleep without odor reactivation. In contrast, 40min of sleep without external reactivations were not sufficient to benefit memory. In the 90-min sleep condition, memory enhancements were associated with time spent in SWS and were independent of the presence or absence of REM sleep. These results suggest that the efficacy of hippocampus-dependent memory consolidation depends on the duration of sleep and particularly SWS. External reactivation cues can accelerate the consolidation process even during shorter sleep episodes.     

The role of learning data in causal reasoning about observations and interventions

Recent studies have shown that people have the capacity to derive interventional predictions for previously unseen actions from observational knowledge, a finding that challenges associative theories of causal learning and reasoning (e.g., Meder, Hagmayer, & Waldmann, 2008). Although some researchers have claimed that such inferences are based mainly on qualitative reasoning about the structure of a causal system (e.g., Sloman, 2005), we propose that people use both the causal structure and its parameters for their inferences. We here employ an observational trial-by-trial learning paradigm to test this prediction. In Experiment 1, the causal strength of the links within a given causal model was varied, whereas in Experiment 2, base rate information was manipulated while keeping the structure of the model constant. The results show that learners’ causal judgments were strongly affected by the observed learning data despite being presented with identical hypotheses about causal structure. The findings show furthermore that participants correctly distinguished between observations and hypothetical interventions. However, they did not adequately differentiate between hypothetical and counterfactual interventions.     

Prevalence and correlates of gambling among 16 to 19-year-old adolescents in Norway

There is evidence that young people are at high risk of developing gambling disorders. The prevalence and correlates of gambling among youth therefore merit closer study. During spring 2004, a sample of 1,351 boys and girls (aged 16–19 years) from 151 high-school classes (clusters) participated in an internet survey about gambling. The response rate was 69.8%. The instruments used in the survey were the Hospital Anxiety and Depression Scale, the Alcohol Use Disorders Identification Test and the Massachusetts Adolescent Gambling Screen, in addition to questions about demography. Controlling for the design effect, the estimated prevalence rate was 2.5% for pathological gambling and 1.9% for problem gambling. In all, 7.3% of the boys and 0.6% of the girls fulfilled the criteria for pathological or problem gambling. The results of item analysis of the DSM-IV subscale of MAGS provide support for differential item functioning between boys and girls. A multiple logistic regression analysis revealed that gender (male: OR = 9.09), depression (OR = 9.23), alcohol abuse (OR = 3.62), and dissociation (OR = 1.96) were related to problem and pathological gambling. These results support the view that gambling disorders are best understood as part of an addictive behavior spectrum ( Jacobs, 2000 ).     

The scientific status of psychoanalytic clinical evidence (III)

Communist ideology is evolving away from its original mould. One of the decisive factors in this process is the rate of acceptance of the ‘Classical’ doctrines by the intellectuals of East‐European countries. In determining the dynamics of the process, the original doctrines and the thinking of the intellectuals are taken as sets of sentences constituting the premisses, and the manifest actual discourse of a Communist country as the set of sentences representing the conclusion. To demonstrate the conclusion from the premisses, heuristic laws are formulated accounting for the various factors conditioning the process of the interaction of Classical Communism and the thinking of the intellectuals. A logical schema of general applicability results, demonstrating the various phases of the evolution of Marxist‐Leninist ideology in East‐European countries.     

PTSD and psychological distress in Icelandic parents of chronically ill children: Does social support have an effect on parental distress?

The purpose of the study was to investigate psychological distress and the prevalence of PTSD among Icelandic parents of chronically ill children, and the potential effects of social support on distress, at two points in time. The Impact on Family scale (IFS), the Trauma Symptom Checklist (TSC), the Harvard Trauma Questionnaire (HTQ) and the Crisis Support Scale (CSS) were completed by 105 parents of children with various diseases (69 mothers and 36 fathers). Despite the heterogeneity of the sample in terms of disease type, PTSD was present in 13.2% of the parents and an additional 28.6% had subclinical PTSD. Time since diagnosis, length of hospitalizations and disease-related daily care predicted 40% of the HTQ total score.     

Dimensional Latent Structure of Early Disruptive Behavior Disorders: A Taxometric Analysis in Preschoolers

Although disruptive behavior disorders (DBDs) are used as a distinct categorical diagnosis in clinical practice, they have repeatedly been described as having a dimensional structure in taxometric analyses. In the current study the authors analyzed the latent status of disruptive behaviors (DB) in a large sample (N?=?2,808) of German preschool children (2–6 years old, mean age 53.7 months, SD?=?13.5, 48.4% girls). The Eyberg Child Behavior Inventory (ECBI) as well as the Strengths and Difficulties Questionnaire (SDQ) were used to compile indicators of the DB core dimensions (Temper Loss, Aggression, Noncompliance, and Low Concern for others). Three widely used taxometric methods (a) MAXEIG, (b) MAMBAC, and (c) L-Mode were applied. Simulation data were created to evaluate the Comparison Curve Fit Index values (CCFIs), which were below 0.45, supporting a dimensional solution. Hence, in the current study the latent structure of DB in preschoolers encompassed differences in degree rather than kind. Researchers and practitioners should be mindful of the dimensional latent status of DB in theory building, assessment, classification, and labeling.