Neurobiologische Grundlagen psychotherapeutischer Verfahren

In the last few years the investigation of the neurobiological basis of psychotherapeutic treatments has gained importance. Therapy-associated functional changes have been studied in a number of different psychiatric diseases. It has been shown that diseases with a central role of emotions (e.g. depression, anxiety disorders, borderline personality disorder) often demonstrate dysfunctions in brain areas that are linked to emotional regulation. Psychotherapeutic interventions can lead to a kind of normalization of brain responses in these areas (e.g. amygdala, ventromedial prefrontal cortex, anterior cingulate cortex, orbitofrontal cortex). In addition, therapy-associated transformations were also demonstrated in areas which are related to attention processes and visual perception. Other studies have aimed at finding neurobiological parameters that can be used to predict a therapeutic outcome or to choose between various therapeutic strategies. For instance, in depression, the amygdala and the anterior cingulate cortex are assumed to play a major role. Altogether, knowledge on the neurobiological basis of psychotherapeutic procedures is limited. A comparatively small number of studies and several methodological problems (e.g. small sample sizes, insufficient control groups, variability of methods used) make it difficult to propose reliable statements.     

Visually guided step descent in children with Williams syndrome

Individuals with Williams syndrome (WS) have impairments in visuospatial tasks and in manual visuomotor control, consistent with parietal and cerebellar abnormalities. Here we examined whether individuals with WS also have difficulties in visually controlling whole-body movements. We investigated visual control of stepping down at a change of level in children with WS (5-16-year-olds), who descended a single step while their movement was kinematically recorded. On each trial step height was set unpredictably, so that visual information was necessary to perceive the step depth and position the legs appropriately before landing. Kinematic measures established that children with WS did not use visual information to slow the leg at an appropriate point during the step. This pattern contrasts with that observed in typically developing 3- and 4-year-old children, implying severe impairment in whole-body visuomotor control in WS. For children with WS, performance was not significantly predicted by low-level visual or balance problems, but improved significantly with verbal age. The results suggest some plasticity and development in WS whole-body control. These data clearly show that visuospatial and visuomotor deficits in WS extend to the locomotor domain. Taken together with evidence for parietal and cerebellar abnormalities in WS, these results also provide new evidence for the role of these circuits in the visual control of whole-body movement.     

Inside-out: comparing internally generated and externally generated basic emotions

A considerable number of mood induction (MI) procedures have been developed to elicit emotion in normal and clinical populations. Although external procedures (e.g., film clips, pictures) are widely used, a number of experiments elicit emotion by using self-generated procedures (e.g., recalling an emotional personal episode). However, no study has directly compared the effectiveness of two types of internal versus external MI across multiple discrete emotions. In the present experiment, 40 undergraduate students watched film clips (external procedure) and recalled personal events (internal procedure) inducing 4 basic emotions (fear, anger, joy, sadness) and later completed a self-report questionnaire. Remarkably, both internal and external procedures elicited target emotions selectively, compared with nontarget emotions. When contrasting the intensity of target emotions, both techniques showed no significant differences, with the exception of Joy, which was more intensely elicited by the internal procedure. Importantly, when considering the overall level of intensity, it was always greater in the internal procedure, for each stimulus. A more detailed investigation of the data suggest that recalling personal events (a type of internal procedure) generates more negative and mixed blends of emotions, which might account for the overall higher intensity of the internal mood induction.     

Estimating discrimination performance in two-alternative forced choice tasks: Routines for MATLAB and R

Ulrich and Vorberg (Attention, Perception, & Psychophysics 71: 1219–1227, 2009) introduced a novel approach for estimating discrimination performance in two-alternative forced choice (2AFC) tasks. This approach avoids pitfalls that are inherent when the order of the standard and the comparison is neglected in estimating the difference limen (DL), as in traditional approaches. The present article provides MATLAB and R routines that implement this novel procedure for estimating DLs. These routines also allow to account for processing failures such as lapses or finger errors and can be applied to experimental designs in which the standard and comparison differ only along the task-relevant dimension, as well as to designs in which the stimuli differ in more than one dimension. In addition, Monte Carlo simulations were conducted to check the quality of our routines.     

Trial-by-trial updating of an internal reference in discrimination tasks: Evidence from effects of stimulus order and trial sequence

In psychophysics, participants are often asked to discriminate between a constant standard and a variable comparison. Previous studies have shown that discrimination performance is better when the comparison follows, rather than precedes, the standard. Prominent difference models of psychophysics and decision making cannot easily explain this order effect. However, a simple extension of this model class involving dynamical updating of an internal reference accounts for this order effect. In addition, this Internal Reference Model (IRM) predicts sequential response effects. We examined the predictions of IRM in two duration discrimination experiments. The obtained results are in agreement with the predictions of IRM, suggesting that participants update their internal reference on every trial. Additional simulations show that IRM also accounts for the negative sequential effects observed in single-stimulus paradigms.     

Vertical and leg stiffness and stretch-shortening cycle changes across maturation during maximal sprint running

The purpose of this study was to investigate whether vertical and leg stiffness, and stretch-shortening cycle (SSC) ability differed in developing athletes of various maturity status during maximal sprint running. Seventy-four male participants between 8 and 16 years of age were categorized into pre-, mid- or post-peak height velocity (PHV) and sprinted for 30 meters on a non-motorized treadmill. Dimensionless vertical stiffness increased significantly (p < .05) from pre-, to mid- and post-PHV state, while dimensionless leg stiffness was significantly higher in post- compared to mid- (18.4%) and pre-PHV participants (44.5%). Eccentric power was significantly lower in pre- compared to the mid- and post-PHV participants. Concentric power increased from pre- to mid- and post-PHV state. An analysis of covariance revealed no significant differences between all groups in dimensionless vertical and leg stiffness, eccentric and concentric time and power when controlling for years from PHV (maturation). Eccentric or concentric power, were found to be the best predictors of maximum velocity across all maturation groups (r² = .37–.68). It seems that maturation affects the ability to absorb and produce power and furthermore these variables are important predictors of maximal running velocity.     

Bayesian Rationality for the Wason Selection Task? A Test of Optimal Data Selection Theory

Oaksford and Chater (1994) proposed to analyse the Wason selection task as an inductive instead of a deductive task. Applying Bayesian statistics, they concluded that the cards that participants tend to select are those with the highest expected information gain. Therefore, their choices seem rational from the perspective of optimal data selection. We tested a central prediction from the theory in three experiments: card selection frequencies should be sensitive to the subjective probability of occurrence for individual cards. In Experiment 1, expected frequencies of the p- and the q-card were manipulated independently by concepts referring to large vs. small sets. Although the manipulation had an effect on card selection frequencies, there was only a weak correlation between the predicted and the observed patterns. In the second experiment, relative frequencies of individual cards were manipulated more directly by explicit frequency information. In addition, participants estimated probabilities for the four logical cases and of the conditional statement itself. The experimental manipulations strongly affected the probability estimates, but were completely unrelated to card selections. This result was replicated in a third experiment. We conclude that our data provide little support for optimal data selection theory.     

Doubly-Latent Models of School Contextual Effects: Integrating Multilevel and Structural Equation Approaches to Control Measurement and Sampling Error

This article is a methodological-substantive synergy. Methodologically, we demonstrate latent-variable contextual models that integrate structural equation models (with multiple indicators) and multilevel models. These models simultaneously control for and unconfound measurement error due to sampling of items at the individual (L1) and group (L2) levels and sampling error due the sampling of persons in the aggregation of L1 characteristics to form L2 constructs. We consider a set of models that are latent or manifest in relation to sampling items (measurement error) and sampling of persons (sampling error) and discuss when different models might be most useful. We demonstrate the flexibility of these 4 core models by extending them to include random slopes, latent (single-level or cross-level) interactions, and latent quadratic effects.

Substantively we use these models to test the big-fish-little-pond effect (BFLPE), showing that individual student levels of academic self-concept (L1-ASC) are positively associated with individual level achievement (L1-ACH) and negatively associated with school-average achievement (L2-ACH)—a finding with important policy implications for the way schools are structured. Extending tests of the BFLPE in new directions, we show that the nonlinear effects of the L1-ACH (a latent quadratic effect) and the interaction between gender and L1-ACH (an L1 × L1 latent interaction) are not significant. Although random-slope models show no significant school-to-school variation in relations between L1-ACH and L1-ASC, the negative effects of L2-ACH (the BFLPE) do vary somewhat with individual L1-ACH.

We conclude with implications for diverse applications of the set of latent contextual models, including recommendations about their implementation, effect size estimates (and confidence intervals) appropriate to multilevel models, and directions for further research in contextual effect analysis.     

Social categorization and group‐motivated interindividual–intergroup discontinuity

Research on the interindividual–intergroup discontinuity effect has demonstrated that intergroup relations are often less cooperative than interindividual relations. The aim of the present paper is to test whether mere social categorization suffices to create a group‐motivated discontinuity effect. In two experiments, we manipulated actors' personal versus social identity salience, whereas controlling for actors' outcome independence (1 : 1) versus interdependence (3 : 3). Making actors' social identity salient using a minimal group treatment was sufficient to increase defection in a Prisoner's Dilemma Game, irrespective of whether this was in an interindividual or intergroup interaction (Experiment 1). Using a Mutual Fate Control matrix in Experiment 2, results indicate that this effect can be attributed to actors' increased motivation to maximize relative differences to outgroup opponents under social identity salience. Copyright © 2012 John Wiley & Sons, Ltd.