Entstehung und Aufrechterhaltung von chronischen Schmerzen

Chronic pain has previously been defined as lasting longer than 3 or 6 months. This criterion, however, does not adequately describe the process of pain becoming chronic. Consequently, pain chronicity is not only assessed by pain duration but by consideration of other factors, such as disability or intensity. A number of learning processes affect pain chronicity as they mediate changes in neural networks involved in pain processing. Furthermore, a number of psychosocial risk factors have been identified that affect not only the transition from acute to chronic pain but also the maintenance of chronic pain. The fear-avoidance model takes into account many of these risk factors to explain the development and maintenance of chronic musculoskeletal pain.     

Video game experience and its influence on visual attention parameters: An investigation using the framework of the Theory of Visual Attention (TVA)

Experts with video game experience, in contrast to non-experienced persons, are superior in multiple domains of visual attention. However, it is an open question which basic aspects of attention underlie this superiority. We approached this question using the framework of Theory of Visual Attention (TVA) with tools that allowed us to assess various parameters that are related to different visual attention aspects (e.g., perception threshold, processing speed, visual short-term memory storage capacity, top-down control, spatial distribution of attention) and that are measurable on the same experimental basis. In Experiment 1, we found advantages of video game experts in perception threshold and visual processing speed; the latter being restricted to the lower positions of the used computer display. The observed advantages were not significantly moderated by general person-related characteristics such as personality traits, sensation seeking, intelligence, social anxiety, or health status. Experiment 2 tested a potential causal link between the expert advantages and video game practice with an intervention protocol. It found no effects of action video gaming on perception threshold, visual short-term memory storage capacity, iconic memory storage, top-down control, and spatial distribution of attention after 15 days of training. However, observations of a selected improvement of processing speed at the lower positions of the computer screen after video game training and of retest effects are suggestive for limited possibilities to improve basic aspects of visual attention (TVA) with practice.     

Independent dimension-weighting mechanisms for visual selection and stimulus identification

Observers respond faster when the task-relevant perceptual dimension (e.g., color) repeats across consecutive trials relative to when it changes. Such dimension repetition benefits (DRBs) occur in different tasks, from singleton feature search to feature discrimination of a stimulus presented on its own. Here, we argue that the DRBs observed in different tasks originate from distinct mechanisms: preselective weighting of dimension-specific feature contrast signals and, respectively, postselective stimulus processing. The multiple-weighting-systems hypothesis predicts significant DRBs across trials of different tasks that share the same weighting mechanism, but not across tasks involving different mechanisms. Experiments 1, 2, and 3 examined DRBs across localization and detection tasks (both involving feature contrast computations); across detection and identification tasks (which presumably involved different weighting systems); and across identification and discrimination tasks (both involving stimulus identification). As expected, significant DRBs were observed across different tasks in Experiments 1 and 3, but not in Experiment 2. These findings support the multiple-weighting-systems hypothesis.     

Personality aspects of entrepreneurship: A look at five meta-analyses

Research on personality aspects of entrepreneurship, recently summarized in five meta-analyses, has intensified during the past two decades. Internationally, entrepreneurship has been recognized as highly important for socio-economic prosperity. After discussing a few basic concepts relating task and context of entrepreneurship to personality characteristics the main results of the meta-analyses are reported. In the system of the Big Five, personality traits make a difference when entrepreneurs are compared with managers (C+, O+, E+, N−, A−). They are also relevant in predicting entrepreneurial intention (C+, O+, N−, E+) and entrepreneurs’ performance (C+, O+, E+, N−). For other more specific scales that have frequently enough been used and could therefore be included in meta-analyses (e.g., readiness for innovation, proactive personality, generalized self-efficacy, stress tolerance, need for autonomy, locus of control) have also been reported significant correlations with business creation and business success. Risk propensity supports business foundation, but not necessarily business success. Achievement motivation is favourable both for business foundation and business success. The effect sizes are mostly small, some moderate. Complementing the results of the meta-analyses, some recent single studies on mediator or moderator effects are briefly reviewed.     

Contextual remapping in visual search after predictable target-location changes

Invariant spatial context can facilitate visual search. For instance, detection of a target is faster if it is presented within a repeatedly encountered, as compared to a novel, layout of nontargets, demonstrating a role of contextual learning for attentional guidance (‘contextual cueing’). Here, we investigated how context-based learning adapts to target location (and identity) changes. Three experiments were performed in which, in an initial learning phase, observers learned to associate a given context with a given target location. A subsequent test phase then introduced identity and/or location changes to the target. The results showed that contextual cueing could not compensate for target changes that were not ‘predictable’ (i.e. learnable). However, for predictable changes, contextual cueing remained effective even immediately after the change. These findings demonstrate that contextual cueing is adaptive to predictable target location changes. Under these conditions, learned contextual associations can be effectively ‘remapped’ to accommodate new task requirements.     

Revisiting the association of aggression and suicidal behavior in schizophrenic inpatients

Our study investigated the association of aggression and suicidal behavior in schizophrenic inpatients. Eight thousand nine hundred one admissions for schizophrenia (1998-2007) to a psychiatric university hospital were included. Schizophrenic suicides (n = 7)/suicide attempters (n = 40) were compared to suicides (n = 30)/suicide attempters (n = 186) with other diagnoses and to schizophrenic non-attempters regarding aggression. Logistic regression analysis was performed to explore risk factors for attempted suicide. Schizophrenic suicides/suicide attempters did not differ from other suicides/suicide attempters or from schizophrenic non-attempters with regard to aggression. Risk of inpatient suicide attempt was increased for patients with attempted suicide at admission, high school graduation, and disorganized subtype. Aggression could not be found to be a predictor of attempted suicide. Aggression seems to have a minor role for suicidal behavior in schizophrenia.     

Two (or three) is one too many: testing the flexibility of contextual cueing with multiple target locations

Visual search for a target object is facilitated when the object is repeatedly presented within an invariant context of surrounding items ("contextual cueing"; Chun & Jiang, Cognitive Psychology, 36, 28-71, 1998). The present study investigated whether such invariant contexts can cue more than one target location. In a series of three experiments, we showed that contextual cueing is significantly reduced when invariant contexts are paired with two rather than one possible target location, whereas no contextual cueing occurs with three distinct target locations. Closer data inspection revealed that one "dominant" target always exhibited substantially more contextual cueing than did the other, "minor" target(s), which caused negative contextual-cueing effects. However, minor targets could benefit from the invariant context when they were spatially close to the dominant target. In sum, our experiments suggest that contextual cueing can guide visual attention to a spatially limited region of the display, only enhancing the detection of targets presented inside that region.     

Affective mediators of intergroup contact: a three-wave longitudinal study in South Africa

Intergroup contact (especially cross-group friendship) is firmly established as a powerful strategy for combating group-based prejudice (Pettigrew & Tropp, 2006). Great advances have been made in understanding how contact reduces prejudice (Brown & Hewstone, 2005), highlighting the importance of affective mediators (Pettigrew & Tropp, 2008). The present study, a 3-wave longitudinal study undertaken among minority-status Colored high school children in South Africa (N = 465), explored the full mediation of the effects of cross-group friendships on positive outgroup attitudes, perceived outgroup variability, and negative action tendencies via positive (affective empathy) and negative (intergroup anxiety) affective mediators simultaneously. The target group was the majority-status White South African outgroup. As predicted, a bidirectional model described the relationship between contact, mediators, and prejudice significantly better over time than either autoregressive or unidirectional longitudinal models. However, full longitudinal mediation was only found in the direction from Time 1 contact to Time 3 prejudice (via Time 2 mediators), supporting the underlying tenet of the contact hypothesis. Specifically, cross-group friendships were positively associated with positive outgroup attitudes (via affective empathy) and perceived outgroup variability (via intergroup anxiety and affective empathy) and were negatively associated with negative action tendencies (via affective empathy). Following Pettigrew and Tropp (2008), we compared two alternative hypotheses regarding the relationship between intergroup anxiety and affective empathy over time. Time 1 intergroup anxiety was indirectly negatively associated with Time 3 affective empathy, via Time 2 cross-group friendships. We discuss the theoretical and empirical contributions of this study and make suggestions for future research.     

The multiple-weighting-systems hypothesis: Theory and empirical support

Observers respond faster when the task-relevant perceptual dimension repeats across consecutive trials (e.g., color-color) relative to when it changes (orientation-color)-the phenomenon termed the dimension repetition effect (DRE). Similarly, when two (or more) different tasks are made to vary randomly across trials, observers are faster when the task repeats, relative to task changes-the phenomenon termed task-switch cost (TSC). Hitherto, the DRE and TSC effects have been discussed independently of each other. Critically, either effect was explained by assuming a single mechanism giving rise to DREs or TSCs. Here, we elaborate strong conceptual similarities between the DRE and TSC effects; we introduce the concept of criterion-specific intertrial sequence effects, with DREs and TSCs being different manifestations of criterion-specific effects. Second, we review available evidence suggesting that none of the single mechanism explanations can readily account for all the findings in the literature. Third, we elaborate on the multiple-weighting-systems (or MWS) hypothesis, a recently proposed account that postulates the existence of several, independent mechanisms sensitive to intertrial sequences. Finally, we test predictions derived from the MWS hypothesis in two novel experiments and discuss the results from both the single- and multiple-mechanism perspectives.