Rudi De Raedt

The Karolinska Directed Emotional Faces: A validation study

Although affective facial pictures are widely used in emotion research, standardised affective stimuli sets are rather scarce, and the existing sets have several limitations. We therefore conducted a validation study of 490 pictures of human facial expressions from the Karolinska Directed Emotional Faces database (KDEF). Pictures were evaluated on emotional content and were rated on an intensity and arousal scale. Results indicate that the database contains a valid set of affective facial pictures. Hit rates, intensity, and arousal of the 20 best KDEF pictures for each basic emotion are provided in an appendix.

Understanding Vulnerability for Depression from a Cognitive Neuroscience Perspective: A Reappraisal of Attentional Factors and a New Conceptual Framework

We propose a framework to understand increases in vulnerability for depression after recurrent episodes that links attention processes and schema activation to negative mood states, by integrating cognitive and neurobiological findings. Depression is characterized by a mood-congruent attentional bias at later stages of information processing. The basic idea of our framework is that decreased activity in prefrontal areas, mediated by the serotonin metabolism which the HPA axis controls, is associated with an impaired attenuation of subcortical regions, resulting in prolonged activation of the amygdala in response to stressors in the environment. Reduced prefrontal control in interaction with depressogenic schemas leads to impaired ability to exert attentional inhibitory control over negative elaborative processes such as rumination, leading in turn to sustained negative affect. These elaborative processes are triggered by the activation of negative schemas after confrontation with stressors. In our framework, attentional impairments are postulated as a crucial process in explaining the increasing vulnerability after depressive episodes, linking cognitive and biological vulnerability factors. We review the empirical data on the biological factors associated with the attentional impairments and detail how they are associated with rumination and mood regulation. The aim of our framework is to stimulate translational research.

Mood-congruent attentional bias in dysphoria: maintained attention to and impaired disengagement from negative information.

Attentional bias to negative information has been proposed to be a cognitive vulnerability factor for the development of depression. In 2 experiments, the authors examined mood-congruent attentional bias in dysphoria. In both experiments, dysphoric and nondysphoric participants performed an attentional task with negative, positive, and neutral word cues preceding a target. Targets appeared either at the same or at the opposite location of the cue. Overall, results indicate that dysphoric participants show maintained attention for negative words at longer stimulus presentations, which is probably caused by impaired attentional disengagement from negative words. Furthermore, nondysphoric participants maintain their attention more strongly to positive words. These results are discussed in relation to recent developments in the pathogenesis and treatment of depression.

The Default Mode Network and Recurrent Depression: A Neurobiological Model of Cognitive Risk Factors

A neurobiological account of cognitive vulnerability for recurrent depression is presented based on recent developments of resting state neural networks. We propose that alterations in the interplay between task positive (TP) and task negative (TN) elements of the Default Mode Network (DMN) act as a neurobiological risk factor for recurrent depression mediated by cognitive mechanisms. In the framework, depression is characterized by an imbalance between TN-TP components leading to an overpowering of TP by TN activity. The TN-TP imbalance is associated with a dysfunctional internally-focused cognitive style as well as a failure to attenuate TN activity in the transition from rest to task. Thus we propose the TN-TP imbalance as overarching neural mechanism involved in crucial cognitive risk factors for recurrent depression, namely rumination, impaired attentional control, and cognitive reactivity. During remission the TN-TP imbalance persists predisposing to vulnerability of recurrent depression. Empirical data to support this model is reviewed. Finally, we specify how this framework can guide future research efforts.

Attentional bias training in depression: Therapeutic effects depend on depression severity

Depressed individuals show maintained attention to negative information and reduced attention for positive information. Selective biases in information processing are considered to have an important role in the origin, maintenance and recurrence of depressive episodes. In two experiments we investigated the effects of attentional bias manipulation on mood and depressive symptoms. In experiment 1 we investigated the effects of attentional bias manipulation compared to a control procedure in a sample of dysphoric students (N = 48) showing mild to severe levels of depressive symptoms. In experiment 2 we investigated the same attentional training procedure in a sample of depressed in- and outpatients (N = 35). Mild improvements on symptom severity were observed in students showing mild depressive symptoms. However, in students showing moderate to severe depressive symptoms, depressive symptoms increased after the training. No beneficial effects of training on top of therapy and/or medication were found in depressed patients. These results indicate that therapeutic effects of attentional bias modification might be dependent on depression severity.

Being Moved Valence Activates Approach-Avoidance Behavior Independently of Evaluation and Approach-Avoidance Intentions

Theories from diverse areas of psychology assume that affective stimuli facilitate approach and avoidance behavior because they elicit motivational orientations that prepare the organism for appropriate responses. Recent evidence casts serious doubt on this assumption. Instead of motivational orientations, evaluative-coding mechanisms may be responsible for the effect of stimulus valence on approach-avoidance responses. Three studies tested contrasting predictions derived from these two accounts. Results supported motivational theories, as stimulus valence facilitated compatible approach-avoidance responses even though participants had no intention to approach or to avoid the stimuli, and the valence of the response labels was dissociated from the approach and avoidance movements (Study 1). Stimulus valence also facilitated compatible approach-avoidance responses when participants were not required to process the valence of the stimuli (Studies 2a and 2b). These findings are at odds with the evaluative-coding account and support the notion of a unique, automatic link between the perception of valence and approach-avoidance behavior.

The Relationship Between Cognitive/Neuropsychological Factors and Car Driving Performance in Older Adults

OBJECTIVES: Because demographic changes produce a society with a growing number of older people, seniors constitute the fastest growing segment of car drivers. The objective of this research project was to identify cognitive factors related to driving problems in older adults. A top‐down approach has been used, testing theory‐driven hypotheses.

The association between depressive symptoms and executive control impairments in response to emotional and non-emotional information

Depression has been linked with impaired executive control and specific impairments in inhibition of negative material. To date, only a few studies have examined the relationship between depressive symptoms and executive functions in response to emotional information. Using a new paradigm, the Affective Shift Task (AST), the present study examined whether depressive symptoms in general, and rumination specifically, are related to impairments in inhibition and set shifting in response to emotional and non-emotional material. The main finding was that depressive symptoms in general were not related to inhibition. Set-shifting impairments were only observed in moderate to severely depressed individuals. Interestingly, rumination was related to inhibition impairments, specifically when processing negative information, as well as impaired set shifting as reflected in a larger shift cost. These results are discussed in relation to cognitive views on vulnerability for depression.

Mood-congruent attention and memory bias in dysphoria: Exploring the coherence among information-processing biases

Recent studies indicate that depression is characterized by mood-congruent attention bias at later stages of information-processing. Moreover, depression has been associated with enhanced recall of negative information. The present study tested the coherence between attention and memory bias in dysphoria. Stable dysphoric (n = 41) and non-dysphoric (n = 41) undergraduates first performed a spatial cueing task that included negative, positive, and neutral words. Words were presented for 250 ms under conditions that allowed or prevented elaborate processing. Memory for the words presented in the cueing task was tested using incidental free recall. Dysphoric individuals exhibited an attention bias for negative words in the condition that allowed elaborate processing, with the attention bias for negative words predicting free recall of negative words. Results demonstrate the coherence of attention and memory bias in dysphoric individuals and provide suggestions on the influence of attention bias on further processing of negative material.

Reaction Times and Performance Variability in Normal Aging, Mild Cognitive Impairment, and Alzheimer's Disease:

This study evaluated whether reaction times (RT) and performance variability are potential markers for the early detection of Alzheimers disease (AD). Cognitively healthy elderly (n = 218), persons with amnestic MCI (a-MCI) (n = 29) and patients with AD (n = 50) were examined with RT tasks with increasing complexity, subdividing RT into a decision and a movement component. Persons with cognitive deterioration demonstrated more intra-individual variability and more slowing than cognitively healthy elderly. The slowing in AD affects both the cognitive and the motor component, while performance variability mainly affects the cognitive component of the RT. Although in a-MCI not all differences reached statistical significance, primarily the cognitive component of the RT is affected in a-MCI. Intra-individual variability and RT of the complex tasks are the best predictors for a-MCI and AD status, respectively. We conclude that performance variability can be regarded as a useful preclinical marker for AD.