Kognitionspsychologie - Cognitive Psychology

 

SFB 1280 Extinction Learning

Project A09: The impact of stress and stress hormones on extinction, renewal, reinstatement and reconsolidation
Stress influences learning and memory processes including conditioning processes occurring during acquisition, extinction and extinction recall of (fear-relevant) associations. These effects are caused by the neuroendocrine stress response leading to a joint and orchestrated activation of the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis. The secreted stress mediators (nor)adrenaline and cortisol influence brain regions crucially involved in extinction and extinction recall (ventromedial prefrontal cortex, amygdala, hippocampus).
Within the SFB1280, we will investigate the impact of administration of the stress hormone cortisol or exposure to psychosocial stress on four domains. Using classical conditioning, effects of cortisol on fear generalization will be tested using fMRI. In a second line of research, we will continue our work regarding the influence of cortisol on reconsolidation processes. Moreover, the influence of acute stress on reinstatement processes will be explored in the third experiment extending our previous renewal research. Last but not least, phase-dependent stress effects on extinction of operant behavior will be characterized allowing testing and comparing appetitive and aversive based extinction learning within the same participants.
In sum, these studies will enhance our mechanistic understanding of the modulation of extinction learning by stress hormones, an area of high relevance for basic science and clinical applications alike.

Contact: Prof. Dr. Oliver Wolf, Dr. Christian Merz, Dr. Shira Meir Drexler, Dr. Valerie Kinner

 

SFB 874 integration and representation of sensory processes

Project B4: Memories of a stressful episode
Stress is known to enhance memory consolidation through the interdependent action of the stress hormones (nor)adrenalin and cortisol. However, what exactly we remember from a stressful episode itself had not been tested in an experimental setting in humans. Studies conducted in our department have demonstrated that stressed participants remember visual items as well as an ambient odour better compared to participants undergoing a stress-free control condition. Moreover, their recognition memory relied more on hippocampal based recollection processes. Furthermore, we could show that olfactory stimuli are effective reminder cues for memories of stressful but not of non-stressful situations. These findings demonstrate that stress enhances memory consolidation and that olfactory stimuli are powerful reminder cues of stressful memories.

Our current studies try to provide a mechanistic understanding of these findings. The role of visual exploration in a stressful situation, measured with eye tracking and stress neuromodulators (cortisol and noradrenalin), is investigated. Possible distinct effects of stress and the stress hormone cortisol on recollection versus familiarity will be investigated for memory consolidation and memory retrieval using behavioural and neuroimaging techniques. The role of olfactory reminder cues will be systematically compared with visual and auditory cues using emotional and neutral stimuli.

Furthermore, effects of stress on hippocampal based perceptual processes will be tested in collaborative experiments. Previous studies demonstrated that the visual perception of spatial scenes relies on the hippocampus, while perceiving objects and faces is hippocampus-independent. Current and future studies investigate to what extent visual perception is influenced by stress and aim to reveal the underlying neural mechanisms of this influence.

Last but not least the impact of stress and stress hormones on non-hippocampal based (cortical) perceptual learning processes will be tested in collaborative experiments.

Together, these studies will lead to an enhanced mechanistic understanding of the enhancing and impairing effects of stress on the representation of sensory processes.

Contact: Anika Pützer, Marcus Paul, Prof. Dr. Oliver T. Wolf

 

DFG-Project (WO 733/15-1): Stress and cognitive emotion regulation processes

The ability to cognitively regulate emotions is of vital importance for us humans. A deficient ability to adaptively regulate one’s (negative) emotion is regarded a major risk factor for the development of mental disorders. Acute psychological stress causes the release of stress hormones (e.g. noradrenalin and cortisol) which influence brain function. Emotionally stress is associated with an increase in negative affect and an enhanced susceptibility to distraction by emotional stimuli. The goal of the present project is the investigation of acute and delayed stress effects on the efficacy of emotion regulation using different cognitive strategies. In addition the presence of sex differences will be characterized. The results of this project will contribute to a better understanding of the impact of stress and stress hormones on emotion regulation processes.

Contact: Lisa Marie Stock, Valerie Kinner, Oliver T. Wolf

 

Other reasearch projects

MERCUR project: Influence of stress on the retrieval of socially relevant fear memories
This project explores the effect of in- and outgroup faces as conditioned stimuli in a differential fear conditioning design and how psychosocial stress exerts an effect on electrodermal correlates of socially modulated extinction recall. The results of this project will contribute to a better understanding of the development and maintenance of potential resentments towards outgroups and factors influencing this relationship. It is funded by the Mercator Research Center Ruhr (MERCUR).

Contact: Christian Merz, Annika Eichholtz