NACH OBEN

Research Interests and Projects

Prof. Dr. Nikolai Axmacher

How are experiences represented in the brain and transformed into memory traces? How do these experiences shape our personality? And how is memory compromised by trauma, innerpsychic conflicts and Alzheimer's dementia? In my group, we are investigating the neural foundations of memory functions and dysfunctions using cognitive neuroscience methods (EEG, fMRI, simultaneous EEG/fMRI, fMRI at 7T, intracranial EEG). Neural network mechanisms are explored via distributed patterns of BOLD activity patterns and EEG oscillations.

I am particularly interested in the processing of specific contents by the brain and how the resulting stimulus specific representations can be decoded using pattern classification algorithms. We are investigating a wide range of memory processes (working memory, long-term memory, memory consolidation during resting state and sleep, autobiographical memory, social memory, repression). Our vision is to track the brain mechanisms that support the transformation of perceptual representations into memory traces and their transformation during complex memory functions

Prof. Dr. Boris Suchan

My research interests focus mainly on the functional organisation of the prefrontal cortex. The prefrontal cortex is associated with highest cognitive functions like working memory and executive functions. To investigate these functions and their anatomical organisation, we use functional magnetic resonance imaging (fMRI) and electroencephalogram (EEG) in combination with source localisation.

Whereas fMRI provides a good spatial resolution, EEG provides a temporal resolution in the range of milliseconds with the additional possibility to localise the generator of the EEG signal using source localisation. One focus of my research is on working memory and its neural correlates. In these studies we look for the neural correlates of the interaction of the subsystems in working memory. Additionally we focus on the neuroanatomical location of the central executive which is involved in manipulation in working memory.

While these studies mostly use fMRI, we use EEG to investigate response evaluation which is another field of interest. The anterior cingulate cortex (ACC) is associated with attention, error detection and response evaluation. Using EEG, a negative peak over central localisation can be observed after the subjects made their responses. As this component was mainly associated with error detection in the literature, results of recent studies yield evidence for a non error related, more evaluative function. We are specifically interested in the functional significance of this component as well as its neuranatomical generator. By analyzing EEG data in a traditional way and additionally with source localisation we aim at characterising the functional significance and the neruoanatomical networks that are associated with this component.

Beside these topics I am using techniques like Voxel Based Morphometry to investigate brain changes in specific diseases e.g. ataxia. At the moment I am starting to use Diffusion Tensor Imaging and Dynamic Causal Modelling techniques to investigate brain functions from a different side