Areas of investigation/research focus
There is growing evidence that effective treatment of dementia should start as early as possible, that is before a large number of nerve cells have died and the patient shows significant clinical symptoms. For such an early diagnosis we today still lack unambiguous biomarkers that could serve as indicators of an impending dementia.
Therefore, our group focuses on searching for such markers. We use new behavioral tests and advanced imaging techniques such as 7 Tesla high-field MRI.
A second focus of our group is on the development of prophylactic therapies such as a combined memory and movement training. It is known that such training can at least delay the signs of dementia. We study how combined cognitive and physical training over a 12-week period affects the memory of subjects with mild cognitive impairment. Thereby, improvements in memory performance and simultaniousy an increase in hippocampal volume (key brain structure for the memory) and the functional plasticity of the brain through MRI were shown.
In addition, we test for blood flow in vessels (perfusion MRI) and changes in biological markers (nerve growth factors). The aim of the study is to investigate how a training should optimally be set up - is an endurance training or a complex training required for a compensation of the dysfunction? Shoul this be combined with a cognitive training and should this be focused more on improving the disturbed functions or the compensation by other functions? How important is the social componentof such training?
An understanding of normal brain function is a prerequisite for understanding cognitive disorders. Therefore, a third focus of our group is on attention and working memory processes in healthy individuals. We intend to examine the hypothesis that the individual capacity of the more dopamine-dependent working memory is strongly correlated with the cholinergic-mediated ability to ignore irrelevant information through selective attention. To this end, behavioral (by distractors caused errors) and neurophysiological markers of selection ability (N2pc from EEG / MEG, modulation of fMRI responses in visual cortex) are set in relation to the individual capacity of working memory and its neurophysiological correlates (contralateral delay activity in the EEG / MEG , parietal activation in fMRI).
In addition to healthy people, also patients with cholinergic and dopaminergic deficits (incipient Alzheimer's or Parkinson's disease) or lesions in brain structures critical for attention filtering and working memoryare tested. We have already investigated patients with circumscribed brain damage after stroke and were able to show which brain structures are critical for filtering attention and working memory storage. We also investigate to which extent polymorphisms in genes coding for the cholinergic or dopaminergic system and the structural integrity of the cholinergic basal forebrain or the dopaminergic midbrain can influence selection or memory capacities. Moreover, we test how these capacities can be improved by medications that specifically raise the level of neurotransmitters.
Cooperation partners of the group:
- Prof. Dr. Stefan Pollmann, Institute for Psychology, Otto-von-Guericke-Universität Magdeburg
- Dr. Dr. Bernhard Baier, Clinic and Out-Patients' Clinic for Neurology, Johannes Gutenberg-Universität Mainz