current
DFG funded Research Unit 1097 "Person Perception Research Unit"
The temporal context of face perception
Project leader
G. Kovacs
Project members of the 1st period
Christian Walther, Daniel Kaiser, Iulia Lavric
Funding period
2010-2012
Objectives
A given picture of a person might look different at different times. The previous encounters with other people or in other words, the temporal context of a given face modify its perception. In our present proposal we will study the effect of previous experiences on face perception using psychophysical, electrophysiological and neuroimaging methods. In most of our planned experiments we will use the powerful paradigm of face adaptation (Kovács et al, 2006), leading to specific, high level aftereffects. In the first set of experiments we will study the similarities and differences of two immediate repetition related phenomena, priming and aftereffects. In a second series of experiments we will study how the variation of the statistical properties of preceding stimuli affects face perception. For this we will use matrixes of multiple faces. In the last set of experiments we will study perceptual decisions, related to faces. In particular, we will compare the effects of bottom-up bias (such as caused by face adaptation) and top-down biases (caused by directed selective attention or by prior predictive information) on perceptual decisions. Altogether our experiments will shed light on the mechanisms of implicit and explicit face representations and on the related decisions that are important in social settings during our everyday life.
For more information see http://www2.uni-jena.de/svw/Allgpsy1/indexppru.html
DFG funded Research Unit 1075 "Regulation and Pathology of Homeostatic Processes for Visual Function"
Subproject 8 "Neuroplasticity in retinotopic visual cortex as a consequence of retinopathologies"
Project leader
Prof. Dr. Mark W. Greenlee
Project members of the 2nd period
Dr. Katharina Rosengarth, Markus Goldhacker, Sabine Brandl-Rühle (in cooperation with Prof. Dr. med. Horst Helbig, Director, University Eye Hospital)
Project members of the 1st period
Dr. Tina Plank, Jozef Frolo, Sabine Brandl-Rühle (in cooperation with Prof. Dr. med. Horst Helbig, Director, University Eye Hospital)
Funding period
since 2008
Objectives
This 3-year project uses functional MRI to determine the extent to which macular degeneration induces neuroplastic alterations in the visual cortex of the affected patients. We will compare the results of a group of 20 patients with a juvenile form of macular degeneration (JMD) to those of patients with age-related macular degeneration (AMD). Our main focus will deal with the issue whether oculomotor training in AMD patients, assisting them to establish a new preferred retinal locus (PRL) for eccentric fixation, can promote cortical reorganization. The results will provide important feedback for therapeutic gains in patients with AMD. They will help guide new training protocols, thereby improving the patients' experienced quality of life.
For more information see: http://www.uni-regensburg.de/FOR1075/index.htm
DFG funded project "Integration of auditory-visual information" (GO 1855/1-1, GR 988/20-2)
Project leaders
Prof. Dr. Mark W. Greenlee, Dr. M. Gondan
Project members
Steven Blurton, Anja Wienbreyer
Funding period
01.04.2011 – 31.03.2013 (GR 988/20-2)
01.04.2009 – 31.03.2011 (GO 1855/1-1)
Objectives
We investigate basic mechanisms of integration of information provided by different sensory systems (e.g. auditory and visual). In basic speeded response tasks, participants receive either auditory information alone, visual information alone, or redundant information via both sensory modalities. Abundant evidence now exists that redundant information is pooled into a common channel (coactivation). In our project we try to describe this process using a computational model (Diffusion Superposition Model, Schwarz, 1994, J Math Psychol): Based on the idea of simple additive superposition of channel activity, the model describes the reaction times observed in simple response tasks with redundant auditory and visual stimuli. In our project we investigate whether the model can equally explain reaction times observed in more complex tasks (Go/Nogo discrimination, choice reactions). Moreover, we manipulate task demands and spatial attention (e.g. Posner-task) to test whether the integration mechanism requires spatial attention. In an EEG study the computational model will be related to neurophysiological data.
past projects
BMBF funded Network "Perceptual Learning"
Subprojects 1, 4 "Brain plasticity and perceptual learning: Experimental analysis and computational modeling" (01GW0761)
Project leader
Prof. Dr. Mark W. Greenlee
Project members
Dr. Katharina Rosengarth, Markus Goldhacker
Funding period
01.01.2008 - 30.06.2011
Objectives
"Perceptual Learning" is a BMBF network funded in the platform "Research collaborations on cognitive performance and relevant disorders in humans".
This collaborative research effort aims to explore the neural mechanisms underlying cortical plasticity in healthy subjects and in patients who learn or re-learn a perceptual task. Our approach is novel since it is strongly guided by methods from computational and cognitive neurosciences and directly applies them to problems arising in clinical neurology and neurorehabilitation. In the experimental part of the project, we plan to employ prototypical tasks that can be learned within a few hours or at most a few days with repeated practice. Before and after this extensive training, our participants will take part in functional and anatomical MR-scan sessions. We will ask the subjects to perform a task for the first time (e.g., speed discrimination of transparent motion). After a sufficient training period, the participants will be scanned again on the same task. We will then compare the MR-correlates of brain structure, brain activation, brain connectivity and neural information processing before and after this training (Project Greenlee).
Furthermore, we plan to examine patients with retrochiasmatic injury and homonymous visual field loss with respect to their global processing capacity in scene perception and in reading at the behavioural-neuropsychological and the functional-neurobiological level. To gain more insight into the neuronal processes underlying neuronal plasticity in adults, fMRI and neuropsychological studies will be conducted before and after an oculomotor training program in patients recovering from posterior infarctions and/or cerebral haemorrhaging (Project Zihl). The results of these basic and clinical investigations will be modelled with mean-field theory and computational models to get a better quantitative description of the neural processes underlying perceptual skill acquisition and reacquisition after brain damage (Projects Neumann, Lang, Deco). Powerful novel data-analysis techniques for functional MRI data will be developed and applied to enhance our ability to extract specific correlates of neuronal plasticity during neurorehabilitation.
A further aim of the research group is to gain a better understanding of how learning takes place in low-level sensory and sensorimotor circuits and compare these processes with those occurring in high-level cognitive learning. Some of the projects will focus on the low-level perceptual learning that occurs when healthy volunteers learn a new task. What changes take place in the brains of adults when they learn a new sensory or sensorimotor task? Moreover, we are interested in the brain changes that take place when patients recover from brain damage. At the macroanatomical level, the neural basis of “scaffolding” processes (Petersson, 1998), where additional brain circuits are temporally recruited to perform supplementary processing during the recovery period, will be investigated. At the microanatomical level, spike timing dependent plasticity (Masquelier and Thorpe, 2007) will be incorporated into models of higher-level motion processing required for velocity discrimination. It remains to be determined how exactly both these macro- and microanatomical changes take place. Finally, we hope to provide clinicians with new imaging approaches and diagnostic tools to map changes in grey and white matter that accompany neural learning processes.
For more information see: http://www.brain-plasticity.org/
BMBF funded Network "Visuo-spatial Cognition"
Subproject 3 "Neural correlates of visual and memory-guided saccades during visual search" (01GW0653)
Project leader
Prof. Dr. Mark W. Greenlee
Project members
Volker Fischer, Markus Raabe
Funding period
01.01.2007 - 30.06.2010
Objectives
"Visuo-spatial Cognition" is a BMBF network funded in the platform "Cognition research".
The goal is to model and analyze brain mechanisms underlying spatial cognition during visual search and visual exploration. A total of 4 German laboratories are collaborating on this project.
For more information see: http://www.visuospatial-cognition.org/
Chair funded projects "Neurodegeneration"
Visuo-spatial information processing in patients with amnestic mild cognitive impairment (aMCI)
Karolina Alichniewicz, Florian Brunner, Helmut Nebl, Dr. Hans-Hermann Klünemann, Prof. Dr. Mark W. Greenlee
This study aims at exploring visuo-spatial information processing in healthy elderly and patients with amnestic mild cognitive impairment (aMCI). Participants undergo an extensive behavioral test battery with the main focus on working memory and attention. Subjects also participate in a pro-/anti-saccade task. With the help of two fMRI experiments we plan to investigate the neural correlates of cognitive processes relevant for working memory and saccadic control and to detect altered/compensatory brain activation patterns in aMCI patients.
In addition the project explores possible benefits of a short-term nordic walking program for aMCI patients and its impact on cognitive performance in behavioral tests as well as on neural brain activation.
Olfactory BOLD-reactions in patients with Parkinson's disease
Carolin Mößnang, Gabriele Frank, Dr. Beate Winner, Prof. Dr. Jürgen Winkler, Prof. Dr. Mark W. Greenlee
Recent studies (e.g. Albers et al., 2006; Masaoka et al., 2007) point to the fact that already in early stages of Parkinson's disease (PD) the olfactory system shows distinct impairments additional to the well known pathological alterations in the basal ganglia. By presenting sniffing sticks as olfactory stimuli to 15 PD-patients and 15 age-matched healthy controls during the fMRI-session in a 3-Tesla-Scanner we will investigate the underlying neurofunctional correlates of this olfactory impairments. We hope to get new insights in the neuropathological processes of Parkinson's disease and to contribute to an effective and reliable diagnostic in early stages of this disease.
Neurofunctional and neuropsychological correlates of pathological ageing: mild cognitive impairment (MCI) and the impact of the genetic risk factor APO E epsilon4
Gabriele Frank, Stefanie Feuerer, Dr. Hans-Hermann Klünemann, Prof. Dr. Mark W. Greenlee
This study deals with the neurofunctional correlates of an important aspect of semantic memory, the recognition of the faces of famous people in MCI-patients, age-matched controls and young healthy subjects by conducting an fMRI experiment (3-Tesla-Scanner). Because it is well known that Apolipoprotein E epsilon4 (APOE epsilon4) is an important genetic risk factor for the development of Alzheimer's disease, a main focus of our study lies on the impact of the APOE status on cortical activation as well as neuropsychological performance of the subject groups mentioned above.
EU FP6 IST Cognitive Systems Integrated Project "Decisions in Motion" (FP6 Project 027198)
Project coordinator
Prof. Dr. Mark W. Greenlee
Project members at University of Regensburg
Dr. Gyula Kovács, Markus Raabe
Funding period
2006 - 2009
Objectives
"Decisions in Motion" is a EU Commission project funded in the platform FP6 IST Cognitive Systems.
The goal is to model and implement fast sensory-based decision making in moving cognitive agents. A total of 8 European laboratories and 2 SMEs are collaborating on this project.
For more information see: http://decisions-in-motion.org/
"BayernBrain3T", funded by Bayerische Forschungsstiftung
Project leaders
University Medical Center Regensburg, Department of Neurology, Prof. Dr. U. Bogdahn
University of Regensburg, Institute of Experimental Psychology, Prof. Dr. M. W. Greenlee
Project partners
Siemens AG
RAPID BioMedical GmbH
Funding period
2004 - 2007
Objectives
"BayernBrain3T" is a research and developmental project funded by Bayerische Forschungsstifung and dedicated to preclinical, neuropsychological and clinical research on a 3T high field MR scanner.
The goal of the project is to develop and optimise medical imaging techniques to evaluate diagnostic and therapeutic methods applied in the context of regeneration of CNS damage in particular and neuronal plasticity in general.
For more information see: http://www.forschungsstiftung.de/ (in German only)
DFG Priority Program "Executive Functions" (SPP 1107)
Subproject 12 "Neural correlates of executive functions in children with ADHD as measured by fMRI and MR-spectroscopy"
Project leader
Prof. Dr. Mark W. Greenlee
Project members
Petra Behlmer-Elster, Markus Raabe, Markus Mühlhan, Jale Özyurt
Funding period
2003 - 2005
Objectives
Attention deficit hyperacitvity disorder (ADHD) is a phenotypically heterogeneous neuropsychiatric disorder that usually manifests itself in early childhood. The pathogenetic factors that lead to ADHD are only partly understood and remain a matter of considerable dispute. Accumulating evidence from on-going research indicates, however, that ADHD reflects a dysfunction of cortical and subcortical systems, and that these neuronal substrates form the basis of executive functions. The goal of the present research proposal is to investigate well diagnosed subgroups of pediatric ADHD patients with functional magnetic resonance imaging (fMRI) and magnet resonance spectroscopy (MRS). Using fMRI we intend to explore the neural correlates of fundamental subprocesses that contribute to executive functioning (such as response inhibition and working memory). Behavorial data recorded during the fMRI experiments can be used to validate possible differences in brain activation. The use of MRS should focus on possible pathologically altered neurochemical processes in ADHD. Using both technologies, we plan to investigate de novo patients clinically diagnosed with ADHD and compare these findings with those collected after treatment with methlyphenidate (MPH; the neuroactive substance e.g. in Ritalin). Such a comparison should reveal the effect of stimulants on the fMRI-BOLD responses to challenging tasks and to altered brain metabolism as revealed by MRS. ADHD-specific patterns of brain activation recorded during tasks that require executive function and/or alterations in neurochemical markers might help to better understand the neural basis of ADHD and might serve as biological markers to objectively validate the diagnosis of the disorder.
DFG funded International Graduate School "Neurosensory Science and Systems: Measuring and Modelling the Processing of Sensory Information and its Applications" (GRK 591)
Workgroup Prof. Dr. Mark W. Greenlee "Functional magnetic resonance imaging in the human visual and oculomotor system"
Participating members
Prof. Dr. Mark W. Greenlee, Ignacio Vallines García (University of Regensburg), Riklef Weerda (University of Oldenburg)
For more information see: Progress reports 2002 and 2005
PhD Theses
2011
Fischer, Volker (2011).
"Analysis of connectivity between local multi-variate patterns of functional MRI data"
Dissertation at the Institute of Biophysics and Physical Biochemistry (supervisor Prof. Dr. E. W. Lang) in collaboration with the Institute of Experimental Psychology (supervisor Prof. Dr. M. W. Greenlee), University of Regensburg.
Manuscript available online.
Alichniewicz, Karolina (2011).
"Neuronale Korrelate der visuell-räumlichen Informationsverarbeitungsprozesse bei Mild Cognitive Impairment"
Dissertation, University of Regensburg.
Manuscript available online.
2010
Heckel, Andreas (2010).
"Processing of pain and emotion in the human brain. An fMRI study"
Dissertation at the Institute of Psychiatry and Psychotherapy at the Medical Faculty (supervisor Prof. Dr. H. E. Klein) in collaboration with the Institute of Experimental Psychology (supervisor Prof. Dr. M. W. Greenlee), University of Regensburg.
Manuscript available online.
2009
Acs, Ferenc (2009).
"Neuronal dynamics of visual movement processing areas: A fMRI investigation of the connectivity of visual processing areas for motion processing and attention in the human brain"
Dissertation, University of Regensburg.
Manuscript available online.
Herpes, Martin (2009).
"Morphometrie cerebraler Veränderungen und psychophysische Erfassung olfaktorischer Störungen bei Morbus Parkinson"
Dissertation at the Medical Faculty (supervisor Prof. Dr. U. Bogdahn) in collaboration with the Institute of Experimental Psychology (supervisor Prof. Dr. M. W. Greenlee), University of Regensburg.
Manuscript available online.
Rosengarth, Katharina (2009).
"Neuronale Korrelate grammatischer und semantischer Prozessierung bei Erwachsenen, Kindern und dysgrammatischen Kindern"
Dissertation at the Philosophic Faculty IV (supervisor Prof. em. Dr. H. Brekle) in collaboration with the Institute of Experimental Psychology (supervisor Prof. Dr. M. W. Greenlee), University of Regensburg.
Manuscript available online.
Frank, Gabriele (2009).
"Neurofunktionelle, neurostrukturelle und neuropsychologische Korrelate gesunden und pathologischen Alterns: der Einfluss des genetischen Risikofaktors ApoE epsilon4"
Dissertation, University of Regensburg.
Manuscript available online.
2007
Vallines García, Ignacio (2007).
"Modulation of neural activity in human visual cortex during saccade programming"
Dissertation, University of Regensburg.
Manuscript available online.
2006
Baumann, Oliver (2006).
"Kortikale Aktivierungsmuster auditiv-visueller Bewegungswahrnehmung während der Ausführung von Augenbewegungen und die Rolle des Neocerebellums in der Augenbewegungssteuerung"
Dissertation, University of Regensburg.
Manuscript available online.
