Associate Professor, Center for Functional and Molecular Imaging
Center for Functional and Molecular Imaging
Georgetown University Medical Center
Preclinical Science Building LM14
3900 Reservoir Rd, NW
Washington DC 20057
Office: (202) 687-5126
Dr. Medvedev's expertise includes noninvasive near-infrared optical imaging, functional connectivity, systems electrophysiology, high density EEG, source localization, signal analysis and neural network modeling. Dr. Medvedev's research interests focus on neural mechanisms of cognitive processes in healthy subjects as well as patients with various types of neurological or mental pathology (epilepsy, Alzheimer’s disease, aphasia, autism spectrum disorders).
Dr. Medvedev leads the EEG and Optical Imaging laboratory within the Center for Functional and Molecular Imaging (CFMI) and his current research combines the new technology of noninvasive near-infrared spectroscopy (NIRS) and NIRS-based functional imaging of the brain with a more traditional electrophysiological analysis of on-going and event-related electrical activity (high density EEG, ERP, evoked and induced oscillations). Hemodynamic (as measured by NIRS) and neuronal (as measured by EEG) responses of the brain are studied to analyze spatiotemporal organization and hemispheric lateralization of cognitive functions such as object recognition, language, executive function as well as pathophysiological mechanisms of neurological diseases. Combination of different technologies to analyze dynamic processes of the brain is supported by advanced methods of signal processing (Independent Component Analysis, spectral analysis, time-frequency analysis, wavelets, Granger causality, directed coherence, cross-frequency coupling). These techniques provide new insights into the integrative mechanisms of cognitive functions and how those processes and mechanisms are disturbed in neurological diseases.