Feindel Brain and Mind Seminar Series: Bridging the gap between BigBrain and functional MRI in humans using biophysical generative models
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Stream via vimeo here.
Kamil Uludag
Koerner Scientist, Krembil Brain Institute, Canada
Abstract: In this talk, I will provide an overview of the physiological processes that contribute to the observed BOLD signal (i.e., the generative biophysical model), including their time course properties within the framework of the physiologically-informed dynamic causal modeling (P-DCM). Specifically, the physiological origin of the so-called BOLD signal “transients” will be discussed, including the initial overshoot, steady-state activation and the post-stimulus undershoot. I argue that incorrect physiological assumptions in the generative model of the BOLD signal can lead to incorrect inferences pertaining to both local neuronal activity and effective connectivity between brain regions. In addition, I introduce the recent laminar BOLD signal model, which extends P-DCM to cortical depths-resolved BOLD signals, allowing for laminar neuronal activity to be determined using high-resolution fMRI data. Finally, I outline a research program to leverage the BigBrain to develop brain-area specific microcircuit models, which can represent the neuronal component of the laminar fMRI signal model.
Bio: Kâmil Uludağ studied from 1992 till 1997 Physics at the Technical University of Berlin. He completed his Ph.D. in Physics in 2003 on Near-Infrared Optical Spectroscopy (Humboldt University, Berlin) and moved for a postdoc position to the Center for Functional MRI (UCSD, San Diego, USA) to work on the physiological and physical basis of functional MRI. In 2004, he was appointed Head of Human Brain Imaging group at the Max-Planck-Institute for Biological Cybernetics, Tübingen. From June 2010 to December 2018, he was Associate Professor in the Faculty of Psychology & Neuroscience and Head of the Department of Cognitive Neuroscience continuing his work on the basis of fMRI utilizing the new Ultra-High Field human MRI scanners (7 and 9.4 Tesla). Since 2019, he is Senior Scientist at the University Health Network (UHN) and Full Professor at the Department of Medical Biophysics, University of Toronto.
Dr. Uludağ is on the editorial board of several neuroimaging journals, served from 2011 to 2013 as Annual Meeting Committee Member of the International Society for Magnetic Resonance Imaging in Medicine (ISMRM) and was elected Chair of the Current Issues of Brain Function study group. He recently edited a textbook “functional MRI: from Nuclear Spins to Brain Functions” (Publisher: Springer).
The Feindel Brain and Mind Seminar Series will advance the vision of Dr. William Feindel (1918–2014), Former Director of the Neuro (1972–1984), to constantly bridge the clinical and research realms. The talks will highlight the latest advances and discoveries in neuropsychology, cognitive neuroscience, and neuroimaging.
Speakers will include scientists from across The Neuro, as well as colleagues and collaborators locally and from around the world. The series is intended to provide a virtual forum for scientists and trainees to continue to foster interdisciplinary exchanges on the mechanisms, diagnosis and treatment of brain and cognitive disorders.
