A Graph Signal Processing Perspective on Human Brain Imaging

Add to your list(s) Download to your calendar using vCal

• Prof. Dimitri Van De Ville, Professor of Bioengineering at the EPFL and the University of Geneva
• Wednesday 29 August 2018, 11:00-12:00
• EEE Department, Room 610 .

If you have a question about this talk, please contact Pier Luigi Dragotti.

State-of-the-art magnetic resonance imaging (MRI) provides unprecedented opportunities to study brain structure (anatomy) and function (physiology). Based on such data, graph representations can be built where nodes are associated to brain regions and edge weights to strengths of structural or functional connections. In particular, structural graphs capture major neural pathways in white matter, while functional graphs map out statistical interdependencies between pairs of regional activity traces. Network analysis of these graphs has revealed emergent system-level properties of brain structure or function, such as efficiency of communication and modular organization. In this talk, graph signal processing (GSP) will be presented as a novel framework to integrate brain structure, contained in the structural graph, with brain function, characterized by activity traces that can be considered as time-dependent graph signals. Such a perspective allows to define graph-filtering operations of brain activity that take into account the anatomical backbone. For instance, we will show how activity can be analyzed in terms of aligned versus liberal with respect to brain structure, or how additional prior information about cognitive systems can be incorporated. The well-known Fourier phase randomization method to generate surrogate data can also be adapted to this new setting. Finally, recent work will highlight how the spatial resolution of this type of analyses can be increased to the voxel level, representing a few ten thousands of nodes.

W. Huang, T. A. W. Bolton, J. D. Medaglia, D. S. Bassett, A. Ribeiro, D. Van De Ville, « A Graph Signal Processing Perspective on Functional Brain Imaging », Proceedings of the IEEE , vol. 106, pp. 868-885, 2018.

Bio: Dimitri Van De Ville received his M.S. and Ph.D. degrees in Computer Science from Ghent University, Belgium in 1998 and 2002, respectively. From 2002 to 2005, he was a post-doctoral fellow at the Biomedical Imaging Group of Prof. Michael Unser at the Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland. In 2005, he became responsible for the Signal Processing Unit at the University of Geneva (UniGE) and Geneva University Hospital (HUG) as part of the Centre d’Imagerie BioMédicale (CIBM), a large imaging initiative of the Lemanic academic institutions. In 2009, he was awarded an SNSF professorship and he started a joint tenure-track professorship at the UniGE (Department of Radiology and Medical Informatics, Faculty of Medicine) and the EPFL (Institute of Bioengineering, School of Engineering). Since 2015 he’s Associate Professor of Bioengineering at both institutions and his lab is located at the newly established Campus Biotech in Geneva. He was a recipient of the Pfizer Research Award 2012, the NARSAD Independent Investigator Award 2014, and the Leenaards Foundation Award 2016.

He has published more than 150 journal papers on signal and image processing, including on wavelet theory and network science, and their application to the biomedical field, in particular functional brain imaging. Recent work on dynamic functional connectivity included evidence that resting-state functional networks can be disentangled in terms of their temporal overlap, which showed a more complete picture of dynamic organization of brain function and opens avenues for more sensitive biomarkers; e.g., in early diagnosis of patients with mild cognitive impairment. His group is also interested in using real-time fMRI for neurofeedback applications and they have released a publicly-available open-source framework for this purpose.

This talk is part of the talks@ee.imperial series.

This talk is included in these lists:

• EEE Department, Room 610
• talks@ee.imperial

Note that ex-directory lists are not shown.