How does the brain enable a cognitive task, for e.g. memory recall? Specific ‘brain networks’ or selective coalitions of brain regions, support specific cognitive tasks. EEG and MEG (Electro- and Magneto- encephalography) are valuable technologies to reveal these brain networks. However, they pose a number a technical challenges in accurately identifying these networks. In this talk, I will present two methods we have developed to: 1) identify brain networks in EEG/MEG data while a person is at rest and 2) identify time-varying ‘brain networks’ in EEG/MEG data as a person performs a task. The first method uses a Multivariate Autoregressive (MVAR) framework to identify ‘brain networks’ while the second method combines the MVAR framework with a Markov model to characterize ‘brain networks’ as they change with time. I will present simulation results which validate these methods, as well as crucial and novel insights gained from applying these methods to experimental EEG/MEG data. Finally, I will describe how I will combine these methods in future research, with biologically informed models, to gain fundamental understanding on mechanisms underpinning brain function. These methods and models would provide powerful means for scientists and clinicians to harness the potential of EEG/MEG to illuminate brain function in health and disease.
Dr. Nitin Williams did his B.E. in Electronics & Communication Engineering (ECE) from Anna University, India before completing a Ph.D. in Computational Neuroscience from University of Reading, UK. He then performed 4 years of post-doctoral research in University of Cambridge, UK. He is currently pursuing post-doctoral research in University of Helsinki, Finland, on a project to identify the Brain Functional Connectome. This project was originally funded by EU flagship Human Brain Project (HBP). His interests are in developing methods and models to understand human neuroscience data, for scientific and clinical applications. He has published 19 peer-reviewed papers, including in Brain, Nature Communications and NeuroImage. He is reviewer for 12 journals in the field, including PLoS Computational Biology and NeuroImage and is on the Editorial Board of the journal Network: Computation in Neural Systems. He was recently awarded a €10,000 post-doctoral research grant by Otto A. Malm Foundation.