Multimodal integration of functional neuroimaging data

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More and more non-invasive neuroimaging techniques are now available to study normal brain functions but also brain disorders. However, it does not exist any ideal exploration technique able to measure precisely when (at a ms scale) and where (at a mm scale) an activity occurred in the brain. Each neuroimaging technique measures through different mechanisms (neuronal electricity, oxygen consumption) part of brain activity, being sometimes more dedicated to the question "where?" (good spatial resolution) or to the question "when?" (good temporal resolution). Each of these techniques having its specific advantages and limitations, analyzing each of them individually only provides partial information regarding underlying brain activity. The objective of my research project is to develop methods to appropriately combine these multimodal data, i.e., data fusion methods, in order to detect additional information that could be missed by considering each modality individually. A typical challenge is to combine modalities measuring directly neuronal activity with high temporal resolution with other modalities measuring indirectly the same function with high spatial resolution, through hemodynamic processes for instance. My project will involve the integration of three promising functional modalities: (1) Simultaneous ElectroEncephaloGraphy (EEG) - MagnetoEncephaloGraphy (MEG) acquisitions, measuring directly on the scalp electric and magnetic components of signals generated by neurons synchronously active (at a ms scale). (2) Simultaneous EEG - functional Magnetic Resonance Imaging fMRI acquisitions to measure, within the whole brain at a second scale, hemodynamic responses that correlate with signals detected on scalp EEG. (3) Simultaneous EEG - Near InfraRed Spectroscopy (NIRS) acquisitions to measure local changes in oxy- and deoxy-hemoglobin at the time of signals detected on scalp EEG, by exploiting absorption properties of infrared light within brain tissues using optic fibres placed on the surface of the head. The principal clinical application of this project will be to combine these three modalities using multimodal data fusion techniques to characterize brain regions involved during epileptic activity.