Systems Neuroscience Institute

Theoretical Neuroscience

The Theoretical Neuroscience Group aims at modelling the activity of the brain both in the normal and in the pathological case. For this purpose, we adopt a “multi-scale” approach. This means trying to understand the brain by binding in a single framework different resolution levels, and/or different time scales. This also means trying to unify different points of view, from mathematical theory of complex systems toward computer-based numerical simulations (looking at the ensemble activity from the graph of elementary components) and behavioral studies.

One of the objectives of the group is to study and understand some neuronal disorders (in particular epilepsy) seen as “dynamical disorder” (as a disorganization of the normal dynamical system).

Dynamics of cognitive processes

The main objective is to uncover the spatiotemporal dynamics underlying cognitive processes. These dynamics are studied using different brain imaging approaches (sEEG, MEG, EEG, TMS, fMRI) combined with sophisticated cognitive and psychophysical paradigms. Of great interest are the changes in the connectivity of the large-scale network when cognitively interacting with different types of contexts. These changes can be slow (such as in learning) or fast (such in predicting) and their emergence can be linked to different types of behavioural dysfunctions that we study in epilepsy, degenerative diseases and hearing impairment. All of our work in DCP can be understood within this framework and comprises behavioural and imaging studies in normal subjects and patients with brain dysfunction including children (dyslexia and hearing impairment), the development of cognitive models for understanding speech processing, anticipatory behaviour and memory decline, and applications to speech rehabilitation, mostly via music rhythmic training concrete.

Physiology and physiopathology of brain networks (PhysioNet)

Cognitive processes depend upon the activity of distributed networks in the brain. Our main goal is to further our understanding of the basic rules of brain dynamics in given behavioural states in physiological conditions, and how these rules are modified in epilepsy. We use a multilevel approach. The Virtual Mouse Brain allows us to virtualize individual mouse brains and study whole brain dynamics. We use multisite in vivo recordings and optogenetics to assess how specific neurons code information during cognitive tasks and how they control the dynamics of large networks, in control and epileptic animals. One level down, we study the relationships between energy metabolism and neuronal activity (in epilepsy and Alzheimer’s disease).

All projects have a clinical finality: we are trying to identify predictive biomarkers of incoming seizures as well as biomarkers of vulnerability to depression and cognitive deficits in epilepsy. We are developing curative approaches for seizures and co-morbidities.

Finally, one part of our activity is devoted to design new in vivo recording devices. We are experimenting multimodal organic probes, to record electro-molecular activity and deliver therapeutic substances for diverse neurological disorders, including epilepsy and Parkinson’s disease.

Dynamical brain mapping

The general objective of the Dynamap team is to develop signal processing strategies for characterizing the spatio-temporal dynamics of brain networks, for both physiological and pathological activity.

With this in view, the first strategy of the team is to combine the strength of different modalities such as EEG, MEG, fMRI, with particular emphasis on simultaneous recordings (EEG-MEG, EEG-fMRI) that allow recording the exact same activity under different points of view. The second strategy is to take the opportunity of intracerebral recordings performed in patients with epilepsy for providing a ‘ground truth’ to which non-invasive methods can be confronted.In basic neuroscience, one application of our work is to provide methodological advances for the users of the MEG platform. In clinics, our tools are intended to improve delineation of the epileptogenic zone for presurgical planning of patients with epilepsy. A particular effort is made towards translation of our work to clinicians and researchers through the multi-platform Anywave software, which architecture specifically aims at allowing fast implementation of algorithms to the end users.