We consider micro-, meso- and macro-scale brain circuits as dynamical systems that collectively produce functional computations and, ultimately, cognition and behavior. Here, the keyword is “collectively”, and, briefly, we could say that “the whole is more (and different) than the sum of the parts”. Analogously, pathologies are usually interpreted in terms of damage to system’s parts (“hardware”), while they may, especially in early stages, build-up from alterations of system’s dynamics (“software”).
We combine data collection with state-of-the-art experimental techniques (R. Goutagny) with sophisticated analytical tools including machine-learning, information theory, network science and computational modeling (D. Battaglia, J. Bahuguna), all conducted at different spatial and temporal scales, to dissect the potential cognitive algorithms mediated by neural oscillations and other neural dynamics patterns. The cross-fertilization between theory and experiments is central in our research. In our agnostic approaches, we try refraining from averaging over long times and many trials, as we believe that fluctuations are not mere noise, but that their spatiotemporal organization and non-linearities conveys rich information which can be revealed without a priori assumptions. We thus naturally focus on phenomena such as oscillatory bursting, cross-frequency coupling, dynamic functional connectivity and switching between states. We adapt our analysis and modelling approaches to very different types of neural signals, from single units and LFPs to brain-wide EEG and fMRI (human, NHP, rodent, cultures…).
We aim at understanding how coordinated neural dynamics mediate information processing relevant to behavior, memory and attention, decision making and sensorimotor coordination functions (with an election focus on hippocampal, cortical and basal ganglia networks). We also aim at identifying how alterations of dynamics translate into functional improvement (e.g. along task learning and development) or functional impairments (e.g. in neurodegenerative diseases or other brain disorders). The dream is to design interventions that would preserve/rescue function by “repairing dynamics” and functional connectivity.
See “unofficial” website for more info…
Oscillatory power and coherence are not stationary, but wildly fluctuate in intensity, frequency and phase. We isolate oscillatory events and show that they individually convey decodable information and that their coordination mediates routing and other primitive info-processing operations.
Functional networks, tracking coordination between neurons or local populations, evolves flexibly in time, in a way which is neither ordered, nor completely disordered. We develop multi-scale metrics of system’s reconfiguration which correlate with cognitive function (and its developmental or pathological changes).
Computational models are useful abstractions to probe (or reverse-engineer) circuit mechanisms, to engender new hypotheses and to extrapolate unexpected consequences of familiar scenarios. We use both spiking and mean-field models, from local micro-circuits up to whole virtual brains.
