Over the past 10 years, neuroscience has recognized the relevance of the concept of connectivity in the understanding of the synergic behavior of the brain. Brain connectivity refers to the descriptors of how the cerebral regions interact at various levels of coupling: anatomical links (described as structural connectivity), statistical dependencies (functional connectivity) and causal relationships (effective connectivity). In parallel with this spatial correspondence between functional regions in the brain, the temporal dynamics of the neural substrate also shows structural component, usually in specific frequency bands (and an implicit time scale, from δ oscillations (1-4Hz) to γ oscillations (>30 Hz) ) but also within the frequency range of infra-slow fluctuations (<1Hz) that is of specific interest in this workshop given its involvement in long-range interactions and its implications for neuroscience (conscious awareness, learning). These so-called scale free dynamic processes have been observed trough non-invasive investigations of the functional brain at rest, mainly in fMRI, EEG and MEG but also during intracranial recordings in electrocorticography (ECoG) in patients with epilepsy.
This 4-days workshop will focus on various methodological aspects (mathematical and statistical) of the 1) the scale-free dynamics (i.e. long-range correlations) inferred from EEG, MEG and fMRI during resting state activity of healthy brain or damaged brains in the context of neurodegenerative pathology; 2) the graph theory and in particular the small-world topology that functional resting state networks exhibit and the difficult question of directions in effective connectivity (Granger causality, …) and 3) the possible relationship between the two previous aspects, in time and space. Both formal aspects of the methodologies and the applications and interpretation of the results in neurosciences will be covered during the workshop. The last session of the workshop will be especially dedicated to a presentation of the connectivity toolbox developed in the Brainstorm software.