The analysis of brain structural and functional architecture is a paradigmatic example of complex systems, since brain organisation and activity emerge as global properties of local interactions at different levels. Graph theory allows to represent the brain as a network introducing different subjects (nodes) and relations (links) and offering a new tool to quantify its macroscopic features as the result of underlying microscopic processes.
Brain networks can be defined at neuronal or regional level linked through structural (axons and grey matter), functional (activity correlations) and effective (functional causality) connections.
This unit work follows several lines of research:
Example of a human functional brain network.
(It's a gif image, click on it!).
- Explore the functional correlations between brain areas using functional magnetic resonance imaging (fMRI) of healthy people. Specifically, we are interested in the modular organisation of the human functional brain network during resting condition. In this perspective, the complete description of multi-scale and multi-level segregation and integration of brain regions represents a challenging issue. Moreover, the temporal dynamics of regional activity interactions represent a further step for a deep understanding of the human functional brain network.
- Investigate the structural connections between ROIs of healthy people by means of diffusion tensor imaging (DTI). We aim to relate the functional and structural organisation of the human brain network in the same subject.
- Wash away the effect of noise, anatomical and functional parcellization, definition of ROIs in the resulting time-series of BOLD signal and brain network construction.
- Analyse modular structure of the brain network in individuals affected by disease as Alzheimer, Schizophrenia, Dementia and compare it withthe case of healthy people.