Figure 2.
Workflow of human brain network construction. To construct a brain network, one can begin with either structural (including either gray or white matter measurements) or functional data (including low frequency fMRI data and high frequency EEG or MEG data). Raw data is conventionally put into a parcellation scheme whereby the brain is subdivided into on the order of 100 regions of interest. For EEG and MEG data, this parcellation is already performed by the sensors. The pairwise association between brain regions is then computed, and usually thresholded to create a binary matrix. A brain network is then constructed from nodes (brain regions) and edges (pairwise associations which were larger than the chosen threshold).