The Difference of Brain Functional Connectivity between Eyes-Closed and Eyes-Open Using Graph Theoretical Analysis

Figure 1

The schematic diagram that an SL matrix was converted to an undirected and unweighted graph by applying a threshold. (a) is an SL matrix and (b) is an undirected and unweighted graph. In case of an unweighted and undirected graph, the black solid dots represent nodes and would be connected by edges when SL exceeded the corresponding threshold. Topological features of graphs can be quantitatively described by a wide variety of measures. For node D, which links three edges, the degree is three, and all the networks’ nodes form a degree distribution. For node A, with neighbors B and C, the clustering coefficient is one. The shortest path between node A and node D consists of three edges, and the shortest path length is three. Otherwise, if one node cannot reach another node, the distance is considered as infinite.