Table 2.
Description | Calculations | |
---|---|---|
Functional Integration (FI) | ||
Number of communities | Number of independent communities detected in a group of specific ROIs. Estimated maximum number of statistically significant clusters in a random network. | |
Mean of the path lengths | The path length of a node i (Li) is the average number of edges that must be crossed to go from node i to the remaining nodes in the network |
where N is the total number of nodes in the network, n is the number of nodes involved and dij is the shortest path length between node i and j. |
Standard deviation of the path lengths | The characteristic path length is a global measure of the network, i.e., there is only one value for the entire network. It consists of the average path length of each node in the network. | |
Functional Segregation (FS) | ||
Global clustering coefficient | This is the average value of the clustering coefficients, which is the fraction of triangles around a node, and is equivalent to the fraction of neighbors of the node that are neighbors among them. | |
Number of triangles | This is the number of connected triangles that can be estimated within a network in Euclidean space. |
An ordered pair in which V is a nonempty set of vertices and E is a set of edges. Where E consists of unordered pairs of vertices such as {x, y} E, then x and y are said to be adjacent. |
Other measures | ||
Density | The network density (D) is the number of edges in the network in proportion to the total number of possible edges. |
where K is the number of edges in the network and N is the total number of nodes in the network. |
Small world (Watts–Strogatz) | Networks that present a higher clustering coefficient than expected by chance and that, in addition, have a characteristic shortest path length. |
A network is said to represent this type of organization if the calculated index is greater than 1. |
Complexity | The number of nodes and alternative paths that exist within a specific network |